Problem STATEMENT:
- When enabling PTRS flag in ulsim, there are multiple scrambling and decoding errors
are observed even with high SNR values
SNR 60dB errors_scrambling 5546/13800
Channel BLER 1.000000e+00, Channel BER 4.018841e-01
ANALYSIS:
- While extracting PTRS RE's, the PUSCH RE count was not updated accordingly for PTRS symbols.
- This results in 0 value LLR's on same positions which cause offset issue in later processing.
IMPLEMENTATION:
* nr_ulsch_demodulation.c
- In case of PTRS symbol, respective total number of PTRS RE's are subtracted from available
PUSCH RE's in each PUSCH Symbol processing.
TESTING
* ulsim.c
- PTRS are enabled for testing and are not enabled by default by this commit.
- Available bit count is adjusted if PTRS is enabled.
VERIFICATION
- Total Scrambling errors after gNb processing shall be only 250 bits (in K=2)
which were replaced with PTRS at UE side while transmission.
SNR 60.000000 errors_scrambling 250/13800
Channel BLER 0.000000e+00, Channel BER 1.811594e-02
- After adjusting available bits in ulsim.c for error calculation
SNR 60.000000: n_errors errors_scrambling 0/13550
Channel BLER 0.000000e+00, Channel BER 0.000000e+00
EXTRA
- Removed white-spaces from all above mentioned files
- Added Global/vim tags to .gitignore file
See merge request oai/openairinterface5g!869
Develop Integration Branch : 2020 week 31
The following Merge Requests have been included:
* MR [861] : Fixes for buffer overrun when L1 information is cleared upon UE removal in
* MR [863] : Small fixes
* MR [864] : Fixed the bug no supporting CellId more than 256
* MR [865] : Fix to have the sony 5g connect in NSA mode
* MR [867] : CI improvements for OCP-enb testing and NSA FR1 testing
* MR [868] : Add chansimuparams
Set n_dmrs_cdm_groups = 1 for now.
Should be fixed accordingly to TS 38.214 section 5.1.6.2
using tables 7.3.1.2.2-1, 7.3.1.2.2-2, 7.3.1.2.2-3, 7.3.1.2.2-4 of TS 38.212
Francesco Mani