Performance Comparison of Coded and Uncoded IEEE 802.16D Systems under Stanford University Interim (SUI)Channels

Abstract

Worldwide Interoperability for Microwave Access (WiMax), standardized asIEEE 802.16d is a popular technology for broadband wireless communication system. Orthogonal Frequency Division Multiplexing (OFDM) is the core of this technology.OFDMreduces Inter-symbol Interference (ISI) and hence improves system performance (i.e., Bit Error Rate (BER)). To improve system performance further error correction coding schemes have been included in WiMax. It is widely accepted thata coded system outperforms an uncodedsystem. But, the performance improvement of a coded system depends on the channel conditions. In this paper, we investigated and compared the performances of a coded and an uncoded WiMaxsystem under a practical channel model called Stanford University Interim (SUI). Different modulation schemes namely BPSK, QPSK, 16-QAM, and 64-QAM have been considered in this work. It is shown that the selection of codedoruncoded WiMaxsystem should depend on the channel condition as well as on the modulation used. It is also shown that anuncoded system outperforms a coded system under some channel conditions.