mac: Phase 4 - cap MU-MIMO group size to active TX antenna count

Reads mac->antenna_state to count active TX ports via
__builtin_popcount(nr_get_tx_antenna_bitmask). Caps the partner-search
while-loop bound to (active_tx - 1), so:
  active_tx = 4 -> up to 4-way MU-MIMO  (3 partners)
  active_tx = 3 -> up to 3-way          (2 partners)
  active_tx = 2 -> up to 2-way          (1 partner)
  active_tx = 1 -> SU-MIMO only         (0 partners)

This couples antenna muting (the existing PHY-side socket control on
port 9999) to spatial parallelism in the MU-MIMO scheduler. Muting a
chain reduces the codebook's orthogonal codeword count, which is the
right semantic for our antenna-muting research: muting reduces the
number of UEs co-scheduled per slot, not the per-UE rate.

Verified runtime behavior on rfsim (30s windows per state):
  TX mask 0x0F:  4-way 952  3-way 484  2-way 333  (full 4-TX)
  TX mask 0x03:  4-way   2  3-way   8  2-way 5935 (2-TX -> 2-way)
  TX mask 0x01:  4-way   0  3-way   0  2-way   11 (1-TX -> SU-MIMO)

Antenna-control commands tested via existing test interface:
  echo "SET TX MASK 0x03" | nc -w 2 localhost 9999

CMakeLists.txt

@@ -919,6 +919,7 @@ set(PHY_SRC_RU
   ${OPENAIR1_DIR}/PHY/MODULATION/gen_75KHz.cpp
   ${OPENAIR1_DIR}/PHY/MODULATION/beamforming.c
   ${OPENAIR1_DIR}/PHY/MODULATION/compute_bf_weights.c
+  ${OPENAIR1_DIR}/PHY/NR_TRANSPORT/nr_antenna_state.c
   ${OPENAIR1_DIR}/PHY/INIT/lte_init_ru.c
   ${OPENAIR1_DIR}/PHY/LTE_TRANSPORT/prach.c
   )
@@ -998,6 +999,7 @@ set(PHY_SRC_UE
   ${OPENAIR1_DIR}/PHY/NR_TRANSPORT/nr_prach.c
   ${OPENAIR1_DIR}/PHY/NR_TRANSPORT/nr_ulsch_llr_computation.c
   ${OPENAIR1_DIR}/PHY/NR_TRANSPORT/nr_ulsch_demodulation.c
+  ${OPENAIR1_DIR}/PHY/NR_TRANSPORT/nr_antenna_control.c
   ${OPENAIR1_DIR}/PHY/NR_REFSIG/ul_ref_seq_nr.c
   ${OPENAIR1_DIR}/PHY/NR_REFSIG/nr_dmrs_rx.c
   ${OPENAIR1_DIR}/PHY/NR_REFSIG/nr_gen_mod_table.c

docker/Dockerfile.nakaolab.test

@@ -0,0 +1,60 @@
+FROM ran-base:latest AS ran-build
+ARG BUILD_OPTION
+
+RUN rm -Rf /oai-ran
+WORKDIR /oai-ran
+COPY . .
+
+# build all targets so final targets can be created afterwards
+RUN /bin/sh oaienv && \
+    cd cmake_targets && \
+    ./build_oai --ninja \
+      --gNB --RU --nrUE -w SIMU -w USRP --build-lib telnetsrv \
+      --build-e2 --cmake-opt -DKPM_VERSION=KPM_V3_00 --cmake-opt -DE2AP_VERSION=E2AP_V3 \
+      --cmake-opt -DCMAKE_C_FLAGS="-Werror" --cmake-opt -DCMAKE_CXX_FLAGS="-Werror" $BUILD_OPTION && \
+    echo "---- ldd on executables ----" && \
+    ldd ran_build/build/*softmodem* ran_build/build/nr-cuup ran_build/build/oairu && \
+    echo "---- ldd on shared libraries ----" && \
+    ldd ran_build/build/*.so
+    
+RUN set -eux; \
+  apt-get update; \
+  DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends \
+    ca-certificates curl wget iproute2 iputils-ping dnsutils jq \
+    iperf iperf3 ffmpeg gdb\
+    nghttp2-client || true; \
+  if ! command -v h2load >/dev/null 2>&1; then \
+    DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends nghttp2 || true; \
+  fi; \
+  wget -O /usr/local/bin/sipp https://github.com/SIPp/sipp/releases/download/v3.7.7/sipp && chmod +x /usr/local/bin/sipp; \
+  rm -rf /var/lib/apt/lists/*
+
+# FlexRIC libraries (built by --build-e2) - only copy service model libraries (*_sm.so)
+# Also rebuild xapp_nakaolab (not built by default in build_oai)
+RUN mkdir -p /usr/local/etc/flexric /usr/local/lib/flexric && \
+    find /oai-ran/openair2/E2AP/flexric/build -name "*_sm.so" -exec cp {} /usr/local/lib/flexric/ \; && \
+    cp /oai-ran/openair2/E2AP/flexric/flexric.conf /usr/local/etc/flexric/ 2>/dev/null || true && \
+    echo "/usr/local/lib/flexric" > /etc/ld.so.conf.d/flexric.conf && ldconfig && \
+    cd /oai-ran/openair2/E2AP/flexric/build && \
+    sed -i 's|/home/[^/]*/openairinterface5g|/oai-ran|g' CMakeCache.txt && \
+    find . -name 'Makefile' -o -name '*.cmake' | xargs sed -i 's|/home/[^/]*/openairinterface5g|/oai-ran|g' 2>/dev/null || true && \
+    rm -f examples/xApp/c/monitor/CMakeFiles/xapp_nakaolab.dir/xapp_nakaolab.c.o && \
+    cmake --build . --target xapp_nakaolab 2>&1 | tail -5 && \
+    ls -la /usr/local/lib/flexric/
+
+# Install netcat for antenna control testing + paramiko for M-Plane NETCONF server
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    netcat-openbsd python3-pip \
+    && pip3 install --break-system-packages paramiko \
+    && rm -rf /var/lib/apt/lists/*
+
+# O-RU M-Plane NETCONF server (o-ran-uplane-conf antenna mask control)
+# Listens on port 831, translates NETCONF edit-config to internal antenna control
+COPY mplane/mplane_server.py /opt/mplane/mplane_server.py
+COPY mplane/wg4-capability.json /opt/mplane/wg4-capability.json
+COPY mplane/gnb-mplane-entrypoint.sh /opt/mplane/gnb-mplane-entrypoint.sh
+RUN chmod +x /opt/mplane/gnb-mplane-entrypoint.sh
+
+EXPOSE 831
+
+ENTRYPOINT ["/bin/bash"]

executables/nr-gnb.c

@@ -24,6 +24,8 @@
 #include "NR_PHY_INTERFACE/NR_IF_Module.h"
 #include "PHY/INIT/nr_phy_init.h"
 #include "PHY/MODULATION/nr_modulation.h"
+#include "openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h"
+#include "PHY/NR_TRANSPORT/nr_antenna_control.h"
 #include "PHY/NR_TRANSPORT/nr_transport_proto.h"
 #include "PHY/TOOLS/tools_defs.h"
 #include "PHY/defs_RU.h"
@@ -372,6 +374,14 @@ void init_eNB_afterRU(void)
      */
     //init_precoding_weights(RC.gNB[inst]);
     init_gNB_Tpool(inst);
+    
+    // antenna control
+    if (nr_antenna_control_start_test_server(&gNB->antenna_state, 9999))
+        LOG_I(PHY, "[ANTENNA_CTRL] Test control server started on port 9999\n");
+    if (inst < RC.nb_nr_macrlc_inst && RC.nrmac && RC.nrmac[inst]) {
+        RC.nrmac[inst]->antenna_state = &gNB->antenna_state;
+        LOG_I(PHY, "[ANTENNA_STATE] Connected MAC scheduler to PHY antenna state for dynamic layer adaptation\n");
+    }
   }
 }
 

mplane/gnb-mplane-entrypoint.sh

@@ -0,0 +1,26 @@
+#!/bin/bash
+# gNB entrypoint with M-Plane NETCONF server
+#
+# Starts the M-Plane server alongside the gNB process.
+# The M-Plane server acts as an O-RU NETCONF endpoint,
+# translating o-ran-uplane-conf edit-config to internal antenna control.
+#
+# Usage: gnb-mplane-entrypoint.sh <gnb-command-args...>
+# Example: gnb-mplane-entrypoint.sh /oai-ran/.../nr-softmodem -O /opt/.../gnb.conf --rfsim
+
+set -e
+
+echo "[gnb-mplane] Starting M-Plane NETCONF server (port ${MPLANE_PORT:-831})..."
+python3 /opt/mplane/mplane_server.py &
+MPLANE_PID=$!
+
+# Give the M-Plane server a moment to start
+sleep 1
+
+if ! kill -0 $MPLANE_PID 2>/dev/null; then
+    echo "[gnb-mplane] WARNING: M-Plane server failed to start, continuing without it"
+fi
+
+# Run the gNB command (passed as arguments)
+echo "[gnb-mplane] Starting gNB: $@"
+exec "$@"

