Tracking a target is a fundamental and crucial problem in wireless sensor networks. It is well known that non-line-of-sight (NLOS) propagation will significantly degrade the tracking accuracy if its effects are ignored. In this paper, a line-of-sight (LOS) identification approach for range-based tracking systems is developed to discard the NLOS measurements. Based on Lp-norm LOS identification ...

In this paper, we present measurement results of the experimental validation of the UWB localization platform under Line-Of-Sight (LOS) and Non-Line-Of-Sight (NLOS) conditions. The platform is based on the Time Difference of Arrival (TDoA) technique and the energy detection receiver. TDoA based localization systems require minimum four anchors to provide 3D position data. In order to deal with ...

Multipath channels can highly reduce the performance of global navigation satellite system (GNSS) time-of-arrival (TOA) estimations, as a non-line-of-sight (NLOS) signal distort estimating accuracy for line-of-sight (LOS) in conventional GNSS receiver. This paper firstly investigates dynamic difference LOS and NLOS signals moving antenna. Then, fractional Fourier transform (FRFT) algorithm is p...

Recently, there has been much interest in accurate determination of mobile user locations in cellular environments. A general approach to this geolocation problem is to gather time-of-arrival measurements from a number of base stations (BSs) and to estimate user locations using the traditional least square approach. However, in non-line-of-sight (NLOS) situations, measurements are significantly...

Mobile terminal location has attracted much interest for its applications in emergency communications, location-sensitive browsing, and resource allocation. This paper introduces the use of nonparametric kernel-based estimators for location of mobile terminals using measurements of propagation delays. It is demonstrated that these estimators perform better than the previously used parametric ma...

In this paper, we investigate the non-line-of-sight (NLOS) propagation identification and correction for time difference of arrival (TDOA) based mobile user location in wireless communication systems. Based on the defined TDOA residual, an NLOS base station identification algorithm is proposed. Different choices of the reference location for the residual calculation are compared via simulation....

Indoor target localization is an essential and fundamental issue for wireless sensor networks (WSN). However, it is rather difficult for WSN to maintain the localization accuracy in line-of-sight (LOS) and non-line-of-sight (NLOS) mixed environment. NLOS propagation always leads to larger ranging error than LOS does. When the target moves in the rooms and corridors, the signal transmission stat...

This paper describes deconvolution method for estimation of channel impulse response. Radio channels in radio system can be completely described by channel impulse response. We can investigate radio channel type from channel impulse response. In environment between transmitter and receiver there exist two main propragation components, Line-of-Sight (LOS) and Non-Line-of-Sight (NLOS), which are ...

The mitigation of NLOS (non-line-of-sight) propagation conditions is one of main challenges in wireless signals based indoor localization. When RFID localization technology is applied in applications, RSS fluctuates frequently due to the shade and multipath effect of RF signal, which could result in localization inaccuracy. In particularly, when tags carriers are walking in LOS (line-of-sight) ...

Non-line-of-sight (NLOS) imaging methods reconstruct scenes hidden around one corner using indirect third-bounce illumination on a visible relay surface. We show how diffuse objects may exhibit specular behaviour in NLOS methods, and fourth- fifth-bounce can encode useful information, such as two corners.