Distributed beamforming for two-way amplify-and-forward relay in cooperative networks

Distributed beamforming is a promising technology in wireless communication. In this paper, we consider its application in the context of AF-based two-way relay. With a full CSI assumption, we make effort to maximize the sum-rate of source nodes S₁ and S₂ by optimizing the design of beamforming weight vector. However, an optimal closed form solution can not be derived for such a problem. Alternatively, we study two sub-optimal algorithms in the criterion of minimization of sum inverse-SNR and maximization of the minimum SNR. A discussion about their performance was presented at last, as well as their advantages and disadvantages.