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openairinterface5g/openair1/PHY/NR_TRANSPORT/nr_dci.c
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/*
* 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_dci.c
* \brief Implements DCI encoding and PDCCH TX procedures (38.212/38.213/38.214). V15.4.0 2019-01.
* \author Guy De Souza
* \date 2018
* \version 0.1
* \company Eurecom
* \email: desouza@eurecom.fr
* \note
* \warning
*/
#include "nr_dci.h"
#include "nr_dlsch.h"
#include "nr_sch_dmrs.h"
#include "PHY/MODULATION/nr_modulation.h"
//#define DEBUG_PDCCH_DMRS
//#define DEBUG_DCI
//#define DEBUG_CHANNEL_CODING
uint16_t nr_get_dci_size(nfapi_nr_dci_format_e format,
nfapi_nr_rnti_type_e rnti_type,
uint16_t N_RB) {
uint16_t size = 0;
switch(format) {
/*Only sizes for 0_0 and 1_0 are correct at the moment*/
case NFAPI_NR_UL_DCI_FORMAT_0_0:
/// fixed: Format identifier 1, Hop flag 1, MCS 5, NDI 1, RV 2, HARQ PID 4, PUSCH TPC 2 Time Domain assgnmt 4 --20
size += 20;
size += (uint8_t)ceil( log2( (N_RB*(N_RB+1))>>1 ) ); // Freq domain assignment -- hopping scenario to be updated
size += nr_get_dci_size(NFAPI_NR_DL_DCI_FORMAT_1_0, rnti_type, N_RB) - size; // Padding to match 1_0 size
// UL/SUL indicator assumed to be 0
break;
case NFAPI_NR_UL_DCI_FORMAT_0_1:
/// fixed: Format identifier 1, MCS 5, NDI 1, RV 2, HARQ PID 4, PUSCH TPC 2, SRS request 2 --17
size += 17;
// Carrier indicator
// UL/SUL indicator
// BWP Indicator
// Freq domain assignment
// Time domain assignment
// VRB to PRB mapping
// Frequency Hopping flag
// 1st DAI
// 2nd DAI
// SRS resource indicator
// Precoding info and number of layers
// Antenna ports
// CSI request
// CBGTI
// PTRS - DMRS association
// beta offset indicator
// DMRS sequence init
break;
case NFAPI_NR_DL_DCI_FORMAT_1_0:
/// fixed: Format identifier 1, VRB2PRB 1, MCS 5, NDI 1, RV 2, HARQ PID 4, DAI 2, PUCCH TPC 2, PUCCH RInd 3, PDSCH to HARQ TInd 3 Time Domain assgnmt 4 -- 28
size += 28;
size += (uint8_t)ceil( log2( (N_RB*(N_RB+1))>>1 ) ); // Freq domain assignment
break;
case NFAPI_NR_DL_DCI_FORMAT_1_1:
// Carrier indicator
size += 1; // Format identifier
// BWP Indicator
// Freq domain assignment
// Time domain assignment
// VRB to PRB mapping
// PRB bundling size indicator
// Rate matching indicator
// ZP CSI-RS trigger
/// TB1- MCS 5, NDI 1, RV 2
size += 8;
// TB2
size += 4 ; // HARQ PID
// DAI
size += 2; // TPC PUCCH
size += 3; // PUCCH resource indicator
size += 3; // PDSCH to HARQ timing indicator
// Antenna ports
// Tx Config Indication
size += 2; // SRS request
// CBGTI
// CBGFI
size += 1; // DMRS sequence init
break;
case NFAPI_NR_DL_DCI_FORMAT_2_0:
break;
case NFAPI_NR_DL_DCI_FORMAT_2_1:
