Modeling Of Cooperative Diversity Of Multiple-Antenna Mobile Terminals In MIMO Systems And Analysis Of The Capacity

Multiple input multiple output (MIMO) 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. This can be well adapted to the demand of development of future wireless communication technology. Theories and practice have proved that technology of MIMO can largely improve the performance and capacity of wireless communication systems. Thus it has made a great progress and becomes one of the key technologies in the next generation of wireless communications.In recent years, researchers bring forward the concept of coordinative diversity, which basic thought is to bring the concept of ad-hoc networks and the way of networking to cell phone system, and achieve space multiplex and diversity gain like MIMO, by using spatial cooperative single-antenna terminals. However, multiple-antenna terminals are the inexorable trend in development. And there is still cooperation in MIMO wireless cell phone networks and therefore cooperative MIMO with multiple-antenna terminals will offer larger spatial diversity gain for wireless communications.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. In order to make good use of MIMO technology, we must study characteristics of MIMO channels, especially the spatial characteristics.We firstly introduce the MIMO system channel characteristics and based on that we focus on the fundamental models and average capacities of several typical channels. Secondly, we model single-node cooperative MIMO with multiple-antenna terminals and deduct its upper and lower bound of capacity from the aspect of information theory. And then we innovatively discuss the influence of all parameters on channel capacity in detail. Finally, we extend single-node cooperation to multiple-node cooperation and analyze its channel capacity, and discuss the influence of parameters like cooperative node on channel capacity.By discussing all parameters' influence on cooperative MIMO system's capacity, we conclude that cooperative MIMO with multiple-antenna terminals is capable to minish the spatial correlation among transmit links and enlarge channel capacity and therefore is a valuable referenced scheme for the development of large-capacity and high-rate wireless communications.