Research On The Performance Analysis And Optimation In Heterogeneous Cloud Radio Access Networks

With the rapid development of emerging services such as intelligent terminals and multimedia,a trend of explosive growth has been shown in wireless data traffic,which puts forward higher requirements in data rate and coverage of the wireless communication networks.Incorporating the cloud computing into heterogeneous networks,the heterogeneous cloud radio access network(H-CRAN)has been proposed as a promising paradigm to enhance both spectral and energy efficiencies.In order to maximize the spectrum efficiency,the macro base stations(MBSs)and the remote radio heads(RRHs)share the same frequency,and this will lead to serious co-channel interference,which becomes one of the major bottlenecks in the improvement of the network performance.In order to effectively optimize the performance of the H-CRAN,precoding strategies for signal processing is critical,and it is a hot research topic in the wireless academic community.This paper focuses on two precoding schemes,namely interference collaboration and beamforming.The interference characteristics of network are analyzed,as well as the system performance metrics,including the overall outage probability,system capacity and average bit error rate,furthermore,the system throughout is optimized under resource allocation.The main contributions are listed as follows:Combined cloud computing with heterogeneous networks,an architecture of H-CRAN was proposed,and the existing precoding schemes are investigated;the two precoding schemes are employed at the MBS,namely the interference coordination and beamforming,further the SINR distribution of received signal for the MBS UE and RRH UE are analyzed,respectively.Based on the derived SINR distribution,expressions for the overall outage probability,system capacity,and average bit error rate under two precoding scheme are derived,simulation results demonstrate that the derived expression are accurate and effective.The relative performance between interference coordination and beamforming are compared under different system metrics.Under two kinds of precoding schemes,the optimization problem about the system capacity under a few constraints through collaborative radio resource allocation has been discussed.Simulation results have been shown to reflect the relationship between the optimization algorithm and system parameters,and a comparison between the two precoding schemes under the same scenario has been done.