From 950c1c060e1890948e5ffb22383a358b4f31fcab Mon Sep 17 00:00:00 2001
From: gabrielC <couturier.gabriel@gmail.com>
Date: Thu, 16 Mar 2017 11:45:07 +0100
Subject: [PATCH] Correction of dlsch channel calculation
---
.../PHY/LTE_TRANSPORT/dlsch_demodulation.c | 23 +++++++++----------
1 file changed, 11 insertions(+), 12 deletions(-)
diff --git a/openair1/PHY/LTE_TRANSPORT/dlsch_demodulation.c b/openair1/PHY/LTE_TRANSPORT/dlsch_demodulation.c
index 5fb11d2db6..efac41a6f0 100644
--- a/openair1/PHY/LTE_TRANSPORT/dlsch_demodulation.c
+++ b/openair1/PHY/LTE_TRANSPORT/dlsch_demodulation.c
@@ -3375,9 +3375,16 @@ void dlsch_channel_level(int **dl_ch_estimates_ext,
symbol_mod = (symbol>=(7-frame_parms->Ncp)) ? symbol-(7-frame_parms->Ncp) : symbol;
- float one_over_nb_re = 0;
- one_over_nb_re = 1/(nb_rb *12);
- int16_t one_over_nb_re_q1_15 = (int16_t)(one_over_nb_re * (float)(1<<15) );
+ if (((symbol_mod == 0) || (symbol_mod == (frame_parms->Ncp-1)))&&(frame_parms->mode1_flag==0))
+ nre=8;
+ else if (((symbol_mod == 0) || (symbol_mod == (frame_parms->Ncp-1)))&&(frame_parms->mode1_flag==1))
+ nre=10;
+ else
+ nre=12;
+
+ double one_over_nb_re = 0.0;
+ one_over_nb_re = 1/((double)(nb_rb*nre));
+ int16_t one_over_nb_re_q1_15 = (int16_t)(one_over_nb_re * (double)(1<<15) );
coeff128 = _mm_set_epi16(one_over_nb_re_q1_15,one_over_nb_re_q1_15,one_over_nb_re_q1_15,one_over_nb_re_q1_15,
one_over_nb_re_q1_15,one_over_nb_re_q1_15,one_over_nb_re_q1_15,one_over_nb_re_q1_15);
@@ -3399,7 +3406,7 @@ void dlsch_channel_level(int **dl_ch_estimates_ext,
dl_ch128+=2;
}
else {
- avg128D = _mm_add_epi32(avg128D,_mm_madd_epi16(dl_ch128[2],dl_ch128[2]));
+ avg128D = _mm_add_epi32(avg128D,_mm_madd_epi16(dl_ch128[2],_mm_srai_epi16(_mm_mulhi_epi16(dl_ch128[2], coeff128),15)));
dl_ch128+=3;
}
/*
@@ -3411,18 +3418,10 @@ void dlsch_channel_level(int **dl_ch_estimates_ext,
*/
}
- if (((symbol_mod == 0) || (symbol_mod == (frame_parms->Ncp-1)))&&(frame_parms->mode1_flag==0))
- nre=8;
- else if (((symbol_mod == 0) || (symbol_mod == (frame_parms->Ncp-1)))&&(frame_parms->mode1_flag==1))
- nre=10;
- else
- nre=12;
-
avg[(aatx<<1)+aarx] =(((int32_t*)&avg128D)[0] +
((int32_t*)&avg128D)[1] +
((int32_t*)&avg128D)[2] +
((int32_t*)&avg128D)[3]);
-
// printf("Channel level : %d\n",avg[(aatx<<1)+aarx]);
}
--
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