Full-Duplex Duplex Backscatter Interference Networks Based on Time-Hopping Time Spread Spectrum
Abstract: Future Internet-of-Things Things (IoT) is expected to wirelessly connect billions of lowlow complexity devices. For wireless information transfer (IT) in IoT IoT, high density of IoT devices and their ad hoc communication result in strong interference, which acts as a bottleneck on wireless IT. Furthermore, battery replacement for the massive number of IoT devices is difficult if not infeasible, making wireless energy en transfer (ET) desirable. This motivates: 1) the design of full-duplex full duplex wireless IT to reduce latency and enable efficient spectrum utilization and 2) the implementation of passive IoT devices using backscatter antennas that enable wireless ET from one device (reader) to another (tag). However, the resultant increase in the density of simultaneous links exacerbates the interference issue. This issue is addressed in this paper by proposing the design of full-duplex full backscatter communication (BackCom) netw networks, orks, where a novel multiple multiple-access scheme based on time-hopping hopping spread spread-spectrum spectrum is designed to enable both oneone way wireless ET and two--way way wireless IT in coexisting backscatter reader reader-tag links. Comprehensive performance analysis of BackCom networks is pr presented in this paper, including forward/backward bit bit-error error rates and wireless ET efficiency and outage probabilities, which accounts for energy harvesting at tags, non non-coherent and coherent detection at tags and readers, respectively, and the effects of asynchronous synchronous transmissions.