A Common Transceiver Design for Nonregenerative Asymmetric and Symmetric Two-Way Relaying With Relaxed Antenna Constraints
Rohit Budhiraja, Ajit Kumar Chaturvedi · IEEE Transactions on Vehicular Technology · 2017
We investigate a novel multiple-input multiple-output common transceiver design for conventional symmetric and recently proposed asymmetric two-way relaying (TWR). In conventional symmetric TWR, a user exchanges data with a base station. Both base station and user can cancel back-propagating interference (BI). In asymmetric TWR, the base station performs TWR with two different users-a transmit-only user and a receive-only user, which experiences BI. The existing asymmetric TWR transceiver designs constraints the number of relay antennas to cancel the BI. The proposed transceiver relaxes these antenna constraints and works seamlessly for both asymmetric and symmetric TWR. Furthermore, the design also enables TWR communication between multiple users and a base station. The proposed design is also shown to have lower complexity than the existing designs. For the proposed transceiver, we maximize its sum rate using geometric programming for different TWR scenarios. We demonstrate using exhaustive numerical simulations that the sum-rate of the proposed design not only matches the best known designs in asymmetric and symmetric TWR literature, but also outperforms them for certain antenna configurations.