Performance Analysis of WiMAX with Different Modulation Techniques

Abstract: Worldwide Interoperability for Microwave Access (WiMAX) is one of the most developing technology in modern wireless communication system for providing voice, data, video and multimedia services on mobile phones at high speeds, cheap rate & unwired transmission. The physical layer of WiMax emphasis on Orthogonal Frequency Division Multiplexing (OFDM) signals. OFDM is a parallel transmission scheme, where a high – rate serial data stream is split up into a set of low – rate sub streams, each of which is modulated on a separate subcarrier. Increasing the number of parallel transmission reduces the data rate that each individual carrier must convey and that lengthens the symbol period. However, in OFDM, no frequency diversity is exploited to improve Bit Error Rate (BER) performance. Today’s OFDM systems attempt to overcome this limitation by application of channel coding and interleaving, which requires a reduction in throughput. OFDM uses different type of modulation and encoding schemes to improve BER performance. In this paper we study WiMax with OFDM transmission system and compared WiMax system by using different modulation schemes such as QAM and QPSK modulation over multi-path fading channels at the cost of small increase in complexity.

Keywords: WiMAX, OFDM, BER