Asymptotic Performances of Near-Optimal Selective Distributed Beamforming for Two-Way Relaying with Partial Channel State Information

In this letter, we consider distributed beamforming (DBF) techniques for a two-way relaying network in which two sources exchange information through K intermediate relays under an aggregate power constraint. Especially, we construct a simple selective DBF that can be obtained at each relay with partial channel state information (CSI). By asymptotic analysis, the proposed selective DBF is shown to achieve full diversity gain K for each source and that the sum of capacities at the two sources increases as log K. Numerical investigation also shows that the selective DBF provides near optimum performance.