134 Abstract — This paper introduces the technology Time of Arrival (TOA) based on chirp pulses (according to IEEE 802.15.4a) as a means to perform localization in Wireless Sensor Networks (WSN’s) active at 2.4 GHz. Advantages and disadvantages of the technology are discussed and act as a guideline for improving localization accuracy. Tests concerning TOA are performed by means of the location ...

We consider time-of-arrival (ToA) estimation of a first arrival-path for a device working in narrowband Internetof-Things (NB-IoT) systems. Due to a limited 180 KHz bandwidth used in NB-IoT, the time-domain auto-correlation function (ACF) of transmitted NB positioning reference signal (NPRS) has a wide main lobe. Without considering that, the performance of ToA estimation can be degraded for tw...

In this paper, we propose a time-of-arrival (TOA) estimation scheme using impulse-radio ultra-wideband (IR-UWB). This scheme is featured by a low sampling rate and is robust against clock drift. Low-rate stroboscopic sampling, which can achieve an equivalent sampling rate as high as the Nyquist sampling rate, is adopted to achieve a high resolution TOA estimate by IR-UWB. Since a long preamble ...

The accuracy of time of arrival (ToA) estimation using wide band signals is characterized. The Cramér-Rao Lower Bound (CRLB) for ToA estimation in multipath conditions is presented in terms of the Ricean K-factor, the ratio of direct to diffuse multipath components. The validity of the CRLB is demonstrated using thousands of measurements, where the K-factor is estimated in the spectral domain. ...

Abstnrer-Location finding for CDMA subscribers using an antenna army at the base station and deploying multiple base stations is studied in this paper. ' b o metbods are considered for radio location: measured time-of-arrival (TOA) and angle-of-anival (AOA), and algorithms to estimate them are presented. The estimated TOA and AOA fmm different base stations are combined via data fusion to estim...

In order to solve the problem of sensor node localization of wireless sensor and actor networks, a range-based time of arrival(TOA) localization algorithm with virtual force and time synchronization(TLAVFTS) in WSAN is proposed in this paper, which uses mobile actors instead of WSN’s anchors, and combines TOA with virtual force on the premise of time synchronization. The algorithm completes nod...

Indoor localization has been a long-standing and important issue in the areas of signal processing and sensor networks that has raised increasing attention recently. One of the key demands in assistive environment is to promptly and accurately determine the state and activities of an inhabitant subject. The indoor localization provides an effective means in tracking the positions, motions, and ...

Source Localization in the non-synchronous mobile system is a very important issue since it only requires synchronized clocks between the based stations (BSs) and can reduce system complexity. There are time-difference-of-arrival (TDOA) and pseudo-range time-of-arrival (TOA) based localization techniques for a non-synchronous mobile system. Although many methods and performance analysis have be...

Low-complexity least-squares (LS) estimators based on time-of-arrival (TOA) or time-difference-of-arrival (TDOA) measurements have been developed to locate a target node with the help of anchors (nodes with known positions). They require to select a reference anchor in order to cancel nuisance parameters or relax stringent synchronization requirements. Thus, their localization performance relie...

Because of the high sampling rate, coherent Time of Arrival (TOA) estimation algorithms are not practical for low cost, low complexity 60 GHz systems. In this paper, energy detect (ED) based non-coherent TOA estimation algorithm is presented. The expected values of the skewness and kurtosis with respect to the signal to noise ratio (SNR) are investigated. It is shown that the ratio of kurtosis ...