diff --git a/openair1/PHY/NR_ESTIMATION/nr_ul_channel_estimation.c b/openair1/PHY/NR_ESTIMATION/nr_ul_channel_estimation.c
index a1684309374aafe5d158da4abb097c4b6229ab9f..109bfbb812913b0d7bfaabb98e7048d86c2233aa 100644
--- a/openair1/PHY/NR_ESTIMATION/nr_ul_channel_estimation.c
+++ b/openair1/PHY/NR_ESTIMATION/nr_ul_channel_estimation.c
@@ -1107,7 +1107,6 @@ int nr_srs_channel_estimation(PHY_VARS_gNB *gNB,
uint16_t noise_real[frame_parms->nb_antennas_rx*nr_srs_info->sc_list_length];
uint16_t noise_imag[frame_parms->nb_antennas_rx*nr_srs_info->sc_list_length];
- int16_t prev_ls_estimated[2];
int16_t ls_estimated[2];
for (int ant = 0; ant < frame_parms->nb_antennas_rx; ant++) {
@@ -1131,27 +1130,25 @@ int nr_srs_channel_estimation(PHY_VARS_gNB *gNB,
ls_estimated[1] = (int16_t)(((int32_t)generated_real*received_imag - (int32_t)generated_imag*received_real)>>nr_srs_info->srs_generated_signal_bits);
srs_ls_estimated_channel[ant][nr_srs_info->sc_list[sc_idx]] = ls_estimated[0] + (((int32_t)ls_estimated[1] << 16) & 0xFFFF0000);
- if(sc_idx>0 && nr_srs_info->sc_list[sc_idx] > nr_srs_info->sc_list[sc_idx - 1]) {
- ls_estimated[0] = (ls_estimated[0] + prev_ls_estimated[0])>>1;
- ls_estimated[1] = (ls_estimated[1] + prev_ls_estimated[1])>>1;
- }
- prev_ls_estimated[0] = (int16_t)(((int32_t)generated_real*received_real + (int32_t)generated_imag*received_imag)>>nr_srs_info->srs_generated_signal_bits);
- prev_ls_estimated[1] = (int16_t)(((int32_t)generated_real*received_imag - (int32_t)generated_imag*received_real)>>nr_srs_info->srs_generated_signal_bits);
-
// Channel interpolation
if(srs_pdu->comb_size == 0) {
- if(sc_idx == 0) {
- multadd_real_vector_complex_scalar(filt8_l0, ls_estimated, srs_estimated_channel16, 8);
- } else if(nr_srs_info->sc_list[sc_idx] < nr_srs_info->sc_list[sc_idx - 1]) {
+ if(sc_idx == 0) { // First subcarrier case
+ // filt8_start is {12288,8192,4096,0,0,0,0,0}
+ multadd_real_vector_complex_scalar(filt8_start, ls_estimated, srs_estimated_channel16, 8);
+ } else if(nr_srs_info->sc_list[sc_idx] < nr_srs_info->sc_list[sc_idx - 1]) { // Start of OFDM symbol case
+ // filt8_start is {12288,8192,4096,0,0,0,0,0}
srs_estimated_channel16 = (int16_t *)&srs_estimated_channel_freq[ant][nr_srs_info->sc_list[sc_idx + 2]] - 8;
- multadd_real_vector_complex_scalar(filt8_l0, ls_estimated, srs_estimated_channel16, 8);
- } else if((sc_idx < (nr_srs_info->sc_list_length - 1) && nr_srs_info->sc_list[sc_idx + 1] < nr_srs_info->sc_list[sc_idx]) || (sc_idx == (nr_srs_info->sc_list_length - 1))) {
- multadd_real_vector_complex_scalar(filt8_m0, ls_estimated, srs_estimated_channel16, 8);
- srs_estimated_channel_freq[ant][nr_srs_info->sc_list[sc_idx] + 1] = srs_estimated_channel_freq[ant][nr_srs_info->sc_list[sc_idx]];
- } else if(sc_idx%2 == 1) {
- multadd_real_vector_complex_scalar(filt8_m0, ls_estimated, srs_estimated_channel16, 8);
- } else if(sc_idx%2 == 0) {
- multadd_real_vector_complex_scalar(filt8_mm0, ls_estimated, srs_estimated_channel16, 8);
+ multadd_real_vector_complex_scalar(filt8_start, ls_estimated, srs_estimated_channel16, 8);
+ } else if((sc_idx < (nr_srs_info->sc_list_length - 1) && nr_srs_info->sc_list[sc_idx + 1] < nr_srs_info->sc_list[sc_idx])
+ || (sc_idx == (nr_srs_info->sc_list_length - 1))) { // End of OFDM symbol or last subcarrier cases
+ // filt8_end is {4096,8192,12288,16384,0,0,0,0}
