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openairinterface5g/openair1/PHY/NR_TRANSPORT/nr_pbch.c
T
Raymond Knopp d7c71252f0 nr_pbchsim: added -I option which runs initial synchronization. without, it just runs pbch decoding 
Still a remaining issue with the SNR normalization, way too low to get errors.
2018-10-25 22:50:35 +02:00

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/*
* Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The OpenAirInterface Software Alliance licenses this file to You under
* the OAI Public License, Version 1.1 (the "License"); you may not use this file
* except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.openairinterface.org/?page_id=698
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*-------------------------------------------------------------------------------
* For more information about the OpenAirInterface (OAI) Software Alliance:
* contact@openairinterface.org
*/
/*! \file PHY/NR_TRANSPORT/nr_pbch.c
* \brief Top-level routines for generating the PBCH/BCH physical/transport channel V15.1 03/2018
* \author Guy De Souza
* \date 2018
* \version 0.1
* \company Eurecom
* \email: desouza@eurecom.fr
* \note
* \warning
*/
#include "PHY/defs_gNB.h"
#include "PHY/NR_TRANSPORT/nr_transport.h"
#include "PHY/LTE_REFSIG/lte_refsig.h"
#include "PHY/sse_intrin.h"
//#define DEBUG_PBCH
//#define DEBUG_PBCH_ENCODING
//#define DEBUG_PBCH_DMRS
//extern short nr_mod_table[NR_MOD_TABLE_SIZE_SHORT];
#include "PHY/NR_REFSIG/nr_mod_table.h"
int nr_generate_pbch_dmrs(uint32_t *gold_pbch_dmrs,
int32_t **txdataF,
int16_t amp,
uint8_t ssb_start_symbol,
nfapi_nr_config_request_t* config,
NR_DL_FRAME_PARMS *frame_parms)
{
int k,l;
int16_t a;
int16_t mod_dmrs[NR_PBCH_DMRS_LENGTH<<1];
uint8_t idx=0;
uint8_t nushift = config->sch_config.physical_cell_id.value &3;
LOG_D(PHY, "PBCH DMRS mapping started at symbol %d shift %d\n", ssb_start_symbol+1, nushift);
/// QPSK modulation
for (int m=0; m<NR_PBCH_DMRS_LENGTH; m++) {
idx = ((((gold_pbch_dmrs[(m<<1)>>5])>>((m<<1)&0x1f))&1)<<1) ^ (((gold_pbch_dmrs[((m<<1)+1)>>5])>>(((m<<1)+1)&0x1f))&1);
mod_dmrs[m<<1] = nr_mod_table[(NR_MOD_TABLE_QPSK_OFFSET + idx)<<1];
mod_dmrs[(m<<1)+1] = nr_mod_table[((NR_MOD_TABLE_QPSK_OFFSET + idx)<<1) + 1];
#ifdef DEBUG_PBCH_DMRS
printf("m %d idx %d gold seq %d b0-b1 %d-%d mod_dmrs %d %d\n", m, idx, gold_pbch_dmrs[(m<<1)>>5], (((gold_pbch_dmrs[(m<<1)>>5])>>((m<<1)&0x1f))&1),
(((gold_pbch_dmrs[((m<<1)+1)>>5])>>(((m<<1)+1)&0x1f))&1), mod_dmrs[(m<<1)], mod_dmrs[(m<<1)+1]);
#endif
}
/// Resource mapping
a = (config->rf_config.tx_antenna_ports.value == 1) ? amp : (amp*ONE_OVER_SQRT2_Q15)>>15;
for (int aa = 0; aa < config->rf_config.tx_antenna_ports.value; aa++)
{
// PBCH DMRS are mapped within the SSB block on every fourth subcarrier starting from nushift of symbols 1, 2, 3
