Collaborative Warning System for Dense Vehicular Networks using MUSIC algorithm DoA Chirag Warty IEEE Member Ahilya Technologies Mumbai, India Email: chiragwarty@ieee.org Richard Wai Yu System Engineer NAVSEA Port Hueneme Los Angeles, USA Email: richard.yu@navy.mil Khaled ElMahgoub Senior Validation Engineer Trimble Navigation Cambridge, USA Email: kelmahgoub@ieee.org Abstract—The problem of providing a collaborative early warning system for multiple moving vehicles against a small size fast moving object like a motorbike. This approach consists of three stages: The first stage consists of detecting the incoming object using a highly directive antenna at 5.0 GHz in license free industrial, scientific and medical (ISM) band. The second stage consists of broadcasting the warning message using a low directivity broad beam antenna, third stage will be detected by receiving vehicles by using direction of arrival (DOA) estimation technique. The position of a fast arriving object can be estimated using the MUSIC algorithm for warning beam DOA estimation. This paper is intended to demonstrate the feasibility of an early detection and warning system using a collaborative vehicle to vehicle communication links. The simulation is performed to show the behavior of detecting and broadcasting antennas as well as performance of the detection algorithm. The process can be further expanded to implement commercial grade detection and warning system. Keywords-collaborative warning system, MUSIC, DoA, beamforming, V2V . I. I NTRODUCTION Adaptive signal processing sensor arrays can be implemented to serve as smart antennas. Smart antennas have two primary aspects: position estimation and beam forming. An array of antenna elements is employed to receive multiple versions of the same signal from a distant source at slightly different locations. The signals are then processed to indicate the position of the source. In a radial coordinate system the azimuthal and elevation angles represent that position. The array steers the principal lobe of the beam pattern towards the estimated Direction-of-Arrival (DoA). This way the maximum power emitted by the antenna is directed towards the desired source resulting in a very high effective antenna gain in that direction. [1] Adaptive antenna arrays also improve the performance of the system by providing robustness against fading channels and reduced interference [8] [3]. The goal of DoA estimation is to use the signal received at sensor array to estimate the directions of the signals from the desired mobile users. The results of DoA estimation are then used to adjust the weights of the adaptive beamformer so that the radiated power is maximized in the desired direction and radiation nulls are placed in the directions of interference signals. A successful design of an adaptive array depends highly on the choice of the DOA estimation algorithm which needs to be highly accurate and robust [3]. In this paper a patch antenna design operating over and ISM band is illustrated [4]. The original MUSIC algorithm was first introduced by Schmidt [7]. This algorithm is able to accommodate different configurations of antenna arrays and is not limited to specific sensitivity patterns. This paper is primarily concerned with spatial processing for position tracking systems. This paper is organized as follows: System model illustrating is described in section 2. Section 3 consists of design and simulation of the detection and broadcast antenna. Section 4 starts by carrying out an analysis of the MUSIC algorithm starting from a basic signal model and then develops a simulation which is used to carry out a performance study of the algorithm. The paper is then concludes with closing remarks. II. SYSTEM MODEL The system can be segregated into three phases. The first phase consists of using a highly directive patch antenna to acknowledge the presence of a fast incoming object supposedly between two traffic lanes. The second phase consists of broadcasting the detected information to the neighboring vehicles as a warning beacon. In the third phase the nodes receiving the warning beacon use the direction of arrival of the beacon to estimate the location of the object by estimating the angle of arrival of the broadcasted beacon. The use of 2.4 GHz and 5.0 GHz license free ISM band with Line of Sight (LOS) propagation is considered. The LOS assumption is justified by general absence of multipath in this model. This paper assumes perfect calibration of the patch antenna. The DOA angles relative to the normal to the antenna are defined by an azimuth angle ϕ and an angle θ. It is assumed that the vehicle is traveling in a dense 2013 Third International Conference on Advances in Computing and Communications 978-0-7695-5033-6/13 $26.00 © 2013 IEEE DOI 10.1109/ICACC.2013.110 228 2013 Third International Conference on Advances in Computing and Communications 978-0-7695-5033-6/13 $26.00 © 2013 IEEE DOI 10.1109/ICACC.2013.110 228