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rfsimulator: for LEO NTN, calculate SAT acceleration towards gNB to determine ta-CommonDriftVariant-r17

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This commit is contained in:
Thomas Schlichter
2025-06-20 11:18:59 +00:00
parent ece430b6c3
commit 7ba63a2052
1 changed files with 8 additions and 0 deletions
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radio/rfsimulator/apply_channelmod.c
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@@ -97,7 +97,12 @@ void rxAddInput(const c16_t *input_sig,
double dist_sat_gnb = 0;
double vel_sat_gnb = 0;
double acc_sat_gnb = 0;
if (channelDesc->modelid == SAT_LEO_TRANS) {
const double acc_sat_x = 0;
const double acc_sat_y = -w_sat * w_sat * radius_sat * sin(w_sat * t);
const double acc_sat_z = -w_sat * w_sat * radius_sat * cos(w_sat * t);
const double pos_gnb_x = 0;
const double pos_gnb_y = 0;
const double pos_gnb_z = radius_earth;
@@ -108,6 +113,7 @@ void rxAddInput(const c16_t *input_sig,
dist_sat_gnb = sqrt(dir_sat_gnb_x * dir_sat_gnb_x + dir_sat_gnb_y * dir_sat_gnb_y + dir_sat_gnb_z * dir_sat_gnb_z);
vel_sat_gnb = (vel_sat_x * dir_sat_gnb_x + vel_sat_y * dir_sat_gnb_y + vel_sat_z * dir_sat_gnb_z) / dist_sat_gnb;
acc_sat_gnb = (acc_sat_x * dir_sat_gnb_x + acc_sat_y * dir_sat_gnb_y + acc_sat_z * dir_sat_gnb_z) / dist_sat_gnb;
}
const double prop_delay = (dist_ue_sat + dist_sat_gnb) / c;
@@ -122,6 +128,7 @@ void rxAddInput(const c16_t *input_sig,
last_TS = TS;
LOG_I(HW, "Satellite orbit: time %f s, Position = (%f, %f, %f), Velocity = (%f, %f, %f)\n", t, pos_sat_x, pos_sat_y, pos_sat_z, vel_sat_x, vel_sat_y, vel_sat_z);
LOG_I(HW, "Uplink delay %f ms, Doppler shift UE->SAT %f kHz\n", prop_delay * 1000, f_Doppler_shift_ue_sat / 1000);
LOG_I(HW, "Satellite velocity towards gNB: %f m/s, acceleration towards gNB: %f m/s²\n", vel_sat_gnb, acc_sat_gnb);
const int samples_per_subframe = channelDesc->sampling_rate / 1000;
const int abs_subframe = TS / samples_per_subframe;
@@ -130,6 +137,7 @@ void rxAddInput(const c16_t *input_sig,
.subframe = abs_subframe % 10,
.delay = 2 * dist_sat_gnb / (c * 4.072e-9),
.drift = 2 * -vel_sat_gnb / (c * 0.2e-9),
.accel = 2 * acc_sat_gnb / (c * 0.2e-10),
.position.X = pos_sat_x / 1.3,
.position.Y = pos_sat_y / 1.3,
.position.Z = pos_sat_z / 1.3,