Optimal transmit power configuration for soft frequency reuse in irregular cellular networks

Optimal configuration of base station (BS) parameters is a key requirement in current cellular networks. For acceptable user (UE) performance, the bandwidth and transmit power parameters of each BS need to be intelligently chosen. Soft frequency reuse (SFR) is a resource allocation algorithm that specifies efficient frequency and power distribution for different locations within a BS. By classifying UEs into two regions based on their signal-to-interference-plus-noise ratio (SINR), SFR adjusts BS parameters to cater for the most vulnerable UEs. However, since typical cellular networks consist of irregular BS placements and varying UE distribution, more dynamic SFR models and schemes need to be developed. In this paper, we present an SFR implementation that provides optimal choices for macro BS transmit power in the different network regions. We show how edge UEs exposed to high levels of inter-cell interference (ICI) can be compensated based on a fairness index. The algorithm is well suited for irregular network deployments and is shown to guarantee edge UE capacity enhancement and a greater control over system performance.