Title :
Secret-key agreement over a non-coherent block-fading MIMO wiretap channel
Author :
Andersson, Mats ; Khisti, Ashish ; Skoglund, Mikael
Author_Institution :
ACCESS Linnaeus Centre, R. Inst. of Technol. (KTH), Stockholm, Sweden
Abstract :
We study secret-key agreement over a non-coherent block-fading multiple input multiple output (MIMO) wiretap channel. We give an achievable scheme based on training and source emulation and analyze the rate in the high SNR regime. Based on this analysis we find the optimal number of antennas to use for training. Our main result is that if the sum of the number of antennas at Alice and Bob is larger than the coherence time of the channel, the achievable rate does not depend on the number of antennas at Eve. In this case source emulation is not needed, and using only training is optimal. We also consider the case when there is no public channel available. In this case we show that secret-key agreement is still possible by using the wireless channel for discussion, giving the same number of secure degrees of freedom as in the case with a public channel.
Keywords :
MIMO communication; antenna arrays; fading channels; SNR regime; antennas; multiple input multiple output wiretap channel; noncoherent block-fading MIMO wiretap channel; optimal number; optimal training; secret key agreement; source emulation; wireless channel; Antennas; Emulation; Fading; Information theory; MIMO; Signal to noise ratio; Training;
Conference_Titel :
Information Theory Workshop (ITW), 2012 IEEE
Conference_Location :
Lausanne
Print_ISBN :
978-1-4673-0224-1
Electronic_ISBN :
978-1-4673-0222-7
DOI :
10.1109/ITW.2012.6404646