Doppler Velocity from I&Q channel

I am new to this field and struggling to find doppler velocity from pure Doppler RADAR. I have I&Q channel, which I beleive is used to find doppler velocity by finding their phase difference ? Any sort of help would be much appreciated

[chane moges]

I am new to this field and struggling to find doppler velocity from pure Doppler RADAR. I have I&Q channel, which I beleive is used to find doppler velocity ,spectral width and SNR using moment method after fft ? Any sort of help would be much appreciated

[Aicha Sow]

@Muhammad Fayyaz Hello, I wanted to know if you actually succeded in finding the velocity from I and Q data of a CW radar.

[Muhammad Fayyaz]

Hi @Aicha Sow,

My research topic changed and later I used micro-Doppler for CNN models. Hence I did not continue with this one. Sorry I know it is not what you might have been expecting

[Aicha Sow]

Hi @Muhammad Fayyaz I was indeed hoping for another answear. But thanks for taking the time to reply.

Answer 1

[Honglei Chen]

There is a Doppler estimation example in Phased Array System Toolbox. You can find it at

https://www.mathworks.com/help/phased/examples/doppler-estimation.html

HTH

[Muhammad Fayyaz]

Hey there, The given example use PULSE RADAR. I have doppler radar CW. This particular radar will not give range or pulses. Hope I am able to clarify my point ?

[Honglei Chen]

In that case the following example may be helpful

https://www.mathworks.com/help/phased/examples/automotive-adaptive-cruise-control-using-fmcw-technology.html

HTH

Answer 2

[Muhammad Fayyaz]

Thanks for the quick response. But I had already seen this example, which is for FREQUENCY MODULATED CW Radar system. I have purely CW system with no such information as required for FMCW or Pulse.

Answer 3

[Honglei Chen]

If you are using a pure CW system, you cannot derive the range information. In that case you just mix the received signal with the transmitted signal, like what is done for range in the FMCW radar example. However, this time all frequency shifts are caused by Doppler shift. So just as shown in the FMCW radar example, once you get the beat frequency, that is your Doppler shift and you can then translate that to speed.

HTH

[Muhammad Fayyaz]

Is there any particular example related to that solution ? Because I havr received a code from company to output I&Q channel and the FFT output of it. What is required to translate that information to spped ?

[Honglei Chen]

If you have FFT output, you can just locate the peak and get the corresponding frequency. To translate that frequency to speed, you can use dop2spped

https://www.mathworks.com/help/phased/ref/dop2speed.html

Note that this is for one way propagation. Since you are using a radar, you probably have two way propagation so you need to divide the result by 2 to get the correct speed.

HTH