/* * 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. *------------------------------------------------------------------------------- * For more information about the OpenAirInterface (OAI) Software Alliance: * contact@openairinterface.org */ /*! \file PHY/LTE_TRANSPORT/dlsch_scrambling.c * \brief Routines for the scrambling procedure of the PDSCH physical channel from 36-211, V8.6 2009-03 * \author R. Knopp * \date 2011 * \version 0.1 * \company Eurecom * \email: knopp@eurecom.fr,florian.kaltenberger@eurecom.fr * \note * \warning */ //#define DEBUG_SCRAMBLING 1 #include "PHY/defs.h" #include "PHY/CODING/extern.h" #include "PHY/CODING/lte_interleaver_inline.h" #include "defs.h" #include "extern.h" #include "PHY/extern.h" #include "UTIL/LOG/vcd_signal_dumper.h" static inline unsigned int lte_gold_scram(unsigned int *x1, unsigned int *x2, unsigned char reset) __attribute__((always_inline)); static inline unsigned int lte_gold_scram(unsigned int *x1, unsigned int *x2, unsigned char reset) { int n; if (reset) { *x1 = 1+ (1<<31); *x2=*x2 ^ ((*x2 ^ (*x2>>1) ^ (*x2>>2) ^ (*x2>>3))<<31); // skip first 50 double words (1600 bits) // printf("n=0 : x1 %x, x2 %x\n",x1,x2); for (n=1; n<50; n++) { *x1 = (*x1>>1) ^ (*x1>>4); *x1 = *x1 ^ (*x1<<31) ^ (*x1<<28); *x2 = (*x2>>1) ^ (*x2>>2) ^ (*x2>>3) ^ (*x2>>4); *x2 = *x2 ^ (*x2<<31) ^ (*x2<<30) ^ (*x2<<29) ^ (*x2<<28); } } *x1 = (*x1>>1) ^ (*x1>>4); *x1 = *x1 ^ (*x1<<31) ^ (*x1<<28); *x2 = (*x2>>1) ^ (*x2>>2) ^ (*x2>>3) ^ (*x2>>4); *x2 = *x2 ^ (*x2<<31) ^ (*x2<<30) ^ (*x2<<29) ^ (*x2<<28); return(*x1^*x2); // printf("n=%d : c %x\n",n,x1^x2); } void dlsch_scrambling(LTE_DL_FRAME_PARMS *frame_parms, int mbsfn_flag, LTE_eNB_DLSCH_t *dlsch, int G, uint8_t q, uint8_t Ns) { int i; // uint8_t reset; uint32_t x1, x2, s=0; uint8_t *dlsch_e=dlsch->harq_processes[dlsch->current_harq_pid]->e; uint8_t *e=dlsch_e; VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME(VCD_SIGNAL_DUMPER_FUNCTIONS_ENB_DLSCH_SCRAMBLING, VCD_FUNCTION_IN); // reset = 1; // x1 is set in lte_gold_generic if (mbsfn_flag == 0) { x2 = (dlsch->rnti<<14) + (q<<13) + ((Ns>>1)<<9) + frame_parms->Nid_cell; //this is c_init in 36.211 Sec 6.3.1 } else { x2 = ((Ns>>1)<<9) + frame_parms->Nid_cell_mbsfn; //this is c_init in 36.211 Sec 6.3.1 } #ifdef DEBUG_SCRAMBLING printf("scrambling: rnti %x, q %d, Ns %d, Nid_cell %d, length %d\n",dlsch->rnti,q,Ns,frame_parms->Nid_cell, G); #endif s = lte_gold_scram(&x1, &x2, 1); for (i=0; i<(1+(G>>5)); i++) { #ifdef DEBUG_SCRAMBLING printf("scrambling %d : %d => ",k,e[k]); #endif e[0] = (e[0]) ^ (s&1); e[1] = (e[1]) ^ ((s>>1)&1); e[2] = (e[2]) ^ ((s>>2)&1); e[3] = (e[3]) ^ ((s>>3)&1); e[4] = (e[4]) ^ ((s>>4)&1); e[5] = (e[5]) ^ ((s>>5)&1); e[6] = (e[6]) ^ ((s>>6)&1); e[7] = (e[7]) ^ ((s>>7)&1); e[8] = (e[8]) ^ ((s>>8)&1); e[9] = (e[9]) ^ ((s>>9)&1); e[10] = (e[10]) ^ ((s>>10)&1); e[11] = (e[11]) ^ ((s>>11)&1); e[12] = (e[12]) ^ ((s>>12)&1); e[13] = (e[13]) ^ ((s>>13)&1); e[14] = (e[14]) ^ ((s>>14)&1); e[15] = (e[15]) ^ ((s>>15)&1); e[16] = (e[16]) ^ ((s>>16)&1); e[17] = (e[17]) ^ ((s>>17)&1); e[18] = (e[18]) ^ ((s>>18)&1); e[19] = (e[19]) ^ ((s>>19)&1); e[20] = (e[20]) ^ ((s>>20)&1); e[21] = (e[21]) ^ ((s>>21)&1); e[22] = (e[22]) ^ ((s>>22)&1); e[23] = (e[23]) ^ ((s>>23)&1); e[24] = (e[24]) ^ ((s>>24)&1); e[25] = (e[25]) ^ ((s>>25)&1); e[26] = (e[26]) ^ ((s>>26)&1); e[27] = (e[27]) ^ ((s>>27)&1); e[28] = (e[28]) ^ ((s>>28)&1); e[29] = (e[29]) ^ ((s>>29)&1); e[30] = (e[30]) ^ ((s>>30)&1); e[31] = (e[31]) ^ ((s>>31)&1); // This is not faster for some unknown reason // ((__m128i *)e)[0] = _mm_xor_si128(((__m128i *)e)[0],((__m128i *)scrambling_lut)[s&65535]); // ((__m128i *)e)[1] = _mm_xor_si128(((__m128i *)e)[1],((__m128i *)scrambling_lut)[s>>16]); #ifdef DEBUG_SCRAMBLING printf("%d\n",e[k]); #endif s = lte_gold_scram(&x1, &x2, 0); e += 32; } VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME(VCD_SIGNAL_DUMPER_FUNCTIONS_ENB_DLSCH_SCRAMBLING, VCD_FUNCTION_OUT); } void dlsch_unscrambling(LTE_DL_FRAME_PARMS *frame_parms, int mbsfn_flag, LTE_UE_DLSCH_t *dlsch, int G, int16_t* llr, uint8_t q, uint8_t Ns) { int i,j,k=0; // uint8_t reset; uint32_t x1, x2, s=0; // reset = 1; // x1 is set in first call to lte_gold_generic if (mbsfn_flag == 0) x2 = (dlsch->rnti<<14) + (q<<13) + ((Ns>>1)<<9) + frame_parms->Nid_cell; //this is c_init in 36.211 Sec 6.3.1 else x2 = ((Ns>>1)<<9) + frame_parms->Nid_cell_mbsfn; //this is c_init in 36.211 Sec 6.3.1 #ifdef DEBUG_SCRAMBLING printf("unscrambling: rnti %x, q %d, Ns %d, Nid_cell %d length %d\n",dlsch->rnti,q,Ns,frame_parms->Nid_cell,G); #endif s = lte_gold_scram(&x1, &x2, 1); for (i=0; i<(1+(G>>5)); i++) { for (j=0; j<32; j++,k++) { #ifdef DEBUG_SCRAMBLING printf("unscrambling %d : %d => ",k,llr[k]); #endif llr[k] = ((2*((s>>j)&1))-1)*llr[k]; #ifdef DEBUG_SCRAMBLING printf("%d\n",llr[k]); #endif } s = lte_gold_scram(&x1, &x2, 0); } } void init_unscrambling_lut() { uint32_t s; int i=0,j; for (s=0;s<=65535;s++) { for (j=0;j<16;j++) { unscrambling_lut[i++] = (int16_t)((((s>>j)&1)<<1)-1); } } } void init_scrambling_lut() { uint32_t s; int i=0,j; for (s=0;s<=65535;s++) { for (j=0;j<16;j++) { scrambling_lut[i++] = (uint8_t)((s>>j)&1); } } }