Low-Power RF Integrated Circuit Receivers for Cellular IoT and OFDM

Abstract

Cellular IoT is a new technology that enables low-power devices to connect to the internet via cellular networks and cell towers via 4G/5G networks with new protocols such as NB-IoT. This opens numerous new applications for IoT devices and new challenges for hardware designers. These challenges include overcoming higher data rates, QAM/OFDM modulation, and complex network synchronization while maintaining low power consumption to enable battery-powered, or even battery-free, operation. In this work, hardware challenges for low-power RF receivers for Cellular IoT applications are investigated. First, two different Wake-Up Radios for Cellular IoT (NB-IoT) are analyzed, fabricated, and tested. These works represent some of the first published works on low-power Cellular IoT receivers and include novel RF front-end and FFT digital demodulation techniques. Second, a novel Phase Noise Canceling Receiver is analyzed, fabricated, and measured which can demodulate QAM16/OFDM data with a <1mW power budget. This novel Phase Noise Cancelling receiver eliminates the need for a high-power LO even for QAM/OFDM data and reduces the need for complex network synchronization.