Design of filters for reliable and secure communications conditional mean estimation at the eavesdropper.
ABSTRACT This paper considers the problem of filter design with secrecy constraints, where two legitimate parties, Alice and Bob, communicate in the presence of an eavesdropper, Eve, over multiple-input multiple-output (MIMO) Gaussian channels. In particular, we consider the design of transmit and receive filters that minimize the mean-squared error (MSE) between the legitimate parties subject to a certain eavesdropper MSE level, in the situation where the eavesdropper MIMO channel is a degraded version of the main MIMO channel. We analyze the penalty in terms of MSE in the eavesdropper channel due to the assumption that optimal linear receive filters are used, while the eavesdropper employs nonlinear conditional mean estimation instead. This penalty is also shown to be negligible in regions of operational interest. We present a set of numerical results to illustrate the main conclusions.
SourceAvailable from: Babak Hassibi[Show abstract] [Hide abstract]
ABSTRACT: We consider the MIMO wiretap channel, that is a MIMO broadcast channel where the transmitter sends some confidential information to one user which is a legitimate receiver, while the other user is an eavesdropper. Perfect secrecy is achieved when the transmitter and the legitimate receiver can communicate at some positive rate, while insuring that the eavesdropper gets zero bits of information. In this paper, we compute the perfect secrecy capacity of the multiple antenna MIMO broadcast channel, where the number of antennas is arbitrary for both the transmitter and the two receivers. Our technique involves a careful study of a Sato-like upper bound via the solution of a certain algebraic Riccati equation.IEEE Transactions on Information Theory 09/2011; 57(8-57):4961 - 4972. DOI:10.1109/TIT.2011.2158487 · 2.65 Impact Factor
Conference Paper: Optimal Precoding for Digital Subscriber Lines[Show abstract] [Hide abstract]
ABSTRACT: We determine the linear precoding policy that maximizes the mutual information for general multiple-input multiple-output (MIMO) Gaussian channels with arbitrary input distributions, by capitalizing on the relationship between mutual information and minimum mean squared error (MMSE). The optimal linear precoder can be computed by means of a fixed- point equation as a function of the channel and the input constellation. We show that diagonalizing the channel matrix does not maximize the information transmission rate for nonGaussian inputs. A full precoding matrix may significantly increase the information transmission rate, even for parallel non-interacting channels. We illustrate the application of our results to typical Gigabit DSL systems.Communications, 2008. ICC '08. IEEE International Conference on; 06/2008
Conference Paper: Secrecy Capacity of Wireless Channels[Show abstract] [Hide abstract]
ABSTRACT: We consider the transmission of confidential data over wireless channels with multiple communicating parties. Based on an information-theoretic problem formulation in which two legitimate partners communicate over a quasi-static fading channel and an eavesdropper observes their transmission through another independent quasi-static fading channel, we define the secrecy capacity in terms of outage probability and provide a complete characterization of the maximum transmission rate at which the eavesdropper is unable to decode any information. In sharp contrast with known results for Gaussian wiretap channels (without feedback), our contribution shows that in the presence of fading information-theoretic security is achievable even when the eavesdropper has a better average signal-to-noise ratio (SNR) than the legitimate receiver - fading thus turns out to be a friend and not a foeInformation Theory, 2006 IEEE International Symposium on; 08/2006