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fembms: FeMBMS top-level routines for generating and decoding the PBCH/BCH physical/transport channel

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Signed-off-by: Javier Morgade <javier.morgade@ieee.org>
This commit is contained in:
Javier Morgade
2020-07-20 10:54:01 +02:00
parent 3d11b3d65d
commit 3fca8304a4
1 changed files with 281 additions and 2 deletions
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openair1/PHY/LTE_TRANSPORT/pbch.c
+281 -2
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@@ -20,12 +20,12 @@
*/
/*! \file PHY/LTE_TRANSPORT/pbch.c
* \brief Top-level routines for generating and decoding the PBCH/BCH physical/transport channel V8.6 2009-03
* \brief Top-level routines for generating and decoding the PBCH/BCH physical/transport channel V8.6 2009-03, V14.1 (FeMBMS)
* \author R. Knopp, F. Kaltenberger
* \date 2011
* \version 0.1
* \company Eurecom
* \email: knopp@eurecom.fr,florian.kaltenberger.fr
* \email: knopp@eurecom.fr,florian.kaltenberger.fr, javier.morgade@ieee.org
* \note
* \warning
*/
@@ -139,6 +139,285 @@ int allocate_pbch_REs_in_RB(LTE_DL_FRAME_PARMS *frame_parms,
return(0);
}
void pbch_scrambling_fembms(LTE_DL_FRAME_PARMS *frame_parms,
uint8_t *pbch_e,
uint32_t length)
{
int i;
uint8_t reset;
uint32_t x1, x2, s=0;
reset = 1;
// x1 is set in lte_gold_generic
x2 = frame_parms->Nid_cell + (1<<9); //this is c_init for FeMBMS in 36.211 Sec 6.6.1
// msg("pbch_scrambling: Nid_cell = %d\n",x2);
for (i=0; i<length; i++) {
if ((i&0x1f)==0) {
s = lte_gold_generic(&x1, &x2, reset);
// printf("lte_gold[%d]=%x\n",i,s);
reset = 0;
}
pbch_e[i] = (pbch_e[i]&1) ^ ((s>>(i&0x1f))&1);
}
}
int generate_pbch_fembms(LTE_eNB_PBCH *eNB_pbch,
int32_t **txdataF,
int amp,
LTE_DL_FRAME_PARMS *frame_parms,
uint8_t *pbch_pdu,
uint8_t frame_mod4)
{
int i, l;
uint32_t pbch_D,pbch_E;//,pbch_coded_bytes;
uint8_t pbch_a[PBCH_A>>3];
uint8_t RCC;
uint32_t nsymb = (frame_parms->Ncp==NORMAL) ? 14:12;
uint32_t pilots;
#ifdef INTERFERENCE_MITIGATION
uint32_t pilots_2;
#endif
uint32_t second_pilot = (frame_parms->Ncp==NORMAL) ? 4 : 3;
uint32_t jj=0;
uint32_t re_allocated=0;
uint32_t rb, re_offset, symbol_offset;
uint16_t amask=0;
pbch_D = 16+PBCH_A;
pbch_E = (frame_parms->Ncp==NORMAL) ? 1920 : 1728; //RE/RB * #RB * bits/RB (QPSK)
// pbch_E_bytes = pbch_coded_bits>>3;
LOG_D(PHY,"%s(eNB_pbch:%p txdataF:%p amp:%d frame_parms:%p pbch_pdu:%p frame_mod4:%d)\n", __FUNCTION__, eNB_pbch, txdataF, amp, frame_parms, pbch_pdu, frame_mod4==0);
if (frame_mod4==0) {
bzero(pbch_a,PBCH_A>>3);
bzero(eNB_pbch->pbch_e,pbch_E);
memset(eNB_pbch->pbch_d,LTE_NULL,96);
// Encode data
// CRC attachment
// crc = (uint16_t) (crc16(pbch_pdu, pbch_crc_bits-16) >> 16);
/*
// scramble crc with PBCH CRC mask (Table 5.3.1.1-1 of 3GPP 36.212-860)
switch (frame_parms->nb_antenna_ports_eNB) {
case 1:
crc = crc ^ (uint16_t) 0;
break;
case 2:
crc = crc ^ (uint16_t) 0xFFFF;
break;
case 4:
crc = crc ^ (uint16_t) 0xAAAA;
break;
default:
msg("[PBCH] Unknown number of TX antennas!\n");
break;
}
*/
// Fix byte endian of PBCH (bit 23 goes in first)
for (i=0; i<(PBCH_A>>3); i++)
pbch_a[(PBCH_A>>3)-i-1] = pbch_pdu[i];
// pbch_data[i] = ((char*) &crc)[0];
// pbch_data[i+1] = ((char*) &crc)[1];
//#ifdef DEBUG_PBCH
for (i=0; i<(PBCH_A>>3); i++)
LOG_D(PHY,"[PBCH] pbch_data[%d] = %x\n",i,pbch_a[i]);
//#endif
if (frame_parms->nb_antenna_ports_eNB == 1)
amask = 0x0000;
else {
