Transceiver Design for Multi-user Multi-antenna Two-way Relay Cellular Systems

TL;DR

This paper develops interference-free transceiver designs for multi-user two-way relay cellular systems with multi-antenna base stations and relay stations, optimizing sum rates and proposing low complexity schemes.

Contribution

It introduces a low complexity transceiver scheme that balances uplink and downlink rates, closely approximating optimal performance achieved by alternating optimization.

Findings

Proposed scheme outperforms existing zero forcing and signal alignment methods.

Performance gap between low complexity scheme and optimal optimization is minimal.

Simulation results validate the effectiveness of the proposed transceiver design.

Abstract

In this paper, we design interference free transceivers for multi-user two-way relay systems, where a multi-antenna base station (BS) simultaneously exchanges information with multiple single-antenna users via a multi-antenna amplify-and-forward relay station (RS). To offer a performance benchmark and provide useful insight into the transceiver structure, we employ alternating optimization to find optimal transceivers at the BS and RS that maximizes the bidirectional sum rate. We then propose a low complexity scheme, where the BS transceiver is the zero-forcing precoder and detector, and the RS transceiver is designed to balance the uplink and downlink sum rates. Simulation results demonstrate that the proposed scheme is superior to the existing zero forcing and signal alignment schemes, and the performance gap between the proposed scheme and the alternating optimization is minor.