///symbol 1 [0+nushift:4:236+nushift] -- 60 mod symbols
k = frame_parms->first_carrier_offset + frame_parms->ssb_start_subcarrier + nushift;
l = ssb_start_symbol + 1;
for (int m = 0; m < 60; m++) {
#ifdef DEBUG_PBCH_DMRS
printf("m %d at k %d of l %d\n", m, k, l);
#endif
((int16_t*)txdataF[aa])[(l*frame_parms->ofdm_symbol_size + k)<<1] = (a * mod_dmrs[m<<1]) >> 15;
((int16_t*)txdataF[aa])[((l*frame_parms->ofdm_symbol_size + k)<<1) + 1] = (a * mod_dmrs[(m<<1) + 1]) >> 15;
#ifdef DEBUG_PBCH_DMRS
printf("(%d,%d)\n",
((int16_t*)txdataF[aa])[(l*frame_parms->ofdm_symbol_size + k)<<1],
((int16_t*)txdataF[aa])[((l*frame_parms->ofdm_symbol_size + k)<<1)+1]);
#endif
k+=4;
if (k >= frame_parms->ofdm_symbol_size)
k-=frame_parms->ofdm_symbol_size;
}
///symbol 2 [0+u:4:44+nushift ; 192+nu:4:236+nushift] -- 24 mod symbols
k = frame_parms->first_carrier_offset + frame_parms->ssb_start_subcarrier + nushift;
l++;
for (int m = 60; m < 84; m++) {
#ifdef DEBUG_PBCH_DMRS
printf("m %d at k %d of l %d\n", m, k, l);
#endif
((int16_t*)txdataF[aa])[(l*frame_parms->ofdm_symbol_size + k)<<1] = (a * mod_dmrs[m<<1]) >> 15;
((int16_t*)txdataF[aa])[((l*frame_parms->ofdm_symbol_size + k)<<1) + 1] = (a * mod_dmrs[(m<<1) + 1]) >> 15;
#ifdef DEBUG_PBCH_DMRS
printf("(%d,%d)\n",
((int16_t*)txdataF[aa])[(l*frame_parms->ofdm_symbol_size + k)<<1],
((int16_t*)txdataF[aa])[((l*frame_parms->ofdm_symbol_size + k)<<1)+1]);
#endif
k+=(m==71)?148:4; // Jump from 44+nu to 192+nu
if (k >= frame_parms->ofdm_symbol_size)
k-=frame_parms->ofdm_symbol_size;
}
///symbol 3 [0+nushift:4:236+nushift] -- 60 mod symbols
k = frame_parms->first_carrier_offset + frame_parms->ssb_start_subcarrier + nushift;
l++;
for (int m = 84; m < NR_PBCH_DMRS_LENGTH; m++) {
#ifdef DEBUG_PBCH_DMRS
printf("m %d at k %d of l %d\n", m, k, l);
#endif
((int16_t*)txdataF[aa])[(l*frame_parms->ofdm_symbol_size + k)<<1] = (a * mod_dmrs[m<<1]) >> 15;
((int16_t*)txdataF[aa])[((l*frame_parms->ofdm_symbol_size + k)<<1) + 1] = (a * mod_dmrs[(m<<1) + 1]) >> 15;
#ifdef DEBUG_PBCH_DMRS
printf("(%d,%d)\n",
((int16_t*)txdataF[aa])[(l*frame_parms->ofdm_symbol_size + k)<<1],
((int16_t*)txdataF[aa])[((l*frame_parms->ofdm_symbol_size + k)<<1)+1]);
#endif
k+=4;
if (k >= frame_parms->ofdm_symbol_size)
k-=frame_parms->ofdm_symbol_size;
}
}
#ifdef DEBUG_PBCH_DMRS
write_output("txdataF_pbch_dmrs.m", "txdataF_pbch_dmrs", txdataF[0], frame_parms->samples_per_frame_wCP>>1, 1, 1);
#endif
return 0;
}
void nr_pbch_scrambling(NR_gNB_PBCH *pbch,
uint32_t Nid,
uint8_t nushift,
uint16_t M,
uint16_t length,
uint8_t encoded)
{
uint8_t reset, offset;
uint32_t x1, x2, s=0;
uint32_t *pbch_e = pbch->pbch_e;
uint32_t unscrambling_mask = 0x100006D;
reset = 1;
// x1 is set in lte_gold_generic
x2 = Nid;
