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Francesco Mani authoredFrancesco Mani authored
nr_dci.c 11.06 KiB
/*
* Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
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* The OpenAirInterface Software Alliance licenses this file to You under
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* 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.
*-------------------------------------------------------------------------------
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*/
/*! \file PHY/NR_TRANSPORT/nr_dci.c
* \brief Implements DCI encoding and PDCCH TX procedures (38.212/38.213/38.214). V15.4.0 2019-01.
* \author Guy De Souza
* \date 2018
* \version 0.1
* \company Eurecom
* \email: desouza@eurecom.fr
* \note
* \warning
*/
#include "nr_dci.h"
#include "nr_dlsch.h"
#include "nr_sch_dmrs.h"
#include "PHY/MODULATION/nr_modulation.h"
#include "common/utils/nr/nr_common.h"
//#define DEBUG_PDCCH_DMRS
//#define DEBUG_DCI
//#define DEBUG_CHANNEL_CODING
void nr_pdcch_scrambling(uint32_t *in,
uint32_t size,
uint32_t Nid,
uint32_t scrambling_RNTI,
uint32_t *out) {
uint8_t reset;
uint32_t x1, x2, s=0;
reset = 1;
x2 = (scrambling_RNTI<<16) + Nid;
LOG_D(PHY,"PDCCH Scrambling x2 %x : scrambling_RNTI %x \n", x2, scrambling_RNTI);
for (int i=0; i<size; i++) {
if ((i&0x1f)==0) {
s = lte_gold_generic(&x1, &x2, reset);
reset = 0;
if (i) {
in++;
out++;
}
}
(*out) ^= ((((*in)>>(i&0x1f))&1) ^ ((s>>(i&0x1f))&1))<<(i&0x1f);
}
}
void nr_generate_dci(PHY_VARS_gNB *gNB,
nfapi_nr_dl_tti_pdcch_pdu_rel15_t *pdcch_pdu_rel15, int32_t *txdataF,
int16_t amp,
NR_DL_FRAME_PARMS *frame_parms,
int slot) {
int16_t mod_dmrs[NR_MAX_CSET_DURATION][NR_MAX_PDCCH_DMRS_LENGTH>>1] __attribute__((aligned(16))); // 3 for the max coreset duration
uint16_t cset_start_sc;
uint8_t cset_start_symb, cset_nsymb;
int k,l,k_prime,dci_idx, dmrs_idx;
// find coreset descriptor
int rb_offset;
int n_rb;
// compute rb_offset and n_prb based on frequency allocation
nr_cce_t cce_list[MAX_DCI_CORESET][NR_MAX_PDCCH_AGG_LEVEL];
nr_fill_cce_list(cce_list,0,pdcch_pdu_rel15);
get_coreset_rballoc(pdcch_pdu_rel15->FreqDomainResource,&n_rb,&rb_offset);
cset_start_sc = frame_parms->first_carrier_offset + (pdcch_pdu_rel15->BWPStart + rb_offset) * NR_NB_SC_PER_RB;
for (int d=0;d<pdcch_pdu_rel15->numDlDci;d++) {
/*The coreset is initialised
* in frequency: the first subcarrier is obtained by adding the first CRB overlapping the SSB and the rb_offset for coreset 0
* or the rb_offset for other coresets
* in time: by its first slot and its first symbol*/
const nfapi_nr_dl_dci_pdu_t *dci_pdu = &pdcch_pdu_rel15->dci_pdu[d];
if(dci_pdu->ScramblingId != gNB->pdcch_gold_init) {
gNB->pdcch_gold_init = dci_pdu->ScramblingId;
nr_init_pdcch_dmrs(gNB, dci_pdu->ScramblingId);
}
uint32_t **gold_pdcch_dmrs = gNB->nr_gold_pdcch_dmrs[slot];
cset_start_symb = pdcch_pdu_rel15->StartSymbolIndex;
cset_nsymb = pdcch_pdu_rel15->DurationSymbols;
dci_idx = 0;
LOG_D(PHY, "pdcch: Coreset rb_offset %d, nb_rb %d BWP Start %d\n",rb_offset,n_rb,pdcch_pdu_rel15->BWPStart);
