Indian Journal of Science and Technology

Abstract

WiMAX is the modern era wireless technology which gained popularity because of its efficiency, high coverage, scalability and high data rates in any terrain. WiMAX is a Wireless Metropolitan Area Network (WMAN) being used globally for broadband access. There is always a demand for improvement in systems, which in the case of WiMAX can be achieved by using a better coding scheme with a proper modulation technique. In this paper, a comparison has been made on performances of different forward error correction codes on two channels- AWGN and Rayleigh channel. AWGN channel simply adds white Gaussian noise to the signal transmitted through it whereas Rayleigh channel is a fading multipath channel whose characteristics vary continuously with time. The results show that Turbo codes perform the best amongst all the coding techniques, and AWGN channel response is much better than the response of Rayleigh channel. This is because there is no line of sight component in Rayleigh channel and having obstructions in the path of the signal leads to signal fading. These results are shown in this paper as graphical analysis between BER and SNR.

Keywords: Additive White Gaussian Noise (AWGN), Bit Error Rate (BER), Signal to Noise Ratio (SNR), Wireless Metropolitan Area Network (WMAN), Worldwide Interoperability for Microwave Access (WiMAX)