Dual-band cooperative backscatter communication system

In this paper, we build a cooperative backscatter communication system in 2.4GHz and 3.5 GHz. A test platform including backscattering modulator, Microcontroller Unit (MCU) and receiver system based on Software Defined Radio (SDR) technology is described. In order to realize the communication in the above bands, an omnidirectional dual-band antenna is designed first. Then a backscattering modulation circuit is designed, and a diplexer with two PIN diodes are used to control the two frequency bands. The carrier transmitting and receiving demodulation system is designed at the receiving end. This paper explains the design strategy of realizing frequency shift keying (FSK) and phase-shift keying (PSK) in the bands simultaneously, and receiving the two signals separately. It can not only meet the communication requirements for different nodes, but also realize rate superposition to improve transmission efficiency.