On the Optimization of Decode-and-Forward Schemes for Two-Way Asymmetric Relaying

In this paper, we consider a two-way asymmetric relaying channel with unmatched traffics from two sources. Aiming at maximizing the sum rate under a minimum rate constraint, we address the optimization problem (in terms of time and power allocation) for two decode-and-forward (DF) strategies, namely, the decode-and-forward with joint modulation (DF-JM) and the decode-and-forward with network-superposition coding (DF-NSC). Closed-form solutions under different relay settings are presented. Numerical results are provided to illustrate the performance gains due to the optimal resource allocation, as well as the achievable rate gaps between two different DF strategies.