How to get target position, and speed value numerically in JRC system using OFDM signal in MATLAB predefined code

Hello all,

I am implementing Joint Radar-Communication Using OFDM Waveforms from this link -https://in.mathworks.com/help/phased/ug/joint-radar-communication-using-pmcw-and-ofdm-waveforms.html.

The code is running fine and also getting the final response plot using 'phased.RangeDopplerResponse'. But I want to receive the targets position value and speed value numerically. Hence I an writing the code as

rangeDopplerMap = step(rdr, Zofdmr);

% Find range and speed values corresponding to the maximum response

[maxResponse, idx] = max(abs(rangeDopplerMap(:)));

% Convert index to subscripts

[row, col] = ind2sub(size(rangeDopplerMap), idx);

% Obtain range and speed values based on the obtained subscripts

specificRange = rng_grid(row);

specificSpeed = dop_grid(col);

% Display or use the specific range and speed values

disp('Specific Range:');

disp(specificRange);

disp('Specific Speed:');

disp(specificSpeed);

where, all the variables have the same name as mantioned in above link. But I am not getting 3 targets(as modeled) position and speed as my wrriten code output. Please help me in that matter.

[Peter Khomchuk]

Hi Soumita,

It looks like you are trying to find target position and speed values by looking where the range-Doppler map has maximums. This approach is not going to work in general. For example, a stronger target might have sidelobes with higher values than some of the weaker targets. In order to get robust results, you need to use a detection algorithm like the constant false alarm rate (CFAR) detector. Here is a link to an example that explains how to use CFAR for getting detections from range-Doppler images, which is exactly what you have in the JRC example you are using as a reference.

Constant False Alarm Rate (CFAR) Detection

[SOUMITA NASKAR]

Yah, got it.

Thanks for response.