Signal Processing Facility Research Articles

A Systematic Approach to the Search for New Technical Solutions for Electronic Equipment at the Initial Stages of Design

A systematic approach is described to search for new technical solutions for radio-electronic units at the stage of technical proposal. It is based on the transformation of the electrical circuit of the device being developed into an object-oriented model reflecting its physical principle of operation. Operators for processing working signals are proposed, which allow choosing alternative technical implementations of fragments of electrical circuits for obtaining new technical solutions. At the same time, parameters are introduced to limit the applicability of operators as part of signal processing facilities to ensure the operability of the radio-electronic device. The proposed approach can be used in the development of new and modernization of existing computer-aided design systems of electronic equipment.

Reconfiguration Using Bio-Inspired Conduction Mode of Field-Effect Transistors toward the Creation of Recyclable Devices

A bio-inspired conduction mode in silicon-based field-effect transistors was studied here using the frequency-dependent reconfiguration principle in a size-reduced circuit architecture. Analog circuits comprising neuromorphic and reconfigurable behavior were analyzed across their physical quantities using a set of equations governing circuit performance. Practical examples were built, analyzed, and discussed from a phenomenological viewpoint. Upon exploiting their reconfiguration properties when semiconductor devices and passive components are interconnected, novel operating principles might inspire optimized signal processing and manufacturing facilities to design circular device-based complex systems.

DSN Transient Observatory

The Deep Space Network (DSN) Transient Observatory (DTO) is a signal processing facility that can monitor up to four DSN downlink bands for astronomically interesting signals. The monitoring is done commensally with reception of deep space mission telemetry. The initial signal processing is done with two CASPER a ROACH1 boards, each handling one or two baseband signals. Each ROACH1 has a 10 GBe interface with a GPU-equipped Debian Linux workstation for additional processing. The initial science programs include monitoring Mars for electrostatic discharges, radio spectral lines, searches for fast radio bursts and pulsars and SETI. The facility will be available to the scientific community through a peer review process.

Advanced~neural network receiver design~to combat multiple channel~impairments

In communication systems, the channel noise is usually assumed to be white and Gaussian distributed. Therefore, an optimum receiver structure designed for the additive white Gaussian noise (AWGN) channel is employed in applications. However, in wireless communication systems, noise is often caused by strong interferences. Moreover, there are other effects such as phase offset that degrade the performance of the receiver. Designing the optimum receiver for different channel models is difficult and not reasonable because channel model and channel statistics are not known at the receiver. In this paper, we propose a neural network-based approach to demodulate the transmitted signal over unknown channels. Naturally, the collection of the training data, design and training of the neural network, and finally reconfiguration of the system according to the designed neural network are implemented on software-defined digital signal processing facilities. In particular, we show that the proposed receiver is capable of jointly canceling the strong interferences and phase offset. Simulation results in various signal environments are presented to illustrate the performance of the proposed system. It is shown that the proposed approach has the same performance as the correlation demodulator structure for AWGN channels, while it has a clear advantage for unknown channel models. Moreover, it is shown that the neural network-based receiver may be used for channel estimation and equalization over Rayleigh channels. Numerical results indicate that the performance of the proposed receiver is very close to the Rayleigh theoretical bound.

HEARING DEVICE WITH A VISUALIZED PSYCHOACOUSTIC VARIABLE AND CORRESPONDING METHOD

The setting and/or adjustment of a hearing device for a user is provided. The hearing device includes a signal processing facility for processing an input sound to form an output sound, with a perceptive model being implemented in the signal processing facility or in a processing facility connected in a data link therewith, with which perceptive model a psychoacoustic variable can be provided in respect of the output sound. A visualization facility, for instance integrated in a remote control comprising the processing facility, is preferably wirelessly connected to the signal processing facility. A value of the psychoacoustic variable can thus be visualized accordingly. In this way an assisting person obtains an item of information relating to the perception of the sound supplied by the hearing device by the user, as a result of which the setting is facilitated for the assisting person.

BEHIND-THE-EAR HEARING DEVICE HAVING AN EXTERNAL, OPTICAL MICROPHONE

An optically unnoticeable and acoustically improved behind-the-ear hearing device having a housing which can be worn behind the ear, a signal processing facility which is arranged in the housing, and which comprises an optoelectrical converter, and at least one optical microphone is provided. The optical microphone is arranged outside the housing and can be positioned in the concha or in the auditory canal. Furthermore, the optical microphone is connected to the signal processing facility by way of an optical wave guide for optical signal transmission purposes. An optical microphone of this type can be realized small and in an unnoticeable fashion on/in an otoplastic, such that during the acoustic recording, the typical frequency behavior through the concha can also be used.