mplane/mplane_server.py

@@ -0,0 +1,602 @@
+#!/usr/bin/env python3
+
+"""
+O-RU M-Plane NETCONF Server for gNB Antenna Control
+
+Lightweight NETCONF/SSH server implementing the O-RAN WG4 M-Plane interface
+for antenna mask configuration (o-ran-uplane-conf.yang).
+
+The gNB acts as an O-RU for antenna control purposes:
+  - Advertises mplane-supported-trx-control-masks (capability report)
+  - Accepts tx-array-antenna-mask-config via NETCONF edit-config
+  - Translates received mask to internal antenna control (localhost:9999)
+  - Sends mplane-trx-control-ant-mask-update notification (logged)
+
+Protocol:
+  SSH transport (paramiko) -> NETCONF base:1.0 framing -> XML RPC processing
+
+Architecture:
+  o1-adapter (O-DU) --NETCONF:831--> mplane_server.py (O-RU) --localhost:9999--> nr_antenna_control.c
+"""
+
+import base64
+import json
+import logging
+import os
+import re
+import signal
+import socket
+import sys
+import threading
+import time
+import xml.etree.ElementTree as ET
+
+import paramiko
+
+# ---------------------------------------------------------------------------
+# Configuration
+# ---------------------------------------------------------------------------
+
+MPLANE_PORT = 831
+MPLANE_USER = MPLANE_PASS = "netconf"
+GNB_CTRL_HOST = "127.0.0.1"
+GNB_CTRL_PORT = 9999
+WG4_CAPABILITY_FILE = "/opt/mplane/wg4-capability.json"
+SSH_HOST_KEY = "/opt/mplane/ssh_host_rsa_key"
+
+NS_NC = "urn:ietf:params:xml:ns:netconf:base:1.0"
+NS_UPLANE = "urn:o-ran:uplane-conf:1.0"
+NETCONF_END = "]]>]]>" # https://www.rfc-editor.org/rfc/rfc4742 NETCONF base:1.0 message delimiter
+
+logging.basicConfig(
+    level=logging.INFO,
+    format="%(asctime)s %(levelname)s %(name)s: %(message)s",
+    datefmt="%Y-%m-%d %H:%M:%S",
+    stream=sys.stdout,
+)
+log = logging.getLogger("mplane-server")
+
+# WG4 Capability (O-RU supported masks)
+def b64_to_mask(b64_str):
+    return int.from_bytes(base64.b64decode(b64_str), byteorder="big")
+
+def mask_to_b64(mask_int):
+    byte_len = max(1, (mask_int.bit_length() + 7) // 8)
+    return base64.b64encode(mask_int.to_bytes(byte_len, byteorder="big")).decode()
+
+
+class Capability:
+    """O-RU capability report: tx-arrays with supported masks."""
+
+    def __init__(self):
+        self.tx_arrays = {}       # name -> {"masks": [{index, b64, int}], ...}
+        self.current_config = {}  # array-name -> {"index": i, "mask_int": m}
+
+    def load(self, path):
+        if not (path and os.path.exists(path)):
+            # Fallback: generate for 4 antennas
+            masks = []
+            for n in range(4, 0, -1):
+                m = (1 << n) - 1
+                masks.append({"index": 4 - n, "b64": mask_to_b64(m), "int": m})
+            self.tx_arrays["tx-array-0"] = {"masks": masks, "columns": 4, "layers": 4}
+            self.current_config["tx-array-0"] = {"index": 0, "mask_int": 0x0F}
+            log.info("Generated fallback capability (4 antennas)")
+            return
+            
+        with open(path) as f:
+            data = json.load(f) # returns a dict
+        for arr in data.get("tx-arrays", []): # blank list for fallback
+            name = arr["name"]
+            cap = arr.get("mplane-trx-control-txarr-capability-info", {})
+            masks = []
+            for m in cap.get("mplane-supported-trx-control-masks", []):
+                masks.append({
+                    "index": m["index"],
+                    "b64": m["antenna-mask"],
+                    "int": b64_to_mask(m["antenna-mask"]),
+                })
+            self.tx_arrays[name] = {
+                "masks": masks,
+                "columns": arr.get("number-of-columns", 4),
+                "layers": arr.get("number-of-array-layers", 4),
+            }
+            # Default: all active (index 0)
+            if masks:
+                self.current_config[name] = {
+                    "index": masks[0]["index"],
+                    "mask_int": masks[0]["int"],
+                }
+        log.info("Loaded capability: %d tx-arrays from %s", len(self.tx_arrays), path)
+
+    def resolve_index(self, array_name, index):
+        arr = self.tx_arrays.get(array_name)
+        if not arr:
+            return None, f"unknown tx-array '{array_name}'"
+        for m in arr["masks"]:
+            if m["index"] == index:
+                return m, ""
+        return None, f"index {index} not in supported masks"
+
+    def resolve_mask(self, array_name, mask_int):
+        arr = self.tx_arrays.get(array_name)
+        if not arr:
+            return None, f"unknown tx-array '{array_name}'"
+        for m in arr["masks"]:
+            if m["int"] == mask_int:
+                return m, ""
+        return None, f"mask 0x{mask_int:02X} not in supported masks"
+
+    def get_capability_xml(self):
+        """Generate o-ran-uplane-conf operational data XML for <get> response."""
+        parts = [f'<user-plane-configuration xmlns="{NS_UPLANE}">']
+        for name, arr in self.tx_arrays.items():
+            parts.append(f"<tx-arrays><name>{name}</name>")
+            parts.append(f"<number-of-columns>{arr['columns']}</number-of-columns>")
+            parts.append(f"<number-of-array-layers>{arr['layers']}</number-of-array-layers>")
+            parts.append("<mplane-trx-control-txarr-capability-info>")
+            for m in arr["masks"]:
+                parts.append("<mplane-supported-trx-control-masks>")
+                parts.append(f"<index>{m['index']}</index>")
+                parts.append(f"<antenna-mask>{m['b64']}</antenna-mask>")
+                parts.append("</mplane-supported-trx-control-masks>")
+            parts.append("</mplane-trx-control-txarr-capability-info>")
+            parts.append("</tx-arrays>")
+        # Current config
+        for aname, cfg in self.current_config.items():
+            parts.append("<tx-array-antenna-mask-config>")
+            parts.append(f"<array-name>{aname}</array-name>")
+            parts.append(f"<antenna-bitmask-index>{cfg['index']}</antenna-bitmask-index>")
+            parts.append("</tx-array-antenna-mask-config>")
+        parts.append("</user-plane-configuration>")
+        return "".join(parts)
+
+
+# ---------------------------------------------------------------------------
+# gNB internal antenna control client (localhost:9999)
+# ---------------------------------------------------------------------------
+
+class GnbCtrlClient:
+    """Connects to the gNB internal test socket to apply antenna masks."""
+
+    def __init__(self, host, port):
+        self.host = host
+        self.port = port
+        self.sock = None
+
+    def connect(self):
+        for attempt in range(30):
+            try:
+                self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+                self.sock.settimeout(5.0)
+                self.sock.connect((self.host, self.port))
+                self._recv()  # consume welcome
+                log.info("Connected to gNB control at %s:%d", self.host, self.port)
+                return True
+            except (socket.error, ConnectionRefusedError) as e:
+                log.debug("gNB ctrl connect attempt %d/30: %s", attempt + 1, e)
+                if self.sock:
+                    self.sock.close()
+                    self.sock = None
+                time.sleep(2)
+        log.warning("Cannot connect to gNB control at %s:%d", self.host, self.port)
+        return False
+
+    def send_command(self, cmd):
+        if not self.sock:
+            if not self.connect():
+                return "ERROR: not connected"
+        try:
+            self.sock.sendall((cmd + "\n").encode())
+            time.sleep(0.1)
+            return self._recv()
+        except (socket.error, BrokenPipeError):
+            log.warning("gNB ctrl connection lost, reconnecting...")
+            self.sock = None
+            if not self.connect():
+                return "ERROR: reconnect failed"
+            self.sock.sendall((cmd + "\n").encode())
+            time.sleep(0.1)
+            return self._recv()
+
+    def _recv(self):
+        self.sock.settimeout(0.5)
+        data = b""
+        try:
+            while True:
+                chunk = self.sock.recv(4096)
+                if not chunk:
+                    break
+                data += chunk
+        except socket.timeout:
+            pass
+        return data.decode("utf-8", errors="ignore")
+
+    def close(self):
+        if self.sock:
+            try:
+                self.sock.sendall(b"QUIT\n")
+            except Exception:
+                pass
+            self.sock.close()
+            self.sock = None
+
+
+# ---------------------------------------------------------------------------
+# NETCONF Session Handler
+# ---------------------------------------------------------------------------
+
+class NetconfSession:
+    """Handle a single NETCONF session on an SSH channel."""
+
+    def __init__(self, channel, capability, gnb_ctrl):
+        self.channel = channel
+        self.cap = capability
+        self.gnb = gnb_ctrl
+        self.session_id = 1
+        self.running = True
+
+    def run(self):
+        try:
+            self._send_hello()
+            hello_msg = self._recv_message()
+            if hello_msg is None:
+                log.warning("Client did not send hello")
+                return
+            log.info("NETCONF hello exchange complete")
+
+            while self.running:
+                msg = self._recv_message()
+                if msg is None:
+                    break
+                self._process_rpc(msg)
+        except Exception as e:
+            log.exception("Session error: %s", e)
+        finally:
+            try:
+                self.channel.close()
+            except Exception:
+                pass
+            log.info("NETCONF session closed")
+
+    def _send_hello(self):
+        hello = (
+            '<?xml version="1.0" encoding="UTF-8"?>'
+            f'<hello xmlns="{NS_NC}">'
+            "<capabilities>"
+            "<capability>urn:ietf:params:netconf:base:1.0</capability>"
+            "<capability>urn:ietf:params:netconf:capability:writable-running:1.0</capability>"
+            "</capabilities>"
+            f"<session-id>{self.session_id}</session-id>"
+            "</hello>"
+        )
+        self._send_message(hello)
+
+    def _send_message(self, xml_str):
+        data = (xml_str + NETCONF_END).encode("utf-8")
+        self.channel.sendall(data)
+
+    def _recv_message(self):
+        buf = b""
+        while self.running:
+            try:
+                self.channel.settimeout(300)
+                chunk = self.channel.recv(65536)
+                if not chunk:
+                    return None
+                buf += chunk
+                text = buf.decode("utf-8", errors="ignore")
+                if NETCONF_END in text:
+                    return text.split(NETCONF_END)[0].strip()
+            except socket.timeout:
+                continue
+            except Exception:
+                return None
+        return None
+
+    def _process_rpc(self, xml_str):
+        # Strip XML declaration if present
+        xml_str = re.sub(r"<\?xml[^?]*\?>", "", xml_str).strip()
+        try:
+            root = ET.fromstring(xml_str)
+        except ET.ParseError as e:
+            log.warning("Malformed RPC: %s", e)
+            self._send_error("0", "malformed-message", "rpc")
+            return
+
+        msg_id = root.get("message-id", "0")
+
+        # Find the operation element
+        for child in root:
+            local_tag = child.tag.split("}")[-1] if "}" in child.tag else child.tag
+
+            if local_tag == "edit-config":
+                self._handle_edit_config(msg_id, child)
+            elif local_tag == "get":
+                self._handle_get(msg_id, child)
+            elif local_tag == "get-config":
+                self._handle_get_config(msg_id, child)
+            elif local_tag == "close-session":
+                self._send_ok(msg_id)
+                self.running = False
+            elif local_tag == "lock" or local_tag == "unlock":
+                self._send_ok(msg_id)
+            else:
+                self._send_error(msg_id, "operation-not-supported", "protocol")
+            return  # Only process first operation
+
+    def _handle_edit_config(self, msg_id, edit_elem):
+        """Handle edit-config for tx-array-antenna-mask-config."""
+        # Find <config> element
+        config_elem = None
+        for child in edit_elem:
+            local = child.tag.split("}")[-1] if "}" in child.tag else child.tag
+            if local == "config":
+                config_elem = child
+                break
+
+        if config_elem is None:
+            self._send_error(msg_id, "missing-element", "protocol",
+                             "Missing <config> element")
+            return
+
+        # Find tx-array-antenna-mask-config under user-plane-configuration
+        mask_config = None
+        for elem in config_elem.iter():
+            local = elem.tag.split("}")[-1] if "}" in elem.tag else elem.tag
+            if local == "tx-array-antenna-mask-config":
+                mask_config = elem
+                break
+
+        if mask_config is None:
+            # No antenna mask config in this edit - accept silently
+            self._send_ok(msg_id)
+            return
+
+        # Extract array-name, antenna-bitmask-index or antenna-bitmask
+        array_name = None
+        bitmask_index = None
+        bitmask_b64 = None
+
+        for child in mask_config:
+            local = child.tag.split("}")[-1] if "}" in child.tag else child.tag
+            if local == "array-name":
+                array_name = child.text.strip() if child.text else None
+            elif local == "antenna-bitmask-index":
+                bitmask_index = int(child.text.strip()) if child.text else None
+            elif local == "antenna-bitmask":
+                bitmask_b64 = child.text.strip() if child.text else None
+
+        if not array_name:
+            self._send_error(msg_id, "missing-element", "application",
+                             "Missing array-name in tx-array-antenna-mask-config")
+            return
+
+        # Resolve the mask
+        resolved = None
+        if bitmask_index is not None:
+            resolved, err = self.cap.resolve_index(array_name, bitmask_index)
+            if not resolved:
+                self._send_error(msg_id, "invalid-value", "application", err)
+                return
+            log.info("M-Plane edit-config: array=%s, antenna-bitmask-index=%d",
+                     array_name, bitmask_index)
+        elif bitmask_b64 is not None:
+            mask_int = b64_to_mask(bitmask_b64)
+            resolved, err = self.cap.resolve_mask(array_name, mask_int)
+            if not resolved:
+                self._send_error(msg_id, "invalid-value", "application", err)
+                return
+            log.info("M-Plane edit-config: array=%s, antenna-bitmask=%s (0x%02X)",
+                     array_name, bitmask_b64, mask_int)
+        else:
+            self._send_error(msg_id, "missing-element", "application",
+                             "Need antenna-bitmask or antenna-bitmask-index")
+            return
+
+        # Apply to gNB via internal control socket
+        mask_int = resolved["int"]
+        resp = self.gnb.send_command(f"SET TX MASK 0x{mask_int:02X}")
+        log.info("Applied mask 0x%02X to gNB: %s", mask_int, resp.strip())
+
+        # Update current config
+        self.cap.current_config[array_name] = {
+            "index": resolved["index"],
+            "mask_int": mask_int,
+        }
+
+        # Log WG4 mplane-trx-control-ant-mask-update notification
+        log.info("WG4 mplane-trx-control-ant-mask-update: "
+                 "array-name='%s', array-type=TX-ARRAY, "
+                 "updated-antenna-mask-index=%d, updated-antenna-mask=%s",
+                 array_name, resolved["index"], resolved["b64"])
+
+        self._send_ok(msg_id)
+
+    def _handle_get(self, msg_id, get_elem):
+        """Handle <get> - return operational data (capability + current config)."""
+        data_xml = self.cap.get_capability_xml()
+        reply = (
+            f'<rpc-reply xmlns="{NS_NC}" message-id="{msg_id}">'
+            f"<data>{data_xml}</data>"
+            "</rpc-reply>"
+        )
+        self._send_message(reply)
+
+    def _handle_get_config(self, msg_id, get_elem):
+        """Handle <get-config> - return running config (current mask config)."""
+        parts = [f'<user-plane-configuration xmlns="{NS_UPLANE}">']
+        for aname, cfg in self.cap.current_config.items():
+            parts.append("<tx-array-antenna-mask-config>")
+            parts.append(f"<array-name>{aname}</array-name>")
+            parts.append(f"<antenna-bitmask-index>{cfg['index']}</antenna-bitmask-index>")
+            parts.append("</tx-array-antenna-mask-config>")
+        parts.append("</user-plane-configuration>")
+        reply = (
+            f'<rpc-reply xmlns="{NS_NC}" message-id="{msg_id}">'
+            f'<data>{"".join(parts)}</data>'
+            "</rpc-reply>"
+        )
+        self._send_message(reply)
+
+    def _send_ok(self, msg_id):
+        reply = (
+            f'<rpc-reply xmlns="{NS_NC}" message-id="{msg_id}">'
+            "<ok/>"
+            "</rpc-reply>"
+        )
+        self._send_message(reply)
+
+    def _send_error(self, msg_id, error_tag, error_type, error_message=""):
+        msg_part = ""
+        if error_message:
+            msg_part = f"<error-message>{error_message}</error-message>"
+        reply = (
+            f'<rpc-reply xmlns="{NS_NC}" message-id="{msg_id}">'
+            "<rpc-error>"
+            f"<error-type>{error_type}</error-type>"
+            f"<error-tag>{error_tag}</error-tag>"
+            "<error-severity>error</error-severity>"
+            f"{msg_part}"
+            "</rpc-error>"
+            "</rpc-reply>"
+        )
+        self._send_message(reply)
+
+
+# ---------------------------------------------------------------------------
+# SSH Server Interface
+# ---------------------------------------------------------------------------
+
+class MplaneSSHServer(paramiko.ServerInterface):
+    def __init__(self):
+        self.subsystem_event = threading.Event()
+
+    def check_channel_request(self, kind, chanid):
+        if kind == "session":
+            return paramiko.OPEN_SUCCEEDED
+        return paramiko.OPEN_FAILED_ADMINISTRATIVELY_PROHIBITED
+
+    def get_allowed_auths(self, username):
+        return "password"
+
+    def check_auth_password(self, username, password):
+        if username == MPLANE_USER and password == MPLANE_PASS:
+            return paramiko.AUTH_SUCCESSFUL
+        return paramiko.AUTH_FAILED
+
+    def check_channel_subsystem_request(self, channel, name):
+        if name == "netconf":
+            self.subsystem_event.set()
+            return True
+        return False
+
+
+# ---------------------------------------------------------------------------
+# Main Server
+# ---------------------------------------------------------------------------
+
+def handle_connection(client_sock, addr, host_key, capability, gnb_ctrl):
+    """Handle a single SSH/NETCONF client connection."""
+    log.info("SSH connection from %s:%d", addr[0], addr[1])
+    transport = None
+    try:
+        transport = paramiko.Transport(client_sock)
+        transport.add_server_key(host_key)
+        server = MplaneSSHServer()
+        transport.start_server(server=server)
+
+        channel = transport.accept(30)
+        if channel is None:
+            log.warning("No channel opened by client")
+            return
+
+        # Wait for NETCONF subsystem request
+        if not server.subsystem_event.wait(10):
+            log.warning("Client did not request netconf subsystem")
+            channel.close()
+            return
+
+        session = NetconfSession(channel, capability, gnb_ctrl)
+        session.run()
+
+    except paramiko.SSHException as e:
+        log.warning("SSH error from %s: %s", addr[0], e)
+    except Exception as e:
+        log.exception("Connection error from %s: %s", addr[0], e)
+    finally:
+        if transport:
+            try:
+                transport.close()
+            except Exception:
+                pass
+
+
+def main():
+    log.info("O-RU M-Plane NETCONF server starting")
+    log.info("  Port: %d", MPLANE_PORT)
+    log.info("  gNB control: %s:%d (internal)", GNB_CTRL_HOST, GNB_CTRL_PORT)
+
+    # Load/generate SSH host key
+    if os.path.exists(SSH_HOST_KEY):
+        host_key = paramiko.RSAKey.from_private_key_file(SSH_HOST_KEY)
+        log.info("Loaded SSH host key from %s", SSH_HOST_KEY)
+    else:
+        host_key = paramiko.RSAKey.generate(2048)
+        os.makedirs(os.path.dirname(SSH_HOST_KEY), exist_ok=True)
+        host_key.write_private_key_file(SSH_HOST_KEY)
+        log.info("Generated SSH host key at %s", SSH_HOST_KEY)
+
+    # Load WG4 capability
+    capability = Capability()
+    capability.load(WG4_CAPABILITY_FILE)
+    for name, arr in capability.tx_arrays.items():
+        log.info("  tx-array '%s': %d supported masks", name, len(arr["masks"]))
+        for m in arr["masks"]:
+            log.info("    index=%d: %s (0x%02X, %d active)",
+                     m["index"], m["b64"], m["int"], bin(m["int"]).count("1"))
+
+    # Connect to gNB internal control
+    gnb_ctrl = GnbCtrlClient(GNB_CTRL_HOST, GNB_CTRL_PORT)
+    gnb_ctrl.connect()
+
+    # Create server socket
+    server_sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    server_sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+    server_sock.bind(("0.0.0.0", MPLANE_PORT))
+    server_sock.listen(5)
+    server_sock.settimeout(1.0)
+
+    shutdown = threading.Event()
+
+    def handle_signal(signum, frame):
+        log.info("Shutdown signal received")
+        shutdown.set()
+
+    signal.signal(signal.SIGTERM, handle_signal)
+    signal.signal(signal.SIGINT, handle_signal)
+
+    log.info("M-Plane NETCONF server ready on port %d", MPLANE_PORT)
+
+    while not shutdown.is_set():
+        try:
+            client_sock, addr = server_sock.accept()
+            t = threading.Thread(
+                target=handle_connection,
+                args=(client_sock, addr, host_key, capability, gnb_ctrl),
+                daemon=True,
+            )
+            t.start()
+        except socket.timeout:
+            continue
+        except Exception as e:
+            if not shutdown.is_set():
+                log.exception("Accept error: %s", e)
+
+    log.info("Shutting down...")
+    server_sock.close()
+    gnb_ctrl.close()
+
+
+if __name__ == "__main__":
+    main()

mplane/wg4-capability.json

@@ -0,0 +1,17 @@
+{
+  "tx-arrays": [
+    {
+      "name": "tx-array-0",
+      "number-of-columns": 4,
+      "number-of-array-layers": 4,
+      "mplane-trx-control-txarr-capability-info": {
+        "mplane-supported-trx-control-masks": [
+          {"index": 0, "antenna-mask": "Dw=="},
+          {"index": 1, "antenna-mask": "Bw=="},
+          {"index": 2, "antenna-mask": "Aw=="},
+          {"index": 3, "antenna-mask": "AQ=="}
+        ]
+      }
+    }
+  ]
+}

openair1/PHY/INIT/nr_init.c

@@ -143,6 +143,9 @@ void phy_init_nr_gNB(PHY_VARS_gNB *gNB)
 
   init_DLSCH_struct(gNB);
 
+  nr_init_antenna_state(&gNB->antenna_state, Ptx, Prx, "tx-array-0", "rx-array-0");
+  LOG_I(PHY, "[ANTENNA_STATE] Initialized with %d TX, %d RX antennas\n", Ptx, Prx);
+
   /* Do NOT allocate per-antenna rxdataF: the gNB gets a pointer to the
    * RU to copy/recover freq-domain memory from there */
   common_vars->rxdataF = (c16_t ***)malloc16(common_vars->num_beams_period * sizeof(c16_t**));

openair1/PHY/MODULATION/beamforming.c

@@ -10,6 +10,7 @@
 #include "PHY/LTE_TRANSPORT/transport_eNB.h"
 #include "modulation_eNB.h"
 #include "common/utils/LOG/vcd_signal_dumper.h"
+#include "PHY/NR_TRANSPORT/nr_antenna_state.h"
 
 int beam_precoding(int32_t **txdataF,
 	           int32_t **txdataF_BF,

openair1/PHY/MODULATION/nr_beamforming.c

@@ -4,6 +4,8 @@
 
 #include "nr_modulation.h"
 #include "openair1/PHY/TOOLS/tools_defs.h"
+#include "PHY/NR_TRANSPORT/nr_antenna_state.h"
+#include "common/utils/LOG/log.h"
 
 void nr_beam_precoding(c16_t **txdataF,
 	               c16_t **txdataF_BF,
@@ -25,3 +27,33 @@ void nr_beam_precoding(c16_t **txdataF,
                        15);
   }
 }
+
+void nr_beam_precoding_with_muting(c16_t **txdataF,
+                                   c16_t **txdataF_BF,
+                                   NR_DL_FRAME_PARMS *frame_parms,
+                                   int32_t ***beam_weights,
+                                   int symbol,
+                                   int aa,
+                                   int nb_antenna_ports,
+                                   int offset,
+                                   const nr_antenna_state_t *ant_state)
+{
+  // Clear output buffer first
+  memset(&txdataF_BF[aa][symbol * frame_parms->ofdm_symbol_size], 0,
+         sizeof(c16_t) * frame_parms->ofdm_symbol_size);
+  // O-RAN energy saving: skip precoding if antenna is muted
+  // This implements transmission blanking per WG4 spec
+  if (ant_state != NULL && !nr_is_tx_antenna_active(ant_state, aa)) {
+    LOG_D(PHY, "[ANTENNA_MUTE] Antenna %d muted, blanking transmission for symbol %d\n",
+          aa, symbol);
+    return;
+  }
+  // Normal precoding for active antennas
+  for (int p = 0; p < nb_antenna_ports; p++) {
+    multadd_cpx_vector((c16_t *)&txdataF[p][(symbol * frame_parms->ofdm_symbol_size) + offset],
+                       (c16_t *)beam_weights[p][aa],
+                       (c16_t *)&txdataF_BF[aa][symbol * frame_parms->ofdm_symbol_size],
+                       frame_parms->ofdm_symbol_size,
+                       15);
+  }
+}

openair1/PHY/MODULATION/nr_modulation.h

@@ -84,6 +84,33 @@ void nr_beam_precoding(c16_t **txdataF,
                        int nb_antenna_ports,
                        int offset);
 
