From a4b86e5a0a236567e0de3b794a587a1e738176a4 Mon Sep 17 00:00:00 2001 From: dvdgrgrtt Date: Thu, 4 Nov 2021 15:29:44 +0100 Subject: [PATCH] Modify PUSCH power normalization The PUSCH signal was normalized to fix the maximum amplitude instead of the transmitted power. --- lib/src/phy/ue/ue_ul_nr.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/lib/src/phy/ue/ue_ul_nr.c b/lib/src/phy/ue/ue_ul_nr.c index a93a2e5a2..16f8a15d2 100644 --- a/lib/src/phy/ue/ue_ul_nr.c +++ b/lib/src/phy/ue/ue_ul_nr.c @@ -133,12 +133,9 @@ int srsran_ue_ul_nr_encode_pusch(srsran_ue_ul_nr_t* q, // Generate signal srsran_ofdm_tx_sf(&q->ifft); - // Normalise to peak - uint32_t max_idx = srsran_vec_max_abs_ci(q->ifft.cfg.out_buffer, q->ifft.sf_sz); - float max_peak = cabsf(q->ifft.cfg.out_buffer[max_idx]); - if (isnormal(max_peak)) { - srsran_vec_sc_prod_cfc(q->ifft.cfg.out_buffer, 0.99f / max_peak, q->ifft.cfg.out_buffer, q->ifft.sf_sz); - } + // Scale iFFT output to compensate for iFFT amplification (due to FFTW implementation). + float scaling = 1 / sqrtf(q->ifft.cfg.symbol_sz); + srsran_vec_sc_prod_cfc(q->ifft.cfg.out_buffer, scaling, q->ifft.cfg.out_buffer, q->ifft.sf_sz); // Apply frequency offset if (isnormal(q->freq_offset_hz)) {