compared both TBc and TBm, results are equivalent (not identical because of interpolation filter)

codegen_fracFdpw/TBc_fracFdpwLFM.m

@@ -19,19 +19,19 @@
 %   - FrFT is computed on the interpolated signal.
 %   - Power spectra are averaged across the entire DPW.
 
-clear
+clearvars -except out
 clc
 close all
 
 %% Signal parameters
 
 N       = 512;
-Nframes = 64;
+Nframes = 1024;
 
 Fs = single(512e6);
 T  = single(1e-6);
 
-B    = single(64e6);
+B    = single(32e6);
 beta = B/T;
 
 %% Time axis
@@ -146,4 +146,134 @@ ylabel('Power (dB)')
 fprintf('\n');
 fprintf('FFT peak bin        : %d\n',idxFFT);
 fprintf('FrFT peak bin       : %d\n',idxFrFT);
-fprintf('\n');
+fprintf('\n');
+
+%% Compare TBc against TBm (optional)
+%
+% If the Simulink model has been executed and produced out.Fsim,
+% compare both implementations.
+
+if exist('out','var')
+
+    fprintf('\n');
+    fprintf('TBc vs TBm Comparison\n');
+    fprintf('---------------------\n');
+
+    Ftbm = out.Fsim;
+
+    %% Dimension check
+
+    fprintf('TBc size : [%d %d]\n', ...
+            size(Ffrft,1), size(Ffrft,2));
+
+    fprintf('TBm size : [%d %d]\n', ...
+            size(Ftbm,1), size(Ftbm,2));
+
+    assert(isequal(size(Ffrft),size(Ftbm)), ...
+           'TBc and TBm dimensions differ.');
+
+    %% Error metrics
+
+    err = Ftbm - Ffrft;
+
+    maxErr = max(abs(err(:)));
+
+    rmsErr = sqrt(mean(abs(err(:)).^2));
+
+    refPeak = max(abs(Ffrft(:)));
+
+    relErr = maxErr / refPeak;
+
+    %% Results
+
+    fprintf('\n');
+    fprintf('Reference peak    : %.9g\n',double(refPeak));
+    fprintf('Maximum error     : %.9g\n',double(maxErr));
+    fprintf('RMS error         : %.9g\n',double(rmsErr));
+    fprintf('Relative error    : %.9g\n',double(relErr));
+
+    if maxErr == 0
+
+        fprintf('\nPASS: Outputs are bit-identical.\n');
+
+    elseif relErr < 1e-5
+
+        fprintf('\nPASS: Outputs are numerically equivalent.\n');
+
+    else
+
+        fprintf('\nWARNING: Outputs differ.\n');
+
+    end
+
+    %% Visual comparison
+
+    frameIdx = 1;
+
+    figure
+
+    subplot(3,1,1)
+
+    plot(abs(Ffrft(:,frameIdx)))
+
+    grid on
+
+    title('TBc Output')
+    xlabel('Bin')
+    ylabel('|F|')
+
+    subplot(3,1,2)
+
+    plot(abs(Ftbm(:,frameIdx)))
+
+    grid on
+
+    title('TBm Output')
+    xlabel('Bin')
+    ylabel('|F|')
+
+    subplot(3,1,3)
+
+    plot(abs(Ftbm(:,frameIdx) - Ffrft(:,frameIdx)))
+
+    grid on
+
+    title('Absolute Error')
+    xlabel('Bin')
+    ylabel('|Error|')
+
+    %% Mean power spectrum comparison
+
+    Ptbc = mean(abs(Ffrft).^2,2);
+
+    Ptbm = mean(abs(Ftbm).^2,2);
+
+    Ptbc_dB = 10*log10(Ptbc/max(Ptbc));
+
+    Ptbm_dB = 10*log10(Ptbm/max(Ptbm));
+
+    figure
+
+    plot(Ptbc_dB,'LineWidth',1.5)
+
+    hold on
+
+    plot(Ptbm_dB,'--','LineWidth',1.5)
+
+    grid on
+
+    ylim([-60 5])
+
+    xlabel('Bin')
+    ylabel('Power (dB)')
+
+    title('TBc vs TBm Mean Power Spectrum')
+
+    legend('TBc','TBm')
+
+else
+
+    fprintf('\n');
+    fprintf('TBm comparison skipped (out.Fsim not found).\n');
+
+end