TY - GEN
T1 - Discrete-Time Poisson Optical Wiretap Channel with Peak Intensity Constraint
AU - Soltani, Morteza
AU - Rezki, Zouheir
N1 - KAUST Repository Item: Exported on 2022-06-30
Acknowledged KAUST grant number(s): OSR-2016- CRG5-2958-01
Acknowledgements: This work has been supported by King Abdullah University of Science and Technology (KAUST), under a competitive research grant (CRG) OSR-2016- CRG5-2958-01.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.
PY - 2019/9/26
Y1 - 2019/9/26
N2 - This paper addresses the discrete-time Poisson wiretap channel (DT-PWC) in an optical wireless communications system based on intensity modulation and direct detection. Subject to nonnegativity and peak intensity as well as bandwidth constraints imposed on the channel input, we study the secrecy-capacity-achieving input distribution of this wiretap channel and prove it to be unique and discrete with a finite number of mass points. Furthermore, we establish that every point on the boundary of the rate-equivocation region of this wiretap channel is also obtained by a unique and discrete input distribution with a finite support. In general, the number of mass point of the optimal distributions are greater than two. This is in contrast with the continuous-time PWC where the secrecy capacity and the entire boundary of the rate-equivocation region are achieved by binary distributions when the signaling bandwidth is not restricted. Additionally, we shed light on the asymptotic behavior of the secrecy capacity in the low intensity regime and observe that the secrecy capacity scales quadratically with the peak intensity constraint. Finally, Our numerical results indicate that there is a tradeoff between the secrecy capacity and the capacity in the sense that both may not be achieved simultaneously.
AB - This paper addresses the discrete-time Poisson wiretap channel (DT-PWC) in an optical wireless communications system based on intensity modulation and direct detection. Subject to nonnegativity and peak intensity as well as bandwidth constraints imposed on the channel input, we study the secrecy-capacity-achieving input distribution of this wiretap channel and prove it to be unique and discrete with a finite number of mass points. Furthermore, we establish that every point on the boundary of the rate-equivocation region of this wiretap channel is also obtained by a unique and discrete input distribution with a finite support. In general, the number of mass point of the optimal distributions are greater than two. This is in contrast with the continuous-time PWC where the secrecy capacity and the entire boundary of the rate-equivocation region are achieved by binary distributions when the signaling bandwidth is not restricted. Additionally, we shed light on the asymptotic behavior of the secrecy capacity in the low intensity regime and observe that the secrecy capacity scales quadratically with the peak intensity constraint. Finally, Our numerical results indicate that there is a tradeoff between the secrecy capacity and the capacity in the sense that both may not be achieved simultaneously.
UR - http://hdl.handle.net/10754/679465
UR - https://ieeexplore.ieee.org/document/8849715/
UR - http://www.scopus.com/inward/record.url?scp=85073166696&partnerID=8YFLogxK
U2 - 10.1109/ISIT.2019.8849715
DO - 10.1109/ISIT.2019.8849715
M3 - Conference contribution
SN - 9781538692912
SP - 136
EP - 140
BT - 2019 IEEE International Symposium on Information Theory (ISIT)
PB - IEEE
ER -