Study On The Antenna Selection Technique Of The Distributed MIMO System In Wireless Network

The rapid development of mobile communication has greatly broadened the scope of business, and people’s demands have become more and more diversified, which put forward higher demands on the capacity of mobile communication system and rate. MIMO(Multiple Input Multiple Output) technique brings on the mobile communication with a new height.Because it has a good performance in improving the system capacity and frequency spectrum utilization rate, researchers have deep interests in it. Distributed MIMO system bases on the combination of MIMO technique and the distributed antenna system, and it effectively solves some problems of traditional MIMO system, such as reducing antenna correlation, shorting distance of signal access. Because it uses a distributed architecture, which has more antennas with sending and receiving, it has higher system capacity.However, the structural characteristics of MIMO system and distributed MIMO system have decided the system which needs more RF links. It leads to the cost of the whole system upgraded, and greatly increases the complexity of the system. Antenna selection technique could find a part of antennas which improve the performance of the system in all antennas for sending and receiving, and it also reduces the RF link. On the premise of ensuring system capacity, it reduces the system cost and complexity. It has a very good prospect of application in large scale distributed antenna system, Two-Way Relay and multiuser MIMO system.This thesis focuses on the research of the antenna selection algorithm in distributed MIMO system. We evaluate its performance from the perspective of channel capacity and computational complexity. Firstly, with building MIMO system channel model and analyzing the influence factors of the capacity, it presents the capacity formula of distributed MIMO system. By simulation, it has verified the results in the different channel environment.Secondly, the thesis mainly researches on several classical antenna selection algorithm, and compares from different aspects on the algorithms, then the results are validated by simulation.Then, it focuses on application of the antenna selection algorithms in distributed MIMO system, and it also has analyzed the performance of the classic algorithm in distributed MIMO system through the simulation.Finally, an improved decreasing selection algorithm is presented from two aspects which include system capacity and complexity. It could compare other algorithms with improved algorithm. The simulation results prove that the improved algorithm not only can approach to capacity of the optimal algorithm, but also effectively reduce the complexity of the system by simplifying the operation.