Diversity–Multiplexing Tradeoff of the Half-Duplex Slow Fading Multiple-Access Relay Channel Based on Generalized Quantize-and-Forward Scheme

This paper investigates the diversity-multiplexing tradeoff (DMT) of the generalized quantize-and-forward (GQF) relaying scheme over the slow fading half-duplex multiple-access relay channel (HD-MARC). The GQF scheme takes into account the multiuser interference at the relay compared with the original quantize-and-forward scheme. The compress-and-forward scheme achieves the optimal DMT for high multiplexing gains when the channel state information (CSI) of the relay-destination (R-D) link is available at the relay. However, having the CSI of the R-D link at relay is not always possible due to the practical considerations of the wireless system. In this paper, the DMT of the GQF scheme is derived without R-D link CSI at the relay. Moreover, the GQF scheme achieves the optimal DMT for the entire range of multiplexing gains.