How to get the impulse responce of the channel nrTDLChannel?

Hello,

I am trying to learn -- how to use the system object nrTDLChannel in Matlab 5G toolbox. In the documentation, there are a few examples available but I am not able to find any example where it plots the impulse response of the channel -- just like it is available in the book. I have attached one picture to explain myself better.

It would be very helpful if you can give me hint on this.

Thanks

Answer 1

[Santosh Fatale]

Hi Sanju,

For a given TDL channel object, the info() object function returns a structure containing information about the object, including the path delays and average path powers. This can be used to depict the long-term average impulse response:

tdl = nrTDLChannel;
tdlinfo = info(tdl);
stem(tdlinfo.PathDelays,db2mag(tdlinfo.AveragePathGains));
xlabel('Path delay (s)');
ylabel('Path magnitude');

Note that this depiction is a simplification as it omits a number of effects:

1. The time variation of actual path magnitudes due to fast fading according to the specified Doppler frequency

2. The presence of separate links between all transmit and receive antennas

3. The path delays are unlikely to be an integer multiple of the input sample rate, so the impulse response for each path is typically the coefficients of an FIR filter implementing a fractional delay, rather than a discrete impulse.

[Sanju Das]

Thanks for the reply