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Simplifying bit shift in the nr_scale_channel() function

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rmagueta
2025-09-25 14:50:37 +02:00
committed by francescomani
parent c88b7bac72
commit 2bf7c2500e
1 changed files with 2 additions and 18 deletions
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openair1/PHY/nr_phy_common/src/nr_phy_common.c
+2 -18
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@@ -427,34 +427,18 @@ void nr_channel_level(const int symbol,
void nr_scale_channel(int size, int ch_estimates_ext[][size], int symb, uint32_t len, int nrOfLayers, int nb_rx, int shift_ch_ext)
{
// Determine scaling amplitude based the symbol
int b = 3;
short ch_amp = 1024 * 8;
if (shift_ch_ext > 3) {
b = 0;
ch_amp >>= (shift_ch_ext - 3);
if (ch_amp == 0) {
ch_amp = 1;
}
} else {
b -= shift_ch_ext;
}
simde__m128i ch_amp128 = simde_mm_set1_epi16(ch_amp); // Q3.13
LOG_D(PHY, "Scaling channel est in OFDM symbol %d by %d\n", symb, ch_amp);
for (int l = 0; l < nrOfLayers; l++) {
for (int aarx = 0; aarx < nb_rx; aarx++) {
simde__m128i *ul_ch128 = (simde__m128i *)&ch_estimates_ext[l * nb_rx + aarx][symb * len];
int loop_end = len >> 2;
for (int i = 0; i < loop_end; i++) {
ul_ch128[i] = simde_mm_mulhi_epi16(ul_ch128[i], ch_amp128);
ul_ch128[i] = simde_mm_slli_epi16(ul_ch128[i], b);
ul_ch128[i] = simde_mm_srai_epi16(ul_ch128[i], shift_ch_ext);
}
// loop for the remaining elements
int start_index = loop_end * 4;
for (int j = start_index; j < len; j++) {
c16_t *temp = ((c16_t *)ul_ch128) + j;
*temp = c16Shift(*temp, b);
*temp = c16Shift(*temp, shift_ch_ext);
}
}
}