Opportunistic full-duplex relay selection for decode-and-forward cooperative networks over Rayleigh fading channels

The performance analysis of optimal relay decode-and-forward (DF) selection for both the full-duplex (FD) and half-duplex (HD) relaying modes is studied, with some important factors such as the distributions of the received signal-to-noise ratio (SNR), the outage probability and the average channel capacity, etc., being taken into account. Different from the conventional relay selection schemes, the trade-off between the FD and HD modes is studied, with the former suffering from the impact of residual self-interference while the latter consuming more channel resources than the former by allocating two orthogonal channels for transmission and reception. The optimal power allocation (OPA) subject to individual power constrains (IPC) and sum power constrains (SPC) are also analyzed in the proposed FD scheme. In particular, the exact closed-form expressions for outage probability of the proposed FD relay selection scheme over independent and identically distributed (i.i.d.) Rayleigh fading channels are derived in this paper, with the validity of the proposed analysis being proven by simulation. It is also shown that the proposed FD scheme outperforms the HD mode in terms of average channel capacity by about 33.1%, provided that the self-interference can be successfully suppressed below the noise power level.