Modeling and Simulation of FIR Filters and Comparison of Frequency Response in Time Domain and Frequency Domain for UMTS

FIR filter is a type of digital signal processing filter whose impulse response is of finite duration because it settles to zero in finite time. FIR filters are used in a range of digital signal processing application and communication area. The main objective of this paper is to modeling and simulation of FIR filter in frequency domain for the UMTS standard and to obtain its advantage over time domain implementation. In this paper firstly we present two FIR filters one in time domain and other in frequency domain. Then we abstract the filter coefficient for time domain implementation and frequency domain implementation of FIR filter by sampling both representation of root raised cosine (RRC) filter. All modeling and simulation performed using MATLAB software. A comparison between a classical time domain FIR implementation, and frequency domain implementation, in terms of computational complexity, Inter symbol interference rejection on the basis of average gain in immunity against ISI, Error Vector Magnitude (EVM) and peak distortion is presented. It is found that frequency domain implementation of FIR filter is better than time domain implementation of FIR filter in all respects. This advantage of FIR filter implementation in frequency domain makes it suitable for its use in 3G communication system.