正交频分多址接入系统中双层毫微微蜂窝资源分配策略

Resource Allocation of Two-Tier Femtocells in OFDMA Networks

针对双层毫微微蜂窝全局频率复用引起的同信道干扰问题,提出了一种基于干扰协调的无线资源分配策略.基于瑞利衰落信道模型推出了层间干扰限制区域半径的表达式,以层间干扰限制区域半径为依据,在层间干扰限制区域半径内,通过分配正交子载波避免毫微微蜂窝的层间干扰,使蜂窝用户下行传输的中断概率满足服务质量(Qo S)要求.理论分析与仿真结果表明,本文策略能够选取合适的干扰限制半径,从而有效避免层间干扰,可为运营商资源分配提供参考.

To avoid the co-channel interference caused by the frequency reuse in two-tier femtocells,this paper proposes a resource allocation strategy based on interference coordination. Assuming the Rayleigh fading channel model,the radius of inter-layer interference restricted areas in two-tier femtocells is derived. By assigning the orthogonal subcarriers to users in interference restricted areas,the interference between femtocell-users within the interference restricted areas can be eliminated,and the downlink outage probability of the cell-users can be satisfied. Theoretical analysis and simulation results show that the proposed method can effectively avoid interference between layers,and thus,give a reference to select the appropriate interference limiting radius.