As packet-mode communications become prevalent in upcoming generations of wireless communications systems, the need to investigate the performance of advanced adaptive signalprocessing techniques in such a context be...
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As packet-mode communications become prevalent in upcoming generations of wireless communications systems, the need to investigate the performance of advanced adaptive signalprocessing techniques in such a context becomes exigent. We evaluate the impact of some of these schemes, namely the adaptive antenna, the adaptive equalization and the decorrelator multiuser detector, in a comparative performance assessment of an uplink joint CDMA/PRMA and a CDMR/ALOHA protocol. Besides the single resource allocation policy for voice-only traffic, the use of multislot and multicode multirate approaches for continuous bit rate (CBR) and variable bit rate video (VBR) traffic transmission is considered. The presented results permit one to analyze the tradeoffs existing between performance and complexity among the different options, allowing then for an integrated design of the medium access control protocols and advanced receiver algorithms.
It is natural to use the Internet in telemedicine. So far, some telemedicine systems have been proposed to interface with the Internet. In these system, "off-the-shelf" instruments were used as medical perip...
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It is natural to use the Internet in telemedicine. So far, some telemedicine systems have been proposed to interface with the Internet. In these system, "off-the-shelf" instruments were used as medical peripheral devices, meaning that a large array of separate devices have to be deployed in an already crowded room. We are currently developing an Internet based telemedicine system. The system has multi-functionality that was realized using virtual instrumentation technology. The Internet was used as a vehicle to deliver the virtual medical instruments and medical data in real time. The system facilitates the extraction of valuable diagnostic information using embedded advanced biomedical signalprocessingalgorithms. We tested the delivery of virtual medical instruments and medical data using pcAnywhere and JAVA applets. In addition, we created a test-bed to send 16 channels of ECG through the Internet using a 300 kpbs cable modem. Our preliminary results demonstrated that the performance of medical virtual instruments is as good as their hardware counterparts because medical signals have low frequencies. It was also demonstrated that the current Internet supports the transmission of real time physiological signals, which provides a vehicle for home based telemonitoring. Compared with other telemedicine techniques, the presented technique transfers not only the medical data, but also the instrument (virtual instrument) and its signalprocessing capability through the Internet.
Cochlear implants are now widely used as a mean for restoring hearing to profoundly deaf people. There is a great variety in performance of the implanted patients, this depends on the state of the cochlea and the rema...
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Cochlear implants are now widely used as a mean for restoring hearing to profoundly deaf people. There is a great variety in performance of the implanted patients, this depends on the state of the cochlea and the remaining nervous terminations, and also it depends on the site and degree of insertion of the electrodes, on the stimulation strategy and even on the rehabilitation process. After the implantation of the prosthesis, the patient must go through a fitting process, and a long procedure of evaluation and rehabilitation. This paper will present an advanced software used by physicians and technicians for the fitting of cochlear implants and the evaluation of the outcomes and that can be used by either specialists or patients during the rehabilitation process. This tool is essentially composed of two parts. The first part is used for the fitting of the implant; it determines the dynamic range of the electric current that can be used with the patient. It also sets which of the different stimulation channels is exploitable. The second part is used for the testing and the evaluation of the outcomes of different stimulation strategies. This part can be used by the clinician as well as by the patient alone to practice with recorded sounds. All published stimulation strategies can be tested with this software and it's easy to use with all the known cochlear prostheses. It is also suitable for researchers that want to experience new stimuli patterns or stimulation algorithms.
Speech/non-speech detection is important in many areas of speech processing technology. In real environments, the speech signal is usually corrupted by background noise, which greatly affects the performance of speech...
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Speech/non-speech detection is important in many areas of speech processing technology. In real environments, the speech signal is usually corrupted by background noise, which greatly affects the performance of speech processing systems. It is well known that a major cause of the efficiency decrease in automatic speech recognition (ASR) is the inaccurate detection of the endpoints. Therefore, high performance speech recognition requires efficient speech detection, especially in noisy environments. The paper describes a robust speech/non-speech detection algorithm with high reliability in very noisy environments. The algorithm is based on the fuzzy polarity correlation method. In order to decide on the speech/non-speech section, we use a similar degree between the positive polarity correlation sequence and the negative polarity correlation sequence for the input speech signal. The evaluation results show that this detection algorithm can obtain higher rates of accuracy in noisy environments.
There are many system proposals for satellite-based multimedia communications that promise high capacity and ease of access. Many of these proposals require advanced switching technology and signalprocessing on-board...
