/*
* 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 1.0 (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.
*-------------------------------------------------------------------------------
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*/
/*! \file PHY/LTE_TRANSPORT/drs_modulation.c
* \brief Top-level routines for generating the Demodulation Reference Signals from 36-211, V8.6 2009-03
* \author R. Knopp, F. Kaltenberger, A. Bhamri
* \date 2011
* \version 0.1
* \company Eurecom
* \email: knopp@eurecom.fr,florian.kaltenberger@eurecom.fr,ankit.bhamri@eurecom.fr
* \note
* \warning
*/
#include "PHY/defs.h"
#include "PHY/extern.h"
#include "PHY/sse_intrin.h"
//#define DEBUG_DRS
int generate_drs_pusch(PHY_VARS_UE *ue,
UE_rxtx_proc_t *proc,
uint8_t eNB_id,
short amp,
unsigned int subframe,
unsigned int first_rb,
unsigned int nb_rb,
uint8_t ant)
{
uint16_t k,l,Msc_RS,Msc_RS_idx,rb,drs_offset;
uint16_t * Msc_idx_ptr;
int subframe_offset,re_offset,symbol_offset;
//uint32_t phase_shift; // phase shift for cyclic delay in DM RS
//uint8_t alpha_ind;
int16_t alpha_re[12] = {32767, 28377, 16383, 0,-16384, -28378,-32768,-28378,-16384, -1, 16383, 28377};
int16_t alpha_im[12] = {0, 16383, 28377, 32767, 28377, 16383, 0,-16384,-28378,-32768,-28378,-16384};
uint8_t cyclic_shift,cyclic_shift0,cyclic_shift1;
LTE_DL_FRAME_PARMS *frame_parms = &ue->frame_parms;
int32_t *txdataF = ue->common_vars.txdataF[ant];
uint32_t u,v,alpha_ind;
uint32_t u0=frame_parms->pusch_config_common.ul_ReferenceSignalsPUSCH.grouphop[subframe<<1];
uint32_t u1=frame_parms->pusch_config_common.ul_ReferenceSignalsPUSCH.grouphop[1+(subframe<<1)];
uint32_t v0=frame_parms->pusch_config_common.ul_ReferenceSignalsPUSCH.seqhop[subframe<<1];
uint32_t v1=frame_parms->pusch_config_common.ul_ReferenceSignalsPUSCH.seqhop[1+(subframe<<1)];
int32_t ref_re,ref_im;
uint8_t harq_pid = subframe2harq_pid(frame_parms,proc->frame_tx,subframe);
cyclic_shift0 = (frame_parms->pusch_config_common.ul_ReferenceSignalsPUSCH.cyclicShift +
ue->ulsch[eNB_id]->harq_processes[harq_pid]->n_DMRS2 +
frame_parms->pusch_config_common.ul_ReferenceSignalsPUSCH.nPRS[subframe<<1]+
((ue->ulsch[0]->cooperation_flag==2)?10:0)+
ant*6) % 12;
// printf("PUSCH.cyclicShift %d, n_DMRS2 %d, nPRS %d\n",frame_parms->pusch_config_common.ul_ReferenceSignalsPUSCH.cyclicShift,ue->ulsch[eNB_id]->n_DMRS2,ue->lte_frame_parms.pusch_config_common.ul_ReferenceSignalsPUSCH.nPRS[subframe<<1]);
cyclic_shift1 = (frame_parms->pusch_config_common.ul_ReferenceSignalsPUSCH.cyclicShift +
ue->ulsch[eNB_id]->harq_processes[harq_pid]->n_DMRS2 +
frame_parms->pusch_config_common.ul_ReferenceSignalsPUSCH.nPRS[(subframe<<1)+1]+
((ue->ulsch[0]->cooperation_flag==2)?10:0)+
ant*6) % 12;
// cyclic_shift0 = 0;
// cyclic_shift1 = 0;
Msc_RS = 12*nb_rb;
#ifdef USER_MODE
