5 research outputs found

    Perceptual models in speech quality assessment and coding

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    The ever-increasing demand for good communications/toll quality speech has created a renewed interest into the perceptual impact of rate compression. Two general areas are investigated in this work, namely speech quality assessment and speech coding. In the field of speech quality assessment, a model is developed which simulates the processing stages of the peripheral auditory system. At the output of the model a "running" auditory spectrum is obtained. This represents the auditory (spectral) equivalent of any acoustic sound such as speech. Auditory spectra from coded speech segments serve as inputs to a second model. This model simulates the information centre in the brain which performs the speech quality assessment. [Continues.

    High speed data transmission over HF radio links

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    The thesis describes the results of research work on techniques for high speed data transmission (2.4 kbit/s) over voice-band HF radio channels. This work has been carried out using extensive computer simulation of the various transmission techniques and the HF radio channels. Firstly, the characteristics of HF radio channels are discussed in detail and an HF channel model, suitable for computer simulation, is developed. The first of two techniques for high data rate transmission over HF links is then introduced, namely, multi-channel (or parallel) DPSK transmission. Parallel transmission is a well known technique in this application but it has been studied and simulated, in order to compare its performance with that of the second, more novel, transmission technique. This is a single channel system employing 4 point QAM signalling at the transmitter and maximum likelihood detection at the receiver. Initially, the parallel system is compared with an idealised serial system employing optimum Viterbi detection at the receiver with all other functions of the serial function assumed perfect. However, having shown the vastly superior performance of this serial system, a more practical serial modem is gradually developed, with further performance comparisons at each stage in this development. The final comparison is made with a very practical form of serial modem in which all practical receiver functions are simulated. Theseinclude a simpler, adaptive near maximum likelihood detector, receiver filtering, channel estimator, carrier phase tracking, timing synchronisation and automatic gain control. Finally, the design and implementation of the serial modem is studied and details of the complexity of a digital, processor-based, realisation are given

    Iterative algorithms for optimal signal reconstruction and parameter identification given noisy and incomplete data

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    Originally published as thesis (Dept. of Electrical Engineering and Computer Science, Ph.D., 1982).Includes bibliographies.Supported in part by the Advanced Research Projects Agency monitored by ONR under Contract N00014-81-K-0742 NR-049-506 Supported in part by the National Science Foundation under Grant ECS80-07102Bruce Ronald Musicus

    Fagen, Inc. v. Rogerson Flats Wind Park, LLC Clerk\u27s Record Dckt. 42684

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    https://digitalcommons.law.uidaho.edu/idaho_supreme_court_record_briefs/6488/thumbnail.jp
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