In this letter, we propose a beamforming and combining scheme for a two-way amplify-and-forward protocol-based communication between two multi-antenna earth stations, via a single antenna satellite relay. Under the shadowed-Rician fading, an approximate expression for the symbol error rate of the scheme is obtained based on the moment generating function (MGF) of the instantaneous received signal-to-noise ratio. The proposed expression of MGF contains finite number of summations of the Meijer-G function. By using an asymptotic property of the Meijer-G function, the analytical diversity order of the proposed scheme is also obtained. It is shown by simulations that the considered two-way satellite relaying scheme can overcome the shadowing with improved diversity by increasing the number of antennas at the earth stations.