Initial Commit.

2025-07-29 21:45:44 +09:00
parent a69350b86e
commit 90231d49ae
38 changed files with 2051 additions and 0 deletions
@@ -0,0 +1,40 @@
+function [esti_ang_deg, P_FT, fft_ang_deg] = df_FFT(snapshot, NFFT, fft_ang, array_struct, Ntarget, plot_flag)
+
+%% FFT algorithm
+Nsnap = size(snapshot, 2);
+
+if isempty(fft_ang)
+    fft_freq = -180 : 360/NFFT : (180 - 360/NFFT);
+    fft_ang_deg = asind(fft_freq / 2 * array_struct.lambda_c / array_struct.unit / 180);
+end
+
+% FFT spectrum
+zero_padded_input = complex(zeros(NFFT, Nsnap));
+zero_padded_input(array_struct.eff_ch_loc+1, :) = snapshot;
+
+if Nsnap == 1
+    P_FT = abs(flipud(fftshift((1/Nsnap) * ((fft(zero_padded_input, NFFT)))').')).^2;
+else
+    P_FT = abs(flipud(fftshift((1/Nsnap) * (sum(fft(zero_padded_input, NFFT),2))').')).^2;
+end
+
+% Plot
+if plot_flag == 1
+    figure()
+    plot(fft_ang_deg, pow2db(abs(P_FT)));
+    grid on
+    xlabel('Angle [deg]')
+    ylabel('Magnitude [dB]')
+end
+
+[pks, pks_ang, ~, ~] = findpeaks(pow2db(abs(P_FT)), fft_ang_deg);
+[~, order] = sort(pks, 'descend');
+if isempty(pks)
+    esti_ang_deg = nan;
+else
+    esti_ang_deg = pks_ang(order(1:Ntarget));
+end
+    
+
+end
+