IJSRD - International Journal for Scientific Research & Development| Vol. 3, Issue 06, 2015 | ISSN (online): 2321-0613

With the development and advancement of Internet, the demand of Wideband High data rate communication services is increasing. This triggered the demand of WiMAX as it supports high data rate and high capacity in mobile Broadband wireless access (BWA). IEEE 802.16e (mobile WiMAX) is better than IEEE 802.16d (fixed WiMAX) as it gives full mobility at vehicular speeds and better performance. The performance of mobile WiMAX is further enhanced by the use of FEC (Forward Error Correction Codes) and the MIMO-OFDM (Multiple input, multiple output-orthogonal frequency division multiplexing) techniques. The combination of FEC and MIMO reduces the possibility of errors and fading and hence enhances the BER performance and spectral efficiency. Further, Rayleigh channel is generally preferred for non line of sight propagation and in environment where multipath fading is more probable. In this paper a comparison is made between the diversity gains of MIMO systems (Spatial Multiplexing) and different modulation order in terms of BER for Zigzag coded QAM modulation scheme.