tailieunhanh - Báo cáo hóa học: "Research Article A Real Orthogonal Space-Time Coded UWB Scheme for Wireless Secure Communications"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article A Real Orthogonal Space-Time Coded UWB Scheme for Wireless Secure Communications | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2009 Article ID 571903 8 pages doi 2009 571903 Research Article A Real Orthogonal Space-Time Coded UWB Scheme for Wireless Secure Communications Yanbing Zhang and Huaiyu Dai Department of Electrical and Computer Engineering NC State University Raleigh NC 27695 USA Correspondence should be addressed to Huaiyu Dai hdai@ Received 1 December 2008 Revised 5 June 2009 Accepted 21 July 2009 Recommended by Merouane Debbah Recent research reveals that information security and information-hiding capabilities can be enhanced by proper exploitation of space-time techniques. Meanwhile intrinsic properties of ultra-wideband UWB signals make it an outstanding candidate for secure applications. In this paper we propose a space-time coding scheme for impulse radio UWB systems. A novel real orthogonal group code is designed for multi-antenna UWB signals to exploit the full spatial diversity gain and achieve the perfect communication secrecy. Its performance in a frequency-selective fading channel is analyzed. The transmission secrecy including low probability of detection LPD low probability of intercept LPI and anti-jamming performance is investigated and some fundamental tradeoffs between these secrecy metrics are also addressed. A comparison of the proposed scheme with the direct sequence spread spectrum DSSS technique is carried out which demonstrates that proper combination of UWB and space-time coding can provide substantial enhancement to wireless secure communications over other concurrent systems. Copyright 2009 Y. Zhang and H. Dai. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. 1. Introduction The rapid expansion and proliferation of the wireless applications especially in military and commercial use .