Study On MIMO-OFDM Technology Based On WMAN

Future wireless communications is developing with higher data-rate, wider ranging and higher mobility. Meanwhile, it raises even larger demand on capacity and quality of communication systems. Recently, Wireless Metropolitan Area Network (WMAN) technology has been developed to meet the requirements of the advanced wireless communications. IEEE 802.16 is the standards of WMAN technology. It can support both the fix and the mobile broadband wireless access approaches.Research has shown that Multiple Input and Multiple Output (MIMO) technique can achieve very high data transmission rate on band limited frequency spectrum. In addition, Orthogonal Frequency Division Multiplexing (OFDM) technique has attracted much attention for its high tolerance to multi-path fading. Therefore, MIMO-OFDM techniques, widely regard as a most promising elution, are efficient for wideband multimedia transmission because of its high ability of anti fading, high channel capacity and high bit-rate data.Based on existing works on MIMO and OFDM, this paper focuses on architecture and application of MIMO-OFDM technique in IEEE802.16-based wireless communications. Beginning with the construction of MIMO channel model, the frame synchronization, carrier frequency offset estimation, channel estimation and space-time/frequency coding approaches are investigated in this thesis. An improved space-time coding scheme for IEEE802.16-based OFDM communications is proposed. Simulations by using Matlab language are carried out and the results show that the new scheme is feasible.Specifically, a simulation platform for MIMO-OFDM WMAN research, including the transmitter, channel as well as the receiver, is presented in this thesis. The SUI channel model which is recommended by the IEEE 802.16d working group is used in the simulations. Performance of each module of the system is examined.