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 Feedback-Based Transmission for Wireless Networks with Energy and Secrecy Constraints | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2011 Article ID313269 11 pages doi 2011 313269 Research Article A Feedback-Based Transmission for Wireless Networks with Energy and Secrecy Constraints Ioannis Krikidis 1 John S. Thompson EURASIP Member 2 Steve McLaughlin EURASIP Member 2 and Peter M. Grant EURASIP Member 2 1 Department of Computer Engineering Informatics University of Patras Rio 26500 Patras Greece 2Institute for Digital Communications The University of Edinburgh Mayfield Road Edinburgh EH9 3JL UK Correspondence should be addressed to Ioannis Krikidis krikidis@ Received 10 July 2010 Revised 29 December 2010 Accepted 19 January 2011 Academic Editor Lin Cai Copyright 2011 Ioannis Krikidis et al. 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. This paper investigates new transmission techniques for clustered feedback-based wireless networks that are characterized by energy and secrecy constraints. The proposed schemes incorporate multiuser diversity gain with an appropriate power allocation PA in order to support a defined Quality-of-Service QoS and jointly achieve lifetime maximization and confidentiality. We show that an adaptive PA scheme that adjusts the transmitted power using instantaneous feedback and suspends the transmission when the required power is higher than a threshold significantly prolongs the network lifetime without affecting the QoS of the network. In addition the adaptation of the transmitted power on the main link improves the secrecy of the network and efficiently protects the source message from eavesdropper attacks. The proposed scheme improves network s confidentiality without requiring any information about the eavesdropper channel and is suitable for practical applications. Another objective of the .
