A Practical Semidynamic Clustering Scheme Using Affinity Propagation in Cooperative Picocells

Coordinated multipoint (CoMP) is corroborated to be an effective technology in mitigating cochannel interference (CCI) and enhancing system performance in picocell systems, which consist of a large number of pico base stations (BSs). In picocell systems, effective CoMP clustering schemes could provide significant gains of system performance such as throughput and cell-edge spectrum efficiency (SE). Moreover, an intrinsic problem of densely deployed networks is the cost of signaling overhead and data exchange between BSs in clusters. In this paper, a novel semidynamic clustering scheme based on affinity propagation for CoMP-Pico is presented to maximize user SE and throughput under the constraint of backhaul cost. Our proposed scheme consists of online and offline stages that can achieve good performance and low complexity. Simulation results show that the proposed scheme yields significant gains of SE and throughput and low running time compared with the existing clustering schemes.

I. Introduction

In heterogeneous small-cell networks (HetSNets), the massive deployment of small base stations (BSs; such as pico BS and femto BS) will cause a serious cochannel interference (CCI) problem [1]. A coordinated multipoint (CoMP) transmission/reception technique is proposed as a key approach to resolving it efficiently. Moreover, CoMP, together with HetSNets, can improve the system coverage and user spectrum efficiency (SE) in Long-Term Evolution Advanced [2]. There are four different scenarios considered for CoMP, including joint transmission, dynamic point selection, dynamic point blanking, and coordinated scheduling/beamforming [3]. In this paper, we will focus on joint transmission, where several BSs form a coordination BS cluster (CBC) to jointly serve the users, where a proper scheduling scheme could mitigate CCI.