MATLAB: How to generate a pulse train of sine waveforms

phasedpulse repetition frequencypulse trainpulse widthradar signalssine waveformzeros

The pulse train needs to be a function of parameters such as pulse-width (PW), pulse repetition frequency (PRF), sampling rate, amplitude, etc.

I know that I can use zeros() to implement a delay between consecutive pulses, in order to represent the pulse train's PRF.

Best Answer

You can take a look at the pulstran function in Signal Processing Toolbox. Here is an example

prf = 1; pw = 0.1;
fs = 1000; f = 20;
T = 0:1/fs:3-1/fs;
D = 0:1/prf:3-1/prf;
Y = pulstran(T,D,@(t)sin(2*pi*f*t).*(t>=0).*(t<pw));
plot(T,Y)

Related Solutions

MATLAB: Trapezoidal pulse generation using gensig() function

The answer is No! .I am not aware of any function which can do that for you. Try to adapt my function for your needs or write your own.

%Does this work for you?
[t,p]=Trapezoidal_pulse(1,3,0.01,1,1,5,8);
figure,plot(t,p)

The function:

%%
function [t,pulse_train]=Trapezoidal_pulse(Amplitude,FlatTopTime,DwellTime,RiseTime,FallTime,DeadTime,Repetitions)
%[t,pulse_train]=Trapezoidal_pulse(Amplitude,FlatTopTime,DwellTime,RiseTime,FallTime,DeadTime,Repetitions)
% All times are of same units
% DwellTime-1/Sampling rate or raster time
% DeadTime- Dead Time after each pulse
%Repetitions -Number of Trapezoidal pulses
if(RiseTime<DwellTime)
    warn('RiseTime<DwellTime: No Ramp up samples')
    rampup_samples=[];
else
    rampup_samples= linspace(0,Amplitude,ceil(RiseTime/DwellTime));
end
if(FallTime<DwellTime)
    warn('FallTime<DwellTime: No Ramp down samples')
    rampdown_samples=[];
else
    rampdown_samples= linspace(Amplitude,0,ceil(FallTime/DwellTime));
end
pulse=[rampup_samples Amplitude*ones(1,ceil(FlatTopTime/DwellTime)) rampdown_samples zeros(1,ceil(DeadTime/DwellTime))];
%bipolar
% pulse_train=repmat(pulse,[Repetitions 1]).'.*(-1*ones(length(pulse),1)).^(0:Repetitions-1);
%unipolar
pulse_train=repmat(pulse,[Repetitions 1]).';
pulse_train=pulse_train(:);
%time
t=(0:(length(pulse_train)-1))*DwellTime;
end

Use doc or edit command to see the ownership and year at which the function is added to matlab.

MATLAB: How to generate a non periodic Chirp signal

Hallo Herr Müller

1. my preferred way to generate signal 'trains' is with command repmat

clear all 
fs = 150000; ts = 1/fs; tpuls = 10e-3;% chirp_with 

f0 = 94; f2 = 9000; N= 20;% number of my chirp

t=0:ts:tpuls; % ungerade zahl endet auf null/t=0:ts:tpuls; 

y = chirp(t, f0, t(end), f2);
figure(1);plot(t, y); grid on;
t2=repmat(t,1,2);
t_guard=zeros(1,300);
y0=[y t_guard]; % daß ist deine y
y2=repmat(y0,1,3);
figure(2);plot(y2);grid on

the function pulstran is also suggested by Mathworks support in

https://uk.mathworks.com/matlabcentral/answers/102437-is-it-possible-to-use-a-user-defined-function-to-be-passed-as-an-argument-to-the-pulstran-function-i?s_tid=srchtitle

but

pulstran only has 3 predefined functions, if one needs a custom function, as it happens in most of the cases, a handle to the custom function, or the same anonymously defined function has to be passed to repmat instead.
you need 2 time vectors, one for the base chirp, and an extended one for the resulting signal.

Following an example with pulstran and custom function:

fs = 150000; ts = 1/fs; tpuls = 10e-3;% chirp_with 
f0 = 94; f2 = 9000; N= 20;% number of my chirp
t=[0:ts:tpuls]; % ungerade zahl endet auf null/t=0:ts:tpuls; 
y = chirp(t, f0, t(end), f2);
figure(1);plot(t, y); grid on;
T = 0:1/fs:3-1/fs;
prf = 1; pw = 0.1;
D = 0:1/prf:3-1/prf;
Y = pulstran(T,D,@(t)chirp(t,f0,t(end),f2).*(t>=0).*(t<pw));
figure(2);plot(T,Y);grid on

you may also want to modify f0 and f2 passed to pulstran by a factor N

T = 0:1/fs:3-1/fs;
prf = 1; pw = 0.4;
D = 0:1/prf:3-1/prf;
N=12; % decimation needed to keep same frequencies
Y = pulstran(T,D,@(t)chirp(t,f0/N,t(end),f2/N).*(t>=0).*(t<pw));
figure(3);plot(T,Y);grid on

note that there is a slight variation in the top frequency of the last pulse compared to the first pulse.

Function pulstran is useful but requires a more elaborate configuration than repmat as shown above, and the simplicity of using only one time vector may also pay off avoiding complications.

you can vary the intervals between chirped pulses either modifying the guard interval from the simple sequence of zeros to diverse lengths when using repmat, or with the parameter D in pulstran

So Herrn Müller

if you find this answer useful would you please be so kind to mark my answer as Accepted Answer?

To any other reader, please if you find this answer of any help solving your question,

please click on the thumbs-up vote link,

Servus und thanks in advance

John BG

<mailto:jgb2012@sky.com jgb2012@sky.com>

Best Answer

Related Solutions

MATLAB: Trapezoidal pulse generation using gensig() function

MATLAB: How to generate a non periodic Chirp signal

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