Multiple Input Multiple Output Wireless Communication Technology

The performance of wireless communication systems is restricted by the fading effects of multi-path propagations. With the rapid growth of wireless internet data services, it becomes very important to enhance the spectral efficiencies of wireless communication techniques. The multiple-input multiple-output (MIMO) is the most promising techniques to cope with these problems. But the wireless channels of MIMO have had the space characteristics and are highly complex. Although MIMO technology can improve the reliability and the achievable transmission rates in wireless systems, the improvement comes with the higher expense of hardware cost. Therefore, cost-effective implementation of MIMO technology remains a major challenge. In this dissertation by using ray-tracing propagation prediction method and statistical MIMO channel model, the performance of MIMO capacity was analyzed. The novel researches included in this dissertation are:1 Ray-tracing method for propagation prediction, MIMO channel model and the implementation of ray-tracing algorithm in C++ are given. And the methods about how to obtain the MIMO channel matrix and how to compute the MIMO channel capacity are proposed.2 The effect of antenna spacing of linear array on MIMO capacity is analyzed in indoor NLOS and LOS propagation environment by using ray tracing, and Rayleigh and Rician MIMO correlation channel models. In order to get the MIMO gains, the appropriate antenna spacing of the antenna array is suggested and the resultant MIMO gains of ray-tracing and statistical channel models are also compared.3 The effects on MIMO capacity of antenna array structures, i.e. linear antennas array, rectangular antennas array and circular antennas array, are analyzed in some typical indoor NLOS and LOS environments by using ray-tracing method. Some important results about how to design array structures to obtain optimum MIMO capacity are obtained.4 MIMO antenna selection methond is the key for implementing of a cost-effective MIMO system. The hybrid antenna selection algorithm which is used for setting a MIMO system with both maximum power and minimum correlation or minimum mutual information is given. The methods proposted can be used to simplify the computation, improve the performance of capacity in lower SNR region, and retain the performance almost entirely in other SNR region.