validation: add checkCounterSamples and verify capture up to 1024 frames on ZCU111

Created checkCounterSamples.m to validate sample continuity, counter wraps,
and frame index progression. Verified counter bypass, sine bypass, and
channelizer modes up to nFrames=1024 across 10 DPWs on ZCU111.

codegen_frft/TBc_lfm_fracF.m

@@ -0,0 +1,142 @@
+%% FrFT Validation Script (Reference vs Original)
+% Author: Canisio Barth
+
+clear; clc; close all;
+
+%% Parameters
+Fs = 512e6;          % Sampling rate
+T  = 1e-6;           % Signal duration
+N  = Fs*T;           % 512 samples
+
+n = (0:N-1).';
+t = (n - N/2)/ Fs;
+
+% Beta range (Hz/s)
+betas = (-32e12 : 8e12 : 32e12);
+
+% Order sweep (for heatmap)
+a_vec = linspace( 0.5,  1.5, 100);
+
+% Center frequency 
+f0 = 0e6;   % center frequency (Hz) — set as needed
+
+%% ============================================================
+%% A) HEATMAP (single chirp, order sweep)
+%% ============================================================
+
+beta0 = 64e12; % pick one chirp for visualization
+
+% Generate LFM chirp
+x = exp(1j*(2*pi*f0*t + pi*beta0*t.^2));
+
+% External interpolation (IMPORTANT)
+x_interp = bizinter(x);
+
+N_interp = length(x_interp);
+N_out = N_interp/2; % after decimation
+
+% Allocate
+FrFT_map_ref = zeros(N_out, length(a_vec));
+FrFT_map_cmp = zeros(N_out, length(a_vec));
+
+for k = 1:length(a_vec)
+    a = a_vec(k);
+
+    % Reference
+    y_ref = fracF_ref(x_interp, a);
+    %y_ref = fracF_cg(x_interp, a);
+
+    % Comparison (original / other implementation)
+    %y_cmp = fracF_cg(x_interp, a);
+    y_cmp = fracF_cg_mex(single(x_interp), single(a));
+
+    FrFT_map_ref(:,k) = y_ref;
+    FrFT_map_cmp(:,k) = double(y_cmp);
+end
+
+% Global relative error
+rel_err_global = norm(FrFT_map_ref(:) - FrFT_map_cmp(:)) / ...
+                 norm(FrFT_map_ref(:));
+
+fprintf('Global relative error: %.3e\n', rel_err_global);
+
+% Plot - Reference
+figure;
+imagesc(a_vec, -N_out/2:N_out/2-1, abs(FrFT_map_ref) / sqrt(N));
+axis xy;
+xlabel('Order a');
+ylabel('Index');
+title('FrFT Magnitude (Reference)');
+colorbar;
+
+% Plot - Comparison
+figure;
+imagesc(a_vec, -N_out/2:N_out/2-1, abs(FrFT_map_cmp) / sqrt(N));
+axis xy;
+xlabel('Order a');
+ylabel('Index');
+title('FrFT Magnitude (Comparison)');
+colorbar;
+
+% Plot - Difference
+figure;
+rel_err_map = abs(FrFT_map_ref - FrFT_map_cmp) ./ ...
+              (abs(FrFT_map_ref) + eps);
+
+imagesc(a_vec, -N_out/2:N_out/2-1, rel_err_map);
+axis xy;
+xlabel('Order a');
+ylabel('Index');
+title('Absolute Difference |Ref - Cmp|');
+colorbar;
+
+
+%% ============================================================
+%% B) PEAK VS BETA (matched order)
+%% ============================================================
+
+peak_ref = zeros(size(betas));
+peak_cmp = zeros(size(betas));
+
+for i = 1:length(betas)
+    beta = betas(i);
+
+    % Generate chirp
+    x = exp(1j*(2*pi*f0*t + pi*beta*t.^2));
+
+    % External interpolation
+    x_interp = bizinter(x);
+
+    % Matched order
+    a = -(2/pi)*atan(Fs/(beta*T));
+
+    % Compute FrFT
+    y_ref = fracF_ref(x_interp, a);
+    %y_ref = fracF_cg(x_interp, a);
+    
+    %y_cmp = fracF_cg(x_interp, a);
+    y_cmp = fracF_cg_mex(single(x_interp), single(a));
+
+    % Normalized peak magnitude
+    peak_ref(i) = max(abs(y_ref)) / sqrt(N);
+    peak_cmp(i) = max(abs(y_cmp)) / sqrt(N);
+end
+
+% Plot peaks
+figure;
+plot(betas/1e12, peak_ref, 'o-', 'LineWidth', 1.5); hold on;
+plot(betas/1e12, peak_cmp, 's--', 'LineWidth', 1.5);
+xlabel('\beta (MHz/\mus)');
+ylabel('Peak Magnitude');
+title('Peak vs Chirp Rate');
+legend('Reference','Comparison');
+grid on;
+
+% Plot relative error
+figure;
+rel_err = abs(peak_ref - peak_cmp) ./ peak_ref;
+plot(betas/1e12, rel_err, 'o-', 'LineWidth', 1.5);
+xlabel('\beta (MHz/\mus)');
+ylabel('Relative Error');
+title('Relative Error between Implementations');
+grid on;