Shared object file *libldpc_t2.so* is created during the compilation. This object is conditionally compiled. Selection of the library to compile is done using *--build-lib ldpc_t2*.
*Required poll mode driver has to be present on the host machine and required DPDK version has to be installed on the host, prior to the build of OAI*
# 5G PHY simulators
## nr_ulsim test
Offload of the channel decoding to the T2 card is in nr_ulsim specified by *-o* option. Example command for running nr_ulsim with LDPC decoding offload to the T2 card:
```
cd ~/openairinterface5g
source oaienv
cd cmake_targets/ran_build/build
sudo ./nr_ulsim -n100 -s20 -m20 -r273 -R273 -o
```
## nr_dlsim test
Offload of the channel encoding to the AMD Xilinx T2 card is in nr_dlsim specified by *-c* option. Example command for running nr_dlsim with LDPC encoding offload to the T2 card:
```
cd ~/openairinterface5g
source oaienv
cd cmake_targets/ran_build/build
sudo ./nr_dlsim -n300 -s30 -R 106 -e 27 -c
```
# OTA test
Offload of the channel encoding and decoding to the AMD Xilinx T2 card is enabled by *--ldpc-offload-enable 1* option.
- offload of the LDPC encoding implemented for MCS > 2, OAI CPU encoder is used for MCS =< 2
- functionality of the LDPC encoding and decoding offload verified in OTA SISO setup with USRP N310 and Quectel RM500Q, blocking of the card reported for MIMO setup (2 layers)
*Note: AMD Xilinx T1 Telco card is not supported anymore.*
printf("SNR %f, Max iterations: %d\n",SNR,dec_iter.n_iter_max[i]);
printf("\n");
printf("\n");
printf("Encoding time mean: %15.3f us\n",(double)time_optim->diff/time_optim->trials/1000.0/get_cpu_freq_GHz());
printf("Encoding time mean: %15.3f us\n",(double)res.time_optim.diff/res.time_optim.trials/1000.0/get_cpu_freq_GHz());
printf("Encoding time std: %15.3f us\n",sqrt((double)time_optim->diff_square/time_optim->trials/pow(1000,2)/pow(get_cpu_freq_GHz(),2)-pow((double)time_optim->diff/time_optim->trials/1000.0/get_cpu_freq_GHz(),2)));
printf("Encoding time std: %15.3f us\n",sqrt((double)res.time_optim.diff_square/res.time_optim.trials/pow(1000,2)/pow(get_cpu_freq_GHz(),2)-pow((double)res.time_optim.diff/res.time_optim.trials/1000.0/get_cpu_freq_GHz(),2)));
printf("Encoding time max: %15.3f us\n",(double)time_optim->max/1000.0/get_cpu_freq_GHz());
printf("Encoding time max: %15.3f us\n",(double)res.time_optim.max/1000.0/get_cpu_freq_GHz());
printf("\n");
printf("\n");
printf("Decoding time mean: %15.3f us\n",(double)time_decoder->diff/time_decoder->trials/1000.0/get_cpu_freq_GHz());
printf("Decoding time mean: %15.3f us\n",(double)res.time_decoder.diff/res.time_decoder.trials/1000.0/get_cpu_freq_GHz());
printf("Decoding time std: %15.3f us\n",sqrt((double)time_decoder->diff_square/time_decoder->trials/pow(1000,2)/pow(get_cpu_freq_GHz(),2)-pow((double)time_decoder->diff/time_decoder->trials/1000.0/get_cpu_freq_GHz(),2)));
printf("Decoding time std: %15.3f us\n",sqrt((double)res.time_decoder.diff_square/res.time_decoder.trials/pow(1000,2)/pow(get_cpu_freq_GHz(),2)-pow((double)res.time_decoder.diff/res.time_decoder.trials/1000.0/get_cpu_freq_GHz(),2)));
printf("Decoding time max: %15.3f us\n",(double)time_decoder->max/1000.0/get_cpu_freq_GHz());
printf("Decoding time max: %15.3f us\n",(double)res.time_decoder.max/1000.0/get_cpu_freq_GHz());
printf("code block ea %d eb %d c %d cab %d r %d\n",ldpc_dec->tb_params.ea,ldpc_dec->tb_params.eb,ldpc_dec->tb_params.c, ldpc_dec->tb_params.cab, ldpc_dec->tb_params.r);
printf("-o Introduce delay in terms of number of samples\n");
printf("-y Number of TX antennas used in gNB\n");
printf("-z Number of RX antennas used in UE\n");
printf("-x Num of layer for PDSCH\n");
printf("-p Precoding matrix index\n");
printf("-i Change channel estimation technique. Arguments list: Frequency domain {0:Linear interpolation, 1:PRB based averaging}, Time domain {0:Estimates of last DMRS symbol, 1:Average of DMRS symbols}\n");
//printf("-j Relative strength of second intefering gNB (in dB) - cell_id mod 3 = 2\n");
printf("-R N_RB_DL\n");
printf("-O oversampling factor (1,2,4,8,16)\n");
printf("-c ldpc offload flag\n");
printf("-A Interpolation_filname Run with Abstraction to generate Scatter plot using interpolation polynomial in file\n");
//printf("-C Generate Calibration information for Abstraction (effective SNR adjustment to remove Pe bias w.r.t. AWGN)\n");
printf("-f raw file containing RRC configuration (generated by gNB)\n");
printf("-F Input filename (.txt format) for RX conformance testing\n");
printf("-a Start PRB for PDSCH\n");
printf("-a Start PRB for PDSCH\n");
printf("-b Number of PRB for PDSCH\n");
printf("-b Number of PRB for PDSCH\n");
printf("-d number of dlsch threads, 0: no dlsch parallelization\n");
printf("-d number of dlsch threads, 0: no dlsch parallelization\n");
...
@@ -597,6 +626,7 @@ int main(int argc, char **argv)
...
@@ -597,6 +626,7 @@ int main(int argc, char **argv)
gNB=RC.gNB[0];
gNB=RC.gNB[0];
gNB->ofdm_offset_divisor=UINT_MAX;
gNB->ofdm_offset_divisor=UINT_MAX;
gNB->ldpc_offload_flag=ldpc_offload_flag;
frame_parms=&gNB->frame_parms;//to be initialized I suppose (maybe not necessary for PBCH)
frame_parms=&gNB->frame_parms;//to be initialized I suppose (maybe not necessary for PBCH)
frame_parms->nb_antennas_tx=n_tx;
frame_parms->nb_antennas_tx=n_tx;
frame_parms->nb_antennas_rx=n_rx;
frame_parms->nb_antennas_rx=n_rx;
...
@@ -1301,7 +1331,10 @@ int main(int argc, char **argv)
...
@@ -1301,7 +1331,10 @@ int main(int argc, char **argv)