Designing FIR and IIR Digital Filters for Low-Power Modems Using SIMULINK and VHDL

This paper presents a comprehensive study on the design and implementation of Finite Impulse Response (FIR) and Infinite Impulse Response (IIR) digital filters tailored for low-power modem applications. With the increasing demand for energy-efficient digital communication systems in Internet of Things (IoT) and mobile technologies, optimizing filters for power and performance is vital. FIR filters were designed using the windowing method, particularly the Hamming window, while IIR filters employed the bilinear transformation method to ensure stability and spectral accuracy. MATLAB was used for algorithmic design and frequency response analysis, whereas SIMULINK provided a dynamic environment to simulate real-time performance under varying signal conditions. The hardware realization was accomplished using VHDL, with synthesis and implementation carried out on FPGA platforms using Xilinx ISE. FIR filters were structured around a tap delay line architecture, offering inherent stability and linear phase characteristics, while IIR filters, though more complex due to feedback components, demonstrate superior power efficiency and sharper frequency cutoff characteristics. This study further explores the trade-offs between signal fidelity, computational complexity, and power consumption, providing insights through mathematical formulations, simulation results, and FPGA synthesis reports. Results indicate that FIR filters are advantageous in applications where linear phase response and stability are crucial, whereas IIR filters are preferable for constrained environments demanding minimal power usage. The comparative analysis suggests that filter selection should be application-specific, and future work may explore hybrid implementations that combine the advantages of both architectures for enhanced performance in next-generation communication systems.