P-MTI: Physical-layer Missing Tag Identification via compressive sensing

RFID systems are emerging platforms that support a variety of pervasive applications. The problem of identifying missing tag in RFID systems has attracted wide attention due to its practical importance. This paper presents P-MTI: a Physical-layer Missing Tag Identification scheme which effectively makes use of the lower layer information and dramatically improves operational efficiency. Unlike conventional approaches, P-MTI looks into the aggregated responses instead of focusing on individual tag responses and extracts useful information from physical layer symbols. P-MTI leverages the sparsity of missing tag events and reconstructs tag responses through compressive sensing. We implement P-MTI and prototype the system based on the USRP software defined radio and Intel WISP platform which demonstrates the efficacy. We also evaluate the performance of P-MTI with extensive simulations and compare with previous approaches under various scenarios. The evaluation shows promising results of P-MTI in terms of identification accuracy, time efficiency, as well as robustness over noisy channels.