Full-Duplex Mimo Relay System Design Based On Scma

Sparse code multiple access (SCMA) is a novel kind of non-orthogonal multiple access technology in which combines ideas of CDMA and OFDMA. It performs well in terms of large-capacity, low time-delay and high data rate and overcomes the deficiency, near-far effect, in CDMA. Coming after low density signature (LDS) technology, SCMA increases extra coding gain though the design of specific codebooks. On the other hand, full-duplex technology utilizes same-time and same-frequency transmission to realize "non-duplex" communication. However, it is crucial to minimize relay self-interference to render full duplex feasible. This paper innovatively combines SCMA with full-duplex multiple-input multiple-output (MIMO) relay, and illustrates the system model and self-interference mitigation scheme: time-domain cancellation and space-domain suppression. The theoretical derivation and simulation results demonstrate that the integration of the two kinds of technology can elevate system capacity and spectral efficiency.