lab5 task1 done, task2 nearly finished

2026-06-22 22:03:28 +02:00
parent 48793b1532
commit eb4d72c7c2
16 changed files with 2727 additions and 0 deletions
@@ -0,0 +1,75 @@
+function res = perform_access_analysis(satSim, queryTime)
+    sat = satSim.sat;
+    ue = satSim.ue;
+
+    ac = access(sat,ue);
+    [status,timeout] = accessStatus(ac);
+    statusIdx = find(status,1);
+    if isempty(statusIdx)
+        disp("Position estimation cannot be performed " + ...
+            "as there is no access between satellite and UE.")
+        return
+    end
+    delete(ac)
+
+    [~,el,r] = aer(ue,sat,queryTime);
+
+    res.distanceToSatellite = r;
+    res.elevationAngleToSatellite = el;
+
+    carrierFrequency = 2e9;
+    [fshift,~,dopplerInfo] = dopplershift( ...
+        sat,ue,queryTime,Frequency=carrierFrequency);
+    res.rangeRate = -1*dopplerInfo.RelativeVelocity;
+
+    [satPos,satVel] = states(sat,queryTime,CoordinateFrame="ecef");
+
+    res.satPos = satPos;
+    res.satVel = satVel;
+
+    if ~isfinite(fshift)
+        return;
+    end
+
+    rng(0)
+    lightspeed = physconst("lightspeed");
+
+    frameDurInSeconds = 10e-3;
+    delayInSeconds = r/lightspeed;
+    nFrames = ceil(delayInSeconds/frameDurInSeconds) + 1;
+    carrier = nrCarrierConfig;
+    pdsch = nrPDSCHConfig;
+    pdsch.DMRS.DMRSAdditionalPosition = 2;
+    [txWaveform,waveformInfo] = ...
+        HelperNRNTNThroughput.generatePDSCHWaveform( ...
+        carrier,pdsch,struct,eye(pdsch.NumLayers),"double",carrier.SlotsPerFrame*nFrames);
+    refGridAllSlots = waveformInfo.ResourceGrid;
+
+    delayInSamples = delayInSeconds.*waveformInfo.SampleRate;
+    integDelaySamples = floor(delayInSamples);
+    fracDelaySamples = (delayInSamples - integDelaySamples);
+    staticDelay = dsp.Delay(Length=integDelaySamples);
+    variableFractionalDelay = dsp.VariableFractionalDelay( ...
+        InterpolationMethod="Farrow", ...
+        FarrowSmallDelayAction="Use off-centered kernel", ...
+        MaximumDelay=1);
+
+    delayedTx = staticDelay(txWaveform);
+    delayedTx = variableFractionalDelay(delayedTx,fracDelaySamples);
+
+    channel = p681LMSChannel;
+    channel.SampleRate = waveformInfo.SampleRate;
+    channel.CarrierFrequency = carrierFrequency;
+    channel.SatelliteDopplerShift = fshift;
+    channel.MobileSpeed = 0;
+    channel.ElevationAngle = el;
+    channel.RandomStream = "mt19937ar with seed";
+    rxWaveform = channel(delayedTx);
+
+    freqSearch = 0.999*fshift:sign(fshift):1.001*fshift;
+    [delayEstSamples,fshiftEst] = HelperNRNTNThroughput.jointTimeFreq( ...
+        carrier,rxWaveform,refGridAllSlots,freqSearch);
+
+    res.rangeEst = delayEstSamples*lightspeed/waveformInfo.SampleRate;
+    res.rangeRateEst = -1*fshiftEst*lightspeed/carrierFrequency;
+end