Performance Limits and Geometric Properties of Array Localization

Abstract

Location-aware networks are of great importance and interest in both civil and military applications. This paper determines the localization accuracy of an agent, which is equipped with an antenna array and localizes itself using wireless measurements with anchor nodes, in a far-field environment. In view of the Cram\'er-Rao bound, we first derive the localization information for static scenarios and demonstrate that such information is a weighed sum of Fisher information matrices from each anchor-antenna measurement pair. Each matrix can be further decomposed into two parts: a distance part with intensity proportional to the squared baseband effective bandwidth of the transmitted signal and a direction part with intensity associated with the normalized anchor-antenna visual angle. Moreover, in dynamic scenarios, we show that the Doppler shift contributes additional direction information, with intensity determined by the agent velocity and the root mean squared time duration of the transmitted signal. In addition, two measures are proposed to evaluate the localization performance of wireless networks with different anchor-agent and array-antenna geometries, and both formulae and simulations are provided for typical anchor deployments and antenna arrays.Comment: to appear in IEEE Transactions on Information Theor

5G mmWave Positioning for Vehicular Networks

“…Recent works revealed that, when using large bandwidths, AOA measurements obtained by Sufficient SINR gain will be available thanks to the use of directional antennas or beamforming with relatively large arrays, compounding the effect of increased bandwidth, thus resulting in the ability to estimate angles and to improve time-delay estimation accuracy with orders of magnitude compared to conventional cellular communications wideband antenna arrays may not further improve position accuracy beyond that provided by TOA measurements at each antenna element, even though, from a practical perspective, separate TOA and AOA estimation still remains the most pragmatic approach [9]. In dynamic scenarios, like the vehicular one, the measurements of the Doppler shifts, if properly exploited, also provide additional Fisher information, with intensity determined by the vehicle's velocity and the root mean square signal duration [9].…”

“…In dynamic scenarios, like the vehicular one, the measurements of the Doppler shifts, if properly exploited, also provide additional Fisher information, with intensity determined by the vehicle's velocity and the root mean square signal duration [9]. While the above general statements apply to all wideband communication systems, dedicated 5G analyses have also been conducted [10][11][12].…”

5G Downlink Multi-Beam Signal Design for LOS Positioning

“…Accurate position information is essential in realizing a variety of new use cases of the fifth generation of mobile communication networks (5G), like smart factories [1] and automated/assisted driving [2]. Many positioning techniques have been developed considering the presence of multiple reference stations (anchors) [3], [4]. However, multi-anchor positioning might be impossible at millimeter-wave (mm-Wave) frequencies with two or more LoS links to different base stations will be challenging.…”

Direct Position Determination of Coherently Distributed Noncircular Sources

“…Numerous studies on this subject have indicated that this field has attracted the attention of scholars in the academe and industry [1][2][3]. In most existing localization algorithms, the target is modeled as a point source, which has the advantages of simple calculation and high precision [4][5][6][7].…”