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The paper deals with the estimation method of a carrier and time of arrival by chirp-like phase-coded sequence. The developed estimation method of the carrier and time of arrival is suitable for primary synchronization upon signal detection in phase and frequency modulation modems. This method is of less computational complexity relative to the realization of matched filter assembly. To implement...
In this paper, we propose a positioning system using a time-synchronized wireless network that can achieve high positioning accuracy without being dependent on any global positioning system (GPS) devices with cm-level accuracy as the main goal and objective. The proposed system utilizes time of arrival (ToA) method to estimate the target's position. Based on the results, we can achieve time synchronization...
The Trustful Space-Time Protocol (TSTP) allows for time synchronization to be performed upon receiving any message from another node in a sensor network, removing the need for explicit synchronization messages. Previous work has shown that TSTP performs well under controlled experimental environments. In this work, we analyze how the quality of synchronization in TSTP is affected when nodes are communicating...
In the paper, operation algorithms of the N-OFDM modem for channels with the Additive White Gaussian Noise (AWGN) are considered. The algorithms are based on the Hartley transform under the optimal demodulation by the estimation of the received signals amplitudes using the Cauchy method. The experimental results for interference immunity estimation are provided for different values of spacing frequencies...
This paper discusses the time synchronization issue in wireless sensor networks. An event-triggered average consensus time synchronization algorithm is proposed. This algorithm uses the average time message from one node's one-hop neighbors to update the clock parameters of the node. And it achieved acceptable synchronization accuracy. We also proposed an event-trigger mechanism to reduce the communication...
Time synchronization over a distributed BLE wireless network poses several challenging problems which may affect the accuracy of time stamping of events recorded by BLE devices. In this paper, we study the accuracy of a time synchronization scheme based on generation of an event in the application program at the time of BLE connection establishment. We discuss the background of the problem, explain...
A time synchronization algorithm for hidden mobile node (HMB), which can only receive signals, joining an existing synchronized underwater Acoustic (UWA) sensor network (UASN) is proposed. In order to obtain the location of the HMB or communicate with it, the local time of the HMB should synchronize with the UASN. However, the propagation delay in UWA channels could not be ignored compared to electromagnetic...
In this paper, we analyze different options to use hardware-based current measurement for time synchronization of Bluetooth Low Energy (BLE) devices. The BLE devices have a specific current draw pattern based on the status of their radio. Using appropriate circuit, the changes in the current pattern can be detected. Based on this principle, we propose several different ways to tackle the time synchronization...
In this paper, we simulate the tri-message time synchronization protocol within the cluster sub net for the MAC layer of underwater acoustic network. Distinguished with the traditional TDMA protocols, all sub nodes are time consistent with the cluster node and the sub nodes can be quickly netted in the improved TDMA protocol. We established a network simulation with a bunch of 6 nodes in OPNET software...
Time synchronization, aiming to provide a common timescale among distributed sensor nodes, is a key enabling technology for many applications, such as collaborative condition monitoring and localization detection. Due to the complexity of time synchronization in wireless sensor networks, the Discrete Event Simulator is recommended to adopt resulting from the feature that the behavior of a complex...
In both wired and wireless networks, time synchronization is an important service for a wide range of applications in distributed systems. This includes radio interferometry. However, literature researches show that many distributed protocols cannot satisfy sub-ns time synchronization accuracy due to asymmetric delay errors, accumulated jitters and because of the strategy used to compute and adjust...
We describe a time-of-arrival-(ToA-) based localization system for smartphones. In this system, the transmitter emits modulated light-emitting diode (LED) light and sound waves, then the smartphone catches them. The smartphone measures the time of flight of sound waves and localizes its position using multilateration. The LED light is used for visible light communication, which also conveys the time...
Keeping a high-precision time base in cloud clusters is still a big challenge, even using the Precision Time Protocol version 2 (PTPv2) specified in IEEE 1588. One of the main factors on this issue is that too many uncertainties in the network path from the master clock to the slave one, which is likely residing on the Kernel-based Virtual Machine (KVM). The Transparent Clock (TC) of PTPv2 may be...
The Smart Cities concept implies the integration of vertical application pillars, such as mobility, smart grid and public illumination, and more, for an optimal management of the resources and a reduction of the energy footprint of large cities. This approach requires the use of existing heterogeneous communication infrastructures to allow a peer to peer interconnection of services exposed by sensors...
The edge filter approach using a distributed feedback laser diode is well suited for interrogating Fiber Bragg Grating micro-seismic sensors. This paper presents the design and implementation of a novel precision edge filter interrogation system based on digital signal processing technology. The experimental study of the temperature tuning characteristics, system composition, and operating principle...
High accurate time synchronization is very important for many applications and industrial environments. In a computer network, synchronization of time for connected devices is provided by the Precision Time Protocol (PTP), which in principal allows for device time synchronization down to microsecond level. However, PTP and network infrastructures are vulnerable to cyber-attacks, which can de-synchronize...
A novel distributed approach based on a factor graph framework, using inter-satellite ranging measurements to achieve simultaneous autonomous orbit determination and time synchronization of networked satellites, is proposed. In order to reduce computation complexity as well as communication overhead considering limited resource constraints onboard, we present a parametric message passing scheme with...
Time synchronization is an essential infrastructure of various applications in sensor networks. In this paper, a time-stamping approach using field-programmable gate array (FPGA) is introduced which is applied to Reference broadcast synchronization (RBS). Then, Dynamic Adjusting Time Synchronization (DATS) protocol is proposed which enables the clock compensation to approach the optimal compensation...
This work examines the feasibility of using Ethernet-based time transfer methods based on White Rabbit technology to discipline all the clock domains of a networked data acquisition system (DAQ). Existing systems provide synchronization capabilities, albeit the performance achieved is often not accurate enough for scientific infrastructures and Smart Grid applications requiring frequency coherent...
White Rabbit precision time protocol (WR-PTP) implements sub-nanosecond synchronization of equipment in the fiber network within the range of 10km. For real applications, it needs additional auxiliary fiber link to calibration the asymmetry of the fiber link, because of the different wavelength of the uplink and downlink light. By implement only one wavelength light for both directions, we greatly...
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