@conference {
	title = {Signal Filtering with Gaussian Quantum States and Canonical Measurements},
	author = {Harger, Robert O., Baras, John S.},
	year = {1977},
	month = {10/1977},
	address = {Ithaca, New York},
	booktitle = {1977 IEEE International Symposium on Information Theory},
	pages = {pp. 74}
}
@conference {
	title = {Linear Filtering with Quantum Mechanical Measurements},
	author = {Baras, John S., Harger, Robert O.},
	year = {1976},
	month = {06/1976},
	abstract = {Filtering problems arising in the quantum electronics are investigated in the quantum mechanical framework. In particular the minimum varience linear estimator based on optimal selection of the present quantum measurement and optimal linear processing of past and present outcomes is found for vector signal processes. Under certain natural assumptions a separation theorum is for the filter is proven~which leads to consideable simplification of the complexity of the filter. Examples from optical communication systems provide a recursive filters and illustrate the results.},
	address = {Leningrad, USSR},
	booktitle = {4th International Symposium on Information Theory},
	pages = {PP. 172-179}
}
@conference {
	title = {Conditional Expectations and Fock Space Representations in Quantum Filtering},
	author = {Baras, John S., Harger, Robert O.},
	year = {1976},
	month = {06/1976},
	abstract = {The role on conditional expectations on von Neumann algebras in the theory of quantum filtering is investigated. The relations characterising the solutions of various quantum filtering problems are interpreted via the notion of conditional expectation. The equations that describe optimal linear quantum filters are represented in Fock space of the analytical functions, and the usefulness of this representation is discussed. Finally some priliminary results on the applications of these methods in non-linear and continous time filtering are described.},
	address = {Leningrad, USSR},
	booktitle = {4th International Symposium on Information Theory},
	pages = {pp. 180-185}
}
@conference {
	title = {Nonclassical Filtering Problems in Quantum Electronics},
	author = {Baras, John S., Harger, Robert O.},
	year = {1975},
	month = {12/1975},
	abstract = {Filtering problems arising in quantum electronics are investigated. In particular, the minimum variance linear filtering problems incorporating quantum mechanical measurements is solved for both scalar and vector signal processes. The simplification of the filter under certain assumptions is demonstrated. Examples from optical communication systems illustrate the result.},
	address = {Houston Texas},
	booktitle = {14th IEEE Decision and Control Conference},
	pages = {pp. 804-806}
}
@conference {
	title = {Multiparameter filtering with Quantum Measurements},
	author = {Baras, John S., Harger, Robert O.},
	year = {1975},
	month = {04/1975},
	abstract = {We analyze here the problem of estimating a member of a vector discrete time process utilizing past and present quantum mechanical~measurements. The minimum variance linear estimator based on optimal present measure-ment selection combined with an optimal linear processing of past measurements is studied. A necessary condition for the optimal extended measurement and the optimal coefficient matri-ces is given which leads to the generation of several more specialized necessary conditions. Certain operator equations related to these necessary conditions are studied and it is found that the conditions are necessary and sufficient in the commutative case. Finally when the average quantum measurement is linear in the random signal and the signal process is pairwise Gaussian, the filter separates: the optimal measurement can be taken the same as the optimal measurement with no regard to past data and the past and present data are processed classically. The results are illustrated by considering the estimator of the amplitude and phase of a laser received in a single-mode ca-vity along with thermal noise; when the random signal sequence satisfies a linear recursion, the estimate can be computed recursively.},
	address = {Baltimore, MD},
	booktitle = {1975 Conference on Information Sciences and Systems},
	pages = {178-184},
	organization = {Johns Hopkins University}
}
@conference {
	title = {Recursive Filtering of Operator Valued Processes in Quantum Estimation},
	author = {Baras, John S., Harger, Robert O., Ephremides, Anthony.},
	year = {1974},
	month = {10/1974},
	abstract = {The unified approach to estimation of a stochastic signal satisfying a dynamical equation through the use of martingale and multiplicity theory is applied, in its infinite dimensional version, to the problem of estimation of a signal via quantum mechanical measurements in an optical communication system. The "state" is an operator valued stochastic process representing~a density operator in the quantum mechanical sense acting in an appropriate Hilbert space. The aim is the derivation of recursion relations for the optimum measurement operators that minimize a quadratic cost function. The Markovian nature of the density operator indexed by the signal process allows for optimum or suboptimum recursive filtering relations that are analogous to the ones in the classical case.},
