Multiple Antennas Technique Based On IEEE802.16d Standard

With the rapid development of wireless communications, the available bandwidth for wireless applications becomes more and more insufficient. Therefore, how to improve data rate without expending bandwidth becomes a key point in modern communication system design. Recently, orthogonal frequency division multiplexing (OFDM) technique and multiple antennas technique, which can be used to increase spectral efficiency and effectively combat with multi-path fading, is widely investigated around the world. As a result, OFDM system combined with multiple antennas technique is a promising approach for enhancing spectral efficiency and improving communication quality.In the thesis, three different system structures of MIMO-OFDM communication system are proposed. The performance of them are investigated .The research is based on the IEEE 802.16d indoor channel model standard. The core detail of the work is as follows.(1) Capacity of an MIMO-OFDM system utilizing both space diversity and polarization diversity is explored. For comparison, the capacity of a system only with space diversity is also analyzed.(2) A new scheme that applying antenna selection algorithm at the transmitter and utilizing beamforming technique at the receiver is suggested. Compared with traditional MIMO-OFDM communication system, the quality of proposed scheme has been significantly improved.(3) A scheme that selecting two optimal beams from directional multi-beams at the tranmitter is presented. In order to verify the validity, the proposed scheme is simulated by MATLAB software tool.(4) The multiple antennas OFDM communication system based on the LabVIEW platform is also designed and simulated, which including transmitter module, receiver module and channel model.