Generation of Chirp Signals in MATLAB

 

for up-chirp generation

fs = 1000;           % Sampling frequency (Hz)
t = 0:1/fs:1;         % Time vector (1 second duration)
f_start = 50;         % Starting frequency (Hz)
f_end = 200;          % Ending frequency (Hz)
% Generate up-chirp signal
up_chirp = chirp(t, f_start, 1, f_end, 'linear');

plot(up_chirp)

Output

 

 

 

 

for down-chirp generation

fs = 1000;           % Sampling frequency (Hz)
t = 0:1/fs:1;         % Time vector (1 second duration)
f_start = 200;         % Starting frequency (Hz)
f_end = 50;          % Ending frequency (Hz)
% Generate up-chirp signal

down_chirp = chirp(t, f_start, 1, f_end, 'linear');

plot(down_chirp)

 Output

 

 

 

 

for decoding of the up-chirp signal

 clc;
clear all;
close all;

fs = 1000;           % Sampling frequency (Hz)
t = 0:1/fs:1;         % Time vector (1 second duration)
f_start = 50;         % Starting frequency (Hz)
f_end = 200;          % Ending frequency (Hz)
% Generate up-chirp signal
up_chirp = chirp(t, f_start, 1, f_end, 'linear');



% Perform Short-Time Fourier Transform (STFT)
window_size = 64;
hop_size = 32;
[spectrogram, frequencies, time] = spectrogram(up_chirp, window_size, hop_size, [], fs);

% Extract instantaneous frequency
instantaneous_frequency = fs/(2*pi) * angle(spectrogram(2,:));
figure(); imagesc(time, frequencies, 10*log10(abs(spectrogram)));

 

 Output

 

 

 

 

for decoding of down-chirp signal  

fs = 1000;           % Sampling frequency (Hz)
t = 0:1/fs:1;         % Time vector (1 second duration)
f_start = 200;         % Starting frequency (Hz)
f_end = 50;          % Ending frequency (Hz)
% Generate up-chirp signal
down_chirp = chirp(t, f_start, 1, f_end, 'linear');



% Perform Short-Time Fourier Transform (STFT)
window_size = 64;
hop_size = 32;
[spectrogram, frequencies, time] = spectrogram(down_chirp, window_size, hop_size, [], fs);

% Extract instantaneous frequency
instantaneous_frequency = fs/(2*pi) * angle(spectrogram(2,:));
figure(); imagesc(time, frequencies, 10*log10(abs(spectrogram)));

Output

  

 

 

 

 

 

 

 

Copy the MATLAB Code from here

%%%%%%%%%%%%%%%%for up-chirp generation%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% fs = 1000; % Sampling frequency (Hz) t = 0:1/fs:1; % Time vector (1 second duration) f_start = 50; % Starting frequency (Hz) f_end = 200; % Ending frequency (Hz) % Generate up-chirp signal up_chirp = chirp(t, f_start, 1, f_end, 'linear'); plot(up_chirp) #####################for down-chirp generation%%%%%%%%%%%%%%%%%%%%%%%%%%% fs = 1000; % Sampling frequency (Hz) t = 0:1/fs:1; % Time vector (1 second duration) f_start = 200; % Starting frequency (Hz) f_end = 50; % Ending frequency (Hz) % Generate up-chirp signal down_chirp = chirp(t, f_start, 1, f_end, 'linear'); plot(down_chirp)