LOG_D(PHY, "pdcch: Coreset starting subcarrier %d on symbol %d (%d symbols)\n", cset_start_sc, cset_start_symb, cset_nsymb);
// DMRS length is per OFDM symbol
uint32_t dmrs_length = n_rb*6; //2(QPSK)*3(per RB)*6(REG per CCE)
uint32_t encoded_length = dci_pdu->AggregationLevel*108; //2(QPSK)*9(per RB)*6(REG per CCE)
LOG_D(PHY, "DL_DCI : rb_offset %d, nb_rb %d, DMRS length per symbol %d\t DCI encoded length %d (precoder_granularity %d,reg_mapping %d),Scrambling_Id %d,ScramblingRNTI %x,PayloadSizeBits %d\n",
rb_offset, n_rb,dmrs_length, encoded_length,pdcch_pdu_rel15->precoderGranularity,pdcch_pdu_rel15->CceRegMappingType,
dci_pdu->ScramblingId,dci_pdu->ScramblingRNTI,dci_pdu->PayloadSizeBits);
dmrs_length += rb_offset*6; // To accommodate more DMRS symbols in case of rb offset
/// DMRS QPSK modulation
for (int symb=cset_start_symb; symb<cset_start_symb + pdcch_pdu_rel15->DurationSymbols; symb++) {
nr_modulation(gold_pdcch_dmrs[symb], dmrs_length, DMRS_MOD_ORDER, mod_dmrs[symb]); //Qm = 2 as DMRS is QPSK modulated
#ifdef DEBUG_PDCCH_DMRS
if(dci_pdu->RNTI!=0xFFFF) {
for (int i=0; i<dmrs_length>>1; i++)
printf("symb %d i %d %p gold seq 0x%08x mod_dmrs %d %d\n", symb, i,
&gold_pdcch_dmrs[symb][i>>5],gold_pdcch_dmrs[symb][i>>5], mod_dmrs[symb][i<<1], mod_dmrs[symb][(i<<1)+1] );
}
#endif
}
/// DCI payload processing
// CRC attachment + Scrambling + Channel coding + Rate matching
uint32_t encoder_output[NR_MAX_DCI_SIZE_DWORD];
uint16_t n_RNTI = dci_pdu->RNTI;
uint16_t Nid = dci_pdu->ScramblingId;
uint16_t scrambling_RNTI = dci_pdu->ScramblingRNTI;
polar_encoder_fast((uint64_t*)dci_pdu->Payload, (void*)encoder_output, n_RNTI, 1,
NR_POLAR_DCI_MESSAGE_TYPE, dci_pdu->PayloadSizeBits, dci_pdu->AggregationLevel);
#ifdef DEBUG_CHANNEL_CODING
//debug dump dci
printf("polar rnti %x,length %d, L %d\n",n_RNTI, dci_pdu->PayloadSizeBits,pdcch_pdu_rel15->dci_pdu->AggregationLevel);
printf("DCI PDU: [0]->0x%lx \t [1]->0x%lx\n",
((uint64_t*)dci_pdu->Payload)[0], ((uint64_t*)dci_pdu->Payload)[1]);
printf("Encoded Payload (length:%d dwords):\n", encoded_length>>5);
for (int i=0; i<encoded_length>>5; i++)
printf("[%d]->0x%08x \t", i,encoder_output[i]);
printf("\n");
#endif
/// Scrambling
uint32_t scrambled_output[NR_MAX_DCI_SIZE_DWORD]= {0};
nr_pdcch_scrambling(encoder_output, encoded_length, Nid, scrambling_RNTI, scrambled_output);
#ifdef DEBUG_CHANNEL_CODING
printf("scrambled output: [0]->0x%08x \t [1]->0x%08x \t [2]->0x%08x \t [3]->0x%08x\t [4]->0x%08x\t [5]->0x%08x\t \
[6]->0x%08x \t [7]->0x%08x \t [8]->0x%08x \t [9]->0x%08x\t [10]->0x%08x\t [11]->0x%08x\n",
scrambled_output[0], scrambled_output[1], scrambled_output[2], scrambled_output[3], scrambled_output[4],scrambled_output[5],
scrambled_output[6], scrambled_output[7], scrambled_output[8], scrambled_output[9], scrambled_output[10],scrambled_output[11] );
#endif
/// QPSK modulation
int16_t mod_dci[NR_MAX_DCI_SIZE>>1] __attribute__((aligned(16)));
nr_modulation(scrambled_output, encoded_length, DMRS_MOD_ORDER, mod_dci); //Qm = 2 as DMRS is QPSK modulated
#ifdef DEBUG_DCI
for (int i=0; i<encoded_length>>1; i++)
printf("i %d mod_dci %d %d\n", i, mod_dci[i<<1], mod_dci[(i<<1)+1] );
#endif
/// Resource mapping
