中文摘要：

在声表面波射频识别系统应用中，多个标签经常会同时出现在阅读器的作用范围内，这样会导致标签难识别。该文的数字波束形成技术被用于解决多标签识别难的问题。通过采用阵列天线，标签的位置可用波达角表示。利用遗传算法在解空间进行并行搜索来寻找波达角的优化值，并根据它生成阵列加权及恢复各个标签的信号。实验结果表明，在某些应用场合，解码结果完全正确。

英文摘要：

In surface acoustic wave （SAW） radio frequency identification system, multiple tags often appear in the field of a reader simultaneously, which result in difficulty in identification. In this paper, digital beamforming is suggested to identify multiple SAW tags. The positions of tags are denoted by direction of arrival （DOA） through using array antenna. Genetic algorithm is presented to find the optimal estimates of DOA. Based on DOA obtained, the array weights are formed and the signals of tags are recovered. The decoding results in experiment depict its good performance in a certain occasions.