Rogue Drone Detection: A Machine Learning Approach

The emerging, practical and observed issue of how to detect rogue drones that carry terrestrial user equipment (UEs) on mobile networks is addressed in this paper. This issue has drawn much attention since the rogue drones may generate excessive interference to mobile networks and may not be allowed by regulations in some regions. In this paper, we propose a novel machine learning approach to identify the rogue drones in mobile networks based on radio measurements. We apply two classification machine learning models, Logistic Regression, and Decision Tree, using features from radio measurements to identify the rogue drones. We find that for high altitudes the proposed machine learning solutions can yield high rogue drone detection rate while not mis-classifying regular ground based UEs as rogue drone UEs. The detection accuracy however degrades at low altitudes.Comment: Submitted to Globecom 201

Investigating the Effect of Antenna Polarization on the Performance of CoMP Systems based on Synchronous Multi-link Measurements

In this master thesis work, the effect of polarization, at the Base Station (BS) side, on the performance of multi-user Coordinated Multipoint (CoMP) systems is studied. This study was performed using synchronous multi-link measurements that took place at the campus of the faculty of Engineering, LTH, Lund University, Lund, Sweden, where two different BS setups were studied. In the first setup, one BS provided with one antenna array consisting of four antenna elements, was used. The antenna aperture size was varied from 0.17 m to 24 m, where different antenna polarizations (single- and cross-polarized arrangements) were considered. In the second setup, we use two BSs located 60 m apart, each of which is provided with two co-located antenna elements spaced by half a wavelength. Two antenna polarizations at the BS are studied: single- and cross-polarized arrangements. In both setups, four virtual users, spaced 0.5 m apart with one cross-polarized antenna were considered. For each setup, the user Multiple Input Multiple Output (MIMO) channels are used to evaluate the sum-rate capacity of the system, where the minimum mean square error (MMSE) beamforming at both the BS and the Mobile Station (MS) was used. Furthermore, in the second setup, the influence of user hand and torso into the MS antenna patterns and hence into the resulting performance was incorporated. For the first setup, i.e., using one BS antenna with variable aperture, it was found that: 1) using cross-polarized antenna elements at the BS improves the sum-rate capacity by about 35% and 72% in Non Line of Sight (NLOS) and Line of Sight (LOS), respectively, if the aperture of the antenna array is small (less than 1 m). 2) Increasing the BS array aperture gives better sum-rate capacity to a certain point, then the improvement saturates. 3) If the BS array aperture is "large enough", then the performance improvement gained from using BS cross-polarized antennas is insignificant compared to using single-polarized ones. For the second setup, i.e., using two BSs each of which is provided with co-located antennas with half a wavelength inter-element spacing, it was found that: the cross-polarized antenna configuration improves the ergodic sum-rate capacity about 50% compared to the single polarization configuration. In addition, increasing the number of antenna (from 1 to 2) at the MS side yielded an improvement of 43% in sum-rate capacity

Experimental Evaluation of the Performance of CoMP Systems for Closely-Located Users Including Users' Body Influence

Based on multi-link synchronous propagation measurements, we study the downlink performance of Coordinated Multi-point (CoMP) systems. The propagation measurements took place in an outdoor micro-cellular environment with two base stations (BSs) located 60 m apart, each equipped with two cross-polarized co-located antennas. We focus on the challenging case of having closely-located users with 0.5 m inter- user distance. We consider four virtual users, each equipped with two antennas, moving along various routes. The patterns of the users' antennas, including the user's body influence, are measured in static scenarios with an upper body phantom and a handset mockup in the LTE 2.5-2.7 GHz band. The users' composite channel matrices are constructed based on: 1) the propagation channel represented by the multipath components extracted from the propagation measurements and 2) the user- influenced antenna pattern. We first analyze the effect of the BS antenna polarization on the collinearity among the users' channel matrices. Then, we evaluate the effect of the BS antenna polarization on improving the system performance, where the performance is evaluated based on two criterion: the number of users that the system is able to serve in the same time-frequency resource, and the achievable sum-rate. It is found that using cross- polarized BS antenna improves the fairness and the sum-rate of the system. It is also found that, in contrast to the case of conventional co-located MIMO, the improvement gained by CoMP systems (with per-BS power control) from using cross-polarized BS antennas is mainly attributed to improving the multiplexing gain of the system while the system's effective power gain has insignificant contribution

Evaluation of the effect of base station antenna polarization on the performance of CoMP transmission techniques based on synchronous multi-link measurements

In this paper, the effect of polarization on the downlink achievable sum-rate of multi-user Cooperative Multi-Point (CoMP) systems is studied using synchronous multi-link channel measurements with two different antenna arrangements. In the first setup, four dual-polarized antenna patches with inter-patch distance varied from half wavelength to 8 m are considered at the base station (BS). In the second setup, two BSs located 60 m apart are used, each is provided with dual-polarized antennas spaced half a wavelength apart. Based on the BS antenna element selection, scenarios with different antenna polarizations at the BSs are considered. We consider four virtual users each is equipped with two antennas (V and H-polarized) with half-wavelength inter-element distance. The users are equally spaced with inter-user distance of about 0.5 m and moving in different routes. For each setup, the 8 × 4 MIMO multi-user channels are used to evaluate the achievable sum-rate of the system, where the minimum mean square error (MMSE) beamforming at both the BS and the mobile station (MS) is used. It is found that the performance improvement gained from using dual-polarized antennas at the BS vanishes if the BS antenna elements are distributed over large distance (i.e., having a large antenna array aperture). However, in the measured environment, for the case of having two BSs each of which is provided with co-located antennas, using dual-polarized antennas provide about 40% improvement in the ergodic sum-rate compared to using single-polarized antennas