Performance of MIMO antenna techniques on IEEE 802.16E

WiMAX systems are based on the IEEE 802.16-2004 and IEEE 802.16e-2005 standards which define a physical (PHY) layer and the Medium Access Control (MAC) layer for broadband wireless access systems operating at frequencies below 11 GHz. Multiple-antenna techniques can be used to increase diversity and improve the Bit Error Rate (BER) performance of wireless systems, increase the cell range, increase the transmitted data rate through spatial multiplexing, and/or reduce interference from other users. In this paper we are going to discuss the use of multiple-antenna techniques in mobile WiMAX systems. We first present a general description of Multi-Input Multi-Output (MIMO) systems, which can be used for different purposes including diversity, spatial multiplexing and interference reduction. Next, we focus on the multi-antenna profiles adopted for WiMAX systems, discuss their relative merits, and address the implementation issues. Finally, we simulate the performance of the different MIMO techniques proposed by the WiMAX forum and compare the results.