break;
case NFAPI_NR_DL_DCI_FORMAT_2_2:
break;
case NFAPI_NR_DL_DCI_FORMAT_2_3:
break;
default:
AssertFatal(1==0, "Invalid NR DCI format %d\n", format);
}
return size;
}
void nr_pdcch_scrambling(uint32_t *in,
uint32_t size,
uint32_t Nid,
uint32_t n_RNTI,
uint32_t *out) {
uint8_t reset;
uint32_t x1, x2, s=0;
reset = 1;
x2 = (n_RNTI<<16) + Nid;
for (int i=0; i<size; i++) {
if ((i&0x1f)==0) {
s = lte_gold_generic(&x1, &x2, reset);
reset = 0;
if (i) {
in++;
out++;
}
}
(*out) ^= ((((*in)>>(i&0x1f))&1) ^ ((s>>(i&0x1f))&1))<<(i&0x1f);
}
}
uint8_t nr_generate_dci_top(nfapi_nr_dl_tti_pdcch_pdu *pdcch_pdu,
nfapi_nr_ul_dci_request_pdus_t *ul_dci_pdu,
uint32_t **gold_pdcch_dmrs,
int32_t *txdataF,
int16_t amp,
NR_DL_FRAME_PARMS frame_parms) {
int16_t mod_dmrs[NR_MAX_CSET_DURATION][NR_MAX_PDCCH_DMRS_LENGTH>>1]; // 3 for the max coreset duration
uint16_t cset_start_sc;
uint8_t cset_start_symb, cset_nsymb;
int k,l,k_prime,dci_idx, dmrs_idx;
/*First iteration: single DCI*/
nfapi_nr_dl_tti_pdcch_pdu_rel15_t *pdcch_pdu_rel15;
// find coreset descriptor
int rb_offset;
int n_rb;
AssertFatal(pdcch_pdu!=NULL || ul_dci_pdu!=NULL,"At least one pointer has to be !NULL\n");
AssertFatal(pdcch_pdu==NULL || ul_dci_pdu==NULL,"Can't handle both DL and UL DCI in same slot\n");
if (pdcch_pdu) pdcch_pdu_rel15 = &pdcch_pdu->pdcch_pdu_rel15;
else if (ul_dci_pdu) pdcch_pdu_rel15 = &ul_dci_pdu->pdcch_pdu.pdcch_pdu_rel15;
get_coreset_rballoc(pdcch_pdu_rel15->FreqDomainResource,&n_rb,&rb_offset);
// compute rb_offset and n_prb based on frequency allocation
if (pdcch_pdu_rel15->CoreSetType == NFAPI_NR_CSET_CONFIG_MIB_SIB1) {
cset_start_sc = frame_parms.first_carrier_offset + (frame_parms.ssb_start_subcarrier/NR_NB_SC_PER_RB +
rb_offset)*NR_NB_SC_PER_RB;
} else
cset_start_sc = frame_parms.first_carrier_offset + rb_offset*NR_NB_SC_PER_RB;
for (int d=0;d<pdcch_pdu_rel15->numDlDci;d++) {
/*The coreset is initialised
* in frequency: the first subcarrier is obtained by adding the first CRB overlapping the SSB and the rb_offset for coreset 0
* or the rb_offset for other coresets
* in time: by its first slot and its first symbol*/
cset_start_symb = pdcch_pdu_rel15->StartSymbolIndex;
cset_nsymb = pdcch_pdu_rel15->DurationSymbols;
dci_idx = 0;
LOG_D(PHY, "Coreset rb_offset %d, nb_rb %d\n",rb_offset,n_rb);
LOG_D(PHY, "Coreset starting subcarrier %d on symbol %d (%d symbols)\n", cset_start_sc, cset_start_symb, cset_nsymb);
// DMRS length is per OFDM symbol
AssertFatal(pdcch_pdu_rel15->CceRegMappingType == NFAPI_NR_CCE_REG_MAPPING_NON_INTERLEAVED,
"Interleaved CCE REG MAPPING not supported\n");
uint32_t dmrs_length = (pdcch_pdu_rel15->CceRegMappingType == NFAPI_NR_CCE_REG_MAPPING_NON_INTERLEAVED)?
