Study On Achievable Rate For Massive MIMO Systems In Ricean Channel

Although traditional small scale multiple-input multiple-output(MIMO)wireless communication technology has been increasingly developed into mature,the spectrum efficiency,energy efficiency and reliability of the performance limitation still exist.Therefore,in 2010 Marzetta proposed massive MIMO technology,which through in-creasing the number of antennas of base station,to take good advantages of the wireless resources of spatial dimensions and improve the performance limitations of small scale MIMO and improve the capacity of the system.Due to the massive MIMO can reduce the transmit power effectively and improve the system performance and many other advantages,which has become one of the most challenging and the most potential re-search direction of 5G mobile communication.However many aspects of this technolo-gy are in the initial stage.Especially the analysis of performance and scheme design for large scale MIMO system in Ricean channel model.Firstly,this paper analyzes the performance of multiuser Ricean Fading channel with uplink system.For system with imperfect channel state information(CSI)and per-fect CSI two cases,respectively at the receiver using MRC and ZF two kinds of linear detection technology to detect,then analyses the achievable rate and the characteristics of the power scaling in some detail,and simulates these theoretical results.The simula-tion results show that without decreasing the performance of rate and the transmit power of each user can be reduced to 1/M,in which M is the number of base station an-tennas,whether it is in a perfect CSI or imperfect CSI.With the increasing of the Ricean factor,in addition to the perfect CSI with ZF detection technology the achievable rate gradually decreases and tends to a fixed value,the achievable rates of other cases are increased with the increasing of the Ricean factor and tend to a constant value.In order to avoid the pilot contamination,then this paper proposes the system scheme based only on line-of-sight(LOS)component and analyses the performance of the achievable rate.Especially,in the equal gain combining detection technology,anal-yses the characteristics of the power scaling of new scheme,which discovers the trans-mit power of each user can be the most scaled down by 1/M.Then we spread to the relay system,and we firstly proposes the achievable rate expressions with one-pair two-way amplify-and-forward relay system and upper bound expressions under three power scaling scheme,which also extend to multi-pair.Then we analyse simulation of the theoretical results.The results show that with the increasing number of relay station antennas,Ricean factor and user transmit power,respectively,the achievable rate with the three cases converges to be a fixed value.When M ??,the achievable rate can be maintained when the transmit power of each user is scaled down by 1/M or the re-lay power is scaled down by 1/M.