+
+/*! \brief NR beam precoding with O-RAN compliant antenna muting
+ * 
+ * Extends nr_beam_precoding to support antenna muting for energy saving
+ * per O-RAN WG4 MPLANE-TRX-CONTROL specification (o-ran-uplane-conf.yang).
+ * When an antenna is muted, transmission is blanked (output zeroed).
+ * 
+ * @param[in] txdataF Input frequency-domain data per antenna port
+ * @param[out] txdataF_BF Output beamformed data per physical antenna
+ * @param[in] frame_parms Frame parameters
+ * @param[in] beam_weights Beamforming weights
+ * @param[in] symbol Current symbol number
+ * @param[in] aa Physical antenna index
+ * @param[in] nb_antenna_ports Number of antenna ports
+ * @param[in] offset Frequency offset
+ * @param[in] ant_state Antenna state for muting control (NULL = all active)
+ */
+void nr_beam_precoding_with_muting(c16_t **txdataF,
+                                   c16_t **txdataF_BF,
+                                   NR_DL_FRAME_PARMS *frame_parms,
+                                   int32_t ***beam_weights,
+                                   int symbol,
+                                   int aa,
+                                   int nb_antenna_ports,
+                                   int offset,
+                                   const nr_antenna_state_t *ant_state);
+
 void apply_nr_rotation_TX(const NR_DL_FRAME_PARMS *fp,
                           c16_t *txdataF,
                           bool is_flat_buff,

openair1/PHY/NR_TRANSPORT/nr_antenna_control.c

@@ -0,0 +1,532 @@
+/*
+ * Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The OpenAirInterface Software Alliance licenses this file to You under
+ * the OAI Public License, Version 1.1  (the "License"); you may not use this file
+ * except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.openairinterface.org/?page_id=698
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *-------------------------------------------------------------------------------
+ * For more information about the OpenAirInterface (OAI) Software Alliance:
+ *      contact@openairinterface.org
+ */
+
+/*! \file PHY/NR_TRANSPORT/nr_antenna_control.c
+ * \brief Antenna control interface implementation with O-RAN M-Plane support
+ * \author OpenAirInterface
+ * \date 2025
+ * \version 2.0
+ */
+
+#include "nr_antenna_control.h"
+#include "common/utils/LOG/log.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <pthread.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <errno.h>
+#include <signal.h>
+
+// Try to include M-Plane header if available
+#ifdef OAI_MPLANE
+#include "radio/fhi_72/mplane/antenna-control.h"
+#include "radio/fhi_72/mplane/ru-mplane-api.h"
+#endif
+
+// Global control state
+static struct {
+  pthread_t thread;
+  int server_fd;
+  nr_antenna_state_t *ant_state;
+  volatile bool running;
+  int port;
+  nr_antenna_ctrl_backend_t backend;
+#ifdef OAI_MPLANE
+  ru_session_t *ru_session;
+#else
+  void *ru_session;
+#endif
+} g_ctrl = {0};
+
+// ============================================================================
+// Test Socket Server Implementation (Development/Testing Mode)
+// ============================================================================
+
+// Process a single command and generate response
+static void process_command(const char *cmd, char *response, size_t resp_size)
+{
+  char cmd_upper[256];
+  strncpy(cmd_upper, cmd, sizeof(cmd_upper) - 1);
+  cmd_upper[sizeof(cmd_upper) - 1] = '\0';
+  
+  // Convert to uppercase for case-insensitive matching
+  for (char *p = cmd_upper; *p; p++) {
+    if (*p >= 'a' && *p <= 'z') *p -= 32;
+  }
+  
+  // Trim whitespace
+  char *p = cmd_upper;
+  while (*p == ' ' || *p == '\t' || *p == '\r' || *p == '\n') p++;
+  char *end = p + strlen(p) - 1;
+  while (end > p && (*end == ' ' || *end == '\t' || *end == '\r' || *end == '\n')) *end-- = '\0';
+  
+  if (strncmp(p, "MUTE TX ", 8) == 0) {
+    int ant_id = atoi(p + 8);
+    nr_mute_tx_antenna(g_ctrl.ant_state, ant_id);
+    snprintf(response, resp_size, "OK: TX antenna %d muted\n", ant_id);
+  }
+  else if (strncmp(p, "UNMUTE TX ", 10) == 0) {
+    int ant_id = atoi(p + 10);
+    nr_unmute_tx_antenna(g_ctrl.ant_state, ant_id);
+    snprintf(response, resp_size, "OK: TX antenna %d unmuted\n", ant_id);
+  }
+  else if (strncmp(p, "MUTE RX ", 8) == 0) {
+    int ant_id = atoi(p + 8);
+    nr_mute_rx_antenna(g_ctrl.ant_state, ant_id);
+    snprintf(response, resp_size, "OK: RX antenna %d muted\n", ant_id);
+  }
+  else if (strncmp(p, "UNMUTE RX ", 10) == 0) {
+    int ant_id = atoi(p + 10);
+    nr_unmute_rx_antenna(g_ctrl.ant_state, ant_id);
+    snprintf(response, resp_size, "OK: RX antenna %d unmuted\n", ant_id);
+  }
+  else if (strncmp(p, "SET TX MASK ", 12) == 0) {
+    unsigned int mask;
+    if (sscanf(p + 12, "%x", &mask) == 1 || sscanf(p + 12, "0X%x", &mask) == 1) {
+      uint8_t old = nr_set_tx_antenna_bitmask(g_ctrl.ant_state, (uint8_t)mask);
+      snprintf(response, resp_size, "OK: TX mask 0x%02X -> 0x%02X\n", old, (uint8_t)mask);
+    } else {
+      snprintf(response, resp_size, "ERROR: Invalid mask format. Use hex (e.g., 0F or 0x0F)\n");
+    }
+  }
+  else if (strncmp(p, "SET RX MASK ", 12) == 0) {
+    unsigned int mask;
+    if (sscanf(p + 12, "%x", &mask) == 1 || sscanf(p + 12, "0X%x", &mask) == 1) {
+      uint8_t old = nr_set_rx_antenna_bitmask(g_ctrl.ant_state, (uint8_t)mask);
+      snprintf(response, resp_size, "OK: RX mask 0x%02X -> 0x%02X\n", old, (uint8_t)mask);
+    } else {
+      snprintf(response, resp_size, "ERROR: Invalid mask format. Use hex (e.g., 0F or 0x0F)\n");
+    }
+  }
+  else if (strcmp(p, "STATUS") == 0) {
+    bool in_recovery = nr_is_in_recovery_mode(g_ctrl.ant_state);
+    snprintf(response, resp_size,
+             "=== Antenna Status ===\n"
+             "TX Array: %s\n"
+             "  Antennas: %d configured, %d active\n"
+             "  Bitmask: 0x%02X\n"
+             "  Antenna 0 protected: %s\n"
+             "RX Array: %s\n"
+             "  Antennas: %d configured, %d active\n"
+             "  Bitmask: 0x%02X\n"
+             "Recovery Mode: %s\n"
+             "Backend: %s\n",
+             g_ctrl.ant_state->tx_array_name,
+             g_ctrl.ant_state->num_tx_antennas,
+             nr_get_active_tx_antenna_count(g_ctrl.ant_state),
+             nr_get_tx_antenna_bitmask(g_ctrl.ant_state),
+             g_ctrl.ant_state->config.protect_antenna0 ? "YES" : "NO",
+             g_ctrl.ant_state->rx_array_name,
+             g_ctrl.ant_state->num_rx_antennas,
+             nr_get_active_rx_antenna_count(g_ctrl.ant_state),
+             nr_get_rx_antenna_bitmask(g_ctrl.ant_state),
+             in_recovery ? "ACTIVE (use identity matrix)" : "OFF",
+             g_ctrl.backend == ANTENNA_CTRL_BACKEND_MPLANE ? "O-RAN M-Plane NETCONF" :
+             g_ctrl.backend == ANTENNA_CTRL_BACKEND_TEST_SOCKET ? "Test Socket (NOT O-RAN)" :
+             "None");
+  }
+  else if (strcmp(p, "STATS") == 0) {
+    uint64_t tx_events, rx_events, muted_slots;
+    nr_get_antenna_stats(g_ctrl.ant_state, &tx_events, &rx_events, &muted_slots);
+    snprintf(response, resp_size,
+             "=== Energy Saving Statistics ===\n"
+             "TX mute events: %lu\n"
+             "RX mute events: %lu\n"
+             "Total muted slots: %lu\n",
+             tx_events, rx_events, muted_slots);
+  }
+  else if (strcmp(p, "RESET STATS") == 0) {
+    nr_reset_antenna_stats(g_ctrl.ant_state);
+    snprintf(response, resp_size, "OK: Statistics reset\n");
+  }
+  else if (strcmp(p, "RESET") == 0 || strcmp(p, "UNMUTE ALL") == 0) {
+    // Reset all antennas to active state with recovery mode
+    nr_unmute_all_tx_antennas(g_ctrl.ant_state);
+    nr_unmute_all_rx_antennas(g_ctrl.ant_state);
+    snprintf(response, resp_size, 
+             "OK: All antennas unmuted (recovery mode: %u ms)\n"
+             "  TX mask: 0x%02X (%d antennas)\n"
+             "  RX mask: 0x%02X (%d antennas)\n",
+             g_ctrl.ant_state->recovery.recovery_duration_ms,
+             nr_get_tx_antenna_bitmask(g_ctrl.ant_state), g_ctrl.ant_state->num_tx_antennas,
+             nr_get_rx_antenna_bitmask(g_ctrl.ant_state), g_ctrl.ant_state->num_rx_antennas);
+  }
+  else if (strcmp(p, "PROTECT ANT0 ON") == 0) {
+    nr_set_antenna0_protection(g_ctrl.ant_state, true);
+    snprintf(response, resp_size, "OK: Antenna 0 protection enabled (SSB)\n");
+  }
+  else if (strcmp(p, "PROTECT ANT0 OFF") == 0) {
+    nr_set_antenna0_protection(g_ctrl.ant_state, false);
+    snprintf(response, resp_size, "OK: Antenna 0 protection disabled (WARNING: may cause UE sync loss)\n");
+  }
+  else if (strcmp(p, "SYNC") == 0) {
+    // Synchronize to RU (only works with M-Plane backend)
+    if (nr_antenna_control_sync_to_ru(g_ctrl.ant_state)) {
+      snprintf(response, resp_size, "OK: Synchronized to RU\n");
+    } else {
+      snprintf(response, resp_size, "ERROR: Sync failed (M-Plane backend required)\n");
+    }
+  }
+  else if (strcmp(p, "HELP") == 0) {
+    snprintf(response, resp_size,
+             "=== Antenna Control ===\n"
+             "MUTE TX/RX <id>   - Mute antenna\n"
+             "UNMUTE TX/RX <id> - Unmute antenna\n"
+             "SET TX/RX MASK <hex> - Set bitmask\n"
+             "STATUS  - Show state\n"
+             "STATS   - Show statistics\n"
+             "RESET   - Unmute all\n"
+             "PROTECT ANT0 ON/OFF\n"
+             "HELP/QUIT\n");
+  }
+  else if (strcmp(p, "QUIT") == 0 || strcmp(p, "EXIT") == 0) {
+    snprintf(response, resp_size, "BYE\n");
+  }
+  else if (strlen(p) == 0) {
+    response[0] = '\0';  // Empty command, no response
+  }
+  else {
+    snprintf(response, resp_size, "ERROR: Unknown command '%s'. Type HELP for usage.\n", cmd);
+  }
+}
+
+// Handle a single client connection
+static void handle_client(int client_fd)
+{
+  char buffer[256];
+  char response[1024];
+  
+  // Send welcome message with warning about non-compliance
+  const char *welcome = 
+    "=== OAI Antenna Control Test Server ===\n"
+    "WARNING: This is a TEST interface, NOT O-RAN compliant!\n"
+    "For production, use NETCONF via radio/fhi_72/mplane/\n"
+    "Type HELP for commands.\n\n";
+  send(client_fd, welcome, strlen(welcome), 0);
+  
+  while (g_ctrl.running) {
+    // Send prompt
+    send(client_fd, "> ", 2, 0);
+    
+    // Receive command
+    ssize_t n = recv(client_fd, buffer, sizeof(buffer) - 1, 0);
+    if (n <= 0) break;
+    
+    buffer[n] = '\0';
+    
+    // Process command
+    process_command(buffer, response, sizeof(response));
+    
+    // Send response
+    if (strlen(response) > 0) {
+      send(client_fd, response, strlen(response), 0);
+    }
+    
+    // Check for quit
+    if (strstr(buffer, "QUIT") || strstr(buffer, "quit") ||
+        strstr(buffer, "EXIT") || strstr(buffer, "exit")) {
+      break;
+    }
+  }
+  
+  close(client_fd);
+  LOG_I(PHY, "[ANTENNA_CTRL] Client disconnected\n");
+}
+
+// Server thread function
+static void *server_thread(void *arg)
+{
+  (void)arg;
+  
+  struct sockaddr_in client_addr;
+  socklen_t addr_len = sizeof(client_addr);
+  
+  LOG_I(PHY, "[ANTENNA_CTRL] Test server listening on port %d\n", g_ctrl.port);
+  
+  while (g_ctrl.running) {
+    // Accept connection with timeout
+    fd_set read_fds;
+    FD_ZERO(&read_fds);
+    FD_SET(g_ctrl.server_fd, &read_fds);
+    
+    struct timeval tv = {.tv_sec = 1, .tv_usec = 0};
+    int ret = select(g_ctrl.server_fd + 1, &read_fds, NULL, NULL, &tv);
+    
+    if (ret <= 0) continue;
+    
+    int client_fd = accept(g_ctrl.server_fd, (struct sockaddr *)&client_addr, &addr_len);
+    if (client_fd < 0) continue;
+    
+    LOG_I(PHY, "[ANTENNA_CTRL] Client connected from %s:%d\n",
+          inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port));
+    
+    handle_client(client_fd);
+  }
+  
+  return NULL;
+}
+
+// ============================================================================
+// Public API Implementation
+// ============================================================================
+
+bool nr_antenna_control_init_mplane(nr_antenna_state_t *ant_state, void *ru_session)
+{
+#ifdef OAI_MPLANE
+  if (g_ctrl.running) {
+    LOG_W(PHY, "[ANTENNA_CTRL] Control interface already active\n");
+    return false;
+  }
+  
+  if (ant_state == NULL || ru_session == NULL) {
+    LOG_E(PHY, "[ANTENNA_CTRL] Invalid parameters\n");
+    return false;
+  }
+  
+  g_ctrl.ant_state = ant_state;
+  g_ctrl.ru_session = (ru_session_t *)ru_session;
+  g_ctrl.backend = ANTENNA_CTRL_BACKEND_MPLANE;
+  g_ctrl.running = true;
+  
+  // Check if RU supports TRX control feature
+  if (!mplane_supports_trx_control(g_ctrl.ru_session)) {
+    LOG_W(PHY, "[ANTENNA_CTRL] RU does not support MPLANE-TRX-CONTROL feature\n");
+    LOG_W(PHY, "[ANTENNA_CTRL] Antenna muting may not work on this RU\n");
+  }
+  
+  LOG_I(PHY, "[ANTENNA_CTRL] Initialized with O-RAN M-Plane NETCONF backend\n");
+  LOG_I(PHY, "[ANTENNA_CTRL] TX array: %s, RX array: %s\n",
+        ant_state->tx_array_name, ant_state->rx_array_name);
+  
+  return true;
+#else
+  LOG_E(PHY, "[ANTENNA_CTRL] M-Plane support not compiled in (OAI_MPLANE not defined)\n");
+  LOG_E(PHY, "[ANTENNA_CTRL] Use nr_antenna_control_start_test_server() for testing\n");
+  return false;
+#endif
+}
+
+bool nr_antenna_control_start_test_server(nr_antenna_state_t *ant_state, int port)
+{
+  if (g_ctrl.running) {
+    LOG_W(PHY, "[ANTENNA_CTRL] Control interface already active\n");
+    return false;
+  }
+  
+  if (ant_state == NULL) {
+    LOG_E(PHY, "[ANTENNA_CTRL] Antenna state is NULL\n");
+    return false;
+  }
+  
+  LOG_W(PHY, "[ANTENNA_CTRL] ======================================================\n");
+  LOG_W(PHY, "[ANTENNA_CTRL] Starting TEST socket server - NOT O-RAN COMPLIANT!\n");
+  LOG_W(PHY, "[ANTENNA_CTRL] For production O-RAN compliance, use M-Plane NETCONF\n");
+  LOG_W(PHY, "[ANTENNA_CTRL] See: radio/fhi_72/mplane/antenna-control-mplane.h\n");
+  LOG_W(PHY, "[ANTENNA_CTRL] ======================================================\n");
+  
+  g_ctrl.ant_state = ant_state;
+  g_ctrl.port = (port > 0) ? port : NR_ANTENNA_CONTROL_TEST_PORT;
+  g_ctrl.backend = ANTENNA_CTRL_BACKEND_TEST_SOCKET;
+  
+  // Create socket
+  g_ctrl.server_fd = socket(AF_INET, SOCK_STREAM, 0);
+  if (g_ctrl.server_fd < 0) {
+    LOG_E(PHY, "[ANTENNA_CTRL] Failed to create socket: %s\n", strerror(errno));
+    return false;
+  }
+  
+  // Allow address reuse
+  int opt = 1;
+  setsockopt(g_ctrl.server_fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
+  
+  // Bind
+  struct sockaddr_in addr = {
+    .sin_family = AF_INET,
+    .sin_addr.s_addr = htonl(INADDR_ANY),
+    .sin_port = htons(g_ctrl.port)
+  };
+  
+  if (bind(g_ctrl.server_fd, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
+    LOG_E(PHY, "[ANTENNA_CTRL] Failed to bind port %d: %s\n", g_ctrl.port, strerror(errno));
+    close(g_ctrl.server_fd);
+    return false;
+  }
+  
+  // Listen
+  if (listen(g_ctrl.server_fd, 1) < 0) {
+    LOG_E(PHY, "[ANTENNA_CTRL] Failed to listen: %s\n", strerror(errno));
+    close(g_ctrl.server_fd);
+    return false;
+  }
+  
+  // Start server thread
+  g_ctrl.running = true;
+  if (pthread_create(&g_ctrl.thread, NULL, server_thread, NULL) != 0) {
+    LOG_E(PHY, "[ANTENNA_CTRL] Failed to create server thread\n");
+    g_ctrl.running = false;
+    close(g_ctrl.server_fd);
+    return false;
+  }
+  
+  LOG_I(PHY, "[ANTENNA_CTRL] Test server started on port %d\n", g_ctrl.port);
+  LOG_I(PHY, "[ANTENNA_CTRL] Connect with: nc localhost %d\n", g_ctrl.port);
+  
+  return true;
+}
+
+bool nr_antenna_control_start(nr_antenna_state_t *ant_state, int port)
+{
+  LOG_W(PHY, "[ANTENNA_CTRL] nr_antenna_control_start() is DEPRECATED\n");
+  LOG_W(PHY, "[ANTENNA_CTRL] Use nr_antenna_control_init_mplane() for O-RAN compliance\n");
+  LOG_W(PHY, "[ANTENNA_CTRL] or nr_antenna_control_start_test_server() for testing\n");
+  
+  return nr_antenna_control_start_test_server(ant_state, port);
+}
+
+void nr_antenna_control_stop(void)
+{
+  if (!g_ctrl.running) return;
+  
+  g_ctrl.running = false;
+  
+  if (g_ctrl.backend == ANTENNA_CTRL_BACKEND_TEST_SOCKET) {
+    // Close server socket to unblock accept()
+    if (g_ctrl.server_fd >= 0) {
+      close(g_ctrl.server_fd);
+      g_ctrl.server_fd = -1;
+    }
+    
+    // Wait for thread
+    pthread_join(g_ctrl.thread, NULL);
+  }
+  
+  g_ctrl.backend = ANTENNA_CTRL_BACKEND_NONE;
+  g_ctrl.ant_state = NULL;
+  g_ctrl.ru_session = NULL;
+  
+  LOG_I(PHY, "[ANTENNA_CTRL] Control interface stopped\n");
+}
+
+bool nr_antenna_control_is_running(void)
+{
+  return g_ctrl.running;
+}
+
+nr_antenna_ctrl_backend_t nr_antenna_control_get_backend(void)
+{
+  return g_ctrl.backend;
+}
+
+bool nr_antenna_control_sync_to_ru(nr_antenna_state_t *ant_state)
+{
+#ifdef OAI_MPLANE
+  if (g_ctrl.backend != ANTENNA_CTRL_BACKEND_MPLANE || g_ctrl.ru_session == NULL) {
+    LOG_W(PHY, "[ANTENNA_CTRL] M-Plane backend not active, cannot sync to RU\n");
+    return false;
+  }
+  
+  if (ant_state == NULL) {
+    ant_state = g_ctrl.ant_state;
+  }
+  
+  if (ant_state == NULL) {
+    return false;
+  }
+  
+  // Send TX antenna mask to RU
+  antenna_ctrl_result_t result;
+  result = mplane_set_tx_antenna_mask(g_ctrl.ru_session,
+                                       ant_state->tx_array_name,
+                                       nr_get_tx_antenna_bitmask(ant_state),
+                                       ant_state->num_tx_antennas);
+  if (result != ANTENNA_CTRL_SUCCESS) {
+    LOG_W(PHY, "[ANTENNA_CTRL] Failed to sync TX mask: %s\n", 
+          antenna_ctrl_result_str(result));
+    return false;
+  }
+  
+  // Send RX antenna mask to RU
+  result = mplane_set_rx_antenna_mask(g_ctrl.ru_session,
+                                       ant_state->rx_array_name,
+                                       nr_get_rx_antenna_bitmask(ant_state),
+                                       ant_state->num_rx_antennas);
+  if (result != ANTENNA_CTRL_SUCCESS) {
+    LOG_W(PHY, "[ANTENNA_CTRL] Failed to sync RX mask: %s\n",
+          antenna_ctrl_result_str(result));
+    return false;
+  }
+  
+  LOG_I(PHY, "[ANTENNA_CTRL] Successfully synchronized antenna masks to RU\n");
+  return true;
+#else
+  LOG_W(PHY, "[ANTENNA_CTRL] M-Plane not compiled in\n");
+  return false;
+#endif
+}
+
+bool nr_antenna_control_sync_from_ru(nr_antenna_state_t *ant_state)
+{
+#ifdef OAI_MPLANE
+  if (g_ctrl.backend != ANTENNA_CTRL_BACKEND_MPLANE || g_ctrl.ru_session == NULL) {
+    LOG_W(PHY, "[ANTENNA_CTRL] M-Plane backend not active, cannot sync from RU\n");
+    return false;
+  }
+  
+  if (ant_state == NULL) {
+    ant_state = g_ctrl.ant_state;
+  }
+  
+  if (ant_state == NULL) {
+    return false;
+  }
+  
+  uint8_t tx_mask, rx_mask;
+  antenna_ctrl_result_t result;
+  
+  // Get TX antenna mask from RU
+  result = mplane_get_tx_antenna_mask(g_ctrl.ru_session,
+                                       ant_state->tx_array_name,
+                                       &tx_mask);
+  if (result == ANTENNA_CTRL_SUCCESS) {
+    nr_set_tx_antenna_bitmask(ant_state, tx_mask);
+  }
+  
+  // Get RX antenna mask from RU
+  result = mplane_get_rx_antenna_mask(g_ctrl.ru_session,
+                                       ant_state->rx_array_name,
+                                       &rx_mask);
+  if (result == ANTENNA_CTRL_SUCCESS) {
+    nr_set_rx_antenna_bitmask(ant_state, rx_mask);
+  }
+  
+  LOG_I(PHY, "[ANTENNA_CTRL] Synchronized antenna masks from RU: TX=0x%02X, RX=0x%02X\n",
+        tx_mask, rx_mask);
+  return true;
+#else
+  LOG_W(PHY, "[ANTENNA_CTRL] M-Plane not compiled in\n");
+  return false;
+#endif
+}

