The Release 16 completion unlocks the road to an exciting phase pertain to the sixth generation (6G) era. Meanwhile, to sustain far-reaching applications with unprecedented challenges in terms of latency and reliability, much interest is already getting intensified toward physical layer specifications of 6G. In support of this vision, this work exhibits the forward-looking perception of full-duplex (FD) cooperative relaying in support of upcoming generations and adopts as a mean concern the critical contribution of hybrid automatic repeat request (HARQ) mechanism to ultra-reliable and low-latency communication (URLLC). Indeed, the HARQ roundtrip time (RTT) is known to include basic physical delays that may cause the HARQ abandonment for the 1 ms latency use case of URLLC. Taking up these challenges, this article proposes a hybrid FD amplify-and-forward (AF)-selective decode-and-forward (SDF) relay-based system for URLLC. Over this build system, two HARQ procedures within which the HARQ RTT is shortened, are suggested to face latency and reliability issues, namely, the proposed and the enhanced HARQ procedures. We develop then an analytical framework of this relay based HARQ system within its different procedures. Finally, using Monte-Carlo simulations, we confirm the theoretical results and compare the proposed relay-assisted HARQ procedures to the source-to-destination (S2D) HARQ-based system where no relay assists the communication between the source and the destination.

中文翻译：

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用于URLLC的全双工中继辅助传输中的HARQ

Release 16的完成完成了通往第六代（6G）时代令人兴奋的阶段的道路。同时，为了维持在延迟和可靠性方面面临前所未有挑战的广泛应用，人们对6G物理层规范的兴趣已经增强。为了支持这一愿景，这项工作展现了对全双工（FD）协作中继的前瞻性感知，以支持后代，并且将混合自动重发请求（HARQ）机制对超可靠的关键贡献作为平均关注点。和低延迟通讯（URLLC）。实际上，已知HARQ往返时间（RTT）包括可能导致URLLC的1 ms延迟使用情况放弃HARQ的基本物理延迟。迎接这些挑战，本文提出了一种用于URLLC的混合FD放大转发（AF），选择性解码转发（SDF）中继系统。在该构建系统上，建议在其中缩短HARQ RTT的两个HARQ程序来面对等待时间和可靠性问题，即所提出的和增强的HARQ程序。然后，我们在不同过程中开发了基于中继的HARQ系统的分析框架。最后，使用蒙特卡洛模拟，我们确认了理论结果，并将建议的中继辅助HARQ程序与基于源到目的地（S2D）HARQ的系统进行了比较，其中没有中继辅助源与目的地之间的通信。建议面对延迟和可靠性问题，即所提出的和增强的HARQ过程。然后，我们在不同过程中开发了基于中继的HARQ系统的分析框架。最后，使用蒙特卡洛模拟，我们确认了理论结果，并将建议的中继辅助HARQ程序与基于源到目的地（S2D）HARQ的系统进行了比较，在该系统中，没有中继辅助源与目的地之间的通信。建议面对延迟和可靠性问题，即所提出的和增强的HARQ过程。然后，我们在不同过程中开发了基于中继的HARQ系统的分析框架。最后，使用蒙特卡洛模拟，我们确认了理论结果，并将建议的中继辅助HARQ程序与基于源到目的地（S2D）HARQ的系统进行了比较，在该系统中，没有中继辅助源与目的地之间的通信。