Richard Roy

Self-employed

A class of covariance matching estimation techniques (COMET) has recently attracted interest in the signal processing community. These techniques have their roots in the statistical literature where they are sometimes referred to as generalized least squares methods. Covariance matching is an alternative to maximum likelihood estimation, providing...

Most high-resolution algorithms for sensor array processing require an eigendecomposition, which is a computation that is difficult to implement in parallel and requires O(M³) multiplications for an M×M matrix, corresponding to M sensors. Beamspace transformation is one way of reducing computation and sometimes improving the estimation a...

The goal of a personal communications service (PCS) system is to provide ubiquitous coverage for a wide variety of wireless services: voice, data, facsimile, and electronic mail to name but a few. The current design trend for these systems is to deploy a large number of small cells, each served by a base station incorporating a conventional antenna...

Tight control of the wafer temperature in rapid thermal processing (RTP) of semiconductor wafers is considered. Of the various techniques for controlling the temperature, model-based control has the potential for attaining the best performance. An identification of a state-space model based on the subspace-fitting technique results in an experiment...

A subspace-fitting formulation of the ESPRIT problem is presented that provides a framework for extending the algorithm to exploit arrays with multiple invariances. In particular, a multiple invariance (MI) ESPRIT algorithm is developed and the asymptotic distribution of the estimates is obtained. Simulations are conducted to verify the analysis an...

Forward/backward (FB) averaging is employed when possible in sensor array processing to improve parameter estimation accuracy by exploiting a centro-symmetry of the signal subspace. While FB averaging effectively doubles the number of data samples, it also introduces intersample correlation. This correlation complicates not only the performance ana...

SDMA A method and apparatus for increasing the capacity and quality of wireless communication between a plurality of remote users and a base station is disclosed. Using mea surements from an array of receiving antennas at the base station, parameters of multiple signals transmitted to the base station from a plurality of users in the same channel...

Recently, a fast signal subspace decomposition technique (FSD) suitable for parallel processing which achieves a significant reduction in computational complexity for large arrays with few sources was developed. Two new detection schemes used in conjunction with the FSD algorithm are presented. One is based on a series of statistical hypothesis tes...

In this review article, various techniques for obtaining estimates of parameters related to the spectrum of an underlying process are discussed. These techniques include the conventional nonparametric FFT approach and more recently developed parametric techniques such as maximum entropy, MUSIC, and ESPRIT, the latter two being classified as signal-...

Most high-resolution algorithms for sensor array processing require an eigendecomposition which is difficult to implement in parallel and costs at least O ( M ³) multiplications for an M × M matrix, corresponding to M sensors. Recently, S.D. Silverstein et al, (1991) presented a subband parallel scheme, which reduced the computation time...

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Simulation of the motion of particles in large molecular chains is computationally complex, generally involving the solution of large systems of differential equations employing iterative techniques. Generating solutions for even very short time intervals can require significant amounts of computational effort. Though the particle trajectories are...

This final report consists of ten sections. The first is a report describing our abilities in the co-site radio frequency interference (RFI) problem. The second is the paper, Heisenberg Wavelets and the Uncertainty Principle, which will be expanded upon and submitted to the appropriate technical journal. The third is a revised version of the paper,...

High-resolution signal parameter estimation is a problem of significance in many signal processing applications. Such applications include direction-of-arrival (DOA) estimation, system identification, and time series analysis. A novel approach to the general problem of signal parameter estimation is described. Though discussed in the context of dir...

Abstractâ€â€?ESPRIT is a recently developed and patented technique for high-resolution estimation of signal parameters. It exploits an invariance structure designed into the sensor array to achieve a reduction in computational requirements of many orders of magnitude over previous techniques such as MUSIC, Burg's MEM, and Capon's ML, and in addi...

ESPRIT is a recently introduced algorithm for direction-of-arrival (DOA) and spectral estimation. Its principal advantage is that parameter estimates are obtained directly, without knowledge (and hence storage) of the parameter manifold and without computation or search of some spectral measure. This advantage is achieved by exploiting a certain in...

Summary form only given, ESPRIT is a patented technique for high-resolution estimation of signal parameters that exploits an invariance structure designed into the sensor array to achieve a reduction in computational requirements of many orders of magnitude over previous techniques such as MUSIC, Burg's MEM, and Capon's ML, with virtually no loss i...

An approach to the general problem of signal parameter estimation is described. The algorithm differs from its predecessor in that a total least-squares rather than a standard least-squares criterion is used. Although discussed in the context of direction-of-arrival estimation, ESPRIT can be applied to a wide variety of problems including accurate...

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The application of a subspace invariance approach (ESPRIT) to the estimation of parameters (frequencies and powers) of cisoids in noise is described. ESPRIT exploits an underlying rotational invariance of signal subspaces spanned by two temporally displaced data sets. The new approach has several advantages including improved resolution over Pisare...

A new approach to Estimation of Signal Parameters by Rotational Invariance Techniques (ESPRIT) is described in the context of direction-of-arrival estimation, but is also applicable to other problems. The method relies on finding the underlying rotation between the common subspaces associated with an array of pairwise-matched and codirectional sens...

A novel approach to the general problem of signal parameter estimation is described. Though the technique (ESPRIT) is discussed in the context of direction-of-arrival estimation, it can be applied to a wide variety of problems including spectral estimation. ESPRIT exploits an underlying rotational invariance among signal subspaces induced by an arr...

The activity of cardiac tissue is associated with electric currents which flow in the conductor formed by the body. These currents produce surface potential differences detected as the electrocardiogram (ECG) and induce magnetic fields detected as the magnetocardiogram (MCG). The electrical activity of the human heart was first detected by Waller i...

The electric activity of cardiac tissue is associated with electric currents which flow in the conductor formed by the body. These currents produce surface potential differences detected as the electrocardiogram (ECG) and induce magnetic fields detected as the magnetocardiogram (MCG). Yhe measurement of the magnetocardiogram differs from the electr...