Link Level Simulation Study of Downlink MIMO and Uplink HARQ in IEEE 802.16e Wimax System
The performance of the UpLink (UL) and DownLink (DL) of IEEE 802.16e-2005 or Worldwide Inter-Operability Microwave Access (WiMAX) standard is studied via extensive computer simulations in this paper. The channel estimation is introduced and its impact on the system performance is evaluated under different channel conditions. The main contribution is to address the impact of the Hybrid Automatic Repeat reQuest (HARQ) protocol on the WiMAX system performance. For DL, the schemes include Single-Input Single-Output (SISO), Alamouti Space-Time Block Coding (STBC), and spatial multiplexing, i.e., vertical coded 2 × 2 Multiple-Input Multiple-Output (MIMO).