(n_rb*6) : (pdcch_pdu_rel15->dci_pdu.AggregationLevel[d]*36/cset_nsymb); //2(QPSK)*3(per RB)*6(REG per CCE)
uint32_t encoded_length = pdcch_pdu_rel15->dci_pdu.AggregationLevel[d]*108; //2(QPSK)*9(per RB)*6(REG per CCE)
LOG_D(PHY, "DMRS length per symbol %d\t DCI encoded length %d (precoder_granularity %d,reg_mapping %d)\n", dmrs_length, encoded_length,pdcch_pdu_rel15->precoderGranularity,pdcch_pdu_rel15->CceRegMappingType);
dmrs_length += rb_offset*6; // To accommodate more DMRS symbols in case of rb offset
/// DMRS QPSK modulation
for (int symb=cset_start_symb; symb<cset_start_symb + pdcch_pdu_rel15->DurationSymbols; symb++) {
nr_modulation(gold_pdcch_dmrs[symb], dmrs_length, DMRS_MOD_ORDER, mod_dmrs[symb]); //Qm = 2 as DMRS is QPSK modulated
#ifdef DEBUG_PDCCH_DMRS
for (int i=0; i<dmrs_length>>1; i++)
printf("symb %d i %d gold seq 0x%08x mod_dmrs %d %d\n", symb, i,
gold_pdcch_dmrs[symb][i>>5], mod_dmrs[symb][i<<1], mod_dmrs[symb][(i<<1)+1] );
#endif
}
/// DCI payload processing
// CRC attachment + Scrambling + Channel coding + Rate matching
uint32_t encoder_output[NR_MAX_DCI_SIZE_DWORD];
uint16_t n_RNTI = pdcch_pdu_rel15->dci_pdu.RNTI[d];
uint16_t Nid = pdcch_pdu_rel15->dci_pdu.ScramblingId[d];
uint16_t scrambing_RNTI = pdcch_pdu_rel15->dci_pdu.ScramblingRNTI[numDlDci];
t_nrPolar_params *currentPtr = nr_polar_params(NR_POLAR_DCI_MESSAGE_TYPE,
pdcch_pdu_rel15->dci_pdu.PayloadSizeBits[d],
pdcch_pdu_rel15->dci_pdu.AggregationLevel[d],
0,NULL);
polar_encoder_fast((uint64_t*)pdcch_pdu_rel15->dci_pdu.Payload[d], encoder_output, n_RNTI,1,currentPtr);
#ifdef DEBUG_CHANNEL_CODING
printf("polar rnti %x,length %d, L %d\n",n_RNTI, pdcch_pdu_rel15->dci_pdu.PayloadSizeBits[d],pdcch_pdu_rel15->dci_pdu.AggregationLevel[d]);
printf("DCI PDU: [0]->0x%lx \t [1]->0x%lx\n",
((uint64_t*)pdcch_pdu_rel15->dci_pdu.Payload[d])[0], ((uint64_t*)pdcch_pdu_rel15->dci_pdu.Payload[d])[1]);
printf("Encoded Payload (length:%d dwords):\n", encoded_length>>5);
for (int i=0; i<encoded_length>>5; i++)
printf("[%d]->0x%08x \t", i,encoder_output[i]);
printf("\n");
#endif
/// Scrambling
uint32_t scrambled_output[NR_MAX_DCI_SIZE_DWORD]= {0};
nr_pdcch_scrambling(encoder_output, encoded_length, Nid, scrambling_RNTI, scrambled_output);
#ifdef DEBUG_CHANNEL_CODING
printf("scrambled output: [0]->0x%08x \t [1]->0x%08x \t [2]->0x%08x \t [3]->0x%08x\t [4]->0x%08x\t [5]->0x%08x\t \
[6]->0x%08x \t [7]->0x%08x \t [8]->0x%08x \t [9]->0x%08x\t [10]->0x%08x\t [11]->0x%08x\n",
scrambled_output[0], scrambled_output[1], scrambled_output[2], scrambled_output[3], scrambled_output[4],scrambled_output[5],
