Resource Allocation Scheme for Multihop Cellular Networks Using Directional Transmission

Multihop cellular networks offer a cost-effective solution to the problem of achieving higher capacity and extending coverage by using relay stations (RSs) deployed within the coverage area of a base station (BS). We herein consider directional transmission based on adaptive beamforming in which multiple users are served at the same time using multiple directional beams; this represents one promising technology that could improve the capacity of multihop cellular network. In directional transmission, severe intra-BS/RS, inter-BS–RS, and inter-RS interferences can occur due to the concurrent transmission and accordingly, system performance can be degraded severely. In this paper, we propose resource allocation to maximize the system capacity of multihop cellular networks by taking into account these severe interferences caused in multihop cellular network using directional transmission. To alleviate the problem of high computational complexity, we propose a sub-optimal scheme. A heuristic scheme is also proposed which can be performed in distributed manner with lower computational complexity. Through simulation results, we show that the use of our proposed schemes increases system capacity.