Given a population S of N tags in an RFID system, the tag-information sampling problem is to randomly choose K distinct tags from S to form a subset T, and then inform each tag in T of a unique integer from {1,2,⋯ ,K}. This is a fundamental problem in many real-time analysis applications of RFID systems, as it enables rapidly selecting a small random tag subset T from a large tag population S and collecting the tag-information from T for analyzing purposes. However, existing protocols for this problem are far from satisfactory due to high communication costs. This paper aims at solving this problem by using a small communication cost. First, a lower bound on communication cost, denoted by C_lb, is obtained for the tag-information sampling problem. Then, a protocol P_s is proposed for solving the studied problem, and is proved to have a communication cost within a factor of 2 of the lower bound C_lb. Lastly, extensive simulation results not only verify the theoretical properties of the proposed protocol but also demonstrate its advantages in comparison with the state-of-art protocols.

给定一个人口小号的Ñ标签的RFID系统中，标签信息采样的问题是随机选择ķ从不同标记小号，以形成一个子集Ť，然后通知每个标签在Ť从{1,2的唯一整数的， ⋯，K }。这是RFID系统许多实时分析应用程序中的一个基本问题，因为它可以从大量标签群体S中快速选择一个小的随机标签子集T并从T中收集标签信息用于分析目的。然而，由于高通信成本，用于该问题的现有协议远远不能令人满意。本文旨在通过使用较小的通信成本来解决此问题。首先，对于标签信息采样问题，获得了用C _lb表示的通信成本的下限。然后，提出了用于解决所研究问题的协议P _s，并被证明具有在下限C _lb的2倍内的通信成本。最后，大量的仿真结果不仅验证了所提出协议的理论特性，而且还展示了与最新协议相比的优势。