Cognitive Backscatter Network: A Spectrum Sharing Paradigm for Passive IoT

In this letter, a novel spectrum sharing system referred to as cognitive backscatter network (CBN) is proposed to support passive Internet of Things (IoT) transmission via backscatter modulation, in which the primary system transmits a sinusoidal carrier in addition to its own signal. In contrast to existing ambient backscatter communications, the proposed CBN does not require perfect symbol synchronization between the IoT and the primary transmissions. We maximize the data rate of the IoT transmission subject to the minimum rate requirement of the primary system by jointly optimizing the time sharing and power allocation parameters. Numerical results have demonstrated the superiority of the proposed CBN over conventional TDMA scheme.