Active Two-Way Backscatter Modulation: An Analytical Study

• Published in: IEEE transactions on wireless communications Vol. 18; no. 3; pp. 1874 - 1886
• Main Authors: Khaledian, Seiran, Farzami, Farhad, Soury, Hamza, Smida, Besma, Erricolo, Danilo
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.03.2019; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Admittance; Backscatter modulation; Backscattering; bidirectional amplifier; Codes; Configurations; Constellations; Data loss; Demodulation; Equivalent circuits; geometric representation; Impedance; IoT; Loaded antennas; Modulation; Modulators; negative resistance; performance evaluation; read-write backscatter tag; Receiving antennas; reflection amplifier; Remote sensors; RFID tags; Tags; Wireless sensor networks
• ISSN: 1536-1276; 1558-2248
• DOI: 10.1109/TWC.2019.2898201

Backscatter modulation (BM), usually used for radio frequency identifications, has the potential to be exploited in a wider range of applications such as the Internet of Things and wireless sensor networks. In this paper, we leverage the BM by increasing its down-link (from reader to tag) and up-link (from tag to reader) ranges. We propose two active two-way BM tag configurations, named parallel and series. For both configurations, we use active loads in the tag modulators to maximize the BM range and implement the desired backscattered constellation, subject to no data loss in the down-link path. Contrary to most existing BM studies, we use Thevenin/Norton equivalent circuit, only to calculate the received power at tag, while we derive the tag backscattered power using the antenna scatterer theorem. Moreover, we obtain a closed-form expression of the average bit error probability (BEP) at the reader in Rician fading channel environment for both tag configurations. We compare the proposed active BM tags with the conventional passive BM tags. The simulation results prove that for an average BEP equal to <inline-formula> <tex-math notation="LaTeX">10^{-{4}} </tex-math></inline-formula>, an SNR improvement of up to 19 and 24 dB can be achieved for parallel and series configurations, respectively.