In this article, we propose a semi-blind full-duplex (FD) amplify-and-forward (AF) relay system with adaptive self-interference (SI) processing assisted by independent component analysis (ICA) for low-latency and high-reliability (LLHR) Internet of Things (IoT). The SI at FD relay is not necessarily canceled as much as possible like the conventional approaches, but is canceled or utilized based on a signal-to-residual-SI ratio (SRSIR) threshold at relay. According to the selected SI processing mode at relay, an ICA-based adaptive semi-blind scheme is proposed for signal separation and detection at destination. The proposed FD relay system not only features reduced signal processing cost of SI cancelation but also achieves a much higher degree of freedom in signal detection. The resulting bit error rate (BER) performance is robust against a wide range of SRSIR, much better than that of conventional FD systems, and close to the ideal case with perfect channel state information (CSI) and perfect SI cancelation. The proposed system also requires negligible spectral overhead as only a nonredundant precoding is needed for ambiguity elimination in ICA. In addition, the proposed system enables full resource utilization with consecutive data transmission at all time and same frequency, leading to much higher throughput and energy efficiency than the time-splitting and power-splitting-based self-energy recycling approaches that utilize only partial resources. Furthermore, an intensive analysis is provided, where the SRSIR thresholds for the adaptive SI processing mode selection and the BER expressions with ICA incurred ambiguities are derived.

中文翻译：

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用于 LLHR 物联网的自适应自干扰消除/利用和 ICA 辅助半盲全双工中继系统


在本文中，我们提出了一种半盲全双工（FD）放大转发（AF）中继系统，具有自适应自干扰（SI）处理，并辅以独​​立分量分析（ICA），以实现低延迟和高延迟。可靠性 (LLHR) 物联网 (IoT)。 FD中继处的SI不一定像传统方法那样被尽可能多地取消，而是基于中继处的信号与剩余SI比(SRSIR)阈值来取消或利用。根据中继站选择的SI处理模式，提出了一种基于ICA的自适应半盲方案，用于目的地的信号分离和检测。所提出的FD中继系统不仅具有降低SI消除的信号处理成本的特点，而且在信号检测方面实现了更高的自由度。由此产生的误码率 (BER) 性能对于各种 SRSIR 都具有鲁棒性，远优于传统 FD 系统，并且接近具有完美信道状态信息 (CSI) 和完美 SI 消除的理想情况。所提出的系统还需要可忽略的频谱开销，因为仅需要非冗余预编码来消除 ICA 中的模糊性。此外，所提出的系统能够在所有时间和相同频率下连续数据传输来充分利用资源，从而比仅利用部分资源的基于时间分割和功率分割的自能量回收方法具有更高的吞吐量和能源效率。此外，还提供了深入的分析，其中导出了用于自适应 SI 处理模式选择的 SRSIR 阈值以及 ICA 引起的模糊度的 BER 表达式。