Use Of Wiener Filter Research Articles

Narrowband Registration of Ultra-Wideband Signal

The research of various parameters influence on the Fresnel reflector focusing properties in particular spatial sizes, the focal point position, etc. is conducted. The version of using a flat Fresnel reflector for receiving ultra-wideband signals with the use of Wiener filtering is suggested.

Quaternion Wiener Deconvolution for Noise Robust Color Image Registration

In this letter, we propose a global method for registering color images with respect to translation. Our approach is based on the idea of representing translations as convolutions with unknown shifted delta functions, and performing Wiener deconvolution in order to recover the shift between two images. We then derive a quaternionic version of the Wiener deconvolution filter in order to register color images. The use of Wiener filter also allows us to explicitly take into account the effect of noise. We prove that the well-known algorithm of phase correlation is a special case of our method, and we experimentally demonstrate the advantages of our approach by comparing it to other known generalizations of the phase correlation algorithm.

Optimum Linear Design of Two-Hop MIMO Relay Networks With QoS Requirements

This paper investigates the optimal design issue of general two-hop amplify-and-forward (AF) MIMO relay networks with one source, one destination and multiple relays, each having multiple antennas. Beginning with the study of the mean-square error (MSE) matrix of the system and the use of Wiener filter for the destination processing, a constrained optimization problem with respect to the unknown relay precoder matrix is formulated with a goal of minimizing the total relay transmit power subject to the MSE-based quality of service (QoS) requirement on each data stream. As the original optimization problem is very difficult to solve, a lower bound of the cost function is pursued to achieve an approximate optimization problem. The modified problem is then solved under the perfect channel state information (CSI) condition using the diagonalization method along with the majorization theory to obtain optimal relay precoder with either nonoptimal or optimal source precoding. It is shown that a convex relay precoding solution is available in the case of nonoptimal source precoding whereas a joint optimal source and relay precoder can be obtained through a multilevel waterfilling algorithm. The optimal design of the relay network under imperfect CSI condition is also considered by modifying the optimization problem with the channel mean and covariance matrix, leading to a robust optimization design of the relay precoder. The proposed technique is validated by Monto Carlo simulations and is also compared with one existing method.

Reduction of Parametric Amplified Noise in Nonlinear Fiber Channels by Use of Wiener Filtering

As a parametric amplified noise, nonlinear phase noise limits the channel capacity in multispan fiber-optics transmissions. In this paper, the reduction of nonlinear phase noise by use of Wiener filtering is studied. Extracting signal from time-domain concepts, parametric amplified noise covering signal spectrum in frequency domain can be suppressed considerably. Timing jitter and ghost pulses due to intrachannel nonlinearities can also be compensated. Nonparametric Wiener filtering is used at the end of six configurations of dispersion compensation (DC) transmission lines: pre- and postlumped DC, distributed DC without optical phase conjugation (OPC), dispersion inversion (DI) about midlink OPC with, respectively, one-for-multispan, single type span and alternate type span on each side of OPC. It is found that single-DI and alternate-DI schemes have higher input power capacity than one-for-multi-DI scheme. Further reductions in the nonlinear phase noise accumulation for all these DC maps are obtained with Wiener filtering, and higher absolute dispersion can decrease signal fluctuation due to nonlinear phase noise, as well.

New optimal filtering approaches for hands-free telecommunication terminals

The use of Wiener filtering to simultaneously reduce all the perturbations at the sound pick-up of hands-free terminals is investigated in this paper. This analysis of perturbation reduction is a global approach as all types of perturbations to desired signal are reduced by a unique filter. Filters derived from this approach are applied in two different contexts: hands-free radiotelephony in cars, where two distinct perturbations have to be considered, noise and acoustic echo; and the teleconference context where the global approach was performed on residual echo remaining after a classical echo cancellation. The use of psychoacoustic properties is also considered in order to improve the quality of the transmitted speech signals.

Use of a nonstationary temporal Wiener filter in nuclear medicine.

The use of the Wiener filter is proposed for temporal filtering of nuclear medicine dynamic studies. This filter adapts to the signal and noise levels of each pixel activity curve in a dynamic study to produce an "optimal" suppression of noise, while maintaining the signal content of the curve. The filter is derived to be a simple function of the power spectrum of the time-activity curve. Examples of its use for temporally filtering gated blood-pool studies for cine viewing and functional image formation are shown.

A portable, low-cost, digital system for room acoustics measurements

A portable digital acquisition and analysis system has been developed around a low-cost microcomputer. The system consists of a programmable transient signal generator and an acquisition and analysis section. Designed principally for impulse response measurements in both full scale and model rooms, the acquisition system has been configured for portability and ease of use in the field. Data is “captured” directly into the computer main memory and is stored in digital form on floppy disks. A resident graphics module can be used to display the impulse response in various forms and to display the sound energy decay curve computed from the impulse response by backward integration. General purpose signal processing software has been written for computation of Fourier transforms, power spectra, cepstra, and digital filtering. The use of Wiener filtering for the deconvolution of room impulse response and source signal is being implemented, and is the subject of a companion paper. Some results of measurements made in existing performance spaces will be presented.

Additional comments on the use of Wiener filtering for the estimation of evoked potentials.

The problem of average potentials filtration in the case of periodic stimulation is discussed in the paper. Some considerations proving the correctness of Wiener filtering processes suggested by Doyle are presented here. The basic assumption of the proof is an approximation of the noise power density by means of a step function.

Some comments on the use of Wiener filtering for the estimation of evoked potentials

It is shown that a previous formulation of the Wiener filter for use in the estimation of evoked potentials (Walter 1969) is incorrect. The origin of anomalies thereby produced is discussed.