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There are many system proposals for satellite-based multimedia communications that promise high capacity and ease of access. Many of these proposals require advanced switching technology and signalprocessing on-board satellites that will directly impact their cost, performance, availability, and time-to-market. Given the amount of commercial and technical risk involved in such complex systems, satellite operators have been looking for solutions that are simpler, yet flexible. One solution is based on a geosynchronous (GEO) satellite system equipped with simple on-board processing and switching. The satellite network is ATM-based and carries heterogeneous traffic. An important feature of this system is allowing for a maximum number of simultaneous users, hence, requiring effective connection admission control (CAC) and bandwidth on demand (BOD) algorithms. Nortel Networks has already developed an innovative CAC and BOD algorithm for the system. We present the BOD performance evaluations of the integrated algorithm. By detailed simulations, we show that the BOD scheme is able to efficiently utilize all available bandwidth and to gain high throughput. We also find that the end-to-end delays for voice traffic in the system falls well within the ITU's QoS specification for GEO-based satellite systems. The application buffer sizes observed in the simulations can serve as a guideline for ground station and satellite on-board memory design.
Summary form only given. Low power VLSI video compression processors are in high demand for the emerging wireless video applications. Video compression processors include VLSI implementation of a motion estimation alg...
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Summary form only given. Low power VLSI video compression processors are in high demand for the emerging wireless video applications. Video compression processors include VLSI implementation of a motion estimation algorithm. Many motion estimation algorithms are found in the literature. Some of them are fast but cannot guarantee an optimal solution; they can be stuck in local optima. Such algorithms are fast, consumes less power when implemented in VLSI, but they can result in high levels of distortion that cannot be accepted in many applications. On the other hand the full search block matching algorithm (FSBM) is computationally intensive and a VLSI implementation of such an algorithm has high power consumption. This paper presents an exhaustive search algorithm for block matching motion estimation. The proposed algorithm reduces the computational load with successive elimination of non-candidate blocks in the search window. Our proposed algorithm assigns each pixel to a category depending on its value. The number of categories is predetermined. The algorithm consists of number of stages, the first of which has the fewer categories, eliminating those search points that are the farthest from the match. The last stage is the FSBM but with fewer search points. This computational reduction leads to low-power VLSI implementation of the algorithm. Also, it leads to faster efficient motion estimation procedure. The correctness of this algorithm and its complexity are proved.
More and more data is produced in the form of videos, which are opaque to textual queries. To allow searching in video data collections, two problems have to be solved: The automatic generation of a searchable index, ...
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More and more data is produced in the form of videos, which are opaque to textual queries. To allow searching in video data collections, two problems have to be solved: The automatic generation of a searchable index, and the effective search in the automatically produced and therefore imperfect index. The ISL View4You system is a prototype of a video indexing and retrieval system which both generates the index and provides a search engine to access it. An end to end evaluation was carried out using real-world data and queries from naive subjects. From the results it can be concluded, errors of the overall system are not due to the index generation, but are introduced by the information retrieval engine (the search). Therefore, the focus of this paper is a comparison of two different search algorithms, LSI (latent semantic indexing) and Okapi (a flavor of the traditional classic vector model approach). The evaluation is carried out on the automatically produced index on a relatively small database, which allows for full manual relevance judgement.
This paper presents a behavioral emulation system called iSAVE (in-System Algorithm Verification), which performs in-system verification of the behavioral description in C of a chip in the context of its application b...
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This paper presents a behavioral emulation system called iSAVE (in-System Algorithm Verification), which performs in-system verification of the behavioral description in C of a chip in the context of its application board at the early design stage. We were able to significantly increase the emulation speed by modeling the interface of the target chip with both the software part, which runs as thread, and the hardware part, mapped into FPGA logic. The proposed idea is validated by demonstrating the behavioral emulation of MP3 decoder chip, as obtained from the public domain MP3 program.
A novel method for the measurement of precision position using an interferometer is proposed This method is to detect the fringe movement of interferograms from the fringe peak positions, which is linearly related to ...
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A novel method for the measurement of precision position using an interferometer is proposed This method is to detect the fringe movement of interferograms from the fringe peak positions, which is linearly related to the displacement of an object. The error analysis and simulation were carried out considering the speckle noise, the Gaussian noise and the wavefront distortions. The results of simulation show that this method is effective for the measurement of precision position. An experiment was implemented for verifying this method.
This paper presents an advanced controller for electric machines (ACE) developed at the Ford Research Laboratory to meet the demanding needs of application and algorithm development. It is based on the TMS320C31 float...
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This paper presents an advanced controller for electric machines (ACE) developed at the Ford Research Laboratory to meet the demanding needs of application and algorithm development. It is based on the TMS320C31 floating point DSP and Motorola 68F333 microcontroller. The focus has been in the electric machine research area, principally for hybrid, electric and fuel cell vehicles. Unique features of the system, both in terms of hardware and software are elaborated. The ACE is a very high performance, rugged, rapid prototyping tool that implements advanced control algorithms and interfaces without any traditional programming. The user, through the graphic user interface (GUI), is able to change various reference inputs and system parameters while the program is running in real-time, and hence observe the effects through the on-board data acquisition. Experimental results for characterization of an induction motor are presented in order to illustrate these features and the advantages of the ACE development system.
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