if (cset_start_sc >= frame_parms->ofdm_symbol_size)
cset_start_sc -= frame_parms->ofdm_symbol_size;
// Get cce_list indices by reg_idx in ascending order
int reg_list_index = 0;
int reg_list_order[NR_MAX_PDCCH_AGG_LEVEL] = {};
for (int p = 0; p < NR_MAX_PDCCH_AGG_LEVEL; p++) {
for(int p2 = 0; p2 < dci_pdu->AggregationLevel; p2++) {
if(cce_list[d][p2].reg_list[0].reg_idx == p * NR_NB_REG_PER_CCE) {
reg_list_order[reg_list_index] = p2;
reg_list_index++;
break;
}
}
}
/*Mapping the encoded DCI along with the DMRS */
for(int symbol_idx = 0; symbol_idx < pdcch_pdu_rel15->DurationSymbols; symbol_idx++) {
for (int cce_count = 0; cce_count < dci_pdu->AggregationLevel; cce_count+=pdcch_pdu_rel15->DurationSymbols) {
int8_t cce_idx = reg_list_order[cce_count];
for (int reg_in_cce_idx = 0; reg_in_cce_idx < NR_NB_REG_PER_CCE; reg_in_cce_idx++) {
k = cset_start_sc + cce_list[d][cce_idx].reg_list[reg_in_cce_idx].start_sc_idx;
if (k >= frame_parms->ofdm_symbol_size)
k -= frame_parms->ofdm_symbol_size;
l = cset_start_symb + symbol_idx;
// dmrs index depends on reference point for k according to 38.211 7.4.1.3.2
if (pdcch_pdu_rel15->CoreSetType == NFAPI_NR_CSET_CONFIG_PDCCH_CONFIG)
dmrs_idx = (cce_list[d][cce_idx].reg_list[reg_in_cce_idx].reg_idx) * 3;
else dmrs_idx = (cce_list[d][cce_idx].reg_list[reg_in_cce_idx].reg_idx + rb_offset) * 3;
k_prime = 0;
for (int m = 0; m < NR_NB_SC_PER_RB; m++) {
if (m == (k_prime << 2) + 1) { // DMRS if not already mapped
((int16_t *) txdataF)[(l * frame_parms->ofdm_symbol_size + k) << 1] =
(amp * mod_dmrs[l][dmrs_idx << 1]) >> 15;
((int16_t *) txdataF)[((l * frame_parms->ofdm_symbol_size + k) << 1) + 1] =
(amp * mod_dmrs[l][(dmrs_idx << 1) + 1]) >> 15;
#ifdef DEBUG_PDCCH_DMRS
LOG_D(PHY,"PDCCH DMRS %d: l %d position %d => (%d,%d)\n",dmrs_idx,l,k,((int16_t *)txdataF)[(l*frame_parms->ofdm_symbol_size + k)<<1],
((int16_t *)txdataF)[((l*frame_parms->ofdm_symbol_size + k)<<1)+1]);
#endif
dmrs_idx++;
k_prime++;
} else { // DCI payload
((int16_t *) txdataF)[(l * frame_parms->ofdm_symbol_size + k) << 1] = (amp * mod_dci[dci_idx << 1]) >> 15;
((int16_t *) txdataF)[((l * frame_parms->ofdm_symbol_size + k) << 1) + 1] =
(amp * mod_dci[(dci_idx << 1) + 1]) >> 15;
#ifdef DEBUG_DCI
LOG_D(PHY,"PDCCH: l %d position %d => (%d,%d)\n",l,k,((int16_t *)txdataF)[(l*frame_parms->ofdm_symbol_size + k)<<1],
((int16_t *)txdataF)[((l*frame_parms->ofdm_symbol_size + k)<<1)+1]);
#endif
dci_idx++;
}
k++;
if (k >= frame_parms->ofdm_symbol_size)
k -= frame_parms->ofdm_symbol_size;
} // m
} // reg_in_cce_idx
} // cce_count
} // symbol_idx
LOG_D(PHY,
"DCI: payloadSize = %d | payload = %llx\n",
dci_pdu->PayloadSizeBits,
*(unsigned long long *)dci_pdu->Payload);
} // for (int d=0;d<pdcch_pdu_rel15->numDlDci;d++)
}
void nr_generate_dci_top(processingData_L1tx_t *msgTx,
int slot,
int32_t *txdataF,
int16_t amp,
NR_DL_FRAME_PARMS *frame_parms) {
for (int i=0; i<msgTx->num_ul_pdcch; i++)
nr_generate_dci(msgTx->gNB,&msgTx->ul_pdcch_pdu[i].pdcch_pdu.pdcch_pdu_rel15,txdataF,amp,frame_parms,slot);
for (int i=0; i<msgTx->num_dl_pdcch; i++)
nr_generate_dci(msgTx->gNB,&msgTx->pdcch_pdu[i].pdcch_pdu_rel15,txdataF,amp,frame_parms,slot);
}