A Modified Directional Frequency Reuse Plan Based on Channel Alternation and Rotation

In previous work, we presented a novel Channel Alternation and Rotation (CAR) scheme that coordinates channel assignment with antenna directivities. In CAR, each cell type is allocated an extra channel set that provides network designer the flexibility to alternate and rotate channels according to nearest front lobe interference avoidant strategy to enhance co-channel interference ratio (C/I). CAR relaxes the constraints assumed in conventional reuse plans to allow deployment of smaller, unconventional reuse cluster sizes based on C/I requirements, thus increases frequency reuse efficiency. In this paper, we present a new reuse plan in which 2 extra channel sets are allocated to each cell type and assigned according to CAR strategy. This reuse plan, referred to as 2x(3+2), increases channel capacity by 20% in comparison with conventional 4x3 reuse plan while still provides signals above the minimum acceptable C/I margin. 2x(3+2) reuse plan is simple and can be implemented without costs.