Improper Signaling for Virtual Full-Duplex Relay Systems

TL;DR

This paper explores how improper signaling and asymmetric time sharing in virtual full-duplex relay systems can mitigate inter-relay interference and enhance achievable data rates.

Contribution

It introduces a joint parameter tuning approach with asymmetric improper signals and time sharing to improve VFD relay performance under interference.

Findings

Achieves significant rate gains through joint parameter optimization.

Demonstrates effectiveness of improper signaling in interference mitigation.

Provides extensive simulations validating the proposed methods.

Abstract

Virtual full-duplex (VFD) is a powerful solution to compensate the rate loss of half-duplex relaying without the need to full-duplex capable nodes. Inter-relay interference (IRI) challenges the operation of VFD relaying systems. Recently, improper signaling is employed at both relays of the VFD to mitigate the IRI by imposing the same signal characteristics for both relays. To further boost the achievable rate performance, asymmetric time sharing VFD relaying system is adopted with different improper signals at the half-duplex relays. The joint tuning of the three design parameters improves the achievable rate performance at different ranges of IRI and different relays locations. Extensive simulation results are presented and analyzed to show the achievable rate gain of the proposed system and understand the system behavior.