How can I make the function STEP, which I am using with comm.LTEMIMOChannel to also decimate efficiently its output

How can I make the function STEP, which I am using with comm.LTEMIMOChannel to also decimate efficiently its output. Meaning I would like it to calculate the filter outputs only every "down_sample_phase" samples. Is it possible to be done efficiently.

Answer 1

[Yue Shang]

You cannot modify the step method of comm.LTEMIMOChannel. But you can do what you need by creating a very simple System object that inherits from comm.LTEMIMOChannel. For example:

classdef MYLTEMIMOChannel < comm.LTEMIMOChannel        

methods(Access = protected)

    function varargout = stepImpl(obj, x, varargin)
      if obj.PathGainsOutputPort
          [y, g] = [e-mail](obj, x, varargin);
          varargout = {y, g};
      else
          varargout = {[e-mail](obj, x, varargin)};
      end

      % Put your decimation code here
    end

end      
end

The MYLTEMIMOChannel and comm.LTEMIMOChannel should behave the same. After you fill in your decimation code, you can replace comm.LTEMIMOChannel by MYLTEMIMOChannel in your code and call the step method to have the filter output decimated.

[Ram]

A very nice answer. Maybe this the direction I am looking for. But no yet still. If I will follow your idea than my channel will still be calculate at the high rate. Where I am interested only at one of the phases of the channel output.