kopia lustrzana https://github.com/proto17/dji_droneid
55 wiersze
1.3 KiB
Matlab
55 wiersze
1.3 KiB
Matlab
clear all;
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symbol_number = 6;
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file_path = ['/opt/dji/collects/zc_symbol_', mat2str(symbol_number), '_15360KSPS_time_domain.fc32'];
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file_handle = fopen(file_path, 'r');
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reals = fread(file_handle, inf, 'single');
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fclose(file_handle);
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received_samples = reals(1:2:end) + 1j * reals(2:2:end);
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figure(1); plot(10 * log10(abs(received_samples).^2));
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root_sequnce_attempts = 1000;
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scores = zeros(root_sequnce_attempts, 1);
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for root=1:length(scores)
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try
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% Not all ZC roots are valid and the function will throw an error if the root is invalid
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zc = zadoffChuSeq(root, 601);
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% Remove the center sample as this is what's done on the transmitter.
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zc = [zc(1:300); zc(302:end)];
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catch
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continue
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end
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% Correlate the
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scores(root) = abs(xcorr(received_samples, zc(1:end), 0, 'normalized')).^2;
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end
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figure(2);
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plot(scores);
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title('ZC Normalized XCorr Results')
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[value, index] = max(scores);
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if (value < 0.7)
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warning('Unable to find matching sequence');
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end
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zc = zadoffChuSeq(index, 601);
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figure(3);
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subplot(2, 1, 1);
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spectrogram(zc);
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title('Calculated ZC')
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subplot(2, 1, 2);
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spectrogram(received_samples);
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title('Received ZC')
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figure(4)
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subplot(2, 1, 1);
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plot(abs(fftshift(fft(zc))).^2);
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title('Calculated ZC')
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subplot(2, 1, 2);
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plot(abs(fftshift(fft(received_samples))).^2);
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title('Received ZC') |