Abstract
Abstract
Worldwide interoperability for Microwave Access (WiMAX) is a broadband wireless technology based on IEEE 802.16 standard . A WiMAX cell which is to be considered in this study applies multicast mode of operation , the main limitation of maximizing the capacity of the system is the signal to noise ratio (subscribers near the base station apply 64 QAM and ¾ Reed Solomon code , while those which are near the border of the cell applies PSK and ½ Reed Solomon code to compensate for the S/N effect). Results indicate that better capacity is achieved by introducing Relay Stations (RSs) and Adaptive Antenna System (AAS) to the cell with TDD mode of operation, other factors like MAC and PHY layers overheads are studied and taken into account in the calculation of the system capacity .
Keywords : WiMAX , Overhead , Capacity , AAS , Relay Stations .