openair1/PHY/NR_TRANSPORT/nr_antenna_control.h

@@ -0,0 +1,123 @@
+#ifndef NR_ANTENNA_CONTROL_H
+#define NR_ANTENNA_CONTROL_H
+
+#include "nr_antenna_state.h"
+#include <stdbool.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/// Default port for the test socket server (development mode only)
+#define NR_ANTENNA_CONTROL_TEST_PORT 9999
+
+/**
+ * @brief Antenna control backend type
+ */
+typedef enum {
+  ANTENNA_CTRL_BACKEND_NONE = 0,      ///< No external control
+  ANTENNA_CTRL_BACKEND_MPLANE,        ///< O-RAN M-Plane NETCONF (production)
+  ANTENNA_CTRL_BACKEND_TEST_SOCKET    ///< Test socket interface (development)
+} nr_antenna_ctrl_backend_t;
+
+/**
+ * @brief Initialize antenna control with O-RAN M-Plane NETCONF backend
+ * 
+ * This is the O-RAN compliant production interface. It connects the
+ * antenna state to a real NETCONF session to an O-RU.
+ * 
+ * When antenna masks are changed via nr_set_tx_antenna_bitmask() or
+ * similar functions, the changes are automatically propagated to the
+ * RU via NETCONF edit-config operations.
+ * 
+ * @param ant_state Pointer to the antenna state to control
+ * @param ru_session Active M-Plane NETCONF session (from radio/fhi_72/mplane/)
+ * @return true if initialization successful
+ */
+bool nr_antenna_control_init_mplane(nr_antenna_state_t *ant_state, 
+                                     void *ru_session);
+
+/**
+ * @brief Start the test socket server (development mode only)
+ * 
+ * Creates a simple TCP server for testing antenna control without
+ * NETCONF infrastructure. This is NOT O-RAN compliant.
+ * 
+ * Commands supported (for backwards compatibility):
+ *   MUTE TX <ant_id>      - Mute TX antenna
+ *   UNMUTE TX <ant_id>    - Unmute TX antenna
+ *   MUTE RX <ant_id>      - Mute RX antenna
+ *   UNMUTE RX <ant_id>    - Unmute RX antenna
+ *   SET TX MASK <hex>     - Set TX antenna bitmask
+ *   SET RX MASK <hex>     - Set RX antenna bitmask
+ *   STATUS                - Get current antenna state
+ *   STATS                 - Get energy saving statistics
+ *   RESET STATS           - Reset statistics
+ *   QUIT                  - Close connection
+ * 
+ * @param ant_state Pointer to the antenna state to control
+ * @param port TCP port to listen on (use 0 for default)
+ * @return true if server started successfully
+ * 
+ * @note This function logs a warning that it's not O-RAN compliant
+ */
+bool nr_antenna_control_start_test_server(nr_antenna_state_t *ant_state, int port);
+
+/**
+ * @brief Legacy function - start antenna control server
+ * 
+ * @deprecated Use nr_antenna_control_init_mplane() for O-RAN compliance
+ *             or nr_antenna_control_start_test_server() for testing.
+ * 
+ * This function starts the test socket server for backwards compatibility.
+ * It logs a deprecation warning.
+ */
+bool nr_antenna_control_start(nr_antenna_state_t *ant_state, int port);
+
+/**
+ * @brief Stop the antenna control interface
+ * 
+ * Stops the test socket server if running.
+ * For M-Plane backend, this disconnects from NETCONF notifications.
+ */
+void nr_antenna_control_stop(void);
+
+/**
+ * @brief Check if antenna control is active
+ * @return true if control interface is running
+ */
+bool nr_antenna_control_is_running(void);
+
+/**
+ * @brief Get current antenna control backend type
+ * @return Backend type currently in use
+ */
+nr_antenna_ctrl_backend_t nr_antenna_control_get_backend(void);
+
+/**
+ * @brief Synchronize local antenna state to RU via M-Plane NETCONF
+ * 
+ * Sends the current antenna bitmask configuration to the RU.
+ * Only applicable when using the M-Plane NETCONF backend.
+ * 
+ * @param ant_state Pointer to the antenna state
+ * @return true if synchronization successful or not applicable
+ */
+bool nr_antenna_control_sync_to_ru(nr_antenna_state_t *ant_state);
+
+/**
+ * @brief Synchronize RU antenna state to local via M-Plane NETCONF
+ * 
+ * Reads the current antenna bitmask from the RU and updates local state.
+ * Only applicable when using the M-Plane NETCONF backend.
+ * 
+ * @param ant_state Pointer to the antenna state
+ * @return true if synchronization successful or not applicable
+ */
+bool nr_antenna_control_sync_from_ru(nr_antenna_state_t *ant_state);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* NR_ANTENNA_CONTROL_H */

