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.

翻译：带内全双工中继（FDR）作为提升无线通信网络覆盖范围和频谱效率的有效方案备受关注。FDR传输的基本问题在于如何消除固有的自干扰，并在中继处对残余自干扰（RSI）进行再利用以改善端到端性能。考虑FDR处的RSI时，整体等效信道可建模为无限冲激响应（IIR）信道。针对该IIR信道，本文提出了一种用于协作OFDM中继系统的预编码、功率增益控制与均衡的联合设计方案。与传统OFDM系统相比，本设计可显著缩短保护间隔长度，从而提升频谱效率。通过分析噪声源，本文评估了所提方案的信噪比（SNR），并提出了一种FDR处的功率增益控制算法。与现有方案相比，所提方案在误比特率（BER）性能上表现更优。