Check the provided MCS index according to the specified table.
Some tables go up to MCS index 27, others up to MCS index 28.
If the MCS index exceeds the allowed limit, assume max. MCS.
- To modify DMRS use -U flag followed by 3 integers
- Example: ./nr_ulsim -U 2 1 0
- 1st Value is the list of arguments -> e.g. 2
- 2nd Value is for TYPE{0=A,1=B} -> e.g. 1
- 3rd Value is for ADD_POS{0,1,2,3} -> e.g. 0
- To enable PTRS use -T flag followed by 3 integers
- Example: ./nr_ulsim -T 2 0 2
- 1st Value is the list of arguments -> e.g. 2
- 2nd Value is for L_PTRS{0,1,2} -> e.g. 0
- 3rd Value is for K_PTRS{2,4} -> e.g. 2
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
Florian Kaltenberger