Multi-User Relay Selection for Full-Duplex Radio

Saman Atapattu (1) , Prathapasinghe Dharmawansa (2) , Marco Di Renzo (3) , Chintha Tellambura (4) , Jamie Evans (5)

1 Swinburne University of Technology [Melbourne]
2 University of Moratuwa
3 L2S - Laboratoire des signaux et systèmes
4 University of Alberta
5 Department of Electrical and Electronic Engineering [Melbourne]

This paper investigates a user-fairness relay selection (RS) problem for decode-and-forward (DF) full-duplex (FD) relay networks where multiple users cooperate with multiple relays in each coherence time. We consider two residual self-interference (RSI) models with or without direct links. We propose a sub-optimal relay selection (SRS) scheme which requires only the instantaneous channel state information (CSI) of source-to-relay and relay-to-destination links. To evaluate performance, the outage probability of SRS is derived for different scenarios depending on RSI models and the availability of direct links. To further investigate, asymptotic expressions are derived for the high transmit power regime. For comparison purposes, i) the average throughputs of FD and half-duplex (HD) modes are derived; ii) non-orthogonal transmission is considered and its performance is discussed with approximations; and iii) the impact of imperfect CSI is investigated with the aid of analysis. While simulation results are provided to verify the analytical results, they reveal interesting fundamental trends. It turns out that a significant throughput degradation occurs with FD mode over HD mode when self-interference is fully proportional to the transmit power. Since all users can communicate in the same coherence time with FD mode, these joint RS schemes are useful for user-fairness low-latency applications.

Mots clés: Full-duplex communications; multiple-user networks; outage probability; relay selection; residual self- interference; throughput

Domaines: Informatique [cs]; Théorie de l'information [cs.IT]

Saman Atapattu, Prathapasinghe Dharmawansa, Marco Di Renzo, Chintha Tellambura, Jamie Evans. Multi-User Relay Selection for Full-Duplex Radio. IEEE Transactions on Communications, 2019, 67 (2), pp.955-972. ⟨10.1109/TCOMM.2018.2877393⟩. ⟨hal-02395808⟩