A Novel Two-Way In-Band Full-Duplex Cooperative System

In this paper, an in-band full-duplex based two-way cooperative (TWC) scheme is presented where, both downlink and uplink transmissions by two users are accommodated in two phases. We consider a system when a node can be a relay with its own communication requirements. A relay user receives far user's downlink data from a base station (BS) and uplink data from a far user, and can transmit its own uplink data to BS in phase 1. Then, the relay user delivers far user's data by decode-and-forward strategy through exclusive OR operation, and receives its own downlink data from BS in phase 2. Considering the traffic features of delay-sensitive uplink and high rate downlink, we adopt a power allocation with high-priority uplink transmission and opportunistic downlink transmission. Analysis on outage probability and ergodic rate is provided and validated by Monte Carlo simulations. It is demonstrated that TWC scheme outperforms one-way cooperative non-orthogonal multiple access scheme in terms of ergodic rate and uplink outage probability under reasonable self-interference cancellation capability.