Capacity Analysis And Energy Efficiency Performance In Massive MIMO System

With the rapid growth of the number of wireless mobile communication devices,the demand for higher rate of wireless mobile communication systems is also increasing.Considering the massive MIMO technology can effectively improve the spatial resolution and array returns of the mobile communication system,large numbers of users can still maintain a high robustness in the presence of strong user interference in the communication system,which can make the transmission rate and capacity of the system to get a big promotion.However,when the number of base stations and the number of users increases step by step,a variety of interference and energy consumption will also increase,which will bring a negative impact on the performance of the system.How to further improve the capacity of the system on the basis of reducing interference and energy consumption has become the keynote of research.So,based on the depth analysis of several existing massive MIMO system models,corresponding improvement schemes are proposed to improve the system capacity in this paper.(1)considering the resource allocation strategy for massive MIMO technology,a new full pilot allocation scheme is proposed based on the RZF encoding scheme,to optimize the channel vectors in the RZF precoding matrix by assigning the limited orthogonal pilot signals to the cell users,and then get the full pilot regularization precoding matrix.In addition,the configuration relationships are optimized at the basis of comprehensive consideration of the base station antennas,the number of users and the pilot frequency reuse factor,and thus suppress more inter cell interference with less user information and higher pilot reuse factors.Simulation results show that the improved full pilot scheme can effectively improve the total capacity of the system.(2)A joint design of precoding and signal detection scheme is proposed in massive MIMO single cell system,by using RZF precoding at the base station to balance the effect of interference between users and noise interference and then use the excellent detection performance of MMSESIC algorithm in the receiver to further reduce the interference signal and achieve the purpose of improving system capacity.The results show that the improved algorithm combined with RZF precoding and MMSE-SIC detection in this paper has good applicability when the interference between users is large.(3)A RVQ quantization scheme for the hybrid ADC of massive MIMO system under the Leslie channel is proposed.Under the working mode of FDD,a reception scheme with high resolution ADC and low resolution ADC is used at the base station to process signals and make the received pilot signal as well as the useful signal have high conversion precision.Then deal with the CSI by using RVQ scheme to reduce the feedback overhead of the system.Finally the MMSE signal detection technique is used to reduce the interference caused by the quantization error,thus cut down the energy consumption and the loss of system performance.