The application of digital signal processing to radio communications
has come of age with the advent of low power, high speed microprocessors
and over the past five years, various transceiver architectures,
utilizing this new technology have been extensively researched. Due
to the flexible nature of a software based transceiver, a myriad of
possible applications exist and currently the emphasis is on the
development of suitable algorithms.
The principal aim of this research is the derivation of optimized
digital signal processing algorithms applicable to three separate
areas of radio communications. Optimized, as used by the author within
this dissertation, implies a reasonable compromise between performance,
complexity and numerical processing efficiency. This compromise
is necessary since the algorithms are applied to a portable transceiver
where power consumption, size and weight are limited.
The digital signal processing algorithms described by this research
is as follows:-
1. The derivation and assessment of a multirate speech amplitude
modulation demodulator which exhibits low distortion (typically
less than 2%) for a wide range of modulation indices, carrier
frequency offsets and deviations. The demodulator is processing
efficient and requires only five multiplications and five decisions
for every output sample.
2. The derivation and assessment of a low sampling rate speech
frequency modulation demodulator for signals whose bandwidth exceed
quarter the sampling frequency. The demodulator exhibits low
distortion (typically less than 2%) and is processing efficient
requiring eighteen multiplications and three decisions for every
output sample.
3. The derivation and assessment of a multirate single-sideband
suppressed carrier automatic frequency control system which is a
combination of a simple second order adaptive line enhancer and
a digital phase-locked loop. The processing efficient automatic
frequency control system is suited for low signal to noise power
conditions, in both stationary and mobile communication channels. / Thesis (Ph.D.)-University of Natal, Durban, 1992.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ukzn/oai:http://researchspace.ukzn.ac.za:10413/6366 |
| Date | January 1992 |
| Creators | Carter, Alan James Auchmuty. |
| Contributors | Broadhurst, Anthony D. |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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