// The Gold sequence is shifted by nushift* M, so we skip (nushift*M /32) double words
for (int i=0; i<(uint16_t)ceil(((float)nushift*M)/32); i++) {
s = lte_gold_generic(&x1, &x2, reset);
reset = 0;
}
// Scrambling is now done with offset (nushift*M)%32
offset = (nushift*M)&0x1f;
#ifdef DEBUG_PBCH_ENCODING
printf("Scrambling params: nushift %d M %d length %d encoded %d offset %d\n", nushift, M, length, encoded, offset);
#endif
for (int i=0; i<length; i++) {
if (((i+offset)&0x1f)==0) {
s = lte_gold_generic(&x1, &x2, reset);
reset = 0;
}
#ifdef DEBUG_PBCH_ENCODING
printf("s: %04x\t", s);
#endif
if (!encoded)
pbch->pbch_a_prime ^= ((unscrambling_mask>>i)&1)? ((pbch->pbch_a_interleaved>>i)&1)<<i : (((pbch->pbch_a_interleaved>>i)&1) ^ ((s>>((i+offset)&0x1f))&1))<<i;
else
pbch_e[i>>5] ^= (((s>>((i+offset)&0x1f))&1)<<(i&0x1f));
}
}
// This portion of code is temporarily kept until the optimized version is validated
uint8_t nr_pbch_payload_interleaving_pattern[32] = {16, 23, 18, 17, 8, 30, 10, 6, 24, 7, 0, 5, 3, 2, 1, 4,
9, 11, 12, 13, 14, 15, 19, 20, 21, 22, 25, 26, 27, 28, 29, 31};
uint8_t nr_pbch_payload_interleaver(uint8_t i) {
uint8_t j_sfn=6, j_hrf=10, j_ssb=11, j_other=14;
if (24<=i && i<=27) //Sfn bits
return nr_pbch_payload_interleaving_pattern[j_sfn + i -24];
else if (i==28) // Hrf bit
return nr_pbch_payload_interleaving_pattern[j_hrf];
else if (29<=i) // Ssb bits
return nr_pbch_payload_interleaving_pattern[j_ssb + (i-29)];
else
return nr_pbch_payload_interleaving_pattern[(j_other + i)&0x1f];
}
/*This pattern takes into account the adjustments for the field specific counters j_sfn, j_hrf, j_ssb and j_other*/
//uint8_t nr_pbch_payload_interleaving_pattern[32] = {1,4,9,11,12,13,14,15,19,20,21,22,25,26,27,28,
// 29,31,16,23,18,17,8,30,10,6,24,7,0,5,3,2};
int nr_generate_pbch(NR_gNB_PBCH *pbch,
t_nrPolar_paramsPtr polar_params,
uint8_t *pbch_pdu,
int32_t **txdataF,
int16_t amp,
uint8_t ssb_start_symbol,
uint8_t n_hf,
uint8_t Lmax,
uint8_t ssb_index,
int sfn,
nfapi_nr_config_request_t* config,
NR_DL_FRAME_PARMS *frame_parms)
{
int k,l,m;
int16_t a;
int16_t mod_pbch_e[NR_POLAR_PBCH_E];
uint8_t idx=0;
uint16_t M;
uint8_t nushift;
uint8_t *xbyte = pbch->pbch_a;
memset((void*) xbyte, 0, 1);
//uint8_t pbch_a_b[32];
// LOG_D(PHY, "PBCH generation started\n");
memset((void*)pbch, 0, sizeof(NR_gNB_PBCH));
///Payload generation
// Fix byte endian
if (!(sfn&7))
for (int i=0; i<(NR_PBCH_PDU_BITS>>3); i++)
pbch->pbch_a[(NR_POLAR_PBCH_PAYLOAD_BITS>>3)-i-1] = pbch_pdu[i];
#ifdef DEBUG_PBCH_ENCODING
printf("Byte endian fix:\n");
for (int i=0; i<4; i++)
printf("pbch_a[%d]: 0x%02x\n", i, pbch->pbch_a[i]);
#endif
// Extra byte generation
for (int i=0; i<4; i++)
(*xbyte) ^= ((sfn>>i)&1)<<i; // 4 lsb of sfn
(*xbyte) ^= n_hf<<4; // half frame index bit
if (Lmax == 64)
