Design, Implementation, and Performance Evaluation of a Flexible Low-Latency Nanowatt Wake-Up Radio Receiver

Abstract

Wireless sensor networks (WSNs) have received significant attention in recent years and have found a wide range of applications, including structural and environmental monitoring, mobile health, home automation, Internet of Things, and others. As these systems are generally battery operated, major research efforts focus on reducing power consumption, especially for communication, as the radio transceiver is one of the most power-hungry components of a WSN. Moreover, with the advent of energy-neutral systems, the emphasis has shifted toward research in microwatt (or even nanowatt) communication protocols or systems. A significant number of wake-up radio receiver (WUR) architectures have been proposed to reduce the communication power of WSN nodes. In this work, we present an optimized ultra-low power (nanowatt) wake-up receiver for use in WSNs, designed with low-cost off-the-shelf components. The wake-up receiver achieves power consumption of 152 nW (with −32 dBm sensitivity), sensitivity up to −55 dBm (with maximum power of 1,2 µW), latency from 8 µs, tunable frequency, and short commands communication. In addition, a low power solution, which includes addressing capability directly in the wake-up receiver, is proposed. Experimental results and simulations demonstrate low power consumption, functionality, and benefits of the design optimization compared with other solutions, as well as the benefits of addressing false positive (FP) outcomes reduction.Index Terms-Nanowatt wake-up radio receiver (WUR), power optimization, ultra-low power, wireless sensor networks (WSNs).

An 868 MHz 7.5 µW wake-up receiver with −60 dBm sensitivity

“…(14). Nevertheless, these results are still better than Gamm et al (2014), Marinkovic andPopovici (2011), andMagno et al (2016). Characteristic WuRx parameters are summarized in Table 4.…”

“…In the end, when the address pattern, encoded in the incoming signal, matches the one configured in the AS3932's registers, the device generates an interrupt to the MCU. In Magno et al (2016), a −55 dBm WuRx is introduced. It utilizes a comparator to digitize the signal coming from the passive envelope detector to further feed it to a MCU.…”

An Ultra-wideband Battery-less Positioning System for Space Applications

“…The DC/DC converter integrates a voltage monitor that is used to control the power supply to the microcontroller unit (MCU) depending on the harvested energy, which must be sufficient to power at least an entire addressing phase and a UWB transmission. The rectified signal from the WUR path of the rectenna is sent to a WUR inspired by [19] and based on a TLV3691 comparator, which detects OOK modulation by the RF source and decodes the tag address with the aid of a MCU. The WUR outputs a digital signal containing the tag address sent by the Power Transfer Unit that is decoded by the ultra-low power MSP430 MCU from TI.…”

Neighbor Discovery Latency in BLE-Like Protocols

“…Shrinking the initial offset successively by γ 0 time units cannot guarantee discovery, since the "overtaking" might repeat. However, let us consider two consecutive skipped advertising packets, e.g., the packets with the offsets Φ [1] and Φ [3] in Figure 3 d). Both packets fulfill the condition that they are the first ones after an advertising packet has "overtaken" the corresponding scan window, and it is Φ [1] − Φ [3] = const.…”