Tuyển tập các báo cáo nghiên cứu về hóa học được đăng trên tạp chí sinh học đề tài : Reconfigurable antennas and configuration selection methods for MIMO ad hoc networks | Kountouriotis et al. EURASIP Journal on Wireless Communications and Networking 2011 2011 147 EURASIP Journal on http content 2011 1 147 Wireless Communications and Networking a SpringerOpen Journal RESEARCH Open Access Reconfigurable antennas and configuration selection methods for MIMO ad hoc networks 1 1 2 1 John Kountouriotis Daniele Piazza Prathaban Mookiah Michele DAmico and Kapil R Dandekar Abstract In this paper we quantify the performance enhancements that can be provided by reconfigurable antennas in an ad hoc network where all nodes employ multiple input multiple output communication techniques. We present two types of reconfigurable antennas a reconfigurable printed dipole array RPDA and a reconfigurable circular patch antenna RCPA . The RPDA and RCPA have a different number of configurations as well as different degrees of pattern diversity between possible configurations. To effectively use these antennas in a network we introduce and quantify the performance of centralized and decentralized antenna configuration selection schemes for reconfiguration at one or both link ends. We use the sum capacity of the network as a metric to quantify the performance of these antennas in measured and simulated network channels. 1. Introduction Research in the area of ad hoc networks has yielded important advances notably in the field of physical layer techniques. In particular a lot of effort has been spent in i applying smart antennas and antenna diversity techniques to ad hoc networks . 1-3 ii developing medium access control protocols suitable for multiple input multiple output MIMO ad hoc networks e. g. 4-6 and iii adaptive algorithms for antenna beamforming in ad hoc networks . 7-9 . Directional antennas like phased arrays 10 11 and switchable parasitic elements antennas 12 13 have been proposed as a solution to reduce the interference of adjacent nodes maximizing overall network throughput 1 3 14 . In order to further .
