AI 中文总结
该研究提出一种全异步URA系统，以前导实现时间同步、极小前导池解决碰撞，其在宽SNR下支持的活跃用户数接近时隙URA系统。
AI 中文摘要
本研究提出一种构建全异步无授权随机接入通信（URA）系统的方法。除了无授权随机接入（URA）的常见特征，如数据包中无用户标识信息、解码面向消息内容外，用户传输时间无任何限制，活跃用户可按需随时传输数据包。所提系统属于前导-有效载荷URA格式类别；与前导通常作为临时用户标识的典型作用不同，此处前导用于时间同步获取。该系统还采用极小的前导池来解决数据包碰撞问题。本文为所提系统提供性能分析与仿真结果，表明在宽范围信噪比（SNR）下，其支持的活跃用户数接近时隙URA系统对应支持的用户数。
英文摘要
In this work we propose an approach to construct a fully asynchronous unsourced random access communications (URA) system. Besides the common URA features such as the absence of the user identification information in the packet and the decoding oriented to receiving the content of the messages, there is no limitation on the user transmission timing. The active users can transmit their packet any time on demand. The proposed system belongs to the class of preamble-payload URA formats. Contrary to the typical role of the preamble to serve as a temporary user identification, the preamble serves for the purpose of timing acquisition. The proposed system also employs a very small pool of preambles to resolve collisions of packets transmitted simultaneously.We provide a performance analysis and simulation results for the proposed system and demonstrate that for a wide range of signal-to-noise ratios (SNR)s the supported numbers of active users are close to the numbers of users supported by a slotted URA system counterpart.
