Synchronization, Channel Estimation And Optimal Allocation Techniques For OFDMA Communication Systems

With high spectrum efficiency, large capacity and immunity for multipath fading, orthogonal frequency division multiplexing access (OFDMA) technique is one of key skills in the fourth generation of mobile communication. In this paper, we discuss the basic principle of OFDMA system, and propose a whole design of transceivers both in BS and in user terminal end. In the system synchronization aspect, we point out the effects of the carrier frequency offset, sampling offset, and symbol timing offset to the system, and investigate the estimation algorithms of carrier frequency offset and timing offset based on polyphase filter banks. In the channel estimation aspect, we investigate the algorithms based on pilot symbol. Accordingly, we propose a series of amendments and new algorithms for synchronization and channel estimation. We also discuss the optimal subcarrier, bit and power allocation algorithm in brief. Finally, we analysis and compare the effectivity and feasibility of these algorithms with Matlab software simulation.