5 research outputs found
Perceptual models in speech quality assessment and coding
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
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
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
https://digitalcommons.law.uidaho.edu/idaho_supreme_court_record_briefs/6488/thumbnail.jp