Optimal spectrum leasing and network beamforming for two-way relay networks

We propose a resource sharing scheme between a primary pair (which owns the spectrum resources) and a secondary pair (which owns a relay infrastructure) in a collaborative manner. The secondary network allows the primary pair to use the relays in order to establish a bidirectional communication between its transceivers. In exchange for this cooperation, the primary pair assigns a portion of its spectral resources to the secondary pair, thereby enabling a two-way communication between the secondary transceivers. Assuming an amplify-and-forward relaying scheme, the relays collectively build two network beamformers, each of which enables communication between the two transceivers in one pair. We propose a max-min optimization problem to calculate the two network parameters in semi-closed forms.