Dwell and Switch PRI sequence of a radar signal

How to generate Dwell and Switch PRI sequence of radar signal in matlab?

Answer 1

[AR]

Hi @PURABI SHARMA,

As of my knowledge, a Dwell-and-Switch PRI sequence is generated by repeating the same Pulse Repetition Interval (PRI) for a fixed number of pulses (dwell) and then switching to a new PRI value. This process cycles through different PRIs to reduce range and Doppler ambiguities.

In MATLAB, such a sequence can be generated using the following approach:

1. Choose a set of distinct Pulse Repetition Interval (PRI) values to cycle through.
2. Decide how many consecutive pulses (dwell) will use the same PRI before switching to the next.
3. For each PRI value, repeat it for the specified dwell (number of pulses), then switch to the next PRI. This creates a sequence.
4. To extend the pattern, repeat the dwell-and-switch sequence for the desired number of cycles.
5. Use the cumulative sum of the PRI sequence to determine the start times of each pulse.
6. Plot the PRI values across pulse indices.

Here is an example MATLAB code:

% Parameters 
numDwells = 3;                 % Number of different PRI values 
dwellPulses = 5;               % Number of pulses per dwell 
PRI_values = [100e-6 120e-6 80e-6]; % PRI set [sec] 

% Generate dwell-and-switch PRI sequence 
PRI_sequence = repelem(PRI_values, dwellPulses);  

% Repeat sequence for multiple cycles 
numCycles = 4; 
PRI_sequence = repmat(PRI_sequence, 1, numCycles); 

% Pulse timing (cumulative sum gives pulse start times) 
pulseTimes = cumsum(PRI_sequence); 

% Plot PRI sequence 
figure; 
stem(1:length(PRI_sequence), PRI_sequence*1e6, 'filled'); 
xlabel('Pulse Index'); 
ylabel('PRI [µs]'); 
title('Dwell-and-Switch PRI Sequence'); 
grid on; 

●

• Each PRI value (100 µs, 120 µs, 80 µs) is repeated for 5 pulses (the dwell).
• After that, the PRI “switches” to the next value.
• The entire sequence repeats for the specified number of cycles.