Thesis-1982-McVerry.pdf (17.06 MB)
High speed data transmission over HF radio links
thesis
posted on 2010-11-01, 11:03 authored by McVerry FrancisThe 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.
History
School
- Mechanical, Electrical and Manufacturing Engineering
Publisher
© Francis McVerryPublication date
1982Notes
A Doctoral Thesis. Submitted in partial fulfillment of the requirements for the award of Doctor of Philosophy of Loughborough University.EThOS Persistent ID
uk.bl.ethos.276963Language
- en