Channel Estimation Technology Research And FPGA Implement Based On OFDMA System

A broadband wireless technology based on IEEE802.16e, WIMAX (WorldwideInteroperability for Microwave Access) can provide high rate data, audio and videoservices in both fixed and mobile environment and meet all the requirements of mobility,broadband and IP-based architecture. It is a very promising wireless access technology.Among a variety of key technologies in WIMAX system, the OFDMA(Orthogonal Frequency Division Multiplexing Access) technology is studied in thisthesis. Firstly, through theoretical analysis, the principle and processes of OFDMAphysical layer are systematically investigated. A relatively integrated and feasiblescheme is proposed in this paper. Then the algorithms of channel estimation based onpilots are researched. Generalization estimation methods including LS, MMSE andLMMSE and several interpolation filter including linear interpolation, Gaussianinterpolation are introduced and compared their performance by simulation. Finally,according practical engineering system, the important parameters in LMMSE arecalculated and channel estimation are designed and implemented in detail based onFPGA (Field Programmable Gate Array),especially Plural on time-multiplier and guidefrequency extraction. And downside link based on IEEE802.16e OFDMA system issimulated.