Research Of Energy Efficiency Optimization Algorithms In Distributed MIMO Systems

With the rapid development of mobile Internet, broadband multi-media service is becoming the dominant service, and the requirement of wireless access rate is growing larger and larger. However the available frequency resource is being tenser and tenser. The new wireless transmitting technologies based on Multiple Input Multiple Output(MIMO) or Multiple Input Multiple Output Orthogonal Frequency Division Multiplexing(MIMO-OFDM), which are key technologies of the next mobile communication system, have largely promoted the link performance. Meanwhile, the expansion of communication industry has intensified the global energy consumption and environment pollution. Therefore, green communication becomes the new hotspot of the communication field.The dissertation has researched on energy efficiency optimization in distributed MIMO and distributed MIMO-OFDM systems. The structures of distributed MIMO and distributed MIMO-OFDM systems have been analyzed deeply. To improve energy efficiency, we focus on a series of researches on antenna selection,and joint antenna selection and power allocation, which are one-dimension resource allocation and resource co-allocation respectively. The main works are as follows:(1) According to the structural feature of distributed MIMO systems,we propose a clustering selection algorithm with large scale fading channel information. Antenna selection range is effectively reduced by using the method of clustering, and iterative algorithm is applied to update parameters. Simulation results show that the proposed algorithm could reduce computation complexity, and improve energy efficiency of distributed MIMO.(2) On the basis of clustering selection algorithm, we further propose incremental algorithm for energy efficiency. The proposed algorithm utilizes the way of several local optimal solutions to approach the global optimal solution to improve energy efficiency of distributed MIMO. Simulation results show that energy efficiency of the proposed algorithm could approach the optimum.(3) The multi-dimension resource co-optimization idea in distributed MIMO-OFDM systems is discussed. On the basis of fast antenna selection and sub-gradient power allocation, we propose a sub-optimal energy efficiency optimization algorithm which joints fast antenna selection and sub-gradient power allocation. The proposed algorithm could tend to the optimal energy efficiency of MIMO-OFDM.