Design of Digital Filters
K. C. Raveendranathan · 2024
This chapter considers advanced techniques for mitigating quantization noise in digital signal processing, focusing on the design and application of digital filters. It begins by discussing the properties and distinctions between Infinite Impulse Response (IIR) and Finite Impulse Response (FIR) filters, providing a detailed exploration of their design using MATLAB. FIR filters are impractical to design and build in the analog regime, due to the fact that analog delay lines are practically hard to build. Hence, almost all analog filters are IIR type. The chapter guides readers through the MATLAB-based design of digital Low-Pass Filters (LPF), High-Pass Filters (HPF), Band-Pass Filters (BPF), Band-Stop Filters/Band-Reject Filters (BSF/BRF), and Comb Filters; using the FilterBuilder App for intuitive filter creation. Special attention is given to digital all-pass filters and the design of moving average filters, emphasizing their roles in noise reduction and signal smoothing. Additionally, the chapter introduces wavelet denoising and Wiener filtering techniques as powerful methods for reducing noise while preserving important signal features. MATLAB exercises are integrated throughout, enabling readers to apply theoretical concepts to real-world scenarios and visualize the effects of different filters on digital signals. This chapter equips readers with the knowledge and tools to design and implement digital filters effectively, addressing quantization noise and enhancing signal quality in digital communication systems.