SyncScatter: Enabling WiFi like synchronization and range for WiFi backscatter Communication

WiFi backscattering can enable direct connectivity of IoT devices with commodity WiFi hardware at low power. However, most existing work in this area has overlooked the importance of synchronization and, as a result, accepted either limited range between the transmitter and the IoT device, reduced throughput via bit repetition, or both. In this paper, we present SyncScatter, which achieves accurate synchronization with incident signals at the IoT device level while realizing maximum possible sensitivity afforded by a backscatter link budget. SyncScatter creates a novel modeling framework and derives the maximal optimal range and synchronization error that the receiver can tolerate without significant performance compromises. Next, SyncScatter builds a novel hierarchical wake-up protocol, which, together with a custom ASIC, achieves a range of 30+ meters and the peak throughput of 500Kbps, with an average power consumption of 30µW.