Hybsync: Nanosecond Wireless Position and Clock Synchronization Based on UWB Communication with Multisensors

PNT (positioning, navigation, and timing) is the core functional part of kinds of wireless sensor network, which can provide high-precision timing and positioning services for cooperative work systems. Unfortunately, the mature wireless PNT schemes are generally based on GNSS and other auxiliary sources to complete the high accuracy synchronization process, which cannot be applied to GNSS degraded and denied environments such as mines, underground application. In order to solve the application problem of high-precision wireless PNT, Hybsync—a novel non-GNSS-aided wireless PNT architecture, is proposed in this paper, which integrates the information from the UWB communication, inertial sensor, and camera to achieve great PNT performance. Hybsync improves the accuracy of time deviation measurement by collecting and recording timestamps in hardware layer, and with the coarse/fine synchronization two-phase calibration, Hybsync greatly improves the accuracy of time deviation adjustment, thus providing accurate time information for the whole system. Besides, Hybsync uses the VINS framework to further integrate the real-time information of IMU and camera to complete the multinode positioning service. Under the premise that the cost is much lower than existing solutions, Hybsync can provide nanosecond-level clock synchronization and centimeter-level positioning. Experiments prove that Hybsync supports high-precision clock synchronization and positioning of more than 10 nodes; the maximum clock synchronization error is 3 ns, and the positioning error is 7 cm. It can provide accurate time and position services for cooperative work systems under complex and GNSS-denied conditions.

Compact Fractal MIMO antenna for UWB applications

In this article, a compact ultra-wide band (UWB) multiple input multiple output (MIMO) antenna system is showed. This antenna is based on fractal Fibonacci circles and operates over wide frequency range from 2.9 to 14.51 GHz. The dielectric used was Duroid substrate with dielectric constant εr = 2.2 and thickness of substrate 1.27 mm. This UWB MIMO antenna is simulated by HFSS. In order to improve the isolation between the elements of the antenna a parasitic structure is used, getting S12 and very low ECC. Also, the Total Active reflection Coefficient (TARC) was obtained. Proposed antenna can be used for UWB communication applications and its size is 64 × 38mm2

UWB Microstrip Patch Antenna with A Highly Directional CPW Fed Design

In this section, we will discuss the design and implementation of a new coplanar waveguide (CPW) antenna, which is designed for use in ultra-wideband (UWB) communication. Two carved ground planes distinguish the radiator from the rest of the chassis. It is necessary to dig a hole in the ruined ground. Circular radiators with rectangular cutouts are excellent for superheterodyne receivers because they have wider bandwidths than other types of radiators. This antenna operates at a frequency of 7 GHz and has a return loss of less than -10 dB. Its working frequency is 7 GHz. When utilising HFSS12, it is possible to determine S11 and VSWR.