DSP Blockset

Part 2 -- Creating a Fixed-Point Filter with the Filter Realization Wizard

Next you will create a fixed-point filter using the Filter Realization Wizard. You will create a filter that reduces the effects of the noise on the signal.

6. Open a new Simulink model, and drag-and-drop a Filter Realization Wizard block from the Filtering / Filter Designs library into the model.
   
   

Note    You do not have to place a Filter Realization Wizard block in a model in order to use it. You can open the GUI from within a library. However, for purposes of this tutorial, we will keep the Filter Realization Wizard block in the model.

7. Double-click the Filter Realization Wizard block in your model. The Realize Model panel of the Filter Design and Analysis Tool (FDATool) appears.
   
   
8. Click the Design Filter button on the bottom left of FDATool. This brings forward the Design Filter panel of the tool.
   
   
9. Set the following fields in the Design Filter panel:
• Set Design Method to IIR -- Constrained Least Pth-norm
• Set Fs to Fs
• Set Fpass to 0.2*Fs
• Set Fstop to 0.25*Fs
• Set Max pole radius to 0.8
• Click the Design Filter button

1. The Design Filter panel should now appear as follows.



10. Click the Set Quantization Parameters button on the bottom left of FDATool. This brings forward the Set Quantization Parameters panel of the tool.
    
    
11. Set the following fields in the Set Quantization Parameters panel:
• Select the Turn quantization on check box.
• Click the Optimization button, which will open the Quantized Optimizations dialog.
• Select the Do not quantize coefficients that are exactly equal to 1 and the Adjust coefficient fraction length such that coefficients do not overflow check boxes.
  
  
• Click OK in the Quantized Optimizations dialog.

1. The Set Quantization Parameters panel should now appear as follows.
   
   

12. Click the Realize Model button on the bottom left of FDATool. This brings forward the Realize Model panel of the tool.
    
    
13. Click the Realize Model button. A block for the new filter appears in your model.
    
    

Note    You do not have to keep the Filter Realization Wizard block in the same model as your Filter block. However, for this tutorial, we will keep the blocks in the same model.

14. Double-click the Filter block in your model. This will bring up the realization of the filter being represented by the block.
    
    

Part 1 -- Creating a Signal with Added Noise

Part 3 -- Building a Model to Filter a Signal