Richard J. Kozick

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Standard linear diversity combining techniques are not effective in combating fading in the presence of non-Gaussian noise. An adaptive spatial diversity receiver is developed for wireless communication channels with slow, flat fading and additive non-Gaussian noise. The noise is modeled as a mixture of Gaussian distributions, and the(More)
Multiple sensor arrays provide the means for highly accurate localization of the (x,y) position of a source. In some applications, such as microphone arrays receiving aeroacoustic signals from ground vehicles, random fluctuations in the air lead to frequency-selective coherence losses in the signals that arrive at widely separated sensors. We present(More)
Stoica and Ng (1998) presented a simple expression for the constrained Cramer-Rao bound (CCRB) when the constraints are given by a differentiable function of the parameter to be estimated. This letter considers the parallel case in developing the CCRB when the parameters are locally fitted to a lower-dimensional parametric model, i.e., the parameters are(More)
In this correspondence, a simple one-dimensional (1-D) differencing operation is applied to bilevel images prior to block coding to produce a sparse binary image that can be encoded efficiently using any of a number of well-known techniques. The difference image can be encoded more efficiently than the original bilevel image whenever the average run length(More)
In this paper, we develop Cramér–Rao bounds (CRBs) for bearing, symbol, and channel estimation of communications signals in flat-fading channels. We do this using the constrained CRB formulation of Gorman and Hero, and Stoica and Ng, with the unknown parameters treated as deterministic constants. The equality constraints may be combined arbitrarily, e.g.,(More)
Cramér-Rao bounds (CRBs) are developed for narrow band source separation, when the sources are constrained to have constant modulus (CM). The bounds are appropriate for multi path CM sources, in blind, semi-blind, or fully known cases. Source separation bounds are contrasted for calibrated and uncalibrated arrays. It is shown that, from the CRB(More)
We study time delay estimation (TDE) on parallel channels with flat fading. Several models for the channel gains are considered, and for each case we present the the maximum likelihood estimator (MLE), the Cramer-Rao bound (CRB), and the Ziv-Zakai bound (ZZB). The bounds facilitate an analysis of the effects of fading and diversity on TDE accuracy over(More)