switch (frame_parms->nb_antenna_ports_eNB) {
case 1:
amask = 0x0000;
break;
case 2:
amask = 0xffff;
break;
case 4:
amask = 0x5555;
}
}
ccodelte_encode(PBCH_A,2,pbch_a,eNB_pbch->pbch_d+96,amask);
#ifdef DEBUG_PBCH_ENCODING
for (i=0; i<16+PBCH_A; i++)
LOG_D(PHY,"%d : (%d,%d,%d)\n",i,*(eNB_pbch->pbch_d+96+(3*i)),*(eNB_pbch->pbch_d+97+(3*i)),*(eNB_pbch->pbch_d+98+(3*i)));
#endif //DEBUG_PBCH_ENCODING
// Bit collection
/*
j2=0;
for (j=0;j<pbch_crc_bits*3+12;j++) {
if ((pbch_coded_data[j]&0x80) > 0) { // bit is to be transmitted
pbch_coded_data2[j2++] = pbch_coded_data[j]&1;
//Bit is repeated
if ((pbch_coded_data[j]&0x40)>0)
pbch_coded_data2[j2++] = pbch_coded_data[j]&1;
}
}
#ifdef DEBUG_PBCH
msg("[PBCH] rate matched bits=%d, pbch_coded_bits=%d, pbch_crc_bits=%d\n",j2,pbch_coded_bits,pbch_crc_bits);
#endif
#ifdef DEBUG_PBCH
LOG_M"pbch_encoded_output2.m","pbch_encoded_out2",
pbch_coded_data2,
pbch_coded_bits,
1,
4);
#endif //DEBUG_PBCH
*/
#ifdef DEBUG_PBCH_ENCODING
LOG_D(PHY,"Doing PBCH interleaving for %d coded bits, e %p\n",pbch_D,eNB_pbch->pbch_e);
#endif
RCC = sub_block_interleaving_cc(pbch_D,eNB_pbch->pbch_d+96,eNB_pbch->pbch_w);
lte_rate_matching_cc(RCC,pbch_E,eNB_pbch->pbch_w,eNB_pbch->pbch_e);
#ifdef DEBUG_PBCH_ENCODING
LOG_D(PHY,"PBCH_e:\n");
for (i=0; i<pbch_E; i++)
LOG_D(PHY,"%d %d\n",i,*(eNB_pbch->pbch_e+i));
LOG_D(PHY,"\n");
#endif
#ifdef DEBUG_PBCH
if (frame_mod4==0) {
LOG_M("pbch_e.m","pbch_e",
eNB_pbch->pbch_e,
pbch_E,
1,
4);
for (i=0; i<16; i++)
printf("e[%d] %d\n",i,eNB_pbch->pbch_e[i]);
}
#endif //DEBUG_PBCH
// scrambling
pbch_scrambling_fembms(frame_parms,
eNB_pbch->pbch_e,
pbch_E);
#ifdef DEBUG_PBCH
if (frame_mod4==0) {
LOG_M("pbch_e_s.m","pbch_e_s",
eNB_pbch->pbch_e,
pbch_E,
1,
4);
for (i=0; i<16; i++)
printf("e_s[%d] %d\n",i,eNB_pbch->pbch_e[i]);
}
#endif //DEBUG_PBCH
} // frame_mod4==0
// modulation and mapping (slot 1, symbols 0..3)
for (l=(nsymb>>1); l<(nsymb>>1)+4; l++) {
pilots=0;
#ifdef INTERFERENCE_MITIGATION
pilots_2 = 0;
#endif
if ((l==0) || (l==(nsymb>>1))) {
pilots=1;
#ifdef INTERFERENCE_MITIGATION
pilots_2=1;
#endif
}
if ((l==1) || (l==(nsymb>>1)+1)) {
pilots=1;
}
if ((l==second_pilot)||(l==(second_pilot+(nsymb>>1)))) {
pilots=1;
}
#ifdef DEBUG_PBCH
LOG_D(PHY,"[PBCH] l=%d, pilots=%d\n",l,pilots);
#endif
re_offset = frame_parms->ofdm_symbol_size-3*12;
symbol_offset = frame_parms->ofdm_symbol_size*l;
for (rb=0; rb<6; rb++) {
#ifdef DEBUG_PBCH
LOG_D(PHY,"RB %d, jj %d, re_offset %d, symbol_offset %d, pilots %d, nushift %d\n",rb,jj,re_offset, symbol_offset, pilots,frame_parms->nushift);
#endif
allocate_pbch_REs_in_RB(frame_parms,
txdataF,
&jj,
re_offset,
symbol_offset,
&eNB_pbch->pbch_e[frame_mod4*(pbch_E>>2)],
pilots,
#ifdef INTERFERENCE_MITIGATION
(pilots_2==1)?(amp/3):amp,
#else
amp,
#endif
&re_allocated);
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)
re_offset=1;
}
// }
}
#ifdef DEBUG_PBCH
printf("[PBCH] txdataF=\n");
for (i=0; i<frame_parms->ofdm_symbol_size; i++) {
printf("%d=>(%d,%d)",i,((short*)&txdataF[0][frame_parms->ofdm_symbol_size*(nsymb>>1)+i])[0],
((short*)&txdataF[0][frame_parms->ofdm_symbol_size*(nsymb>>1)+i])[1]);
if (frame_parms->nb_antenna_ports_eNB!=1) {
printf("(%d,%d)\n",((short*)&txdataF[1][frame_parms->ofdm_symbol_size*(nsymb>>1)+i])[0],
((short*)&txdataF[1][frame_parms->ofdm_symbol_size*(nsymb>>1)+i])[1]);
} else {
printf("\n");
}
}
#endif
return(0);
}
void pbch_scrambling(LTE_DL_FRAME_PARMS *frame_parms,
uint8_t *pbch_e,
uint32_t length)