Space-Time Line Coded Regenerative Two-Way Relay Systems with Power Control

In this Letter, a general space–time line code (STLC)-based two-way relay (TWR) method is proposed to enable a power control for individual data streams transmitted to source nodes. Optimal power control factors are derived to ensure fairness between two source nodes under per-antenna power constraints. When the two-way channels are unbalanced, numerical results verify that the proposed method outperforms the existing TWR methods, an STLC TWR method without power control, and a space division multiple-access-based TWR method.