Abstract
Because of the expansion in the wireless communication system, peoples develop Worldwide Interoperability for Microwave Access (Wimax) in order to achieve higher quality of internet. It not only improved the shortcoming of distance constraint in wireless local area network (WLAN), but also substituted for the wiring structure of wired network. This thesis focused on the design and implementation of an outer receiver processor based on IEEE 802.16 2004 specification. First, we explain the theory of every defining block in 802.16 2004, and derive pertinent algorithm for each block in order for later circuit design. Then we improve the decoder and demodulation structure to save the cost of hardware. The proposed outer receiver system is first simulated with matlab and VHDL. Finally we verify its correctness in FPGA. The decoder and demodulation are implemented with a new method. In the procedure of demodulation, the demodulator outputs the probability values instead of 0s and 1s which act like the metric values and can be used directly in the following soft-decision viterbi decoder. Therefore, it can save the hardware cost of metric computation in viterbi decoder while maintains acceptable processing speed. As a result, we can increase the sliding window size to improve the error-correction ability on user’s demand.