Relay selection scheme using directional antennas for cellular networks

Cellular base stations are expensive to install as they require the operator to lease real estate and establish back-haul connectivity to the public network. With increasing demand for bandwidth, service providers are installing more and more relay base stations to supplement the main base station. Although relays help increase the coverage and capacity of the network, they also end up raising the net interference in the system. Decentralized relay selection algorithms that do not take interference into account, could end up under-using the capacity of the network. In this paper we propose a two-hop decentralized relay selection scheme using directional antennas that mitigates the effects of interference and performs better than the ldquonearest relay selectionrdquo algorithm in networks with less number of relay stations. Furthermore we propose a relaying scheme where the network adaptively chooses a relay selection algorithm to use, based on the current number of relay stations in the network.