蜂窝网络下行链路中基于干扰图的干扰对齐算法

The Technology of Interference Alignment Based on Interference Graph in the Downlink of Multiuser Cellular Networks

针对多用户蜂窝网络的下行链路,提出了基于干扰图的干扰对齐算法。首先用干扰图表示蜂窝网络的小区间干扰(ICI)分布,每五个相邻小区划分为一簇。然后在簇内先根据对称信道和不对称信道,分别设计接收波束赋形矩阵将四个ICI对齐到两个干扰子空间,再设计发送波束赋形矩阵与干扰子空间正交。最后通过簇的平移实现蜂窝网络内所有活动小区的干扰对齐。该算法减少了基站和用户的天线数及计算复杂度。仿真结果表明所提算法消除了ICI、用户间干扰(IUI)及簇间干扰,有效提高了蜂窝网络容量。

For the downlink of multiuser cellular networks with two users per cell,an interference alignment algorithm based on interference graph is proposed. We first select five adjacent cells to be partitioned into a small cluster from the interference graph which represents the distribution of inter-cell interference. For the symmetric and asymmetric channels,we design the receive beamforming matrices to align all the inter-cell interference or group inter-cell interference into a subspace separately. Then,consider the inter-clusters interference,we can also align it to inter-cell interference subspace.And the transmit beamforming matrices orthogonal to the interference subspace which is figured out in clusters. Finally,we can achieve the interference alignment of all the active cells in the cellular networks by clusters＇ translation. The proposed algorithm can reduce both the transmitting and receiving antennas and the computational complexity. Simulation results show that the proposed algorithm eliminates the inter-cluster interference,inter-users interference and inter-clusters interference simultaneously. It effectively improves the capacity of the cellular networks.