	address = {Notre Dame, Indiana},
	booktitle = {1974 IEEE International Symposium on Information Theory}
}
@article {
	title = {Quantum Mechanical Linear Filtering of Vector Signal Processes},
	author = {Baras, John S., Harger, Robert O.},
	year = {1977},
	month = {11/1977},
	abstract = {The problem of estimating a member of a discrete-time vector process from past and present quantum mechanical measurements is considered; specifically, the minimum-variance linear estimator based on optimal present measurements is studied. Necessary and sufficient conditions that characterize the optimal processing matrix coefficients and the optimal measurements are discussed and interpreted. The optimal linear filter is compared to the optimal quantum estimator without postprocessing of past data. When the signal sequence is pairwise Gaussian and the optimal quantum measurement without postprocessing has the properties that it is linear in a specific sense and that its outcome and the corresponding element of the signal sequence are jointly Gaussian, then the optimal linear filter separates. That is, the optimal measurement can be taken to be the same as the optimal measurement without regard to past data, and the past and present data are processed classically. The results are illustrated by considering the filtering of the in-phase and quadrature amplitudes of a laser field received in a single-mode cavity along with thermal noise. In this case, when the random signal sequence satisfies a linear recursion, the estimate can be computed recursively in a very efficient manner.},
	pages = {pp. 683-693},
	volume = {Vol. IT-23},
	number = {No. 6},
	journal = {IEEE Transactions. on Information Theory}
}
@conference {
	title = {Quantum Mechanical Linear Filtering of Vector Signal Processes},
	author = {Baras, John S., Harger, Robert O.},
	year = {1977},
	month = {11/1977},
	abstract = {The problem of estimating a member of a discretetime vector process from past and present quantum mechanical measurements is considered; specifically, the minimum-variance linear estimator based on optimal present measurements is studied. Necessary and sufficient conditions that characterize the optimal processing matrix coefficients and the optimal measurements are discussed and interpreted. The optimal linear filter is compared to the optimal quantum estimator without postprocessing of past data. When the signal sequence is pairwise Gaussian and the optimal quantum measurement without postprocessing has the properties that it is linear in a specific sense and that its outcome and the corresponding element of the signal sequence are jointly Gaussian, then the optimal linear filter separates. That is, the optimal measurement can be taken to be the same as the optimal measurement without regard to past data, and the past and present data are processed classically. The results are illustrated by considering the filtering of the in-phase and quadrature amplitudes of a laser field received in a single-mode cavity along with thermal noise. In this case, when the random signal sequence satisfies a linear recursion, the estimate can be computed recursively in a very efficient manner.},
	booktitle = {IEEE Transactions on Information Theory},
	pages = {pp. 683-693}
}
@article {
	title = {Quantum Mechanical Linear Filtering of Random Signal Sequences},
	author = {Baras, John S., Harger, Robert O., Park, Young H.},
	year = {1976},
	month = {01/1976},
	abstract = {The problem of estimating a member of a scalar random signal sequence with quantum-mechanical measurements is considered. The minimum variance linear estimator based on an optimal present quantum measurement and optimal linear processing of past measurements is found. When the average optimal measurement without post-processing, for a fixed signal, is linear in the random signal and the signal sequence is pairwise Gaussian, the optimal processing separates: the optimal measurement is the same as the optimal measurement without regard to past data, and the past and present data are processed classically. The results are illustrated by considering the estimator of the real amplitude of a laser signal received in a single-mode cavity along with thermal noise; when the random signal sequence satisfies a linear recursion, the estimate can be computed recursively. For a one-step memory signal sequence, it is shown that the optimal observable generally differs from the optimal observable disregarding the past; the optimal measurement can be computed recursively.},
	pages = {pp. 59-64},
	volume = {Vol. IT-22},
	number = {No. 1},
	journal = {IEEE Transactions on Information Theory}
}
