On the gains of fixed relays in cellular networks with intercell interference

In this paper, we consider a cellular network assisted by fixed relay stations (RS), which are used by mobile stations (MS) to access the base station (BS) via a relaying strategy, namely Amplify-and-forward (AF) and Compress-and-forward (CF). We analyze the achievable sum-of-rates for uplink communications. It is assumed that mobile signals and relay signals are emitted on orthogonal bands, with the possibility of having a larger bandwidth (BW) on the relay-to-base links. Our key result is that with a relay bandwidth just twice that of the mobile´s bandwidth, the system capacity approaches that of an ideal distributed antenna system (DAS), while the ideal DAS requires new backhaul links with very high capacity. Moreover, with the successive interference cancellation (SIC) decoder at the BS, it is shown that under certain conditions the fairness performance in terms of minimum user rates achieved by relay-assisted cellular systems is the same as that of an ideal DAS.