MIMO techniques and full frequency reuse in mobile WiMAX systems

We first review recent developments in multiple-input multiple-output (MIMO) techniques for mobile WiMAX systems and discuss full-rate and high-rate space-time codes of low decoder complexity. Next, we discuss the frequency reuse issue in sectored cells and point out the limitations due to overlapping of antenna radiation patterns of adjacent sectors and the resulting interference. Then, we discuss several frequency reuse concepts for the uplink and for the downlink. Some of these techniques are half rate, while others are full rate, both of them providing transmit diversity.