An investigation into antenna diversity for handheld transceivers in mobile radio communications
An investigation into antenna diversity for handheld transceivers in mobile radio communications
Antenna diversity applied at the handheld transceiver is investigated. One of the impairments of mobile radio communications is the fading of the signal envelope received at the mobile antenna terminals. We carried out a theoretical study of the fading phenomenon by deriving expressions for the received signal using certain statistical source model distributions. We show explicitly the dependence of the received signal on the antenna effective length vector. In our software simulations we generated fading signal envelopes and analysed their statistics. We performed a measurement indoors to examine the fading of signals in buildings. The expression derived for the correlation highlights factors which can be varied to achieve a low correlation coefficient. Orthogonal radiation patterns over the source domain would provide the ideal zero correlation coefficient condition for antenna diversity. We examined the theoretical improvements that can be achieved by using diversity. There are different classes of diversity but the spectrally efficient ones such as spatial, polarisation and field component concern us. The mutual coupling between antennas in a diversity array affects the average received power. We derive expressions which can be used to evaluate the mutual coupling effects in an antenna diversity array. A careful study of the method of moments was undertaken where we wrote two method of moments programs and modified one of the commercially available ones. With the method of moments we made impedance and radiation pattern predictions. We validated these methods of moments programs with some measurements we made and others in the literature. The predicted radiation patterns were used in the analysis of the portable antennas configurations we examined. We propose a spatial diversity array and a spatial-polarisation diversity configuration for the handheld transceiver which will achieve a low correlation coefficient between received signals. Our study of minimum scattering antenna reinforces clearly a previous claim that the normalised mutual resistance between canonical minimum scattering antennas is equal to the correlation coefficient. For two monopole antennas of length 0.25 λ or less positioned on the handheld transceiver case this is approximately true.
University of Southampton
1991
Glasgow, Telbert Roger
(1991)
An investigation into antenna diversity for handheld transceivers in mobile radio communications.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
Antenna diversity applied at the handheld transceiver is investigated. One of the impairments of mobile radio communications is the fading of the signal envelope received at the mobile antenna terminals. We carried out a theoretical study of the fading phenomenon by deriving expressions for the received signal using certain statistical source model distributions. We show explicitly the dependence of the received signal on the antenna effective length vector. In our software simulations we generated fading signal envelopes and analysed their statistics. We performed a measurement indoors to examine the fading of signals in buildings. The expression derived for the correlation highlights factors which can be varied to achieve a low correlation coefficient. Orthogonal radiation patterns over the source domain would provide the ideal zero correlation coefficient condition for antenna diversity. We examined the theoretical improvements that can be achieved by using diversity. There are different classes of diversity but the spectrally efficient ones such as spatial, polarisation and field component concern us. The mutual coupling between antennas in a diversity array affects the average received power. We derive expressions which can be used to evaluate the mutual coupling effects in an antenna diversity array. A careful study of the method of moments was undertaken where we wrote two method of moments programs and modified one of the commercially available ones. With the method of moments we made impedance and radiation pattern predictions. We validated these methods of moments programs with some measurements we made and others in the literature. The predicted radiation patterns were used in the analysis of the portable antennas configurations we examined. We propose a spatial diversity array and a spatial-polarisation diversity configuration for the handheld transceiver which will achieve a low correlation coefficient between received signals. Our study of minimum scattering antenna reinforces clearly a previous claim that the normalised mutual resistance between canonical minimum scattering antennas is equal to the correlation coefficient. For two monopole antennas of length 0.25 λ or less positioned on the handheld transceiver case this is approximately true.
This record has no associated files available for download.
More information
Published date: 1991
Identifiers
Local EPrints ID: 460597
URI: http://eprints.soton.ac.uk/id/eprint/460597
PURE UUID: 6df9b8d2-902e-4c68-8cf8-35245c5f3e66
Catalogue record
Date deposited: 04 Jul 2022 18:25
Last modified: 04 Jul 2022 18:25
Export record
Contributors
Author:
Telbert Roger Glasgow
Download statistics
Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.
View more statistics