The question of robust direct communication in vehicular networks is discussed. In most stateof-the-art approaches, there is no central entity controlling channel access, so there may be arbitrary interference from other parties. Thus, a suitable channel model for Vehicle-to-X (V2X) communication is the Arbitrarily Varying Channel (AVC). Employing multiple antennas on a vehicle or sending over ...

This paper evaluates the tradeoffs involved in using directional antennas in ad hoc routing. Although problems with utilizing directional antennas have been visited in the past, the research has been confined mostly to medium access control. To determine whether directional antennas are beneficial to ad hoc networks, it is necessary to evaluate the impact of directional antennas on the performa...

in recent years reflectarray antennas have received considerable attention due to their unique capabilities. however, due to their large size, analyzing the performance of these antennas using traditional full wave finite-difference and finite-element techniques requires considerable computational resources. in this paper, we present an efficient method to accurately analyze these class of ante...

detection of stealth targets calls for employment of high-power radars which itself relies on usage of high-gain antennas like large parabolic reflectors. in the past few years, using of an array with many small reflectors instead of a large reflector antenna has been considered. this method provides enhanced eirp by a factor of n2 where n is the number of array antennas. regarding improvement ...

Background: Direction finding (DF) based on MUSIC algorithm has been studied and implemented in the wireless communications lab. Simulation results, measurement setup are shown in the figures below. Most of the direction finding (DF) algorithms require multiple antennas with at least í µí¼†/2 spacing. Also, performance of the DF algorithms mainly relies on  Number of antennas in the antenna ar...

An analysis is made of Maximum Likelihood Decoding (MLD) in a wireless Space Division Multiplexing (SDM) link, where information is transmitted and received simultaneously over several transmit and receive antennas to achieve large data rates and high spectral efficiencies. It is proven that maximum likelihood decoding obtains a diversity order equal to the number of receive antennas, independe...

In this paper various layered planar periodic structures which provide miniaturization of planar antennas are proposed and discussed. The proposed designs are based on two concepts, reactive impedance surfaces and complementary periodic structures. In the proposed structures, complementary periodic rings and slots are patterned on the intermediate boundaries of the dielectric layers. A patch an...