Abstract
Nowadays, the Internet-of-Things (IoT)-related applications require the design of low-cost and low-power wireless sensor nodes. Although backscatter radio communication is a mature technology used in radio frequency identification (RFID) applications, ambient backscattering is a novel approach taking advantage of ambient signals to simplify wireless system topologies to just a sensor node and a receiver circuit eliminating the need for a dedicated carrier source. This work introduces two novel wireless tags that utilize broadcast frequency modulated (FM) signals for backscatter communication. The first tag uses binary modulation and the second, a high-order modulation technique for the communication. Each proof-of-concept tag consists of an ultra-low power microcontroller (MCU) and a radio frequency (RF) front-end for wireless communication. The MCU can accumulate data from sensors through an analog-to-digital converter (ADC), while it transmits the information back to the receiver through the front-end. In the first tag, the front-end uses On-Off keying (OOK) binary modulation and FM0 encoding on ambient FM signals. The second design utilizes the four-pulse amplitude modulation (4-PAM) and uses a digital-to-analog converter (DAC) for the RF front-end control. The receiver consists of a commercial low-cost software defined radio (SDR) that downconverts the received signal to baseband and decodes it using a suitable signal processing algorithm. Both prototype tags were demonstrated indoors using an FM station at 34.5 km away. The first tag with binary modulation was tested for a 5 m tag-reader distance, and it was demonstrated by backscattering information at 2.5 kbps featuring an energy per packet of 36.9 µJ. Using the 4-PAM, the second prototype was demonstrated over a 2 m tag-reader distance for a low bit rate of 328 bps with power consumption only 27 µW.
Original language | English |
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Title of host publication | Wireless Power Transmission for Sustainable Electronics |
Publisher | Wiley |
Chapter | 5 |
Pages | 117-143 |
Number of pages | 27 |
ISBN (Electronic) | 9781119578598 |
ISBN (Print) | 9781119578543 |
DOIs | |
Publication status | Published - 2020 |
Keywords
- Ambient backscattering
- Backscatter communication
- FM modulation
- Internet-of-things (IoT)
- Pulse amplitude modulation (PAM)
- Radio frequency identification (RFID) sensors
- Software-defined radio (SDR)
ASJC Scopus subject areas
- General Engineering