Msc_idx_ptr = (uint16_t*) bsearch(&Msc_RS, dftsizes, 33, sizeof(uint16_t), compareints);
if (Msc_idx_ptr)
Msc_RS_idx = Msc_idx_ptr - dftsizes;
else {
LOG_I(PHY,"generate_drs_pusch: index for Msc_RS=%d not found\n",Msc_RS);
return(-1);
}
#else
uint8_t b;
for (b=0; b<33; b++)
if (Msc_RS==dftsizes[b])
Msc_RS_idx = b;
#endif
#ifdef DEBUG_DRS
printf("[PHY] drs_modulation: Msc_RS = %d, Msc_RS_idx = %d,cyclic_shift %d, u0 %d, v0 %d, u1 %d, v1 %d,cshift0 %d,cshift1 %d\n",Msc_RS, Msc_RS_idx,cyclic_shift,u0,v0,u1,v1,cyclic_shift0,cyclic_shift1);
#endif
for (l = (3 - frame_parms->Ncp),u=u0,v=v0,cyclic_shift=cyclic_shift0;
l<frame_parms->symbols_per_tti;
l += (7 - frame_parms->Ncp),u=u1,v=v1,cyclic_shift=cyclic_shift1) {
drs_offset = 0; // printf("drs_modulation: Msc_RS = %d, Msc_RS_idx = %d\n",Msc_RS, Msc_RS_idx);
re_offset = frame_parms->first_carrier_offset;
subframe_offset = subframe*frame_parms->symbols_per_tti*frame_parms->ofdm_symbol_size;
symbol_offset = subframe_offset + frame_parms->ofdm_symbol_size*l;
#ifdef DEBUG_DRS
printf("generate_drs_pusch: symbol_offset %d, subframe offset %d, cyclic shift %d\n",symbol_offset,subframe_offset,cyclic_shift);
#endif
alpha_ind = 0;
for (rb=0; rb<frame_parms->N_RB_UL; rb++) {
if ((rb >= first_rb) && (rb<(first_rb+nb_rb))) {
#ifdef DEBUG_DRS
printf("generate_drs_pusch: doing RB %d, re_offset=%d, drs_offset=%d,cyclic shift %d\n",rb,re_offset,drs_offset,cyclic_shift);
#endif
for (k=0; k<12; k++) {
ref_re = (int32_t) ul_ref_sigs[u][v][Msc_RS_idx][drs_offset<<1];
ref_im = (int32_t) ul_ref_sigs[u][v][Msc_RS_idx][(drs_offset<<1)+1];
((int16_t*) txdataF)[2*(symbol_offset + re_offset)] = (int16_t) (((ref_re*alpha_re[alpha_ind]) -
(ref_im*alpha_im[alpha_ind]))>>15);
((int16_t*) txdataF)[2*(symbol_offset + re_offset)+1] = (int16_t) (((ref_re*alpha_im[alpha_ind]) +
(ref_im*alpha_re[alpha_ind]))>>15);
((short*) txdataF)[2*(symbol_offset + re_offset)] = (short) ((((short*) txdataF)[2*(symbol_offset + re_offset)]*(int32_t)amp)>>15);
((short*) txdataF)[2*(symbol_offset + re_offset)+1] = (short) ((((short*) txdataF)[2*(symbol_offset + re_offset)+1]*(int32_t)amp)>>15);
alpha_ind = (alpha_ind + cyclic_shift);
if (alpha_ind > 11)
alpha_ind-=12;
#ifdef DEBUG_DRS
printf("symbol_offset %d, alpha_ind %d , re_offset %d : (%d,%d)\n",
symbol_offset,
alpha_ind,
re_offset,
((short*) txdataF)[2*(symbol_offset + re_offset)],
((short*) txdataF)[2*(symbol_offset + re_offset)+1]);
#endif // DEBUG_DRS
re_offset++;
drs_offset++;
if (re_offset >= frame_parms->ofdm_symbol_size)
re_offset = 0;
}
} else {
re_offset+=12; // go to next RB
// check if we crossed the symbol boundary and skip DC
if (re_offset >= frame_parms->ofdm_symbol_size) {
if (frame_parms->N_RB_DL&1) // odd number of RBs
re_offset=6;
else // even number of RBs (doesn't straddle DC)
re_offset=0;
}
}
}
}
return(0);
}