Open AccessAdaptive continuous variable quantum key distribution based on channel estimation
Author(s) -
Changhua Zhu,
Nan Chen,
Changxing Pei,
Dongxiao Quan,
YI Yun-hui
Publication year - 2009
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.58.2184
Subject(s) - quantum key distribution , gaussian , key (lock) , channel (broadcasting) , computer science , continuous variable , intensity (physics) , homodyne detection , physics , statistical physics , optics , quantum , telecommunications , quantum mechanics , statistics , mathematics , computer security
In order to obtain steady key rate for a continuous variable quantum key distribution system, Alice should adaptively adjust the intensity of optical pulses she sents. In this paper, an optical fiber channel is taken as the additive bosonic quantum Gaussian channel. It is proven that a Gaussian channel transforms Gaussian states into Gaussian states. The maximum-likelihood method is used to estimate the channel parameters after balanced homodyne detection. Then, Alice can change the intensity of optical pulses adaptively according to the estimated noise level, thereby a steady key rate can be obtained.