000			04459nam a22002537a 4500
008			210223b2009 a|||f mb|| 00| 0 eng d
040			_aEG-CaNU _cEG-CaNU
041	0		_aeng _beng
082			_a005
100	0		_aKarim Abulmakarem Mohamed Khalil _9259
245	1		_aDelay-Limited Secure Communication Over Fading Channels / _cKarim Abulmakarem Mohamed Khalil
260			_c2009
300			_a59 p. _bill. _c21 cm.
500			_3Supervisor: Moustafa Youssef
502			_aThesis (M.A.)—Nile University, Egypt, 2009 .
504			_a"Includes bibliographical references"
505	0		_aContents: Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 The Wireless Channel . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Previous Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.3 System Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.4 Outline and Contribution . . . . . . . . . . . . . . . . . . . . . . . 10 2. Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.1 Physical Layer Security . . . . . . . . . . . . . . . . . . . . . . . . 12 2.2 Delay Limited Communication . . . . . . . . . . . . . . . . . . . . 14 2.2.1 Ergodic vs Delay Limited Setting: Capacity and Power Control 15 2.2.2 Transmitter CSI . . . . . . . . . . . . . . . . . . . . . . . . 16 viii 3. Full Transmitter CSI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 3.1 Upper Bound on the Delay Limited Secrecy Capacity . . . . . . . . 18 3.2 Achievable Delay Limited Secrecy Rate . . . . . . . . . . . . . . . . 19 3.2.1 Achievability Proof . . . . . . . . . . . . . . . . . . . . . . . 20 3.2.2 Remarks on the achievability scheme . . . . . . . . . . . . . 27 3.3 Asymptotic Optimality of the Achievable Rate . . . . . . . . . . . 27 3.4 Numerical Results . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 4. Only Main Channel CSI . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 4.1 Upper Bound on the Delay Limited Secrecy Capacity . . . . . . . . 30 4.2 Achievable Delay Limited Secrecy Rate . . . . . . . . . . . . . . . . 31 4.2.1 Proof of the Achievable Scheme . . . . . . . . . . . . . . . . 32 4.3 Numerical Results . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 5. Conclusions and Future Work . . . . . . . . . . . . . . . . . . . . . . . . 38 Appendices: A. Random Binning Scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 B. Ergodic Secrecy Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . 42 B.1 Full Transmitter CSI . . . . . . . . . . . . . . . . . . . . . . . . . . 42 B.2 Only Main Channel CSI . . . . . . . . . . . . . . . . . . . . . . . . 43 Bibliography . . . .
520	3		_aAbstract: Many wireless applications are limited by different forms of delay constraints. These applications range from the most basic voice communication to the more demanding multimedia streaming. However, due to its broadcast nature, the wireless channel is vulnerable to eavesdropping and other security threats. Therefore, techniques that satisfy both the delay limitation and the confidentiality requirement are of definite interest. This motivates our analysis of the fundamental (information theoretic) limits of secure communication over fading channels subject to strict deadlines. In this thesis, we study the delay limited secrecy capacity of the flat fading channel under two different assumptions on the available transmitter channel state information (CSI). The first scenario assumes perfect prior knowledge of both the main and eavesdropper channel gains. Here, upper and lower bounds on the delay limited secrecy capacity are derived, and shown to be tight in the high signal-to-noise ratio (SNR) regime. In the second scenario, only the main channel CSI is assumed to be available at the transmitter where, remarkably, we establish the achievability of a non-zero delay-limited secure rate, for a wide class of channel distributions, with a high probability. In the two cases, our achievability arguments are based on a novel two-stage key-sharing approach that overcomes the secrecy outage phenomenon observed in earlier works.
546			_aText in English, abstracts in English.
650		4	_aWireless Technologies _9327
655		7	_2NULIB _aDissertation, Academic _9187
690			_aWireless Technologies _9327
942			_2ddc _cTH
999			_c8967 _d8967