FIR Filter Design with Kaiser Window

Filters play a major role in designing signal processing systems. Between analog filters and digital filters, digital filters are superior to the analog filters in many aspects. When designing, two types of digital filters can be observed based on their impulse response.

• FIR filters Finite extended Impulse Response
• IIR filters Infinite extended Impulse Response

There are two methods to design FIR digital filters,

• Windowing method
• Weighted Chebyshev method

Detailed descriptions of the two methods are available in [1]. Amongst these two methods, the windowing method is simpler than optimizing method. Windowing method is used in conjunction with the Fourier Transform. In this method, the infinite length of the Fourier Transformed transfer function is truncated using a window function. Text [1] includes several different window functions. Among all the window functions, Kaiser Window contains adjustable main lobe width and a ripple ratio, resulting high quality filter transfer function which fulfills all the specifications.

This report contains the manual design and implementation of the digital FIR band pass filter using the Kaiser Window method. Since parameter values such as main lobe width, transition bandwidth and ripple ratio can be adjusted in the Kaiser window, it provides a high quality filter which satisfies all the specification requirements and meets all the aspects of the FIR filters.

Click here to generate Kaiser Window manually using the MATLAB software without using in built functions.

Reference

1. A.Antoniou, Digital Signal Processing : Signals, Systems and Filters, McGraw-Hill,
2006.