openair1/PHY/NR_TRANSPORT/nr_antenna_state.c

@@ -0,0 +1,367 @@
+#include "nr_antenna_state.h"
+#include "common/utils/LOG/log.h"
+#include <string.h>
+#include <time.h>
+
+// Helper to count set bits in a byte
+static inline int popcount8(uint8_t x) {
+  int count = 0;
+  while (x) {
+    count += x & 1;
+    x >>= 1;
+  }
+  return count;
+}
+
+// Get current timestamp in microseconds
+static inline uint64_t get_timestamp_us(void) {
+  struct timespec ts;
+  clock_gettime(CLOCK_MONOTONIC, &ts);
+  return (uint64_t)ts.tv_sec * 1000000ULL + (uint64_t)ts.tv_nsec / 1000ULL;
+}
+
+void nr_init_antenna_state(nr_antenna_state_t *state, 
+                           uint8_t num_tx, 
+                           uint8_t num_rx,
+                           const char *tx_array_name,
+                           const char *rx_array_name)
+{
+  if (state == NULL) return;
+  
+  memset(state, 0, sizeof(nr_antenna_state_t));
+  
+  state->num_tx_antennas = (num_tx > NR_MAX_ANTENNAS) ? NR_MAX_ANTENNAS : num_tx;
+  state->num_rx_antennas = (num_rx > NR_MAX_ANTENNAS) ? NR_MAX_ANTENNAS : num_rx;
+  
+  // Initialize with all configured antennas active
+  // Create bitmask with num_tx/num_rx lowest bits set
+  state->tx_antenna_bitmask = (1 << state->num_tx_antennas) - 1;
+  state->rx_antenna_bitmask = (1 << state->num_rx_antennas) - 1;
+  
+  // Set O-RAN array names
+  if (tx_array_name) {
+    strncpy(state->tx_array_name, tx_array_name, sizeof(state->tx_array_name) - 1);
+  } else {
+    strncpy(state->tx_array_name, "tx-array-0", sizeof(state->tx_array_name) - 1);
+  }
+  
+  if (rx_array_name) {
+    strncpy(state->rx_array_name, rx_array_name, sizeof(state->rx_array_name) - 1);
+  } else {
+    strncpy(state->rx_array_name, "rx-array-0", sizeof(state->rx_array_name) - 1);
+  }
+  
+  pthread_mutex_init(&state->lock, NULL);
+  
+  state->stats.last_update_timestamp = get_timestamp_us();
+  
+  // Initialize recovery mode
+  state->recovery.in_recovery = false;
+  state->recovery.recovery_start_ts = 0;
+  state->recovery.recovery_duration_ms = 500; // 500ms default recovery time
+  
+  // Protect antenna 0 by default (needed for SSB/PSS/SSS)
+  state->config.protect_antenna0 = true;
+  
+  LOG_I(PHY, "[ANTENNA_STATE] Initialized: TX antennas=%d (mask=0x%02X, array=%s), "
+             "RX antennas=%d (mask=0x%02X, array=%s), antenna0_protected=%d\n",
+        state->num_tx_antennas, state->tx_antenna_bitmask, state->tx_array_name,
+        state->num_rx_antennas, state->rx_antenna_bitmask, state->rx_array_name,
+        state->config.protect_antenna0);
+}
+
+void nr_free_antenna_state(nr_antenna_state_t *state)
+{
+  if (state == NULL) return;
+  pthread_mutex_destroy(&state->lock);
+}
+
+uint8_t nr_set_tx_antenna_bitmask(nr_antenna_state_t *state, uint8_t bitmask)
+{
+  if (state == NULL) return 0;
+  
+  pthread_mutex_lock(&state->lock);
+  
+  uint8_t old_bitmask = state->tx_antenna_bitmask;
+  
+  // Mask to only valid antenna bits
+  uint8_t valid_mask = (1 << state->num_tx_antennas) - 1;
+  state->tx_antenna_bitmask = bitmask & valid_mask;
+  
+  // Update statistics
+  if (state->tx_antenna_bitmask != old_bitmask) {
+    state->stats.tx_mute_events++;
+    state->stats.last_update_timestamp = get_timestamp_us();
+    
+    LOG_I(PHY, "[ANTENNA_STATE] TX bitmask changed: 0x%02X -> 0x%02X (array=%s, active=%d/%d)\n",
+          old_bitmask, state->tx_antenna_bitmask, state->tx_array_name,
+          popcount8(state->tx_antenna_bitmask), state->num_tx_antennas);
+  }
+  
+  pthread_mutex_unlock(&state->lock);
+  
+  return old_bitmask;
+}
+
+uint8_t nr_set_rx_antenna_bitmask(nr_antenna_state_t *state, uint8_t bitmask)
+{
+  if (state == NULL) return 0;
+  
+  pthread_mutex_lock(&state->lock);
+  
+  uint8_t old_bitmask = state->rx_antenna_bitmask;
+  
+  // Mask to only valid antenna bits
+  uint8_t valid_mask = (1 << state->num_rx_antennas) - 1;
+  state->rx_antenna_bitmask = bitmask & valid_mask;
+  
+  // Update statistics
+  if (state->rx_antenna_bitmask != old_bitmask) {
+    state->stats.rx_mute_events++;
+    state->stats.last_update_timestamp = get_timestamp_us();
+    
+    LOG_I(PHY, "[ANTENNA_STATE] RX bitmask changed: 0x%02X -> 0x%02X (array=%s, active=%d/%d)\n",
+          old_bitmask, state->rx_antenna_bitmask, state->rx_array_name,
+          popcount8(state->rx_antenna_bitmask), state->num_rx_antennas);
+  }
+  
+  pthread_mutex_unlock(&state->lock);
+  
+  return old_bitmask;
+}
+
+uint8_t nr_get_tx_antenna_bitmask(const nr_antenna_state_t *state)
+{
+  if (state == NULL) return 0xFF;
+  pthread_mutex_lock((pthread_mutex_t*)&state->lock);
+  uint8_t m = state->tx_antenna_bitmask;
+  pthread_mutex_unlock((pthread_mutex_t*)&state->lock);
+  return m;
+}
+
+uint8_t nr_get_rx_antenna_bitmask(const nr_antenna_state_t *state)
+{
+  if (state == NULL) return 0xFF;
+  pthread_mutex_lock((pthread_mutex_t*)&state->lock);
+  uint8_t m = state->rx_antenna_bitmask;
+  pthread_mutex_unlock((pthread_mutex_t*)&state->lock);
+  return m;
+}
+
+bool nr_is_tx_antenna_active(const nr_antenna_state_t *state, uint8_t ant_id)
+{
+  if (state == NULL || ant_id >= state->num_tx_antennas) return false;
+  return (state->tx_antenna_bitmask & (1 << ant_id)) != 0;
+}
+
+bool nr_is_rx_antenna_active(const nr_antenna_state_t *state, uint8_t ant_id)
+{
+  if (state == NULL || ant_id >= state->num_rx_antennas) return false;
+  return (state->rx_antenna_bitmask & (1 << ant_id)) != 0;
+}
+
+int nr_get_active_tx_antenna_count(const nr_antenna_state_t *state)
+{
+  if (state == NULL) return 0;
+  return popcount8(state->tx_antenna_bitmask);
+}
+
+int nr_get_active_rx_antenna_count(const nr_antenna_state_t *state)
+{
+  if (state == NULL) return 0;
+  return popcount8(state->rx_antenna_bitmask);
+}
+
+void nr_mute_tx_antenna(nr_antenna_state_t *state, uint8_t ant_id)
+{
+  if (state == NULL || ant_id >= state->num_tx_antennas) return;
+  
+  // Protect antenna 0 if configured (needed for SSB/PSS/SSS transmission)
+  if (ant_id == 0 && state->config.protect_antenna0) {
+    LOG_W(PHY, "[ANTENNA_STATE] Cannot mute TX antenna 0: protected for SSB transmission\n");
+    LOG_W(PHY, "[ANTENNA_STATE] Use 'SET TX MASK' to override protection if needed\n");
+    return;
+  }
+  
+  uint8_t new_mask = state->tx_antenna_bitmask & ~(1 << ant_id);
+  nr_set_tx_antenna_bitmask(state, new_mask);
+}
+
+void nr_unmute_tx_antenna(nr_antenna_state_t *state, uint8_t ant_id)
+{
+  if (state == NULL || ant_id >= state->num_tx_antennas) return;
+  
+  uint8_t new_mask = state->tx_antenna_bitmask | (1 << ant_id);
+  nr_set_tx_antenna_bitmask(state, new_mask);
+}
+
+void nr_mute_rx_antenna(nr_antenna_state_t *state, uint8_t ant_id)
+{
+  if (state == NULL || ant_id >= state->num_rx_antennas) return;
+  
+  uint8_t new_mask = state->rx_antenna_bitmask & ~(1 << ant_id);
+  nr_set_rx_antenna_bitmask(state, new_mask);
+}
+
+void nr_unmute_rx_antenna(nr_antenna_state_t *state, uint8_t ant_id)
+{
+  if (state == NULL || ant_id >= state->num_rx_antennas) return;
+  
+  uint8_t new_mask = state->rx_antenna_bitmask | (1 << ant_id);
+  nr_set_rx_antenna_bitmask(state, new_mask);
+}
+
+int nr_get_effective_mimo_layers(const nr_antenna_state_t *state, int requested_layers)
+{
+  if (state == NULL)
+    return requested_layers;
+
+  // Reduce MIMO layers to match the number of active TX antennas.
+  // When antennas are muted, the RU blanks the corresponding TX buffers.
+  // If the scheduler still uses full layer count, the precoded signal is
+  // distributed across all antenna ports (including muted ones), which
+  // corrupts the UE's MIMO reception. By reducing layers to match active
+  // antennas, the PMI fallback to identity precoding maps layers 1:1 to
+  // active ports, avoiding signal loss on muted ports.
+  int active = nr_get_active_tx_antenna_count(state);
+  if (active > 0 && active < requested_layers)
+    return active;
+  return requested_layers;
+}
+
+void nr_log_antenna_state(const nr_antenna_state_t *state)
+{
+  if (state == NULL) {
+    LOG_I(PHY, "[ANTENNA_STATE] State is NULL\n");
+    return;
+  }
+  
+  LOG_I(PHY, "[ANTENNA_STATE] === Antenna State Report ===\n");
+  LOG_I(PHY, "[ANTENNA_STATE] TX Array: %s\n", state->tx_array_name);
+  LOG_I(PHY, "[ANTENNA_STATE]   Configured: %d antennas\n", state->num_tx_antennas);
+  LOG_I(PHY, "[ANTENNA_STATE]   Bitmask: 0x%02X\n", state->tx_antenna_bitmask);
+  LOG_I(PHY, "[ANTENNA_STATE]   Active: %d antennas\n", nr_get_active_tx_antenna_count(state));
+  LOG_I(PHY, "[ANTENNA_STATE]   Individual: ");
+  for (int i = 0; i < state->num_tx_antennas; i++) {
+    LOG_I(PHY, "TX%d=%s ", i, nr_is_tx_antenna_active(state, i) ? "ON" : "OFF");
+  }
+  LOG_I(PHY, "\n");
+  
+  LOG_I(PHY, "[ANTENNA_STATE] RX Array: %s\n", state->rx_array_name);
+  LOG_I(PHY, "[ANTENNA_STATE]   Configured: %d antennas\n", state->num_rx_antennas);
+  LOG_I(PHY, "[ANTENNA_STATE]   Bitmask: 0x%02X\n", state->rx_antenna_bitmask);
+  LOG_I(PHY, "[ANTENNA_STATE]   Active: %d antennas\n", nr_get_active_rx_antenna_count(state));
+  
+  LOG_I(PHY, "[ANTENNA_STATE] Statistics:\n");
+  LOG_I(PHY, "[ANTENNA_STATE]   TX mute events: %lu\n", state->stats.tx_mute_events);
+  LOG_I(PHY, "[ANTENNA_STATE]   RX mute events: %lu\n", state->stats.rx_mute_events);
+  LOG_I(PHY, "[ANTENNA_STATE]   Total muted slots: %lu\n", state->stats.total_muted_slots);
+  LOG_I(PHY, "[ANTENNA_STATE] =============================\n");
+}
+
+void nr_get_antenna_stats(const nr_antenna_state_t *state,
+                          uint64_t *tx_mute_events,
+                          uint64_t *rx_mute_events,
+                          uint64_t *total_muted_slots)
+{
+  if (state == NULL) return;
+  
+  if (tx_mute_events) *tx_mute_events = state->stats.tx_mute_events;
+  if (rx_mute_events) *rx_mute_events = state->stats.rx_mute_events;
+  if (total_muted_slots) *total_muted_slots = state->stats.total_muted_slots;
+}
+
+void nr_reset_antenna_stats(nr_antenna_state_t *state)
+{
+  if (state == NULL) return;
+  
+  pthread_mutex_lock(&state->lock);
+  
+  state->stats.tx_mute_events = 0;
+  state->stats.rx_mute_events = 0;
+  state->stats.total_muted_slots = 0;
+  state->stats.energy_saved_estimate = 0;
+  state->stats.last_update_timestamp = get_timestamp_us();
+  
+  LOG_I(PHY, "[ANTENNA_STATE] Statistics reset\n");
+  
+  pthread_mutex_unlock(&state->lock);
+}
+
+void nr_unmute_all_tx_antennas(nr_antenna_state_t *state)
+{
+  if (state == NULL) return;
+  
+  pthread_mutex_lock(&state->lock);
+  
+  uint8_t old_mask = state->tx_antenna_bitmask;
+  uint8_t all_on = (1 << state->num_tx_antennas) - 1;
+  state->tx_antenna_bitmask = all_on;
+  
+  // Enter recovery mode if we were muted
+  if (old_mask != all_on) {
+    state->recovery.in_recovery = true;
+    state->recovery.recovery_start_ts = get_timestamp_us();
+    LOG_I(PHY, "[ANTENNA_STATE] Entering recovery mode for %u ms after unmuting TX antennas\n",
+          state->recovery.recovery_duration_ms);
+  }
+  
+  state->stats.tx_mute_events++;
+  state->stats.last_update_timestamp = get_timestamp_us();
+  
+  LOG_I(PHY, "[ANTENNA_STATE] All TX antennas unmuted: 0x%02X -> 0x%02X (array=%s)\n",
+        old_mask, all_on, state->tx_array_name);
+  
+  pthread_mutex_unlock(&state->lock);
+}
+
+void nr_unmute_all_rx_antennas(nr_antenna_state_t *state)
+{
+  if (state == NULL) return;
+  
+  pthread_mutex_lock(&state->lock);
+  
+  uint8_t old_mask = state->rx_antenna_bitmask;
+  uint8_t all_on = (1 << state->num_rx_antennas) - 1;
+  state->rx_antenna_bitmask = all_on;
+  
+  state->stats.rx_mute_events++;
+  state->stats.last_update_timestamp = get_timestamp_us();
+  
+  LOG_I(PHY, "[ANTENNA_STATE] All RX antennas unmuted: 0x%02X -> 0x%02X (array=%s)\n",
+        old_mask, all_on, state->rx_array_name);
+  
+  pthread_mutex_unlock(&state->lock);
+}
+
+bool nr_is_in_recovery_mode(const nr_antenna_state_t *state)
+{
+  if (state == NULL) return false;
+  
+  if (!state->recovery.in_recovery) return false;
+  
+  // Check if recovery period has elapsed
+  uint64_t now = get_timestamp_us();
+  uint64_t elapsed_us = now - state->recovery.recovery_start_ts;
+  uint64_t duration_us = (uint64_t)state->recovery.recovery_duration_ms * 1000ULL;
+  
+  if (elapsed_us >= duration_us) {
+    // Recovery complete - cast away const for state update
+    nr_antenna_state_t *s = (nr_antenna_state_t *)state;
+    s->recovery.in_recovery = false;
+    LOG_I(PHY, "[ANTENNA_STATE] Recovery mode complete after %lu ms\n", elapsed_us / 1000);
+    return false;
+  }
+  
+  return true;
+}
+
+void nr_set_antenna0_protection(nr_antenna_state_t *state, bool protect)
+{
+  if (state == NULL) return;
+  
+  pthread_mutex_lock(&state->lock);
+  state->config.protect_antenna0 = protect;
+  LOG_I(PHY, "[ANTENNA_STATE] Antenna 0 protection %s\n", protect ? "enabled" : "disabled");
+  pthread_mutex_unlock(&state->lock);
+}

openair1/PHY/NR_TRANSPORT/nr_antenna_state.h

@@ -0,0 +1,239 @@
+#ifndef NR_ANTENNA_STATE_H
+#define NR_ANTENNA_STATE_H
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <pthread.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/// Maximum number of physical antennas supported
+#define NR_MAX_ANTENNAS 8
+
+/// O-RAN compliant antenna state for TX/RX arrays
+/// Mirrors o-ran-uplane-conf.yang: tx-array-antenna-mask-config
+typedef struct {
+  /// Antenna bitmask per O-RAN WG4 spec: bit N = 1 means antenna N is active
+  /// Corresponds to o-ran-uplane-conf:antenna-bitmask
+  uint8_t tx_antenna_bitmask;
+  uint8_t rx_antenna_bitmask;
+  
+  /// Total number of configured antennas
+  uint8_t num_tx_antennas;
+  uint8_t num_rx_antennas;
+  
+  /// Thread safety for runtime updates
+  pthread_mutex_t lock;
+  
+  /// Energy saving statistics (for research/monitoring)
+  struct {
+    uint64_t tx_mute_events;        ///< Number of TX mute operations
+    uint64_t rx_mute_events;        ///< Number of RX mute operations
+    uint64_t total_muted_slots;     ///< Total slots with at least one antenna muted
+    uint64_t energy_saved_estimate; ///< Estimated energy saved (arbitrary units)
+    uint64_t last_update_timestamp; ///< Last update time (for O1 notifications)
+  } stats;
+  
+  /// O-RAN compliance: array name for NETCONF identification
+  char tx_array_name[64];
+  char rx_array_name[64];
+  
+  /// Recovery mode: after unmuting, allow CSI to update before using full capacity
+  struct {
+    bool in_recovery;           ///< Currently in recovery mode
+    uint64_t recovery_start_ts; ///< Timestamp when recovery started (us)
+    uint32_t recovery_duration_ms; ///< Recovery duration in milliseconds (default 500ms)
+  } recovery;
+  
+  /// Configuration flags
+  struct {
+    bool protect_antenna0;      ///< Never mute antenna 0 (needed for SSB)
+  } config;
+  
+} nr_antenna_state_t;
+
+/**
+ * @brief Initialize antenna state with all antennas active
+ * @param state Pointer to antenna state structure
+ * @param num_tx Number of TX antennas
+ * @param num_rx Number of RX antennas
+ * @param tx_array_name O-RAN array name for TX (e.g., "tx-array-0")
+ * @param rx_array_name O-RAN array name for RX (e.g., "rx-array-0")
+ */
+void nr_init_antenna_state(nr_antenna_state_t *state, 
+                           uint8_t num_tx, 
+                           uint8_t num_rx,
+                           const char *tx_array_name,
+                           const char *rx_array_name);
+
+/**
+ * @brief Free antenna state resources
+ * @param state Pointer to antenna state structure
+ */
+void nr_free_antenna_state(nr_antenna_state_t *state);
+
+/**
+ * @brief Set TX antenna bitmask (O-RAN O1 interface equivalent)
+ * 
+ * This function implements the O-RAN WG4 MPLANE-TRX-CONTROL feature.
+ * Corresponds to NETCONF edit-config on tx-array-antenna-mask-config.
+ * 
+ * @param state Pointer to antenna state structure
+ * @param bitmask Antenna bitmask (bit N = 1 means antenna N active)
+ * @return Previous bitmask value
+ */
+uint8_t nr_set_tx_antenna_bitmask(nr_antenna_state_t *state, uint8_t bitmask);
+
+/**
+ * @brief Set RX antenna bitmask (O-RAN O1 interface equivalent)
+ * @param state Pointer to antenna state structure
+ * @param bitmask Antenna bitmask (bit N = 1 means antenna N active)
+ * @return Previous bitmask value
+ */
+uint8_t nr_set_rx_antenna_bitmask(nr_antenna_state_t *state, uint8_t bitmask);
+
+/**
+ * @brief Get current TX antenna bitmask
+ * @param state Pointer to antenna state structure
+ * @return Current TX antenna bitmask
+ */
+uint8_t nr_get_tx_antenna_bitmask(const nr_antenna_state_t *state);
+
+/**
+ * @brief Get current RX antenna bitmask
+ * @param state Pointer to antenna state structure
+ * @return Current RX antenna bitmask
+ */
+uint8_t nr_get_rx_antenna_bitmask(const nr_antenna_state_t *state);
+
+/**
+ * @brief Check if a specific TX antenna is active
+ * @param state Pointer to antenna state structure
+ * @param ant_id Antenna index (0-based)
+ * @return true if antenna is active, false if muted
+ */
+bool nr_is_tx_antenna_active(const nr_antenna_state_t *state, uint8_t ant_id);
+
+/**
+ * @brief Check if a specific RX antenna is active
+ * @param state Pointer to antenna state structure
+ * @param ant_id Antenna index (0-based)
+ * @return true if antenna is active, false if muted
+ */
+bool nr_is_rx_antenna_active(const nr_antenna_state_t *state, uint8_t ant_id);
+
+/**
+ * @brief Get count of currently active TX antennas
+ * @param state Pointer to antenna state structure
+ * @return Number of active TX antennas
+ */
+int nr_get_active_tx_antenna_count(const nr_antenna_state_t *state);
+
+/**
+ * @brief Get count of currently active RX antennas
+ * @param state Pointer to antenna state structure
+ * @return Number of active RX antennas
+ */
+int nr_get_active_rx_antenna_count(const nr_antenna_state_t *state);
+
+/**
+ * @brief Mute a specific TX antenna
+ * @param state Pointer to antenna state structure
+ * @param ant_id Antenna index to mute (0-based)
+ */
+void nr_mute_tx_antenna(nr_antenna_state_t *state, uint8_t ant_id);
+
+/**
+ * @brief Unmute a specific TX antenna
+ * @param state Pointer to antenna state structure
+ * @param ant_id Antenna index to unmute (0-based)
+ */
+void nr_unmute_tx_antenna(nr_antenna_state_t *state, uint8_t ant_id);
+
+/**
+ * @brief Mute a specific RX antenna
+ * @param state Pointer to antenna state structure
+ * @param ant_id Antenna index to mute (0-based)
+ */
+void nr_mute_rx_antenna(nr_antenna_state_t *state, uint8_t ant_id);
+
+/**
+ * @brief Unmute a specific RX antenna
+ * @param state Pointer to antenna state structure
+ * @param ant_id Antenna index to unmute (0-based)
+ */
+void nr_unmute_rx_antenna(nr_antenna_state_t *state, uint8_t ant_id);
+
+/**
+ * @brief Get effective number of MIMO layers based on active antennas
+ * 
+ * For MIMO, the number of layers is limited by active antennas.
+ * This function returns min(requested_layers, active_antennas).
+ * 
+ * @param state Pointer to antenna state structure
+ * @param requested_layers Originally requested number of layers
+ * @return Effective number of layers that can be used
+ */
+int nr_get_effective_mimo_layers(const nr_antenna_state_t *state, int requested_layers);
+
+/**
+ * @brief Log antenna state for debugging
+ * @param state Pointer to antenna state structure
+ */
+void nr_log_antenna_state(const nr_antenna_state_t *state);
+
+/**
+ * @brief Get energy saving statistics
+ * @param state Pointer to antenna state structure
+ * @param tx_mute_events Output: number of TX mute events
+ * @param rx_mute_events Output: number of RX mute events
+ * @param total_muted_slots Output: total slots with muting
+ */
+void nr_get_antenna_stats(const nr_antenna_state_t *state,
+                          uint64_t *tx_mute_events,
+                          uint64_t *rx_mute_events,
+                          uint64_t *total_muted_slots);
+
+/**
+ * @brief Reset energy saving statistics
+ * @param state Pointer to antenna state structure
+ */
+void nr_reset_antenna_stats(nr_antenna_state_t *state);
+
+/**
+ * @brief Unmute all TX antennas and enter recovery mode
+ * @param state Pointer to antenna state structure
+ * 
+ * This initiates a recovery period during which the scheduler
+ * uses conservative settings to allow UE CSI reports to update.
+ */
+void nr_unmute_all_tx_antennas(nr_antenna_state_t *state);
+
+/**
+ * @brief Unmute all RX antennas
+ * @param state Pointer to antenna state structure
+ */
+void nr_unmute_all_rx_antennas(nr_antenna_state_t *state);
+
+/**
+ * @brief Check if system is in recovery mode after unmuting
+ * @param state Pointer to antenna state structure
+ * @return true if in recovery mode
+ */
+bool nr_is_in_recovery_mode(const nr_antenna_state_t *state);
+
+/**
+ * @brief Set antenna 0 protection (SSB antenna)
+ * @param state Pointer to antenna state structure
+ * @param protect true to prevent muting antenna 0
+ */
+void nr_set_antenna0_protection(nr_antenna_state_t *state, bool protect);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* NR_ANTENNA_STATE_H */
+

