Next Article in Journal
Information Entropy of Influenza A Segment 7
Next Article in Special Issue
An Assessment of Hermite Function Based Approximations of Mutual Information Applied to Independent Component Analysis
Previous Article in Journal / Special Issue
Comparison of Statistical Dynamical, Square Root and Ensemble Kalman Filters
Open AccessArticle

Intercept Capacity: Unknown Unitary Transformation

1
Department of Electrical and Electronic Engineering, University of Melbourne, Australia
2
EWRD, DSTO, PO Box 1500, Edinburgh, Australia
*
Author to whom correspondence should be addressed.
Entropy 2008, 10(4), 722-735; https://doi.org/10.3390/e10040722
Received: 22 May 2008 / Accepted: 10 November 2008 / Published: 20 November 2008
We consider the problem of intercepting communications signals between Multiple-Input Multiple-Output (MIMO) communication systems. To correctly detect a transmitted message it is necessary to know the gain matrix that represents the channel between the transmitter and the receiver. However, even if the receiver has knowledge of the message symbol set, it may not be possible to estimate the channel matrix. Blind Source Separation (BSS) techniques, such as Independent Component Analysis (ICA) can go some way to extracting independent signals from individual transmission antennae but these may have been preprocessed in a manner unknown to the receiver. In this paper we consider the situation where a communications interception system has prior knowledge of the message symbol set, the channel matrix between the transmission system and the interception system and is able to resolve the transmissionss from independent antennae. The question then becomes: what is the mutual information available to the interceptor when an unknown unitary transformation matrix is employed by the transmitter. View Full-Text
Keywords: Communications; Unitary; BSS Communications; Unitary; BSS
Show Figures

Figure 1

MDPI and ACS Style

Kitchen, J.; Moran, B.; Howard, S.D. Intercept Capacity: Unknown Unitary Transformation. Entropy 2008, 10, 722-735.

Show more citation formats Show less citations formats

Article Access Map by Country/Region

1
Only visits after 24 November 2015 are recorded.
Back to TopTop