TR2009-092

Opportunistic Cell Edge Selection in Multi-Cell OFDMA Networks



We propose an intercell downlink orthogonal frequency division multiple access (OFDMA) scheduling technique in a sectorized cellular network. Adjacent sectors from neighboring cells form a cluster and each OFDMA resource block is allocated to the rate-maximizing sector. Compared to a cellular network that uses conventional fractional frequency reuse (FFR) technique, our proposed system requires only slightly more backhaul traffic while providing an appreciable performance gain. Intercell scheduling, which grants a resource exclusively to the rate-maximizing cell within a cluster is a simple and powerful base station cooperation technique that balances non-cooperation and full cooperation. We find out that a tri-sectored network is particularly well-suited to applying inter-sector scheduling as each cluster is relatively isolated from other clusters. We provide an option to adjust the load on backhaul traffic by adjusting the granularity of the OFDMA resource under contention. We also provide an option to optimally swap resources. Analysis on performance gain for a few configurations are given. Simulations are provided to verify and illustrate the claimed performance gain.