Author(s)

Seyed Hamid Safavi, Mehrdad Ardebilipour

Faculty of Electrical and Computer Engineering, K.N.Toosi University of Technology, Tehran, Iran.

In this paper, we study the problem of distributed relay beamforming for a bidirectional cognitive relay network which consists of two secondary transceivers and K cognitive relay nodes and a primary network with a transmitter and receiver, using underlay model. For effective use of spectrum, we propose a Multiple Access Broadcasting (MABC) two-way relaying scheme for cognitive networks. The two transceivers transmit their data towards the relays and then relays retransmit the processed form of signal towards the receiver. Our aim is to design the beamforming coefficients to maximize quality of service (QoS) for the secondary network while satisfying tolerable interference constraint for the primary network. We show that this approach yields a closed-form solution. Our simulation results show that the maximum achievable SINR improved while the tolerable interference temperature becomes not strict for primary receiver.

Cognitive Radio; Two-Way Relay Networks; Beamforming

S. Hamid Safavi and M. Ardebilipour, "Distributed Relay Beamforming in Cognitive Two-Way Networks: SINR Balancing Approach," International Journal of Communications, Network and System Sciences, Vol. 5 No. 10, 2012, pp. 678-683. doi: 10.4236/ijcns.2012.510070.