基于泊松点过程分布的多蜂窝协作系统中干扰对齐技术研究

Research on Interference Alignment Technique in Multi-cell Cooperative Systems Based on Poisson Point Process

在多蜂窝MIMO(Multiple-Input Multiple-Output)协作通信系统中,该文研究了基站站点服从泊松点过程(PPP)分布时,协作基站(BSs)和用户对采用干扰对齐技术的中断概率和网络吞吐量性能,推导了完全信道状态信息(CSI)和部分CSI两种情况下的上述性能的解析表达式,并分析了系统性能与协作参数的单调关系。仿真分析发现:在完全CSI情况下,网络吞吐量随着基站密度、协作基站数、天线数的增加而增加;在部分CSI情况下,由于综合考虑了信道训练和有限反馈带来的资源开销以及量化CSI引入的信道失真,存在一个使网络吞吐量最大的最优协作基站数,当天线数较少或用户移动速度较小时,应有较多的基站参与协作,当天线数较多或用户移动速度较大时,应适当减少协作基站数。

In the multi-cell MIMO （Multiple-Input Multiple-Output） cooperative communication system, the performances of outage probability and network throughput of interference alignment applied by the cooperative Base Stations （BSs） and users are investigated when the locations of the BSs follow Poisson Point Process （PPP） distribution, and the analytical expressions of the above performances are derived under the conditions of perfect Channel State Information （CSI） and imperfect CSI, respectively. The monotonic relationships between the system performances and the cooperation parameters are also analyzed. The simulation analyses reveal that, under the condition of perfect CSI, the network throughput improves with the increase of BS density, the number of cooperative BSs and the number of antennas; under the condition of imperfect CSI, considering both the resource overhead of channel training and limited feedback and the channel distortion induced by quantized CSI, there exists an optimal number of BSs which can maximize the network throughput. When the number of antenna is small or the velocity of mobile user is not so high, more BSs are expected to participate into the cooperation, and when the number of antenna or the velocity of mobile user is large, the number of cooperative BSs should be appropriately reduced.