Concurrent backscatter streaming from batteryless and wireless sensor tags with multiple subcarrier multiple access

Nitish Rajoria, Yuki Igarashi, Jin Mitsugi, Yuusuke Kawakita, Haruhisa Ichikawa

Research output: Contribution to journalArticlepeer-review

11 Citations (Scopus)


This paper proposes a novel multiple access method that enables concurrent sensor data streaming from multiple batteryless, wireless sensor tags. The access method is a pseudo-FDMA scheme based on the subcarrier backscatter communication principle, which is widely employed in passive RFID and radar systems. Concurrency is realized by assigning a dedicated subcarrier to each sensor tag and letting all sensor tags backscatter simultaneously. Because of the nature of the subcarrier, which is produced by constant rate switching of antenna impedance without any channel filter in the sensor tag, the tag-to-reader link always exhibits harmonics. Thus, it is important to reject harmonics when concurrent data streaming is required. This paper proposes a harmonics rejecting receiver to allow simultaneous multiple subcarrier usage. This paper particularly focuses on analog sensor data streaming which minimizes the functional requirements on the sensor tag and frequency bandwidth. The harmonics rejection receiver is realized by carefully handling group delay and phase delay of the subcarrier envelope and the carrier signal to accurately produce replica of the harmonics by introducing Hilbert and inverse Hilbert transformations. A numerical simulator with Simulink and a hardware implementation with USRP and LabVIEW have been developed. Simulations and experiments reveal that even if the CIR before harmonics rejection is 0 dB, the proposed receiver recovers the original sensor data with over 0.98 cross-correlation.

Original languageEnglish
Pages (from-to)2121-2128
Number of pages8
JournalIEICE Transactions on Communications
Issue number12
Publication statusPublished - 2017 Dec


  • Backscatter communication
  • Harmonic rejection
  • Multiple access

ASJC Scopus subject areas

  • Software
  • Computer Networks and Communications
  • Electrical and Electronic Engineering


Dive into the research topics of 'Concurrent backscatter streaming from batteryless and wireless sensor tags with multiple subcarrier multiple access'. Together they form a unique fingerprint.

Cite this