Rate and Outage Analysis of Cellular User Assisted Full-Duplex Multicarrier Device-to-Device System

Full-duplex (FD) device-to-device (D2D) communication emerges as a promising technology to fulfill the spectral efficiency requirement for the fifth generation and beyond cellular networks. This paper presents rate and outage analysis for orthogonal frequency division multiplexing based FD D2D framework underlying cellular communications. The cellular user equipment (CUE) acts as a decode-and-forward (DF) FD relay for D2D communications. A selection algorithm is proposed to select CUE as a DF relay under certain and uncertain channel state information conditions. In addition, an expression is derived to calculate the distance between the CU-base station and the CUE-D2D transmitter considering a preset cellular and first-hop outage condition. An analytical closed-form expression for the outage probability is derived for CUE and D2D links. Moreover, the proposed framework achieves lower outages for larger distances while eliminating a separate relay cluster required for relay-assisted D2D arrangement. The simulation study closely matches the analytical results validating the mathematical model.