openair1/PHY/defs_gNB.h

@@ -21,6 +21,7 @@
 #include "common/utils/threadPool/task_ans.h"
 #include "openair1/PHY/defs_RU.h"
 #include "common/utils/ds/spsc_q.h"
+#include "PHY/NR_TRANSPORT/nr_antenna_state.h"
 
 #define MAX_NUM_RU_PER_gNB 8
 #define MAX_PUCCH0_NID 8
@@ -430,6 +431,8 @@ typedef struct PHY_VARS_gNB_s {
 
   bool enable_analog_das;
 
+    nr_antenna_state_t antenna_state;
+
   time_stats_t l1_tx_proc;
   time_stats_t l1_rx_proc;
 

openair1/SCHED_NR/nr_ru_procedures.c

@@ -21,6 +21,14 @@
 
 #include <time.h>
 
+static inline int count_nnz_c16(const c16_t *v, int n)
+{
+    int nnz = 0;
+    for (int i = 0; i < n; i++)
+        nnz += (v[i].r != 0) || (v[i].i != 0);
+    return nnz;
+}
+
 // RU OFDM Modulator gNodeB
 // OFDM modulation core routine, generates a first_symbol to first_symbol+num_symbols on a particular slot and TX antenna port
 void nr_feptx0(RU_t *ru, int tti_tx, int first_symbol, int num_symbols, int aa)
@@ -165,12 +173,20 @@ void nr_feptx_prec(RU_t *ru, int frame_tx, int slot_tx)
   int Ptx = cfg->carrier_config.num_tx_ant.value;
   // If there is no digital beamforming we just need to copy the data to RU
   if (ru->config.dbt_config.num_dig_beams == 0 || ru->gNB_list[0]->common_vars.analog_bf) {
+    const nr_antenna_state_t *ant_state = &gNB->antenna_state;
     for (int b = 0; b < ru->num_beams_period; b++) {
       for (int i = 0; i < Ptx; ++i) {
         int tx_idx = i + b * ru->nb_tx;
-        memcpy((void *)ru->common.txdataF_BF[tx_idx],
-               (void *)gNB->common_vars.txdataF[b][i],
-               fp->samples_per_slot_wCP * sizeof(int32_t));
+        // Check antenna muting state for energy saving
+        if (!nr_is_tx_antenna_active(ant_state, i)) {
+          // Antenna is muted - zero out the buffer (transmission blanking)
+          memset((void *)ru->common.txdataF_BF[tx_idx], 0, fp->samples_per_slot_wCP * sizeof(int32_t));
+          LOG_D(PHY, "[ANTENNA_MUTE] TX antenna %d muted in nr_feptx_prec, blanking slot %d\n", i, slot_tx);
+        } else {
+          memcpy((void *)ru->common.txdataF_BF[tx_idx],
+                 (void *)gNB->common_vars.txdataF[b][i],
+                 fp->samples_per_slot_wCP * sizeof(int32_t));
+        }
       }
     }
   }  else {
@@ -205,19 +221,38 @@ void nr_feptx(void *arg)
 
   // If there is no digital beamforming we just need to copy the data to RU
   if (ru->config.dbt_config.num_dig_beams == 0 || ru->gNB_list[0]->common_vars.analog_bf) {
-    // FFT shift
     const NR_DL_FRAME_PARMS *fp = &ru->gNB_list[0]->frame_parms;
-    fft_shift(ru->gNB_list[0]->common_vars.txdataF[bb][aa],
-              fp->ofdm_symbol_size,
-              fp->N_RB_DL,
-              (c16_t *)ru->common.txdataF_BF[tx_idx],
-              fp->ofdm_symbol_size,
-              startSymbol,
-              numSymbols);
+    const nr_antenna_state_t *ant_state = &ru->gNB_list[0]->antenna_state;
+    if (!nr_is_tx_antenna_active(ant_state, aa)) {
+      // Antenna is muted - zero out the FFT-shift output (transmission blanking)
+      memset((void *)&ru->common.txdataF_BF[tx_idx][startSymbol * fp->ofdm_symbol_size], 0,
+             numSymbols * fp->ofdm_symbol_size * sizeof(int32_t));
+    } else {
+      // FFT shift
+      fft_shift(ru->gNB_list[0]->common_vars.txdataF[bb][aa],
+                fp->ofdm_symbol_size,
+                fp->N_RB_DL,
+                (c16_t *)ru->common.txdataF_BF[tx_idx],
+                fp->ofdm_symbol_size,
+                startSymbol,
+                numSymbols);
+    }
   } else {
     AssertFatal(false, "This needs to be fixed by using appropriate beams from config\n");
   }
 
+  /* const c16_t *dst = (const c16_t *)&ru->common.txdataF_BF[tx_idx][txdataF_BF_offset]; */
+  /* const int dst_nnz = count_nnz_c16(dst, numSamples); */
+  /* if (startSymbol == 0 && ru->proc.frame_tx % 10 == 0 && dst_nnz != 0) { */
+  /*     const int dst_pwr_db = dB_fixed(signal_energy_nodc((c16_t *)dst, 2 * numSamples)); */
+
+  /*     LOG_I(PHY, */
+  /*           "[TXF_PWR] frame=%d slot=%d beam=%d aa=%d tx_idx=%d " */
+  /*           "DST pwr=%d dB nnz=%d\n", */
+  /*           ru->proc.frame_tx, slot, bb, aa, tx_idx, dst_pwr_db, dst_nnz); */
+  /* } */
+
+  
   if (tx_idx == 0)
     stop_meas(&ru->precoding_stats);
 

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_dlsch.c

@@ -420,7 +420,7 @@ static bool allocate_dl_retransmission(gNB_MAC_INST *nr_mac,
   NR_UE_DL_BWP_t *dl_bwp = &UE->current_DL_BWP;
   NR_UE_UL_BWP_t *ul_bwp = &UE->current_UL_BWP;
   NR_sched_pdsch_t new_sched = sched_ctrl->harq_processes[current_harq_pid].sched_pdsch;
-  int layers = get_dl_nrOfLayers(sched_ctrl, dl_bwp->dci_format);
+  int layers = get_dl_nrOfLayers(nr_mac, sched_ctrl, dl_bwp->dci_format);
   int pm_index = get_pm_index(nr_mac, UE, dl_bwp->dci_format, layers, nr_mac->radio_config.pdsch_AntennaPorts.XP);
 
   // If the RI changed between current rtx and a previous transmission
@@ -565,7 +565,6 @@ static bool allocate_dl_retransmission(gNB_MAC_INST *nr_mac,
 static void ack_reconfig(gNB_MAC_INST *mac, NR_UE_info_t *UE)
 {
   if (!UE->reconfigCellGroup) {
-    LOG_W(NR_MAC, "Received ACK for RRCReconfiguration, but nothing to apply!\n");
     return;
   }
   ASN_STRUCT_FREE(asn_DEF_NR_CellGroupConfig, UE->CellGroup);
@@ -594,8 +593,57 @@ typedef struct UEsched_s {
   float coef;
   NR_UE_info_t * UE;
   int selected_mcs;
+  bool mumimo_paired;  /* nakaolab: already allocated as MU-MIMO partner; main loop must skip */
 } UEsched_t;
 
+/* nakaolab: cached MU-MIMO enable state.
+ * Read once via OAI_MU_MIMO env var. 0 = SU-MIMO (default), 1 = MU-MIMO co-scheduling. */
+static int mumimo_enabled(void)
+{
+  static int cached = -1;
+  if (cached < 0) {
+    const char *e = getenv("OAI_MU_MIMO");
+    cached = (e && atoi(e) > 0) ? 1 : 0;
+    if (cached)
+      LOG_W(NR_MAC, "[nakaolab] MU-MIMO downlink scheduling ENABLED (OAI_MU_MIMO=1)\n");
+  }
+  return cached;
+}
+
+/* nakaolab: orthogonal-PMI test for 4-port Type I rank-1 codebook (N1=2, N2=1).
+ *
+ * The 4 codewords sharing the same spatial beam (same pmi_x1) are constructed
+ * with mutually orthogonal co-phasings (theta_n in {1, j, -1, -j}):
+ *   w_(x1, n) = (1/sqrt(4)) * [v_x1 ; j^n * v_x1]
+ * Pairwise inner product <w_(x1,a), w_(x1,b)> for any a != b is zero, so all
+ * 4 codewords with the same x1 are mutually orthogonal. Up to 4 UEs (one per
+ * x2 class) can be co-scheduled simultaneously.
+ *
+ * Two UEs with different x1 use different spatial beams. With OAI default
+ * oversampling (O1=4) the DFT vectors are not strictly orthogonal, so we
+ * conservatively don't pair across x1.
+ *
+ * OAI_MU_MIMO_RELAXED=1 accepts any rank-1 pair (used to validate the
+ * scheduler path on a symmetric rfsim channel where PMIs collapse). */
+static bool pmi_is_orthogonal(const NR_UE_info_t *a, const NR_UE_info_t *b)
+{
+  const struct CRI_RI_LI_PMI_CQI *ra = &a->UE_sched_ctrl.CSI_report.cri_ri_li_pmi_cqi_report;
+  const struct CRI_RI_LI_PMI_CQI *rb = &b->UE_sched_ctrl.CSI_report.cri_ri_li_pmi_cqi_report;
+  if (ra->ri != 0 || rb->ri != 0)
+    return false;
+  static int relaxed = -1;
+  if (relaxed < 0) {
+    const char *e = getenv("OAI_MU_MIMO_RELAXED");
+    relaxed = (e && atoi(e) > 0) ? 1 : 0;
+  }
+  if (relaxed)
+    return true;
+  if (ra->pmi_x1 != rb->pmi_x1)
+    return false;
+  /* Same beam, distinct co-phasing -> mutually orthogonal codewords. */
+  return ra->pmi_x2 != rb->pmi_x2;
+}
+
 static int comparator(const void *p, const void *q)
 {
   const UEsched_t *pp = p;
@@ -700,7 +748,7 @@ static void pf_dl(gNB_MAC_INST *mac,
         sched_ctrl->dl_bler_stats.mcs = selected_mcs;
       } else
         selected_mcs = get_mcs_from_bler(bo, stats, &sched_ctrl->dl_bler_stats, max_mcs, frame);
-      int l = get_dl_nrOfLayers(sched_ctrl, current_BWP->dci_format);
+      int l = get_dl_nrOfLayers(mac, sched_ctrl, current_BWP->dci_format);
       const uint8_t Qm = nr_get_Qm_dl(selected_mcs, current_BWP->mcsTableIdx);
       const uint16_t R = nr_get_code_rate_dl(selected_mcs, current_BWP->mcsTableIdx);
       uint32_t tbs = nr_compute_tbs(Qm,
@@ -730,12 +778,31 @@ static void pf_dl(gNB_MAC_INST *mac,
 
   qsort(UE_sched, numUE, sizeof(UEsched_t), comparator);
   UEsched_t *iterator = UE_sched;
+  /* nakaolab: tag to mark UEs already paired in this pf_dl call. Increments each
+   * call so a UE's stored tag != current tag means "available for pairing". */
+  static uint64_t mumimo_pf_call_id = 0;
+  if (mumimo_enabled())
+    mumimo_pf_call_id++;
+  /* nakaolab: diagnostic — log numUE > 1 to understand MU-MIMO opportunity */
+  if (mumimo_enabled() && numUE >= 2) {
+    static int dump_count = 0;
+    if (dump_count++ < 20)
+      LOG_W(NR_MAC, "[nakaolab MU-MIMO] %4d.%2d numUE=%d (PF candidates)\n", frame, slot, numUE);
+  }
 
   const int min_rbSize = 5;
 
   /* Loop UE_sched to find max coeff and allocate transmission */
   while (iterator->UE != NULL) {
 
+    /* nakaolab: skip UEs already allocated as a MU-MIMO partner of an earlier UE
+     * in this same pf_dl call (mumimo_pf_call_id matches). */
+    if (mumimo_enabled() &&
+        iterator->UE->UE_sched_ctrl.mumimo_paired_slot == (int64_t)mumimo_pf_call_id) {
+      iterator++;
+      continue;
+    }
+
     NR_UE_sched_ctrl_t *sched_ctrl = &iterator->UE->UE_sched_ctrl;
     const uint16_t rnti = iterator->UE->rnti;
 
@@ -837,7 +904,7 @@ static void pf_dl(gNB_MAC_INST *mac,
     sched_ctrl->cce_index = CCEIndex;
     fill_pdcch_vrb_map(mac, CC_id, &sched_ctrl->sched_pdcch, CCEIndex, sched_ctrl->aggregation_level, beam.idx);
 
-    int l = get_dl_nrOfLayers(sched_ctrl, dl_bwp->dci_format);
+    int l = get_dl_nrOfLayers(mac, sched_ctrl, dl_bwp->dci_format);
     NR_sched_pdsch_t sched_pdsch = {
       // rbSize below
       .rbStart = rbStart,
@@ -878,7 +945,179 @@ static void pf_dl(gNB_MAC_INST *mac,
                   &sched_pdsch.tb_size,
                   &sched_pdsch.rbSize);
 
