If you're interested in generating pulsed waveforms of a Gold sequence, the Phased Array System Toolbox™ offers several options for creating baseband pulsed waveforms. Below is an example demonstrating how to create both Rectangular and Linear Frequency Modulated (LFM) pulses.
The code below generates a Gold sequence followed by modulating two types of waveforms: a Rectangular waveform and a Linear Frequency Modulated (LFM) waveform. Each bit of the Gold sequence determines whether a pulse or a zero sequence is appended to the final waveform. The result is a concatenation series of pulses that can be visualized.
% Define parameters
N = 63; % Number of bits
PRF = 50000; % Pulse Repetition Frequency in Hz
Fs = 100e6; % Sampling frequency in Hz
BW = 10e5; % Bandwidth in Hz
PW = 2/BW; % Pulse width
% Configure the Gold sequence generator
code2 = comm.GoldSequence('FirstPolynomial','x^6+x+1', ...
'FirstInitialConditions',[0 0 0 0 0 1], ...
'SecondPolynomial','x^6 + x^5 + x^4 + x^3 + x^2 + x + 1', ...
'SecondInitialConditions',[0 0 0 0 0 1], 'Index',2, ...
'SamplesPerFrame',63);
% Generate the Gold sequence
gold_Code = code2();
% Create rectangular and LFM waveform objects
rectWaveform = phased.RectangularWaveform('PulseWidth', PW, ...
'PRF', PRF, ...
'SampleRate', Fs);
linearFMWaveform = phased.LinearFMWaveform('PRF', PRF, ...
'PulseWidth', PW, ...
'SampleRate', Fs, ...
'SweepBandwidth', 200e4);
% Generate base pulses
basePulseRect = rectWaveform();
basePulseLinearFM = linearFMWaveform();
% Initialize waveforms
waveformRec = [];
waveformLinearFM = [];
% Create the modulated waveform
for i = 1:N
if gold_Code(i) == 1
waveformRec = [waveformRec; basePulseRect]; % Append pulse for bit 1
waveformLinearFM = [waveformLinearFM; basePulseLinearFM];
else
waveformRec = [waveformRec; zeros(size(basePulseRect))]; % Append zeros for bit 0
waveformLinearFM = [waveformLinearFM; zeros(size(basePulseLinearFM))];
end
end
% Time vector for the entire waveform
t = (0:length(waveformRec)-1) / Fs;
% Plot the waveforms
figure;
subplot(2,1,1)
plot(t, waveformRec);
xlabel('Time (s)');
ylabel('Amplitude');
title('Rectangular Pulsed Waveform of Gold Code');
grid on;
axis([0 N/PRF -0.2 1.2])
subplot(2,1,2)
plot(t, real(waveformLinearFM));
xlabel('Time (s)');
ylabel('Amplitude');
title('Linear Frequency Modulated Pulsed Waveform of Gold Code');
grid on;
axis([0 N/PRF -1.2 1.2])
Feel free to adjust the parameters to meet your specific application or specifications.
To know more on the Pulsed Waveforms, please refer to the following documentations
