Parminder Singh
b288eafd1e
FEATURE STATEMENT: - Introduce linear phase error noise model in Uplink at UE - Perform common phase error (CPE) estimation and compensation at gNB SOLUTION: - A linear phase shift model is introduced in simulation. - PTRS symbols are used to perform estimation of CPE from DMRS compensated signal - The estimated values are interpolated in time domain and signal is compensated for the CPE. - PTRS processing is done in Frequency Domain for each symbol in a slot and LLR's are calculated for each symbol accordingly. IMPLEMENTATION: * sim.h/channle_sim.c - Linear Phase Noise Generation model definition. * nr_ul_channel_estimation.c/nr_ul_estimation.h - CPE estimation from PTRS and DMRS compensated signal. * nr_dmrs_rx.c/nr_refsig.h - Regenerate PTRS symbols at gNB. * nr_ulsch_demodulation.c - Removed old PTRS processing code and move to a common PTRS processing function * defs_gNB.h/init.c - New PTRS variables definition and initialization * nr_ulsch_ue.c - Corrected PTRS parameter to get new PTRS symbols for each OFDM symbol TESTING * ulsim.c - Added Phase noise, Enable PTRS signal and verified the output. VERIFICATION - The LLR are rotated back with estimated CPE and no error is observed in scrambling/decoding
This directory contains files related to initialization of variables/structures init_top.c : initialize top-level variables and signal buffers, FFT twiddle factors, etc. lte_init.c : LTE specific initlization routines (DLSCH/ULSCH signal buffers for RX, data buffers for TX, etc.) lte_param_init.c: used only in unitary simulations. initializes the global variables eNB and UE. lte_parms.c: contains init_frame_parms to initialize frame parameters structure