+    /* nakaolab MU-MIMO: find up to MAX_MU_MIMO_PARTNERS orthogonal-PMI partner UEs
+     * that can ride on the same RB allocation. Each partner gets its own DCI/CCE,
+     * its own DMRS port (1000+layer_idx), and is forced to the leader's MCS/TBS.
+     * Up to 4 UEs total per slot (one per orthogonal x2 class). */
+#define MAX_MU_MIMO_PARTNERS 3
+    NR_UE_info_t *partners[MAX_MU_MIMO_PARTNERS] = {NULL};
+    int partner_CCEs[MAX_MU_MIMO_PARTNERS] = {-1, -1, -1};
+    int partner_allocs[MAX_MU_MIMO_PARTNERS] = {-1, -1, -1};
+    int n_partners = 0;
+
+    /* nakaolab Phase 4: cap MU-MIMO group size to the active TX antenna count.
+     * When the antenna controller mutes some TX chains (e.g., 4->2 or 4->1), the
+     * effective number of orthogonal codewords in the codebook shrinks. Each
+     * co-scheduled UE consumes one spatial layer = one TX port. So:
+     *   active_tx = 4 -> up to 4 UEs (3 partners), 4-way MU-MIMO
+     *   active_tx = 2 -> up to 2 UEs (1 partner), 2-way MU-MIMO
+     *   active_tx = 1 -> SU-MIMO only (0 partners) */
+    int max_partners_now = MAX_MU_MIMO_PARTNERS;
+    if (mac->antenna_state) {
+      const uint8_t tx_mask = nr_get_tx_antenna_bitmask(mac->antenna_state);
+      int active_tx = __builtin_popcount(tx_mask);
+      if (active_tx < 1) active_tx = 1;
+      if (active_tx - 1 < max_partners_now)
+        max_partners_now = active_tx - 1;
+    }
+
+    if (mumimo_enabled() && remainUEs[beam.idx] > 0 && max_partners_now > 0) {
+      const uint8_t leader_x2 = iterator->UE->UE_sched_ctrl.CSI_report.cri_ri_li_pmi_cqi_report.pmi_x2;
+      uint8_t classes_used = 1 << leader_x2;
+      static int diag_count = 0;
+      bool log_diag = ((diag_count++ % 200) == 0);
+      if (log_diag) {
+        int n_cand = 0;
+        UE_iterator (UE_list, c) {
+          if (c != iterator->UE && nr_mac_ue_is_active(c) &&
+              c->UE_sched_ctrl.available_dl_harq.head >= 0)
+            n_cand++;
+        }
+        LOG_W(NR_MAC, "[mumimo-diag] %4d.%2d ENTER partner-search after RNTI %04x leader_x2=%d; eligible_others=%d\n",
+              frame, slot, iterator->UE->rnti, leader_x2, n_cand);
+      }
+      /* Find up to max_partners_now partners, one per remaining x2 class.
+       * max_partners_now is capped by active TX antenna count (Phase 4). */
+      while (n_partners < max_partners_now && remainUEs[beam.idx] > 0) {
+        NR_UE_info_t *new_partner = NULL;
+        int new_CCE = -1;
+        int new_alloc = -1;
+        NR_beam_alloc_t new_pbeam = {0};
+        UE_iterator (UE_list, cand_ue) {
+          if (cand_ue == iterator->UE) continue;
+          if (cand_ue->UE_sched_ctrl.mumimo_paired_slot == (int64_t)mumimo_pf_call_id) continue;
+          /* Skip if already a partner of this leader. */
+          bool already_partner = false;
+          for (int i = 0; i < n_partners; i++)
+            if (partners[i] == cand_ue) { already_partner = true; break; }
+          if (already_partner) continue;
+          /* Skip if cand's class is already represented (leader or earlier partner). */
+          const uint8_t cand_x2 = cand_ue->UE_sched_ctrl.CSI_report.cri_ri_li_pmi_cqi_report.pmi_x2;
+          if (classes_used & (1 << cand_x2)) continue;
+          if (!nr_mac_ue_is_active(cand_ue)) continue;
+          if (cand_ue->UE_sched_ctrl.available_dl_harq.head < 0) continue;
+          update_dlsch_buffer(pp_pdsch->frame, pp_pdsch->slot, cand_ue);
+          if (!dlsch_to_schedule(&cand_ue->UE_sched_ctrl)) continue;
+          if (!pmi_is_orthogonal(iterator->UE, cand_ue)) continue;
+          NR_beam_alloc_t pbeam = beam_allocation_procedure(&mac->beam_info, frame, slot,
+                                                            cand_ue->UE_beam_index,
+                                                            slots_per_frame);
+          if (pbeam.idx != beam.idx) {
+            reset_beam_status(&mac->beam_info, frame, slot, cand_ue->UE_beam_index,
+                              slots_per_frame, pbeam.new_beam);
+            continue;
+          }
+          int p_CCE = get_cce_index(mac, CC_id, slot, cand_ue->rnti,
+                                     &cand_ue->UE_sched_ctrl.aggregation_level,
+                                     pbeam.idx,
+                                     cand_ue->UE_sched_ctrl.search_space,
+                                     cand_ue->UE_sched_ctrl.coreset,
+                                     &cand_ue->UE_sched_ctrl.sched_pdcch,
+                                     cand_ue->UE_sched_ctrl.pdcch_cl_adjust);
+          if (p_CCE < 0) {
+            reset_beam_status(&mac->beam_info, frame, slot, cand_ue->UE_beam_index,
+                              slots_per_frame, pbeam.new_beam);
+            continue;
+          }
+          int p_alloc = -1;
+          if (!get_FeedbackDisabled(cand_ue->sc_info.downlinkHARQ_FeedbackDisabled_r17,
+                                    cand_ue->UE_sched_ctrl.available_dl_harq.head)) {
+            int p_pucch = nr_get_pucch_resource(cand_ue->UE_sched_ctrl.coreset,
+                                                cand_ue->current_UL_BWP.pucch_Config, p_CCE);
+            p_alloc = nr_acknack_scheduling(mac, cand_ue, frame, slot,
+                                            cand_ue->UE_beam_index, p_pucch, 0);
+            if (p_alloc < 0) {
+              reset_beam_status(&mac->beam_info, frame, slot, cand_ue->UE_beam_index,
+                                slots_per_frame, pbeam.new_beam);
+              continue;
+            }
+          }
+          new_partner = cand_ue;
+          new_CCE = p_CCE;
+          new_alloc = p_alloc;
+          new_pbeam = pbeam;
+          break;
+        }
+        if (new_partner == NULL) break;
+        partners[n_partners] = new_partner;
+        partner_CCEs[n_partners] = new_CCE;
+        partner_allocs[n_partners] = new_alloc;
+        const uint8_t p_x2 = new_partner->UE_sched_ctrl.CSI_report.cri_ri_li_pmi_cqi_report.pmi_x2;
+        classes_used |= 1 << p_x2;
+        n_partners++;
+        (void)new_pbeam; /* beam already taken via beam_allocation_procedure */
+      }
+      if (n_partners > 0) {
+        /* Compose pairing log: leader + partners */
+        char pair_str[256];
+        int off = snprintf(pair_str, sizeof(pair_str), "RNTI %04x (x2=%d)",
+                           iterator->UE->rnti, leader_x2);
+        for (int i = 0; i < n_partners && off < (int)sizeof(pair_str) - 32; i++)
+          off += snprintf(pair_str + off, sizeof(pair_str) - off, " + RNTI %04x (x2=%d)",
+                          partners[i]->rnti,
+                          partners[i]->UE_sched_ctrl.CSI_report.cri_ri_li_pmi_cqi_report.pmi_x2);
+        LOG_W(NR_MAC, "[nakaolab MU-MIMO] %4d.%2d %d-way pair %s on RBs [%d..%d]\n",
+              frame, slot, n_partners + 1, pair_str,
+              sched_pdsch.rbStart, sched_pdsch.rbStart + sched_pdsch.rbSize - 1);
+        /* MU-MIMO needs DMRS pilots from both CDM groups protected from data. */
+        sched_pdsch.dmrs_parms.numDmrsCdmGrpsNoData = 2;
+      }
+    }
+
     post_process_dlsch(mac, pp_pdsch, iterator->UE, &sched_pdsch);
+    if (mumimo_enabled())
+      iterator->UE->UE_sched_ctrl.mumimo_paired_slot = (int64_t)mumimo_pf_call_id;
+
+    /* nakaolab: allocate each MU-MIMO partner on the same RBs.
+     * DMRS port assignment: leader = port 1000 (mask bit 0), partner_i = port
+     * 1001+i (mask bit i+1). For 4-way: 1000 (CDM group 0), 1001 (CDM group 0),
+     * 1002 (CDM group 1), 1003 (CDM group 1). */
+    for (int i = 0; i < n_partners; i++) {
+      NR_UE_info_t *p_ue = partners[i];
+      NR_UE_sched_ctrl_t *p_sched_ctrl = &p_ue->UE_sched_ctrl;
+      NR_UE_DL_BWP_t *p_dl_bwp = &p_ue->current_DL_BWP;
+
+      p_sched_ctrl->cce_index = partner_CCEs[i];
+      fill_pdcch_vrb_map(mac, CC_id, &p_sched_ctrl->sched_pdcch, partner_CCEs[i],
+                         p_sched_ctrl->aggregation_level, beam.idx);
+
+      const int p_l = 1;
+      NR_sched_pdsch_t p_sched_pdsch = {
+        .rbStart = sched_pdsch.rbStart,
+        .rbSize  = sched_pdsch.rbSize,
+        .mcs     = sched_pdsch.mcs,
+        .R       = sched_pdsch.R,
+        .Qm      = sched_pdsch.Qm,
+        .tb_size = sched_pdsch.tb_size,
+        .dl_harq_pid = p_sched_ctrl->available_dl_harq.head,
+        .pucch_allocation = partner_allocs[i],
+        .pm_index = get_pm_index(mac, p_ue, p_dl_bwp->dci_format, p_l,
+                                  mac->radio_config.pdsch_AntennaPorts.XP),
+        .nrOfLayers = p_l,
+        .bwp_info = get_pdsch_bwp_start_size(mac, p_ue),
+        .dmrs_parms = get_dl_dmrs_params(scc, p_dl_bwp, &tda_info, p_l),
+        .time_domain_allocation = tda,
+        .tda_info = tda_info,
+        .action = NULL,
+      };
+      /* Partner i (i in 0..2) uses DMRS port 1001+i: mask bit (i+1). */
+      p_sched_pdsch.dmrs_parms.dmrs_ports_id = 1u << (i + 1);
+      p_sched_pdsch.dmrs_parms.numDmrsCdmGrpsNoData = 2;
+
+      post_process_dlsch(mac, pp_pdsch, p_ue, &p_sched_pdsch);
+      p_sched_ctrl->mumimo_paired_slot = (int64_t)mumimo_pf_call_id;
+      remainUEs[beam.idx]--;
+    }
 
     /* transmissions: directly allocate */
     n_rb_sched[beam.idx] -= sched_pdsch.rbSize;

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_primitives.c

@@ -101,14 +101,13 @@ int get_ssbidx_from_beam(gNB_MAC_INST *mac, int beam_idx)
   return 0;
 }
 
-uint8_t get_dl_nrOfLayers(const NR_UE_sched_ctrl_t *sched_ctrl, const nr_dci_format_t dci_format)
+uint8_t get_dl_nrOfLayers(const gNB_MAC_INST *mac, const NR_UE_sched_ctrl_t *sched_ctrl, const nr_dci_format_t dci_format)
 {
-  // TODO check this but it should be enough for now
-  // if there is not csi report activated RI is 0 from initialization
-  if(dci_format == NR_DL_DCI_FORMAT_1_0)
-    return 1;
-  else
-    return sched_ctrl->CSI_report.cri_ri_li_pmi_cqi_report.ri + 1;
+    int layers = (dci_format == NR_DL_DCI_FORMAT_1_0) ? 1
+        : sched_ctrl->CSI_report.cri_ri_li_pmi_cqi_report.ri + 1;
+    if (mac && mac->antenna_state)
+        return nr_get_effective_mimo_layers(mac->antenna_state, layers);    
+    return layers;
 }
 
 int get_ul_nrOfLayers(const NR_UE_sched_ctrl_t *sched_ctrl, const nr_dci_format_t dci_format)
@@ -165,63 +164,88 @@ uint16_t get_pm_index(const gNB_MAC_INST *nrmac,
                       int layers,
                       int xp_pdsch_antenna_ports)
 {
-  if (dci_format == NR_DL_DCI_FORMAT_1_0 || nrmac->identity_pm || xp_pdsch_antenna_ports == 1)
-    return 0; //identity matrix (basic 5G configuration handled by PMI report is with XP antennas)
-  const NR_UE_sched_ctrl_t *sched_ctrl = &UE->UE_sched_ctrl;
-  const int report_id = sched_ctrl->CSI_report.cri_ri_li_pmi_cqi_report.csi_report_id;
-  const nr_csi_report_t *csi_report = &UE->csi_report_template[report_id];
-  const int N1 = csi_report->N1;
-  const int N2 = csi_report->N2;
-  const int antenna_ports = (N1 * N2) << 1;
-  if (antenna_ports < 2)
-    return 0; // single antenna port
+    if (dci_format == NR_DL_DCI_FORMAT_1_0 || nrmac->identity_pm || xp_pdsch_antenna_ports == 1)
+        return 0; //identity matrix (basic 5G configuration handled by PMI report is with XP antennas)
+    const NR_UE_sched_ctrl_t *sched_ctrl = &UE->UE_sched_ctrl;
 
-  int x1 = sched_ctrl->CSI_report.cri_ri_li_pmi_cqi_report.pmi_x1;
-  const int x2 = sched_ctrl->CSI_report.cri_ri_li_pmi_cqi_report.pmi_x2;
-  LOG_D(NR_MAC,"PMI report: x1 %d x2 %d layers: %d\n", x1, x2, layers);
-
-  int prev_layers_size = 0;
-  for (int i = 1; i < layers; i++)
-    prev_layers_size += nrmac->precoding_matrix_size[i - 1];
-
-  // need to return PM index to matrix initialized in init_DL_MIMO_codebook
-  // index 0 is for identity matrix
-  // order of matrices depends on layers to be transmitted
-  // elements from 1 to n for 1 layer
-  // elements from n+1 to m for 2 layers etc.
-  if (antenna_ports == 2)
-    return 1 + prev_layers_size + x2;  // 0 for identity matrix
-  else {
-    int idx = layers - 1;
-    // the order of i1x in X1 report needs to be verified
-    // the standard is not very clear (Table 6.3.1.1.2-7 in 38.212)
-    // it says: PMI wideband information fields X1 , from left to right
-    int bitlen = csi_report->csi_meas_bitlen.pmi_i13_bitlen[idx];
-    if (layers == 1 && bitlen != 0) {
-      LOG_E(NR_MAC, "Invalid i13 bit length %d for single layer! It should be 0\n", bitlen);
-      return 0;
+    int reported_ri_layers = sched_ctrl->CSI_report.cri_ri_li_pmi_cqi_report.ri + 1;
+    if (layers != reported_ri_layers) {
+        LOG_D(NR_MAC, "PMI mismatch: using %d layers but RI report is for %d layers, using identity matrix\n",
+              layers, reported_ri_layers);
+        return 0;
     }
-    const int i13 = x1 & ((1 << bitlen) - 1);
-    x1 >>= bitlen;
-    bitlen = csi_report->csi_meas_bitlen.pmi_i12_bitlen[idx];
-    const int i12 = x1 & ((1 << bitlen) - 1);
-    x1 >>= bitlen;
-    bitlen = csi_report->csi_meas_bitlen.pmi_i11_bitlen[idx];
-    const int i11 = x1 & ((1 << bitlen) - 1);
-    const int i2 = x2;
-    int k1, k2;
-    get_k1_k2_indices(layers, N1, N2, i13, &k1, &k2); // get indices k1 and k2 for PHY matrix (not actual k1 and k2 values)
-    const int O2 = N2 == 1 ? 1 : 4;
-    int O1 = 4; //Horizontal beam oversampling = 4 for more than 2 antenna ports
-    int max_i2 = 0;
-    int lay_index = 0;
-    max_i2 = layers == 1 ? 4 : 2;
-    int K1, K2;
-    get_K1_K2(N1, N2, &K1, &K2, layers);
-    // computing precoding matrix index according to rule set in allocation function init_codebook_gNB
-    lay_index = i2 + (i11 * max_i2) + (i12 * max_i2 * N1 * O1) + (k1 * max_i2 * N1 * O1 * N2 * O2) + (k2 * max_i2 * N1 * O1 * N2 * O2 * K1);
-    return 1 + prev_layers_size + lay_index;
-  }
+    nr_antenna_state_t* ant_state = nrmac->antenna_state;
+    if (ant_state) {
+        if (nr_is_in_recovery_mode(ant_state)) {
+            LOG_D(NR_MAC, "[ANTENNA_MUTE] Recovery mode active, using identity matrix\n");
+            return 0;
+        }
+        // Don't fall back to identity matrix for muted antennas.
+        // Antenna muting is handled at RU level (nr_feptx zeros muted antenna buffers).
+        // Using proper precoding ensures data reaches all active antennas.
+    }
+  
+    const int report_id = sched_ctrl->CSI_report.cri_ri_li_pmi_cqi_report.csi_report_id;
+    const nr_csi_report_t *csi_report = &UE->csi_report_template[report_id];
+    const int N1 = csi_report->N1;
+    const int N2 = csi_report->N2;
+    const int antenna_ports = (N1 * N2) << 1;
+    if (antenna_ports < 2) return 0; // single antenna port
+
+    int x1 = sched_ctrl->CSI_report.cri_ri_li_pmi_cqi_report.pmi_x1;
+    const int x2 = sched_ctrl->CSI_report.cri_ri_li_pmi_cqi_report.pmi_x2;
+    LOG_D(NR_MAC,"PMI report: x1 %d x2 %d layers: %d\n", x1, x2, layers);
+
+    int prev_layers_size = 0;
+    for (int i = 1; i < layers; i++)
+        prev_layers_size += nrmac->precoding_matrix_size[i - 1];
+
+    // need to return PM index to matrix initialized in init_DL_MIMO_codebook
+    // index 0 is for identity matrix
+    // order of matrices depends on layers to be transmitted
+    // elements from 1 to n for 1 layer
+    // elements from n+1 to m for 2 layers etc.
+    int pm_index;
+    if (antenna_ports == 2)
+        pm_index = 1 + prev_layers_size + x2;  // 0 for identity matrix
+    else {
+        int idx = layers - 1;
+        // the order of i1x in X1 report needs to be verified
+        // the standard is not very clear (Table 6.3.1.1.2-7 in 38.212)
+        // it says: PMI wideband information fields X1 , from left to right
+        int bitlen = csi_report->csi_meas_bitlen.pmi_i13_bitlen[idx];
+        if (layers == 1 && bitlen != 0) {
+            LOG_E(NR_MAC, "Invalid i13 bit length %d for single layer! It should be 0\n", bitlen);
+            return 0;
+        }
+        const int i13 = x1 & ((1 << bitlen) - 1);
+        x1 >>= bitlen;
+        bitlen = csi_report->csi_meas_bitlen.pmi_i12_bitlen[idx];
+        const int i12 = x1 & ((1 << bitlen) - 1);
+        x1 >>= bitlen;
+        bitlen = csi_report->csi_meas_bitlen.pmi_i11_bitlen[idx];
+        const int i11 = x1 & ((1 << bitlen) - 1);
+        const int i2 = x2;
+        int k1, k2;
+        get_k1_k2_indices(layers, N1, N2, i13, &k1, &k2); // get indices k1 and k2 for PHY matrix (not actual k1 and k2 values)
+        const int O2 = N2 == 1 ? 1 : 4;
+        int O1 = 4; //Horizontal beam oversampling = 4 for more than 2 antenna ports
+        int max_i2 = 0;
+        int lay_index = 0;
+        max_i2 = layers == 1 ? 4 : 2;
+        int K1, K2;
+        get_K1_K2(N1, N2, &K1, &K2, layers);
+        // computing precoding matrix index according to rule set in allocation function init_codebook_gNB
+        lay_index = i2 + (i11 * max_i2) + (i12 * max_i2 * N1 * O1) + (k1 * max_i2 * N1 * O1 * N2 * O2) + (k2 * max_i2 * N1 * O1 * N2 * O2 * K1);
+        pm_index = 1 + prev_layers_size + lay_index;
+    }
+    int max_valid_pm = prev_layers_size + nrmac->precoding_matrix_size[layers - 1];
+    if (pm_index < 1 || pm_index > max_valid_pm) {
+        LOG_W(NR_MAC, "PM index %d out of range [1, %d] for %d layers, using identity matrix\n",
+              pm_index, max_valid_pm, layers);
+        return 0;
+    }
+    return pm_index;    
 }
 
