Radio Source Localization in Multipath Channels Using EM Lens Assisted Massive Antennas Arrays

Abstract

The focusing ability of the lens antennas can significantly contribute to perform precise radio localization with low complexity in a massive antennas array (MAA) system. Thus, by combining lens antennas with an MAA, we propose an approach for radio source localization through an angle of arrival (AoA) estimation in a multipath propagation scenario. We discuss two simplified antenna selection techniques to select and process the focused subsets of antennas. Then, we implement a low-complexity time of arrival estimation scheme to detect the first arrival path (FAP) that contains the actual AoA information. Finally, the FAP signal is processed to estimate the AoA very efficiently, by applying one of the traditional subspace-based methods. To further simplify the system architecture with only slight degradation in performance, we also propose a mixed analog-digital AoA estimation structure based on the application of the sum-difference signal patterns technique. The simulated root mean squared error performance curves as a function of the signal-to-noise-ratio demonstrate that the proposed approach is capable of providing good AoA estimation results while considerably reducing the overall system complexity compared with the MAA system without the lens.

A Lens-Array-Based Measurement Technique for Spatial Angle

“…It can be seen that the smaller the distance between two adjacent lens elements is, the more information will be obtained, which is also more conducive to improving the experimental accuracy. Therefore, this paper selected the distance of lens array as 0.5mm, the refractive index of lens material as 1.49, the focal length of each lens element as 6mm and the radius of curvature as 2.94mm [16][17][18][19][20].…”

Radio Positioning With EM Processing of the Spherical Wavefront

“…From (44) it is not easy to get insights about the impact of various parameters on the SIR. A possibility to simplify the model is to consider only distance variations Δd, with Δθ = 0, and assuming cos θ ≈ 1, which is true when users are close to the boresight direction.…”

“…With the advent of millimeter-waves (mm-wave)-based solutions, direct positioning is in principle possible even with antenna arrays with limited aperture [41] or by the exploitation of distributed architectures [42], [43]. However, this requires the presence of a huge amount of antenna elements, each connected to a RF chain, which could lead to an extremely complex receiver, as they usually contain several electronic components, such as analog to digital converters (ADC), mixers, local oscillators etc., [44].…”

Connectivity-Based Localization in Ultra-Dense Networks: CRLB, Theoretical Variance, and MLE

“…Equation (17) shows that (r i ) only depends on the distance r i for a given system. Substituting (10)- (17) into (9), it can be derived as shown in the Appendix that the CRLB for the connectivity-based localization technique is:…”

“…Most of these studies are based on a single path of measurements. To further improve positioning accuracy, AOA-based location algorithms using multiple antenna arrays were proposed in [17], [18] for multipath propagation environments. Additionally, many geometric dilutions of precision and Cramer-Rao lower bounds (CRLBs) were derived in literature [19]- [25].…”