Optimal collaborative resource allocation in multi-carrier two-way relay networks

Assuming a bidirectional communication scheme, we study the problem of collaborative resource sharing between two transceiver pairs in a multi-carrier scenario. The primary pair which owns the spectral resources, is required to have a guaranteed rate between its users. Assuming no direct link between the users in each pair, the primary network allows a secondary pair, which owns the relay infrastructure, to use the spectral resources in order to establish a bidirectional communication between its transceivers. In exchange for this cooperation, the primary pair utilizes the relay infrastructure, thereby enabling a two-way communication between its transceivers. Considering an amplify-and-forward relaying scheme in each subchannel, the relays collectively build two network beamformers each of which enables communication between the two transceivers in one pair. Aiming to optimally calculate the parameters of the two networks, we investigate the problem of maximizing the secondary network average sum-rate subject to two spectral power masks for the two networks while providing a minimum sum-rate to the primary pair in a multi-relay scenario. We show that this design problem can be cast as a linear programming problem, hence it can be solved efficiently.