The Simulation Research Of STBC-based MIMO-OFDM Wireless Communication System With High-speed Channel

This paper mainly studies a wireless mobile communication system which combines multiple-input multiple-output (MIMO) with orthogonal frequency division multiplexing (OFDM) technology under the high speed mobile channel. OFDM technology is a common way to effectively combat frequency-selective shading, and MIMO technology can be used to achieve diversity gain. Under the special channel of the high-speed mobile environments, frequency-selective and time-variety characteristics are two main factors affecting the quality of wireless communication system. By using MIMO-OFDM technology, the system can both overcome the impact of the frequency-selective fading and achieve the diversity gain, thereby reducing the inter-channel interference (ICI) caused by the time-varying channels.The paper uses classic Alamouti space-time block coding (STBC) as diversity means of MIMO system. Via the orthogonal design of STC at transmitter, the system can both achieve the diversity gain and simplify the receiver complexity. Firstly, MIMO and OFDM systems can be implemented respectively in the Matlab programming environment, and then we combine them together to design the MIMO-OFDM simulation platform based on STBC for high-speed mobile channel. In the simulation experiment, the channel uses the Clarke-Jack model to generate the fuction which simulates the amplitude fading of high-speed mobile channel, and the multipath fading channel is also taken into consideration. Finally, the paper simulates and evaluates the bit error rate performance of the classic Alamouti STBC based on the MIMO-OFDM wireless mobile communication system for two transmitting antennas and one receiving antenna under the high-speed mobile channel and flat Rayleigh fading channel. The simulation results show that the MIMO-OFDM system can be efficiently and effectively against the adverse distortions of high speed mobile channel, which can be applicable to high-speed railway communications system in the future (no less than350km/h).