Fix UL chanel estimates mapping in 2-layer MMSE receiver
This MR addresses a degradation in UL throughput observed in 4x4 MIMO
tests, starting from 2025.w17.
The issue was traced to incoherent indexing in the ul_ch_estimates_ext
when handling 4-antenna UL configurations.
Improvements for LDPC encoding
AVX512 modifications for LDPC encoding: interleaving, ZC384 BG1, output
formatting for encoder, segmentation (memcpy instead of loop). some
improvement in TX for aarch64 in same places where AVX512 support was
added. Also, rate matching and interleaving are done on bytes containing
8 segments and reformatting of the output is done at the end of segment
processing instead of after ldpc encoding.
This improves the overall performance of the NR DL transmitter in gNB
See the merge request description for numbers.
Since this branch aims to bring all the encoded segments packed and contiguous,
it doesn't make anymore sense to have one output array per segment.
Therefore this commit moves the output array to the TB instead of the segment and adapts its size.
TODO: Adapt the size of f where it is relevant.
1. 3GPP Rate-matching/interleaving on 8-segment blocks, deinterleaving at output of multi-segment processing.
2. Bit-packing done in nrLDPC_coding_segment_encoder.c now instead of nr_scrambling.
Interestingly, it improves performance significantly too.
Tested for AVX512 only for now.
The functions nr_generate_csi_rs() and nr_ue_generate_csi_rs() are
identical. This commit removes nr_ue_generate_csi_rs() and moves
nr_generate_csi_rs() to nr_phy_common_csirs.c so both gNB and UE can use
the same function.
Improve radio for Metanoia RU (and likely others)
We introduced a regression that lowered the achievable DL throughput
with at least the Metanoia RU (i.e., in the configuration and the UE
that we use). git bisect showed up one commit, which does not seem
necessary. We just revert this commit, as it improves the throughput and
does not seem to have a negative impact on performance.
Further, increase RLC buffers a bit. Limit 7.2 pipeline number of layers
to 2.
remove ul_ch_estimates_time to save memory
remove ul_ch_estimates_time that saves 50MB memory to access in RAM, and
make better quality scope data passing (no race)
Use memcpy in nr_prach.c to fill txdata buffer.
Remove global tables related to PRACH generation.
Add new function to compute modulo multiplicative inverse and use it
directly to get inverse instead of LUT.
Removed nr_ru table and compute the values in-place.
In UE, added new flag root_seq_computed in nrUE_config to only compute
the sequence once after new nrUE_config is received.
Long PRACH extends beyond a slot. Changes necessary to mark future slots
that may contain prach in ru, phy and mac functions.
In RU, the PRACH IDFT is done only after receiving last slot and marks
for L1 to start processing. The L1 processes at the last prach slot and
reports to MAC with the first slot index.
In MAC scheduler, the VRB for future slots are also marked as used.
PRACH scheduler is called in advance one frame minus num prach slots.
fix(nrLDPC_coding): timers in DL encoding, fix(ldpctest): Confusion in sizes
Main improvements:
1. fix(ldpctest): Confusion in sizes
IMPORTANT: This fix makes that ldpctest now works with BG2 and K' != K!
(Worth double checking with more cases than I did check with though)
The variable block_length had an ambiguous role and was used as both K and
Kprime. This was leading to arrays with wrong sizes and functions with wrong
arguments. Now there is not anymore block_length but K and Kprime.
Kprime can be set with the command line argument -l.
There was also some problems with array allocation for segments with length
not divisible by 8. A proper sizing with ((size_in_bits + 7) & ~7) / 8 was
used.
A proper masking of the last byte containing payload bits was also added to
keep filler bits to 0 after random initialization.
2. fix(nrLDPC_coding): timers in DL encoding
While timers were available for rate matching and interleaving in the new
interface, these timers were not merged to rate matching and interleaving
timers in nr_dlsch_coding.
The aggregation level search order for PDCCH candidates is modified:
- the search starts from desired_agg_level_index, which is a value from 0 to 4
proportial to pdcch_cl_adjust.
- pdcch_cl_adjust is a value between 0 and 1 that indicates PDCCH channel quality
by averaging HARQ DTX rate. A value of 0 means perfect channel, a value o 1 means
impaired channel.
francescomani