Capacity of Gaussian Relay Channel with Orthogonal Components and Non-causal Interference at the Source

Abstract

In this work, we consider a relay channel model, with an out-of-band relay, in which the interference signal is available non-causally only at the source. The case in which the relay operates over different frequency bands with respect to the direct link is investigated. In particular, the source-destination (S-D), the source-relay (S-R) and the relay-destination (R-D) links are designed to be pairwise orthogonal. This may model a communication scenario in which the direct link (S-D) is parallel to the multihop channel (S-R-D). For this channel model, we establish the capacity of the Gaussian relay channel by showing that the developed upper and lower bounds are equal. In particular, the capacity results are obtained in which the relay may operate in either a full-duplex mode or a half-duplex mode.

Keywords: Relay Channel, Decode and Forward, Orthogonal Transmission Bands, Gaussian Channel.