for (int i=0; i<3; i++)
(*xbyte) ^= ((ssb_index>>(3+i))&1)<<(5+i); // resp. 4th, 5th and 6th bits of ssb_index
else
(*xbyte) ^= ((config->sch_config.ssb_subcarrier_offset.value>>5)&1)<<5; //MSB of k_SSB
#ifdef DEBUG_PBCH_ENCODING
printf("Extra byte:\n");
for (int i=0; i<4; i++)
printf("pbch_a[%d]: 0x%02x\n", i, pbch->pbch_a[i]);
#endif
// Payload interleaving
uint32_t in=0, out=0;
for (int i=0; i<NR_POLAR_PBCH_PAYLOAD_BITS>>3; i++)
in |= (uint32_t)(pbch->pbch_a[i]<<((3-i)<<3));
for (int i=0; i<32; i++) {
pbch->pbch_a_interleaved |= ((in>>i)&1)<<(nr_pbch_payload_interleaver(i));//nr_pbch_payload_interleaving_pattern[i]
#ifdef DEBUG_PBCH_ENCODING
printf("i %d in 0x%08x out 0x%08x ilv %d (in>>i)&1) %d\n", i, in, pbch->pbch_a_interleaved, nr_pbch_payload_interleaver(i), (in>>i)&1);
#endif
}
#ifdef DEBUG_PBCH_ENCODING
printf("Interleaving:\n");
printf("pbch_a_interleaved: 0x%08x\n", pbch->pbch_a_interleaved);
#endif
// Scrambling
M = (Lmax == 64)? (NR_POLAR_PBCH_PAYLOAD_BITS - 6) : (NR_POLAR_PBCH_PAYLOAD_BITS - 3);
nushift = (((sfn>>2)&1)<<1) ^ ((sfn>>1)&1);
pbch->pbch_a_prime = 0;
nr_pbch_scrambling(pbch, (uint32_t)config->sch_config.physical_cell_id.value, nushift, M, NR_POLAR_PBCH_PAYLOAD_BITS, 0);
#ifdef DEBUG_PBCH_ENCODING
printf("Payload scrambling: nushift %d M %d sfn3 %d sfn2 %d\n", nushift, M, (sfn>>2)&1, (sfn>>1)&1);
printf("pbch_a_prime: 0x%08x\n", pbch->pbch_a_prime);
#endif
/// CRC, coding and rate matching
polar_encoder (&pbch->pbch_a_prime, pbch->pbch_e, polar_params);
#ifdef DEBUG_PBCH_ENCODING
printf("Channel coding:\n");
for (int i=0; i<NR_POLAR_PBCH_E_DWORD; i++)
printf("pbch_e[%d]: 0x%08x\t", i, pbch->pbch_e[i]);
printf("\n");
#endif
/// Scrambling
M = NR_POLAR_PBCH_E;
nushift = (Lmax==4)? ssb_index&3 : ssb_index&7;
nr_pbch_scrambling(pbch, (uint32_t)config->sch_config.physical_cell_id.value, nushift, M, NR_POLAR_PBCH_E, 1);
#ifdef DEBUG_PBCH_ENCODING
printf("Scrambling:\n");
for (int i=0; i<NR_POLAR_PBCH_E_DWORD; i++)
printf("pbch_e[%d]: 0x%08x\t", i, pbch->pbch_e[i]);
printf("\n");
#endif
/// QPSK modulation
for (int i=0; i<NR_POLAR_PBCH_E>>1; i++){
idx = (((pbch->pbch_e[(i<<1)>>5]>>((i<<1)&0x1f))&1)<<1) ^ ((pbch->pbch_e[((i<<1)+1)>>5]>>(((i<<1)+1)&0x1f))&1);
mod_pbch_e[i<<1] = nr_mod_table[(NR_MOD_TABLE_QPSK_OFFSET + idx)<<1];
mod_pbch_e[(i<<1)+1] = nr_mod_table[((NR_MOD_TABLE_QPSK_OFFSET + idx)<<1)+1];
#ifdef DEBUG_PBCH
printf("i %d idx %d mod_pbch %d %d\n", i, idx, mod_pbch_e[2*i], mod_pbch_e[2*i+1]);
#endif
}
/// Resource mapping
nushift = config->sch_config.physical_cell_id.value &3;
a = (config->rf_config.tx_antenna_ports.value == 1) ? amp : (amp*ONE_OVER_SQRT2_Q15)>>15;
for (int aa = 0; aa < config->rf_config.tx_antenna_ports.value; aa++)
{
// PBCH modulated symbols are mapped within the SSB block on symbols 1, 2, 3 excluding the subcarriers used for the PBCH DMRS