+ multadd_real_vector_complex_scalar(filt8_end, ls_estimated, srs_estimated_channel16, 8);
+ } else if(sc_idx%2 == 1) { // 1st middle case
+ // filt8_middle2 is {4096,8192,8192,8192,4096,0,0,0}
+ multadd_real_vector_complex_scalar(filt8_middle2, ls_estimated, srs_estimated_channel16, 8);
+ } else if(sc_idx%2 == 0) { // 2nd middle case
+ // filt8_middle4 is {0,0,4096,8192,8192,8192,4096,0}
+ multadd_real_vector_complex_scalar(filt8_middle4, ls_estimated, srs_estimated_channel16, 8);
srs_estimated_channel16 = (int16_t *)&srs_estimated_channel_freq[ant][nr_srs_info->sc_list[sc_idx]];
}
} else {
@@ -1173,9 +1170,6 @@ int nr_srs_channel_estimation(PHY_VARS_gNB *gNB,
}
}
- noise_real[ant*nr_srs_info->sc_list_length + sc_idx] = abs(prev_ls_estimated[0] - (int16_t)(srs_estimated_channel_freq[ant][nr_srs_info->sc_list[sc_idx]] & 0xFFFF));
- noise_imag[ant*nr_srs_info->sc_list_length + sc_idx] = abs(prev_ls_estimated[1] - (int16_t)((srs_estimated_channel_freq[ant][nr_srs_info->sc_list[sc_idx]] >> 16) & 0xFFFF));
-
#ifdef SRS_DEBUG
uint64_t subcarrier_offset = frame_parms->first_carrier_offset + srs_pdu->bwp_start*12;
int subcarrier_log = nr_srs_info->sc_list[sc_idx]-subcarrier_offset;
@@ -1193,10 +1187,16 @@ int nr_srs_channel_estimation(PHY_VARS_gNB *gNB,
subcarrier_log,
generated_real, generated_imag,
received_real, received_imag,
- prev_ls_estimated[0], prev_ls_estimated[1]);
+ ls_estimated[0], ls_estimated[1]);
#endif
}
+ // Compute noise
+ for(int sc_idx = 0; sc_idx < nr_srs_info->sc_list_length; sc_idx++) {
+ noise_real[ant*nr_srs_info->sc_list_length + sc_idx] = abs((int16_t)((srs_ls_estimated_channel[ant][nr_srs_info->sc_list[sc_idx]]-srs_estimated_channel_freq[ant][nr_srs_info->sc_list[sc_idx]]) & 0xFFFF));
+ noise_imag[ant*nr_srs_info->sc_list_length + sc_idx] = abs((int16_t)(((srs_ls_estimated_channel[ant][nr_srs_info->sc_list[sc_idx]]-srs_estimated_channel_freq[ant][nr_srs_info->sc_list[sc_idx]]) >> 16) & 0xFFFF));
+ }
+
// Convert to time domain
freq2time(gNB->frame_parms.ofdm_symbol_size,
(int16_t*) srs_estimated_channel_freq[ant],
diff --git a/openair1/PHY/NR_UE_ESTIMATION/filt16a_32.c b/openair1/PHY/NR_UE_ESTIMATION/filt16a_32.c
index 65ae28825201321ced5139d9bc785e2284f1f076..5152f6eb65fc5b077a19f159ee0380882fa40906 100644
--- a/openair1/PHY/NR_UE_ESTIMATION/filt16a_32.c
+++ b/openair1/PHY/NR_UE_ESTIMATION/filt16a_32.c
@@ -260,3 +260,16 @@ short filt8_avlip5[8] = {
short filt8_avlip6[8] = {
13653,15019,16384,16384,16384,16384,16384,16384};
+
+// Comb size 2
+short filt8_start[8] = {
+ 12288,8192,4096,0,0,0,0,0};
+
+short filt8_middle2[8] = {
+ 4096,8192,8192,8192,4096,0,0,0};
+
+short filt8_middle4[8] = {
+ 0,0,4096,8192,8192,8192,4096,0};
+
+short filt8_end[8] = {
+ 4096,8192,12288,16384,0,0,0,0};
\ No newline at end of file
diff --git a/openair1/PHY/NR_UE_ESTIMATION/filt16a_32.h b/openair1/PHY/NR_UE_ESTIMATION/filt16a_32.h
index e28736b51daf45dc7c133f1f210d46c89abfd571..6ddc03ecd9d331f6da7078ef4222f07aae20c0f5 100644
--- a/openair1/PHY/NR_UE_ESTIMATION/filt16a_32.h
+++ b/openair1/PHY/NR_UE_ESTIMATION/filt16a_32.h
@@ -182,4 +182,10 @@ extern short filt8_avlip4[8];
extern short filt8_avlip5[8];
extern short filt8_avlip6[8];
+
+/*Comb size 2*/
+extern short filt8_start[8];
+extern short filt8_middle2[8];
+extern short filt8_middle4[8];
+extern short filt8_end[8];
#endif