Files
openairinterface5g/openair1
Rakesh Mundlamuri be3ad2beba rewrite srs channel estimation to fix memory alignment in SRS channel estimation
The memory alignment is required to use c16multaddVectRealComplex
in SRS channel interpolation. With a change in SRS comb_offset, the
existing algorithm was giving segmentation fault.

The existing srs channel estimation required memory alignment at two
stages. 1. When k = 0 (the first srs subcarrier), 2. When subcarrier <
K_TC (wrapped around after ofdm_symbol_size). Thus two memory alignments
are required leading to complications.

The srs channel estimation is now simplified to do it linearly instead of
wrapping around. This simplified the memory alignment required only when
k = 0.
2026-01-09 20:49:46 +05:30
..

This folder contains the software for layer 1 of the OpenAirInterface eNB and UE as well as the unitary simulators

|-- PHY			   // contains all signal processing related to physical layer (used in real-time AND simulation)

General remarks: every directory contains at least defs.h (for declaration of structure and functions), vars.h (for definitions of variables), and extern.h (variables are defined only once in xxx-softmodem.c (for real-time HW operation) or a top-level simulation (in SIMULATION/xxx), if variables are needed in another file, use extern.h)

|   |-- CODING		   // turbo and convolutional (de-)coders, rate-matching, crc generation (implementation of 36-212)
|   |   `-- TESTBENCH      // This contains unitary testbenches for the different channel coders/decoders
|   |-- INIT		   // variables defined in vars.h are initialzed here (memory allocation)
|   |-- LTE_ESTIMATION     // estimation for LTE
|   |-- LTE_REFSIG 	   // reference signals for LTE (sync and pilot sequences) reference signals from 36-211 
|   |-- NR_REFSIG 	   // reference signals for NR (sync and pilot sequences) reference signals from 38-211
|   |-- LTE_TRANSPORT      // these are the top level routines for different transport and physical channels (for example DL-SCH, PSS) implements a subset of 36-211,36-212
|   |-- LTE_UE_TRANSPORT      // these are the top level routines for different transport and physical channels (for example DL-SCH, PSS) implements a subset of 36-211,36-212
|   |-- NR_TRANSPORT      // these are the top level routines for different transport and physical channels (for example DL-SCH, PSS) implements a subset of 38-211,38-212
|   |-- NR_UE_TRANSPORT      // these are the top level routines for different transport and physical channels (for example DL-SCH, PSS) implements a subset of 38-211,38-212
|   |-- NBIoT_TRANSPORT      // these are the top level routines for different transport and physical channels for NB-IoT
|   |-- MODULATION	   // modulation and demodulation includes FFT/SC-FDMA front-end processing from 36-211
|   |-- TOOLS		   // tools like (I)FFT, vector operations, matrix multiplication, etc.
|   |   `-- FFTTEST        // unitary testbench for FFT routines
|   |-- defs.h		  // top level defs.h (includes spec_defs, impl_defs and all defs.h of subdirectories)
|   |-- extern.h
|   |-- impl_defs.h       // non-LTE openair implementation
|   |-- impl_defs_top.h   // general implementaion defs
|   |-- spec_defs.h
|   |-- spec_defs_top.h
|   |-- types.h
|   `-- vars.h		  
|-- SCHED		  // schedules the different LTE eNB functions
|   |-- defs.h
|   |-- extern.h
|   |-- phy_procedures_lte_eNb.c // LTE PHY procedures for eNB (from 36-213) 
|   |-- phy_procedures_lte_common.c  // LTE PHY procedures common for UE and eNB (from 36-213)
|   |-- prach_procedures.c  //LTE PRACH  procedures (from 36-213)
|   |-- ru_procedures.c  //RU  procedures
|   |-- fapi_l1.c  //L1 side of the FAPI interface
|   |-- phy_mac_stub.c  //MAC stub that generates channels when used in phy-test-mode
|   |-- rt_compat.h
|   `-- vars.h
|-- SCHED_UE		  // schedules the different LTE UE functions
|   |-- phy_procedures_lte_ue.c  // LTE PHY procedures for UE (from 36-213)
|   |-- pucch_pc.c // power control for PUCCH
|   |-- pusch_pc.c // power control for PUSCH
|   |-- srs_pc.c // power control for SRS
|-- SCHED_NB_IOT		  // same as above for NB-IOT
|-- SCHED_NR		  // same as above for NR gNB
|-- SCHED_NR_UE		  // same as above for NR UE
|-- SIMULATION		 // contains simulation routines to test PHY
|   |-- LTE_PHY          // LTE simulation testbenches for unitary simulation of transport/physical channels
|   |   |-- pbchsim.c       // PBCH simulation testbench
|   |   |-- pdcchsim.c      // PCFICH/PHICH/PDCCH (DCI) simulation testbench
|   |   |-- dlsim.c         // PDSCH simulation testbench
|   |   |-- ulsim.c         // PUSCH simulation testbench
|   |   |-- pucchsim.c      // PUCCH simulation testbench
|   |-- RF  		    // RF simulation tools
|   |-- ETH_TRANSPORT
|   `-- TOOLS