Performance of Full-Duplex AF Relaying in the Presence of Residual Self-Interference

Abstract

This paper investigates the error and diversity performances of full-duplex (FD) amplify-and-forward (AF) singlerelay systems under the effect of residual self-interference. The variance of this interference is assumed to be proportional to the λ-th power of the transmitted power (0 ≤ λ ≤ 1). The study considers the cooperative linear relaying protocol with direct source-destination link and the dual-hop scheme without direct link, both under uncoded and coded frameworks. At first, closedform pairwise error probability expressions are derived for the uncoded systems, which are then used to obtain tight bounds to the bit error rate (BER) of the coded systems. To shed an insight on the diversity behavior, asymptotic expressions at high transmission powers are also presented. Different from previous works that treat the direct link as interference, this paper shows that FD linear relaying systems with a suitable precoder can attain the same diversity function as their half-duplex (HD) counterparts. However, further analysis shows that HD orthogonal AF using a superposition constellation is asymptotically optimal in terms of maximum coding gain. In addition, it is shown that the diversity of FD dual-hop systems is a decreasing function of λ and is equal to zero when λ = 1. Although HD relaying is asymptotically optimal under the considered protocols and interference model, illustrative results show that FD relaying is advantageous at practical BER levels when λ is sufficiently small.

Outage probability of multi‐hop networks with amplify‐and‐forward full‐duplex relaying

“…Since the selfinterference is a bottleneck in full-duplex systems, its cancellation in analogue [3,8] and digital domains [4,9] has been widely studied. After applying the cancellation techniques there still remains inevitable residual self-interference (RSI) which is often modelled as Gaussian noise with a fixed variance [10].…”

Cognitive full-duplex relay networks under the peak interference power constraint of multiple primary users

“…Moreover, the effect of FD techniques on relay networks has attracted wide attention recently [14][15][16]. The authors in [17][18][19] investigated a FD, dual-hop, AF system, in which the self-interference variance was modeled as a function of transmit power. In [20], the authors studied different relay selection policies based on the availability of system's channel state information (CSI) at the source node of a multiple AF FD relay system.…”

Outage performance of relay-assisted transmissions in cognitive full-duplex relay networks

“…However, in the past, because of self-interference, full-duplex operation mode was considered impractical, but the improvement of antenna technology and signal processing techniques now make it feasible. Recently, several studies on full-duplex relaying take the effect of residual loop interference into account [21][22][23][24][25][26][27]. It should be pointed out that some of the above works only considered the non-cooperative dual-hop or multi-hop approach in full-duplex relaying with selfinterference [21,24] or completely ignored self-interference [21,23,25].…”

“…While these non-cooperative full-duplex relaying schemes allow the source to transmit continuously, their performances such as bit error rate and outage probability, have been shown to be severely degraded with the residual self-interference [23,24]. Recently, some authors have investigated the cooperative full-duplex relaying with the loop interference [26,27]. They studied the optimal power allocation scheme and the corresponding capacity limit of a full-duplex dual-hop amplify-and-forward relay system under residual self-interference in [26] and investigated the error and diversity performances of a full-duplex amplify-and-forward single relay system under the effect of residual self-interference in [27].…”

“…Recently, some authors have investigated the cooperative full-duplex relaying with the loop interference [26,27]. They studied the optimal power allocation scheme and the corresponding capacity limit of a full-duplex dual-hop amplify-and-forward relay system under residual self-interference in [26] and investigated the error and diversity performances of a full-duplex amplify-and-forward single relay system under the effect of residual self-interference in [27].…”