Cooperative Fractional Frequency Reuse Based on Partial Connectivity Among Clients

This paper develops a novel fractional frequency reuse (FFR) technique to reduce co-channel interference in broadband cellular wireless networks. In contrast to methods proposed earlier, this technique relies on peer-to-peer connectivity among clients and is based on user cooperation: clients bargain for spectrum by exchanging channel quality metrics and jointly find the sub-channel allocation which maximizes throughput. Assuming full connectivity among clients, the spectral efficiency performance of client-centric FFR is studied analytically in conjunction with the use of opportunistic scheduling techniques that realize multiuser diversity gains with increasing network density and this serves as an upper bound on the achievable performance gain. The method is then extended to the clustered case, in which clients are partially-connected, a more typical situation in practice. Finally, a system-level study for an IEEE 802.16 based broadband cellular system in realistic propagation environments is conducted and demonstrates a promising performance gain.