DSP Blockset

Step 1 -- Get the Coefficients of the Predesigned Filters.   For the purposes of this example, we assume you already predesigned your lowpass and highpass filters, possibly by using one of the following filter design techniques:

• Use Signal Processing Toolbox functions -- Type the following commands at the MATLAB command line:

• [N Fo Ao W] = remezord([0.2 0.5],[1 0], ...
  [5.750112778453722e-002,1.000000000000001e-004]);
  
  lopassNum = remez(N,Fo,Ao,W,{16});
  
  [N Fo Ao W] = remezord([0.2 0.5],[0 1], ...
  [1.000000000000001e-004 5.750112778453722e-002]);
  
  hipassNum = remez(N,Fo,Ao,W,{16});
  

• Use Digital Filter Design block -- Rather than type the above commands, use the Digital Filter Design block to design the same filters as in Example: Using the Digital Filter Design Block to Design, Analyze, and Implement a Filter. Then export the filters to the MATLAB workspace to the variables lopassNum and hipassNum as described in Exporting a Filter from FDATool.

Implementing Predesigned Filters with the Digital Filter Block

Step 2 -- Get Necessary Blocks