scrambled_output[6], scrambled_output[7], scrambled_output[8], scrambled_output[9], scrambled_output[10],scrambled_output[11] );
#endif
/// QPSK modulation
int16_t mod_dci[NR_MAX_DCI_SIZE>>1];
nr_modulation(scrambled_output, encoded_length, DMRS_MOD_ORDER, mod_dci); //Qm = 2 as DMRS is QPSK modulated
#ifdef DEBUG_DCI
for (int i=0; i<encoded_length>>1; i++)
printf("i %d mod_dci %d %d\n", i, mod_dci[i<<1], mod_dci[(i<<1)+1] );
#endif
/// Resource mapping
if (cset_start_sc >= frame_parms.ofdm_symbol_size)
cset_start_sc -= frame_parms.ofdm_symbol_size;
/*Reorder REG list for a freq first mapping*/
uint8_t nb_regs = pdcch_pdu_rel15->dci_pdu.AggregationLevel[d]*NR_NB_REG_PER_CCE;
/*Mapping the encoded DCI along with the DMRS */
for (int reg_idx=0; reg_idx<nb_regs; reg_idx++) {
k = cset_start_sc + (12*reg_idx/cset_nsymb);
if (k >= frame_parms.ofdm_symbol_size)
k -= frame_parms.ofdm_symbol_size;
l = cset_start_symb + ((reg_idx/cset_nsymb)%cset_nsymb);
// dmrs index depends on reference point for k according to 38.211 7.4.1.3.2
if (pdcch_pdu_rel15->CoreSetType == NFAPI_NR_CSET_CONFIG_PDCCH_CONFIG)
dmrs_idx = (reg_idx/cset_nsymb)*3;
else
dmrs_idx = ((reg_idx/cset_nsymb)+rb_offset)*3;
k_prime = 0;
for (int m=0; m<NR_NB_SC_PER_RB; m++) {
if ( m == (k_prime<<2)+1) { // DMRS if not already mapped
if (pdcch_pdu_rel15->CceRegMappingType == NFAPI_NR_CCE_REG_MAPPING_NON_INTERLEAVED) {
((int16_t *)txdataF)[(l*frame_parms.ofdm_symbol_size + k)<<1] = (2*amp * mod_dmrs[l][dmrs_idx<<1]) >> 15;
((int16_t *)txdataF)[((l*frame_parms.ofdm_symbol_size + k)<<1) + 1] = (2*amp * mod_dmrs[l][(dmrs_idx<<1) + 1]) >> 15;
#ifdef DEBUG_PDCCH_DMRS
printf("PDCCH DMRS: l %d position %d => (%d,%d)\n",l,k,((int16_t *)txdataF)[(l*frame_parms.ofdm_symbol_size + k)<<1],
((int16_t *)txdataF)[((l*frame_parms.ofdm_symbol_size + k)<<1)+1]);
#endif
dmrs_idx++;
}
k_prime++;
} else { // DCI payload
((int16_t *)txdataF)[(l*frame_parms.ofdm_symbol_size + k)<<1] = (amp * mod_dci[dci_idx<<1]) >> 15;
((int16_t *)txdataF)[((l*frame_parms.ofdm_symbol_size + k)<<1) + 1] = (amp * mod_dci[(dci_idx<<1) + 1]) >> 15;
#ifdef DEBUG_DCI
printf("PDCCH: l %d position %d => (%d,%d)\n",l,k,((int16_t *)txdataF)[(l*frame_parms.ofdm_symbol_size + k)<<1],
((int16_t *)txdataF)[((l*frame_parms.ofdm_symbol_size + k)<<1)+1]);
#endif
dci_idx++;
}
k++;
if (k >= frame_parms.ofdm_symbol_size)
k -= frame_parms.ofdm_symbol_size;
} // m
} // reg_idx
} // for (int d=0;d<pdcch_pdu_rel15->numDlDci;d++)
return 0;
}