Distributed Beamforming for Two-Way DF Relay Cognitive Networks Under Primary–Secondary Mutual Interference

In this paper, we consider collaborative beamforming for a cooperative two-way relay spectrum-sharing system where a pair of secondary transceivers communicates via a set of secondary decode-and-forward (DF) relays in the presence of multiple primary transceivers. Among the available relays, only those that receive the signals reliably participate in the cooperative beamforming process and use net...