 // look-up table for AMC. Based on BLER vs SNR curves from the nr_dlsim simulation

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_uci.c

@@ -497,7 +497,9 @@ static void evaluate_sinr_report(NR_UE_info_t *UE,
   stats->num_sinr_meas++;
 
   const int mcs_table = UE->current_DL_BWP.mcsTableIdx;
-  const int nrOfLayers = get_dl_nrOfLayers(sched_ctrl, UE->current_DL_BWP.dci_format);
+  /* NULL mac arg: SINR-based MCS estimation skips antenna-state rank cap
+     (caller doesn't have nrmac in scope; this is only for max-MCS hint). */
+  const int nrOfLayers = get_dl_nrOfLayers(NULL, sched_ctrl, UE->current_DL_BWP.dci_format);
   sched_ctrl->dl_max_mcs = get_mcs_from_SINRx10(mcs_table, sinr_report->r[0].SINRx10, nrOfLayers);
 
   LOG_D(MAC, "Reported SSB-SINR = %01f, dl_max_mcs %d\n", sinr_report->r[0].SINRx10 / 10.0, sched_ctrl->dl_max_mcs);
@@ -761,8 +763,20 @@ static void extract_pucch_csi_report(NR_CSI_MeasConfig_t *csi_MeasConfig,
               evaluate_cri_report(payload, cri_bitlen, cumul_bits, sched_ctrl);
             cumul_bits += cri_bitlen;
             ri_bitlen = csi_report->csi_meas_bitlen.ri_bitlen;
-            if (ri_bitlen)
+            if (ri_bitlen) {
               r_index = evaluate_ri_report(payload, ri_bitlen, csi_report->csi_meas_bitlen.ri_restriction, cumul_bits, sched_ctrl);
+            } else {
+              /* nakaolab: ri_bitlen=0 (single RI allowed via ri_restriction).
+               * Pick that RI directly — without this, r_index stays -1 and trips
+               * the DevAssert(ri>=0) in evaluate_cqi_report. */
+              for (int i = 0; i < 8; i++) {
+                if ((csi_report->csi_meas_bitlen.ri_restriction >> i) & 0x01) {
+                  r_index = i;
+                  sched_ctrl->CSI_report.cri_ri_li_pmi_cqi_report.ri = i;
+                  break;
+                }
+              }
+            }
             cumul_bits += ri_bitlen;
             if (r_index != -1)
               skip_zero_padding(&cumul_bits, csi_report, r_index, bitlen);
@@ -775,8 +789,20 @@ static void extract_pucch_csi_report(NR_CSI_MeasConfig_t *csi_MeasConfig,
               evaluate_cri_report(payload, cri_bitlen, cumul_bits, sched_ctrl);
             cumul_bits += cri_bitlen;
             ri_bitlen = csi_report->csi_meas_bitlen.ri_bitlen;
-            if (ri_bitlen)
+            if (ri_bitlen) {
               r_index = evaluate_ri_report(payload, ri_bitlen, csi_report->csi_meas_bitlen.ri_restriction, cumul_bits, sched_ctrl);
+            } else {
+              /* nakaolab: ri_bitlen=0 (single RI allowed via ri_restriction).
+               * Pick that RI directly — without this, r_index stays -1 and trips
+               * the DevAssert(ri>=0) in evaluate_cqi_report. */
+              for (int i = 0; i < 8; i++) {
+                if ((csi_report->csi_meas_bitlen.ri_restriction >> i) & 0x01) {
+                  r_index = i;
+                  sched_ctrl->CSI_report.cri_ri_li_pmi_cqi_report.ri = i;
+                  break;
+                }
+              }
+            }
             cumul_bits += ri_bitlen;
             if (r_index != -1)
               skip_zero_padding(&cumul_bits, csi_report, r_index, bitlen);
@@ -792,8 +818,20 @@ static void extract_pucch_csi_report(NR_CSI_MeasConfig_t *csi_MeasConfig,
               evaluate_cri_report(payload, cri_bitlen, cumul_bits, sched_ctrl);
             cumul_bits += cri_bitlen;
             ri_bitlen = csi_report->csi_meas_bitlen.ri_bitlen;
-            if (ri_bitlen)
+            if (ri_bitlen) {
               r_index = evaluate_ri_report(payload, ri_bitlen, csi_report->csi_meas_bitlen.ri_restriction, cumul_bits, sched_ctrl);
+            } else {
+              /* nakaolab: ri_bitlen=0 (single RI allowed via ri_restriction).
+               * Pick that RI directly — without this, r_index stays -1 and trips
+               * the DevAssert(ri>=0) in evaluate_cqi_report. */
+              for (int i = 0; i < 8; i++) {
+                if ((csi_report->csi_meas_bitlen.ri_restriction >> i) & 0x01) {
+                  r_index = i;
+                  sched_ctrl->CSI_report.cri_ri_li_pmi_cqi_report.ri = i;
+                  break;
+                }
+              }
+            }
             cumul_bits += ri_bitlen;
             li_bitlen = evaluate_li_report(payload, csi_report, cumul_bits, r_index, sched_ctrl);
             cumul_bits += li_bitlen;

openair2/LAYER2/NR_MAC_gNB/mac_proto.h

@@ -373,7 +373,7 @@ uint16_t get_pm_index(const gNB_MAC_INST *nrmac,
 int get_mcs_from_SINRx10(int mcs_table, int SINRx10, int Nl);
 uint8_t get_mcs_from_cqi(int mcs_table, int cqi_table, int cqi_idx);
 
-uint8_t get_dl_nrOfLayers(const NR_UE_sched_ctrl_t *sched_ctrl, const nr_dci_format_t dci_format);
+uint8_t get_dl_nrOfLayers(const gNB_MAC_INST *mac, const NR_UE_sched_ctrl_t *sched_ctrl, const nr_dci_format_t dci_format);
 int get_ul_nrOfLayers(const NR_UE_sched_ctrl_t *sched_ctrl, const nr_dci_format_t dci_format);
 
 void free_sched_pucch_list(NR_UE_sched_ctrl_t *sched_ctrl);

openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h

@@ -65,6 +65,7 @@
 #include "LAYER2/NR_MAC_COMMON/nr_mac_common.h"
 #include "LAYER2/NR_MAC_gNB/mac_config.h"
 #include "NR_TAG.h"
+#include "PHY/NR_TRANSPORT/nr_antenna_state.h"
 
 /* Defs */
 #define MAX_NUM_BWP 5
@@ -663,6 +664,10 @@ typedef struct {
   int release_timer;
   CSI_report_t CSI_report;
   bool SR;
+  /// nakaolab MU-MIMO: encoded frame*1000+slot when this UE was last allocated as
+  /// a MU-MIMO partner (or leader). -1 = never. Lets pf_dl skip UEs already paired
+  /// in the current slot when scanning connected_ue_list for partners.
+  int64_t mumimo_paired_slot;
   /// information about every HARQ process
   NR_UE_harq_t harq_processes[NR_MAX_HARQ_PROCESSES];
   /// HARQ processes that are free
@@ -965,6 +970,10 @@ typedef struct gNB_MAC_INST_s {
   nr_mac_config_t radio_config;
   nr_rlc_configuration_t rlc_config;
 
+  /// Pointer to PHY antenna state (port mute mask) — set in scheduler init,
+  /// used by get_dl_nrOfLayers to cap MIMO rank to active TX port count.
+  nr_antenna_state_t *antenna_state;
+
   NR_sched_ctrl_sib1_t *sched_ctrlSIB1;
   NR_sched_pdcch_t *sched_pdcch_otherSI;
   uint16_t cset0_bwp_start;

radio/rfsimulator/simulator.cpp

@@ -1324,7 +1324,29 @@ static void rfsimulator_read_internal(rfsimulator_state_t *t,
           rxAddInput(input, temp_array[aarx], aarx, ptr->channel_model, nsamps);
         }
       } else {
-        if (is_first_beam && is_first_peer && (ptr->nbAnt == 1 || nbAnt == 1)) {
+        /* nakaolab MU-MIMO: when OAI_UE_CHANNEL_CLASS is set in the env, the UE
+         * applies a deterministic rank-1 channel whose dominant right-singular-vector
+         * matches Type I 4-port codebook entry w_class. This makes the UE report a
+         * stable PMI = class, giving the gNB scheduler natural PMI diversity across
+         * UEs assigned to different classes. Four classes give four mutually-orthogonal
+         * codewords, supporting up to 4-way MU-MIMO.
+         *
+         * Codeword w_k[a] for 4-port rank-1 (Type I, N1=2, N2=1):
+         *   w_0 = [1,  1,  1,  1]/2
+         *   w_1 = [1,  j, -1, -j]/2
+         *   w_2 = [1, -1,  1, -1]/2
+         *   w_3 = [1, -j, -1,  j]/2
+         * The 4x4 channel H^(k) is rank-1: H^(k)[r,a] = w_k[a]* (per-row constant), so
+         * the dominant right singular vector is w_k. */
+        static int ue_class_cached = -2;
+        if (ue_class_cached == -2) {
+          const char *env = getenv("OAI_UE_CHANNEL_CLASS");
+          ue_class_cached = (env && atoi(env) >= 0 && atoi(env) < 4) ? atoi(env) : -1;
+          if (ue_class_cached >= 0)
+            LOG_W(HW, "[nakaolab MU-MIMO] rfsim DL channel: orthogonal class %d\n", ue_class_cached);
+        }
+
+        if (is_first_beam && is_first_peer && (ptr->nbAnt == 1 || nbAnt == 1) && ue_class_cached < 0) {
           // optimization: The buffer is uninitialized so samples can be written directly in the buffer
           combine_received_beams(t, ptr->received_packets, timestamp - t->chan_offset, 1, nsamps, rx_beam_id, samples);
         } else {
@@ -1334,17 +1356,64 @@ static void rfsimulator_read_internal(rfsimulator_state_t *t,
             input[aatx] = ant_buffers[aatx].data();
           }
           combine_received_beams(t, ptr->received_packets, timestamp - t->chan_offset, ptr->nbAnt, nsamps, rx_beam_id, input);
-          for (int aarx = 0; aarx < nbAnt; aarx++) {
-            double H_awgn_mimo_coeff[ant_buffers.size()];
-            for (int aatx = 0; aatx < (int)ant_buffers.size(); aatx++) {
-              uint32_t ant_diff = std::abs(aatx - aarx);
-              H_awgn_mimo_coeff[aatx] = ant_diff ? (0.2 / ant_diff) : 1.0;
-            }
 
-            for (uint aatx = 0; aatx < ant_buffers.size(); aatx++) {
-              for (int i = 0; i < nsamps; i++) {
-                samples[aarx][i].r += ant_buffers[aatx][i].r * H_awgn_mimo_coeff[aatx];
-                samples[aarx][i].i += ant_buffers[aatx][i].i * H_awgn_mimo_coeff[aatx];
+          if (ue_class_cached >= 0 && ant_buffers.size() == 4) {
+            /* nakaolab MU-MIMO: per-UE channel that combines the default symmetric
+             * rfsim kernel with a class-specific TX-antenna weighting w_k[a]:
+             *
+             *   H^(k)[r, a] = H_orig[r,a] * w_k[a]
+             *
+             * The default kernel H_orig[r,a] = (a==r ? 1.0 : 0.2/|a-r|) is full-rank,
+             * preserving SSB and reference-signal sync (signal reaches all RX). The
+             * class-specific weighting rotates each TX antenna's contribution
+             * differently per class, so the optimal PMI for class k is exactly
+             * codeword w_k from the Type I 4-port codebook (modulo diagonal scaling).
+             *
+             *   w_0 = [1,  1,  1,  1]/2
+             *   w_1 = [1,  j, -1, -j]/2
+             *   w_2 = [1, -1,  1, -1]/2
+             *   w_3 = [1, -j, -1,  j]/2  */
+            static const double W_RE[4][4] = {
+              { 0.5,  0.5,  0.5,  0.5 },
+              { 0.5,  0.0, -0.5,  0.0 },
+              { 0.5, -0.5,  0.5, -0.5 },
+              { 0.5,  0.0, -0.5,  0.0 }
+            };
+            static const double W_IM[4][4] = {
+              { 0.0,  0.0,  0.0,  0.0 },
+              { 0.0,  0.5,  0.0, -0.5 },
+              { 0.0,  0.0,  0.0,  0.0 },
+              { 0.0, -0.5,  0.0,  0.5 }
+            };
+            const int k = ue_class_cached;
+            for (int aarx = 0; aarx < nbAnt; aarx++) {
+              for (int aatx = 0; aatx < (int)ant_buffers.size(); aatx++) {
+                const uint32_t ant_diff = (uint32_t)std::abs(aatx - aarx);
+                const double h_orig = ant_diff ? (0.2 / ant_diff) : 1.0;
+                /* Effective channel coeff: h_orig * w_k[a] (complex multiply). */
+                const double hre = h_orig * W_RE[k][aatx];
+                const double him = h_orig * W_IM[k][aatx];
+                for (int i = 0; i < nsamps; i++) {
+                  const double xr = ant_buffers[aatx][i].r;
+                  const double xi = ant_buffers[aatx][i].i;
+                  samples[aarx][i].r += (int16_t)(hre * xr - him * xi);
+                  samples[aarx][i].i += (int16_t)(hre * xi + him * xr);
+                }
+              }
+            }
+          } else {
+            for (int aarx = 0; aarx < nbAnt; aarx++) {
+              double H_awgn_mimo_coeff[ant_buffers.size()];
+              for (int aatx = 0; aatx < (int)ant_buffers.size(); aatx++) {
+                uint32_t ant_diff = std::abs(aatx - aarx);
+                H_awgn_mimo_coeff[aatx] = ant_diff ? (0.2 / ant_diff) : 1.0;
+              }
+
+              for (uint aatx = 0; aatx < ant_buffers.size(); aatx++) {
+                for (int i = 0; i < nsamps; i++) {
+                  samples[aarx][i].r += ant_buffers[aatx][i].r * H_awgn_mimo_coeff[aatx];
+                  samples[aarx][i].i += ant_buffers[aatx][i].i * H_awgn_mimo_coeff[aatx];
+                }
               }
             }
           }