///symbol 1 [0:239] -- 180 mod symbols
k = frame_parms->first_carrier_offset + frame_parms->ssb_start_subcarrier;
l = ssb_start_symbol + 1;
m = 0;
for (int ssb_sc_idx = 0; ssb_sc_idx < 240; ssb_sc_idx++) {
if ((ssb_sc_idx&3) == nushift) { //skip DMRS
k++;
continue;
}
else {
#ifdef DEBUG_PBCH
printf("m %d ssb_sc_idx %d at k %d of l %d\n", m, ssb_sc_idx, k, l);
#endif
((int16_t*)txdataF[aa])[(l*frame_parms->ofdm_symbol_size + k)<<1] = (a * mod_pbch_e[m<<1]) >> 15;
((int16_t*)txdataF[aa])[((l*frame_parms->ofdm_symbol_size + k)<<1) + 1] = (a * mod_pbch_e[(m<<1) + 1]) >> 15;
k++;
m++;
}
if (k >= frame_parms->ofdm_symbol_size)
k-=frame_parms->ofdm_symbol_size;
}
///symbol 2 [0:47 ; 192:239] -- 72 mod symbols
k = frame_parms->first_carrier_offset + frame_parms->ssb_start_subcarrier;
l++;
m=180;
for (int ssb_sc_idx = 0; ssb_sc_idx < 48; ssb_sc_idx++) {
if ((ssb_sc_idx&3) == nushift) {
k++;
continue;
}
else {
#ifdef DEBUG_PBCH
printf("m %d ssb_sc_idx %d at k %d of l %d\n", m, ssb_sc_idx, k, l);
#endif
((int16_t*)txdataF[aa])[(l*frame_parms->ofdm_symbol_size + k)<<1] = (a * mod_pbch_e[m<<1]) >> 15;
((int16_t*)txdataF[aa])[((l*frame_parms->ofdm_symbol_size + k)<<1) + 1] = (a * mod_pbch_e[(m<<1) + 1]) >> 15;
k++;
m++;
}
if (k >= frame_parms->ofdm_symbol_size)
k-=frame_parms->ofdm_symbol_size;
}
k += 144;
if (k >= frame_parms->ofdm_symbol_size)
k-=frame_parms->ofdm_symbol_size;
m=216;
for (int ssb_sc_idx = 192; ssb_sc_idx < 240; ssb_sc_idx++) {
if ((ssb_sc_idx&3) == nushift) {
k++;
continue;
}
else {
#ifdef DEBUG_PBCH
printf("m %d ssb_sc_idx %d at k %d of l %d\n", m, ssb_sc_idx, k, l);
#endif
((int16_t*)txdataF[aa])[(l*frame_parms->ofdm_symbol_size + k)<<1] = (a * mod_pbch_e[m<<1]) >> 15;
((int16_t*)txdataF[aa])[((l*frame_parms->ofdm_symbol_size + k)<<1) + 1] = (a * mod_pbch_e[(m<<1) + 1]) >> 15;
k++;
m++;
}
if (k >= frame_parms->ofdm_symbol_size)
k-=frame_parms->ofdm_symbol_size;
}
///symbol 3 [0:239] -- 180 mod symbols
k = frame_parms->first_carrier_offset + frame_parms->ssb_start_subcarrier;
l++;
m=252;
for (int ssb_sc_idx = 0; ssb_sc_idx < 240; ssb_sc_idx++) {
if ((ssb_sc_idx&3) == nushift) {
k++;
continue;
}
else {
#ifdef DEBUG_PBCH
printf("m %d ssb_sc_idx %d at k %d of l %d\n", m, ssb_sc_idx, k, l);
#endif
((int16_t*)txdataF[aa])[(l*frame_parms->ofdm_symbol_size + k)<<1] = (a * mod_pbch_e[m<<1]) >> 15;
((int16_t*)txdataF[aa])[((l*frame_parms->ofdm_symbol_size + k)<<1) + 1] = (a * mod_pbch_e[(m<<1) + 1]) >> 15;
k++;
m++;
}
if (k >= frame_parms->ofdm_symbol_size)
k-=frame_parms->ofdm_symbol_size;
}
}
#ifdef DEBUG_PBCH
write_output("txdataF_pbch.m", "txdataF_pbch", txdataF[0], frame_parms->samples_per_frame_wCP>>1, 1, 1);
#endif
return 0;
}
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