基于智能天线的相干多径环境的标签信号提取方法

Extraction method of coherent multi-path tag signals based on smart antenna

针对射频识别系统中标签信号在相干多径环境下难以提取的问题,提出一种采用智能天线技术来提取相干标签信号的方法。以均匀直线阵为基础,利用子阵输出的相关信息,采用前后向空间平滑技术对相干的阵列接收信号进行预处理,再用多重信号分类(MUSIC)算法正确估计出波达方向(DOA)用以提取标签信号。性能仿真和实验结果表明,该方法具有较低的信噪比门限和较高的分辨能力。

Aiming at the difficulty of RFID tag signal extraction in coherent multi-path environment, an extraction method of coherent tag signals based on smart antenna is presented. Based on uniform linear array, the received coherent array signals are preprocessed by adopting forward-backward spatial smoothing technique and taking advantage of the correlation information of subarray output. Then, by applying multiple signal classification （MUSIC） algorithm, the direction-of-arrivals （DOAs） of coherent signals are estimated properly and are used to extract the tag signals. Simulation results and experiments demonstrate that the method possesses a lower SNR threshold as well as a better resolving ability, and increases the success rate of extracting tag signals in coherent multi-path environment.