FMCW Transmitted and Received Waveform

HI, I am trying to create Range-Doppler Map for FMCW.

I have attached the TX and RX signal. I know the typical graph but I want to confirm am I going in the right direction or not.

Answer 1

[Abhimenyu]

Hi Sara,

I understand that you are trying to develop a range-doppler map for FMCW.

Please refer to the following steps to achieve the above,

• Generate the transmitted and received signals for FMCW radar, considering the carrier frequency, sweep bandwidth, sweep time, and target range and velocity.
• Perform a “dechirp” operation on the received signal using the transmitted signal as a reference. This will produce a beat signal that contains the range and doppler information of the target.
• Perform a fast Fourier transform (“fft”) on the beat signal along the fast time dimension to obtain the range spectrum.
• Perform another FFT on the range spectrum along the slow time dimension to obtain the doppler spectrum.
• Plot the magnitude of the doppler spectrum in decibels as a function of range and doppler frequency or radial speed.

You can also use “phased.RangeDopplerResponse” object to create the map.

The transmitted and received waveforms provided are correct if they are using slow time MIMO-FMCW and interference mitigation.

Below are some useful documentation links to “dechirp” function, “fft” function and “phased.RangeDopplerResponse” object respectively:

• https://www.mathworks.com/help/phased/ref/dechirp.html
• https://www.mathworks.com/help/matlab/ref/fft.html
• https://www.mathworks.com/help/phased/ref/phased.rangedopplerresponse-system-object.html

I hope this helps!

Thank you,

Abhimenyu.