METHOD FOR THE TIME−CONTROLLED ADJUSTMENT OF A HEARING APPARATUS AND CORRESPONDING HEARING APPARATUS

The training of a hearing apparatus in respect of an individual adjustment is to be developed in a more user-friendly manner. To this end, provision is firstly made to automatically classify a hearing situation, to adjust a parameter of the signal processing facility of the hearing apparatus and to automatically learn the adjusted parameters for the current hearing situation. A temporal monitoring of the steps “classifying” and “adjusting” is however carried out here and the automatic learning is only triggered if the classified hearing situation and the adjustment of the parameters have not changed over a predetermined time period. This not only simplifies the training, but also enables a more rapid training by means of automatically triggered training events.

Commercialization of Prognostics Systems Leveraging Commercial Off- The-Shelf Instrumentation, Analysis, and Data Base Technologies

There are many facets of a prognostics and health management system. Facets include data collection systems that monitor machine parameters; signal processing facilities that sort, analyze and extract features from collected data; pattern matching algorithms that work to identify machine degradation modes; database systems that organize, trend, compare and report information; communications that synchronize prognostic system information with business functions including plant operations; and finally visualization features that allow interested personnel the ability to view data, reports, and information from within the intranet or across the internet.A prognostic system includes all of these facets, with details of each varying to match specific needs of specific machinery. To profitably commercialize a prognostic system, a generic yet flexible framework is adopted which allows customization of individual facets. Customization of one facet does not materially impact another. This paper describes the framework, and provides case studies of successful implementation.

A feasible noise estimation algorithm for resource-limited sensor systems

Fault tolerance and self-checking capabilities are key features of modern smart sensors, which often require the integration of additional signal processing facilities. In high-volume production areas such as automotive applications, however, optimized controllers are employed that typically have only limited computing resources. This paper examines several algorithms to assess the noise in a quasi-closed loop measurement channel under the assumption that the stimulus can be held constant during noise measurement. Starting from the definition of standard deviation, we propose several modifications and obtain an easy-to-implement algorithm relying entirely on addition and shift operations. Numerical experiments based on simulated and measured noise verify the practicability of the approach. The proposed algorithm has already been successfully implemented in a capacitive angular speed sensor system for automotive applications.

Parallel integration of ODEs based on convolution algorithms

We consider parallel computing methods for ODEs based on the potential parallelism of convolution algorithms. Detailed presentations of fast convolution algorithms are provided. Implementations of our methods on signal processors and special processors are described. The main emphasis is concentrated on applications of powerful parallel signal processing facilities in ODE computations. By using convolution algorithms we show some treatments of parallel computing in finite fields. As an example of our approach we discuss integrating Lorenz's model.

Analysis of gating errors in time domain antenna measurements

Although relatively new, the principle of measuring the radiation pattern of an antenna using the time domain rather than frequency domain is well known and relies on gating out unwanted reflections. Time domain measurements on horn and spiral antennas illustrate the need for error criteria and in this paper the nature of the gating error, and its relationship to the anti-interference enclosure size and the antenna frequency response, are investigated by both analytical and computer simulation methods. The results show that a lower frequency antenna can be expected to require a larger enclosure for a given gating error and that, for small enclosures, the time domain method has advantages over the conventional frequency domain method. The practical implementation of time domain measurement involves other factors such as the effects of aliasing, the need for a high quality reference channel for calibration, matching and noise levels. It is concluded that, in the time domain method, the amount of absorbent material in a chamber may be reduced but at the expense of a fast signal processing facility and, to some extent, a more critical equipment installation.

Measurement of velocities and diameters of small particles by using fast digital circuits for the on‐line evaluation of laser‐doppler‐signals

AbstractInspection of the scattered light by two photodetectors makes it possible to investigate the velocities of droplets as well as their size in disperse systems and has some advantages against related methods. When this method is used, the size of the droplets can be derived from the phase difference of the signals from the first and the second photodetector.Special problems of this method are discussed in the paper. A system with fast signal processing facilities, working mostly digitally, was developed in order to solve these problems. This system derives several digital signals from the signals of high frequencies that are gained from the photodetectors. These digital signals are combined by digital circuits of the ECL‐type. The resulting pulse series are fed into several digital counters. The data from the counters and from some other inputs are further processed by a real time computer that was developed for this special task, using an 8088 micro processor. This real time computer is connected to an ordinary personal computer by a parallel interface.

Hybrid system for fast data reduction of long-term blood-pressure recordings

Fast analysis of long-term intra-arterial blood-pressure recordings can be approached in various ways. We describe a low cost system, consisting of a hybrid preprocessor and a minicomputer, which can either perform fast data reduction, producing simple statistical information to aid patient management, or be used as the basis of a more comprehensive signal processing facility for research purposes. The preprocessor saves computer time by detecting and measuring the systolic and diastolic points, thereby allowing recordings to be processed 25 times faster than they were recorded. Attention has been given to the special problems of calibration and artefact rejection. Data conversion accuracy was found to be within 2% on a typical recording. The system can run automatically if required to ease the task of routine blood-pressure tape processing.