Research And Implementation Of Space-Time-Frequency Wireless Channel Simulator

Multiple input multiple output system is one of the big breakthroughs in recent research of wireless communication. MIMO technology is a spatial diversity technique which is used to increase the transmission rate, enhance the system capability and improve the transmission quality in the power and spectrum limited wireless channel. In order to make good use of MIMO technology, we must study characteristics of MIMO channels, especially the spatial characteristics. In most cases, they are not independent between any of two antennae in the multiple-antenna channels and there are spatial correlations, while in conventional channels all antennae are independent. Consequently, the correlation characteristics of MIMO channel should be studied to found the integrated wireless channel model which reflects the fading characteristics of the space, time and frequency domains, and therefore, the study and performance analysis of MIMO system will be more convenient.The evolution and development of MIMO wireless channel models and modeling techniques were surveyed at the beginning of the thesis, and then the development of channel simulator based on hardware was investigated. A variety of concentrated problems and fundamental questions are summarized, and consequently the main topic of this thesis is introduced.Firstly, the MIMO channel models and modeling methods were summarized, in the main body of this thesis, and the merits and shortcomings of these methods were given. Then, the spatial correlation characteristics in three kinds of distributions as well as their effects on channel capability were discussed. A simulation platform of the wireless MIMO channel was founded using Matlab and also the results were analyzed and demonstrated. Besides, an implementation scheme of MIMO channel simulator was provided based on hardware. In addition, a DSP-based MIMO channel simulator was designed using this scheme. At last, an object-oriented man-machine interface was developed for parameters passing, and therefore the integrated MIMO channel simulator system was facilitated and more flexible.It can be verified that the designed MIMO channel simulator reflects the characteristics of the real channel from the investment of the whole MIMO channel simulator system. Moreover, the number of antennas in the transmitter and receiver can be selected randomly in the designed simulator, and the hardware can be easily implemented that better quality-value ratio can be realized. To sum up, the designed MIMO channel simulator is quiet flexible and effective.