Sánchez-Pastor Jesús, Miriya Thanthrige Udaya S K P, Ilgac Furkan, Jiménez-Sáez Alejandro, Jung Peter, Sezgin Aydin, Jakoby Rolf
Institute of Microwave Engineering and Photonics, Technical University of Darmstadt, 64283 Darmstadt, Germany.
Institute of Digital Communication Systems, Ruhr University Bochum, 44801 Bochum, Germany.
Sensors (Basel). 2021 Oct 14;21(20):6842. doi: 10.3390/s21206842.
Self-localization based on passive RFID-based has many potential applications. One of the main challenges it faces is the suppression of the reflected signals from unwanted objects (i.e., clutter). Typically, the clutter echoes are much stronger than the backscattered signals of the passive tag landmarks used in such scenarios. Therefore, successful tag detection can be very challenging. We consider two types of tags, namely low-Q and high-Q tags. The high-Q tag features a sparse frequency response, whereas the low-Q tag presents a broad frequency response. Further, the clutter usually showcases a short-lived response. In this work, we propose an iterative algorithm based on a low-rank plus sparse recovery approach (RPCA) to mitigate clutter and retrieve the landmark response. In addition to that, we compare the proposed approach with the well-known time-gating technique. It turns out that RPCA outperforms significantly time-gating for low-Q tags, achieving clutter suppression and tag identification when clutter encroaches on the time-gating window span, whereas it also increases the backscattered power at resonance by approximately 12 dB at 80 cm for high-Q tags. Altogether, RPCA seems a promising approach to improve the identification of passive indoor self-localization tag landmarks.
基于无源射频识别（RFID）的自定位具有许多潜在应用。它面临的主要挑战之一是抑制来自不需要物体（即杂波）的反射信号。通常，杂波回波比此类场景中使用的无源标签地标物的反向散射信号要强得多。因此，成功检测标签可能非常具有挑战性。我们考虑两种类型的标签，即低Q值标签和高Q值标签。高Q值标签具有稀疏的频率响应，而低Q值标签呈现出较宽的频率响应。此外，杂波通常表现出短暂的响应。在这项工作中，我们提出了一种基于低秩加稀疏恢复方法（RPCA）的迭代算法，以减轻杂波并检索地标物响应。除此之外，我们将所提出的方法与著名的时间选通技术进行了比较。结果表明，对于低Q值标签，RPCA的性能明显优于时间选通技术，当杂波侵入时间选通窗口跨度时，能够实现杂波抑制和标签识别，而对于高Q值标签，它还能在80厘米处将共振时的反向散射功率提高约12分贝。总之，RPCA似乎是一种有前途的方法，可以改进无源室内自定位标签地标的识别。
