A Joint Design for Full-duplex OFDM AF Relay System with Precoded Short Guard Interval

TL;DR

This paper proposes a joint design for full-duplex OFDM relay systems that reduces guard interval length, improves spectral efficiency, and enhances BER performance by effectively managing residual self-interference.

Contribution

It introduces a novel joint design for precoding, power control, and equalization tailored for IIR channel models in full-duplex OFDM relays, reducing guard interval length.

Findings

Reduced guard interval length compared to traditional OFDM.

Improved spectral efficiency and BER performance.

Effective power gain control algorithm for residual self-interference.

Abstract

In-band full-duplex relay (FDR) has attracted much attention as an effective solution to improve the coverage and spectral efficiency in wireless communication networks. The basic problem for FDR transmission is how to eliminate the inherent self-interference and re-use the residual self-interference (RSI) at the relay to improve the end-to-end performance. Considering the RSI at the FDR, the overall equivalent channel can be modeled as an infinite impulse response (IIR) channel. For this IIR channel, a joint design for precoding, power gain control and equalization of cooperative OFDM relay systems is presented. Compared with the traditional OFDM systems, the length of the guard interval for the proposed design can be distinctly reduced, thereby improving the spectral efficiency. By analyzing the noise sources, this paper evaluates the signal to noise ratio (SNR) of the proposed scheme and presents a power gain control algorithm at the FDR. Compared with the existing schemes, the proposed scheme shows a superior bit error rate (BER) performance.