Nika Ghaderi
c54f0f7955
This commit refactors the CPU-based channel model for improved reusability and extends it with single-precision floating-point support. This serves as a performance and correctness baseline for the new CUDA implementation. Key changes include: - The original double-based multipath_channel function is refactored to remove hardcoded antenna dimensions from its signature. It now accepts dynamically sized arrays, making it more flexible for use in simulators like dlsim and ulsim. - A new multipath_channel_float function is introduced to operate on float data types, matching the GPU's native format. - A corresponding add_noise_float function is also added to complete the floating-point CPU pipeline. - The new float-based functions are designed to work with an interleaved IQ sample format ([I, Q, I, Q]), which is more suitable for vectorized (SSE) and GPU processing.
89 lines
3.1 KiB
C
89 lines
3.1 KiB
C
/*
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* Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership.
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* The OpenAirInterface Software Alliance licenses this file to You under
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* the OAI Public License, Version 1.1 (the "License"); you may not use this file
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* except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.openairinterface.org/?page_id=698
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*-------------------------------------------------------------------------------
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* For more information about the OpenAirInterface (OAI) Software Alliance:
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* contact@openairinterface.org
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*/
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#include <math.h>
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#include "sim.h"
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/* linear phase noise model */
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void phase_noise(double ts, int16_t *InRe, int16_t *InIm)
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{
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static uint64_t i = 0;
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double fd = 300; // 0.01*30000
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double phase = (double)(i * fd * ts);
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c16_t rot = get_sin_cos(phase);
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c16_t val = {.r = *InRe, .i = *InIm};
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val = c16mulShift(val, rot, 14);
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*InRe = val.r;
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*InIm = val.i;
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i++;
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}
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void add_noise(c16_t **rxdata,
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const double **r_re,
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const double **r_im,
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const double sigma,
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const int length,
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const int slot_offset,
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const double ts,
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const int delay,
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const uint16_t pdu_bit_map,
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const uint16_t ptrs_bit_map,
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const uint8_t nb_antennas_rx)
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{
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for (int i = 0; i < length; i++) {
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for (int ap = 0; ap < nb_antennas_rx; ap++) {
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c16_t *rxd = &rxdata[ap][slot_offset + i + delay];
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rxd->r = r_re[ap][i] + sqrt(sigma / 2) * gaussZiggurat(0.0, 1.0); // convert to fixed point
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rxd->i = r_im[ap][i] + sqrt(sigma / 2) * gaussZiggurat(0.0, 1.0);
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/* Add phase noise if enabled */
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if (pdu_bit_map & ptrs_bit_map) {
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phase_noise(ts, &rxdata[ap][slot_offset + i + delay].r, &rxdata[ap][slot_offset + i + delay].i);
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}
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}
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}
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}
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void add_noise_float(c16_t **rxdata,
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const float **r_re,
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const float **r_im,
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const float sigma,
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const int length,
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const int slot_offset,
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const double ts,
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const int delay,
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bool apply_phase_noise,
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const uint8_t nb_antennas_rx)
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{
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float sqrt_sigma_div2 = sqrtf(sigma / 2.0f);
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for (int i = 0; i < length; i++) {
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for (int ap = 0; ap < nb_antennas_rx; ap++) {
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c16_t *rxd = &rxdata[ap][slot_offset + i + delay];
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rxd->r = (int16_t)(r_re[ap][i] + (gaussZiggurat(0.0, 1.0) * sqrt_sigma_div2));
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rxd->i = (int16_t)(r_im[ap][i] + (gaussZiggurat(0.0, 1.0) * sqrt_sigma_div2));
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if (apply_phase_noise) {
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phase_noise(ts, &rxd->r, &rxd->i);
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}
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}
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}
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}
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