Cellular Multiuser Two-Way MIMO AF Relaying via Signal Space Alignment: Minimum Weighted SINR Maximization

In this paper, we consider linear MIMO transceiver design for a cellular two-way amplify-and-forward relaying system consisting of a single multiantenna base station, a single multiantenna relay station, and multiple multiantenna mobile stations (MSs). Due to the two-way transmission, the MSs could suffer from tremendous multiuser interference. We apply an interference management model exploiting signal space alignment and propose a transceiver design algorithm, which allows for alleviating the loss in spectral efficiency due to half-duplex operation and providing flexible performance optimization accounting for each user´s quality of service priorities. Numerical comparisons to conventional two-way relaying schemes based on bidirectional channel inversion and spatial division multiple access-only processing show that the proposed scheme achieves superior error rate and average data rate performance.