Fiber-connected UWB sensor network for high-resolution localization using optical time-division multiplexing

Abstract

A fiber-connected ultra-wideband (UWB) sensor network for high-resolution localization which consists of a central station and several sensor nodes is proposed and demonstrated. To make the central station easily identify the received UWB pulses from different sensor nodes, optical time-division multiplexing (OTDM), realized by inserting a certain length of optical fiber between every two sensor nodes, is implemented. Due to the OTDM technology, the UWB pulses received by different sensors are mapped into different time slots, so neither parameter estimation nor clock synchronization is required in the UWB sensor node. All complex signal processing is completed in the central station, which greatly improve the localization accuracy and simplify the system. A proof-of-concept experiment for two-dimensional localization is demonstrated. Spatial resolution as high as 3.9 cm is achieved.

Fiber-connected position localization sensor networks

“…In addition, clock synchronization between the sensor nodes is complicated and has limited accuracy, which degrades again the localization accuracy [6,10]. Photonic approaches to realize position localization can achieve high-resolution and provide the possibility to move the signal processing from sensor nodes to the central station, thanks to the low loss, immunity to EMI and broad bandwidth brought by the photonic technologies [11][12][13][14].…”

“…In this paper, we present a review on the recent works of position localization based on photonic technologies [11,12]. A fiber-connected ultra-wideband (UWB) sensor network using optical time-division multiplexing (OTDM) is proposed to realize high-resolution localization, and a spatial resolution as high as 3.9 cm is achieved [11].…”

“…A fiber-connected ultra-wideband (UWB) sensor network using optical time-division multiplexing (OTDM) is proposed to realize high-resolution localization, and a spatial resolution as high as 3.9 cm is achieved [11]. A length of single-mode fiber (SMF) is placed between every two electrical-to-optical conversion modules (EOMs) to introduce a proper time delay for the implementation of OTDM.…”

“…Fig. 1 Schematic diagram of the proposed fiber-connected UWB sensor network using OTDM [11]. EA: electrical amplifier; EOM: electrical-to-optical conversion module; PD: photodetector; LD: laser diode; SMF: single-mode fiber.…”

“…(a) Geometric model of the OTDM-based UWB sensor network; (b)The waveforms recorded at the output of the PD; Cross-correlation results for achieving TDOAs for (c) node A and (d) node B[11].…”