ESPAR Antenna-Based WSN Node With DoA Estimation Capability

Abstract

In this paper, we present a low-cost energy-efficient electronically steerable parasitic array radiator (ESPAR) antenna-based wireless sensor network (WSN) node designed for IEEE 802.15.4 standard that is capable of performing direction of arrival (DoA) estimation in real-life outdoor environments. To this end, we propose the WSN node architecture, design and realization that utilizes NXP JN5168 radio frequency (RF) wireless transceiver and a microcontroller integrated with ESPAR antenna beam-switching circuits. To incorporate DoA estimation capability into the developed single-board WSN node, power-pattern cross-correlation (PPCC) algorithm, that relies solely on received signal strength (RSS) values measured by the transceiver at the antenna output for every considered directional antenna radiation pattern, has been adapted and implemented in a simple microcontroller embedded within NXP JN5168 integrated circuit. Measurements conducted in an outdoor environment show that the proposed low-cost WSN node can successfully provide DoA estimation results, which may be used to enhance WSN capabilities in practical applications. The obtained root mean square (RMS) DoA estimation errors are 7.91 • , 6.58 • and 9.47 • for distances between WSN nodes equal to 3 m, 5 m and 10 m respectively. INDEX TERMS Internet of Things (IoT), wireless sensor network (WSN), switched-beam antenna, electronically steerable parasitic array radiator (ESPAR) antenna, direction-of-arrival (DoA), received signal strength (RSS).

Calibration-Free Single-Anchor Indoor Localization Using an ESPAR Antenna

“…The benefit of such an approach is that it can be integrated with the most popular wireless communication standards such as Wi-Fi and BLE to reduce the number of base stations used as APs. The most promising switched-beam antenna concepts, which can be used in practical single-anchor localization systems, are those that are inexpensive for mass production and easy to integrate with low-cost transceivers, with simple microcontrollers performing RSS measurements and localization estimation [ 26 , 38 ].…”

“…As a result, a directional radiation pattern, as shown in Figure 2 , can be created and rotated with a discrete step, forming 12 different directional radiation patterns. The utilization of FET switches brings a significant reduction of power consumption via the antenna circuit as compared to varactor-based solutions [ 46 ] and can be successfully used in DoA estimation of battery-powered IoT modules [ 38 , 47 ].…”

Precise Angle Estimation by Jointly Using Spatial/Temporal Change of Channel State Information and Its Application in Pedestrian Positioning

“…Pedestrian-vehicle angle can be estimated by different methods, leveraging an ESPAR antenna (using simple RSSI information) [17] or an antenna array (using phase information) [11][18] [19]. When a signal is received by an antenna array, there is a small difference (∆ = • cos ) in the signal propagation distance between two adjacent antennas (Left of Figure 2), and it causes a signal phase difference ∆ = 2 ⋅ ∆ / , where is the wavelength of the signal.…”

Relay-Aided Wireless Sensor Network Discovery Algorithm for Dense Industrial IoT Utilizing ESPAR Antennas

“…More detailed examination of modern heterogeneous WSNs based usually on IEEE 802.15 standard that are used for IIoT solutions is required due to the limited hardware capabilities (simple low-cost end devices), much higher network density and demanding propagation environment. To address all the problems mentioned above, a novel approach that combines the concept of network layering presented in our work [37] and sensor nodes equipped with the ESPAR antenna [38], [39], [40] has been proposed in this paper. In [37], a routing algorithm was presented that optimizes the energy consumption and minimizes the latency by searching an optimal routing scheme.…”

“…In [37], a routing algorithm was presented that optimizes the energy consumption and minimizes the latency by searching an optimal routing scheme. In this work, we leave out the routing aspects and focus on finding an optimal layered network structure by introducing relay nodes equipped with ESPAR antennas and are capable to change the radiation pattern based on the network requirements [40]. Differently from [37], we consider the link QoS to discover the network structure.…”