{"id":{"repo_id":"cape-town","oai_identifier":"oai:open.uct.ac.za:11427/9471"},"canonical_url":"https://search.dev.ndltd.org/etd/cape-town/oai:open.uct.ac.za:11427/9471","repository":{"repo_id":"cape-town","name":"University of Cape Town","base_url":"https://open.uct.ac.za/oai/request"},"display":{"title":"Multi-h synchronisation for codes with long constraints-length","abstract":"This dissertation investigates the synchronisation of Multi-h signals with a long constraint length. However, Multi-h codes exhibiting a long constraint length invariably also exhibit a large denominator q. Since traditional methods for synchronising Multi-h signals utilises a q-th power law device, where the frequency spectrum of the qth power of the signal renders all the necessary frequencies for synchronisation, we suspect that a large q could be detrimental. When simulated, it turns out that the qth power law device fails to deliver distinct (and useable) frequency components at a q size of about 8. Unfortunately, the most useful codes have denominators starting at a size of q equals 32. This called for a novel approach to synchronisation. One device that shows much potential is the new Massey-Hodgart coherent MSK demodulator. In a significant departure from standard quadrature structures, this MSK demodulator uses matched filter detection with a pair of reference signals at the two MSK signaling frequencies; an optimal maximum-likelihood bit decision is then formed over two bit intervals. The reference signals are recovered by a pair of decision-switched Costas loops, which are tightly integrated with the demodulator structure. The goal was to modify the Massey-Hodgart MSK demodulator into a Multi-h synchroniser that contained matched filter detection for all the frequencies in the Multi-h signal. The reference frequencies would still be decision switched and recovered by Costas loops.","abstract_html":"This dissertation investigates the synchronisation of Multi-h signals with a long constraint length. However, Multi-h codes exhibiting a long constraint length invariably also exhibit a large denominator q. Since traditional methods for synchronising Multi-h signals utilises a q-th power law device, where the frequency spectrum of the qth power of the signal renders all the necessary frequencies for synchronisation, we suspect that a large q could be detrimental. When simulated, it turns out that the qth power law device fails to deliver distinct (and useable) frequency components at a q size of about 8. Unfortunately, the most useful codes have denominators starting at a size of q equals 32. This called for a novel approach to synchronisation. One device that shows much potential is the new Massey-Hodgart coherent MSK demodulator. In a significant departure from standard quadrature structures, this MSK demodulator uses matched filter detection with a pair of reference signals at the two MSK signaling frequencies; an optimal maximum-likelihood bit decision is then formed over two bit intervals. The reference signals are recovered by a pair of decision-switched Costas loops, which are tightly integrated with the demodulator structure. The goal was to modify the Massey-Hodgart MSK demodulator into a Multi-h synchroniser that contained matched filter detection for all the frequencies in the Multi-h signal. The reference frequencies would still be decision switched and recovered by Costas loops.","abstract_has_math":false,"creators":["Nel, Eugéne Johannes"],"institution":"Department of Electrical Engineering","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Braun, Robin"],"committee_chairs":[],"committee_members":[],"year":1997,"date_issued":"1997","date_published":"1997","updated_at":"2026-07-24T01:34:19Z","subjects":[],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/11427/9471","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Braun, Robin"]},{"key":"dc:creator","label":"Author","values":["Nel, Eugéne Johannes"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-11-10T08:54:52Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-11-10T08:54:52Z"]},{"key":"dc:date.issued","label":"Date","values":["1997"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["Department of Electrical Engineering"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Cape Town"]},{"key":"dc:type","label":"Dc Type","values":["Master Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Masters"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["MSc"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/11427/9471"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Bibliography: p. 64."]},{"key":"dc:description.abstract","label":"Abstract","values":["This dissertation investigates the synchronisation of Multi-h signals with a long constraint length. However, Multi-h codes exhibiting a long constraint length invariably also exhibit a large denominator q. Since traditional methods for synchronising Multi-h signals utilises a q-th power law device, where the frequency spectrum of the qth power of the signal renders all the necessary frequencies for synchronisation, we suspect that a large q could be detrimental. When simulated, it turns out that the qth power law device fails to deliver distinct (and useable) frequency components at a q size of about 8. Unfortunately, the most useful codes have denominators starting at a size of q equals 32. This called for a novel approach to synchronisation. One device that shows much potential is the new Massey-Hodgart coherent MSK demodulator. In a significant departure from standard quadrature structures, this MSK demodulator uses matched filter detection with a pair of reference signals at the two MSK signaling frequencies; an optimal maximum-likelihood bit decision is then formed over two bit intervals. The reference signals are recovered by a pair of decision-switched Costas loops, which are tightly integrated with the demodulator structure. The goal was to modify the Massey-Hodgart MSK demodulator into a Multi-h synchroniser that contained matched filter detection for all the frequencies in the Multi-h signal. The reference frequencies would still be decision switched and recovered by Costas loops."]},{"key":"dc:title","label":"Title","values":["Multi-h synchronisation for codes with long constraints-length"]}]}],"canonical_facts":{"dc:contributor.advisor":["Braun, Robin"],"dc:creator":["Nel, Eugéne Johannes"],"dc:date.accessioned":["2014-11-10T08:54:52Z"],"dc:date.available":["2014-11-10T08:54:52Z"],"dc:date.issued":["1997"],"dc:description":["Bibliography: p. 64."],"dc:description.abstract":["This dissertation investigates the synchronisation of Multi-h signals with a long constraint length. However, Multi-h codes exhibiting a long constraint length invariably also exhibit a large denominator q. Since traditional methods for synchronising Multi-h signals utilises a q-th power law device, where the frequency spectrum of the qth power of the signal renders all the necessary frequencies for synchronisation, we suspect that a large q could be detrimental. When simulated, it turns out that the qth power law device fails to deliver distinct (and useable) frequency components at a q size of about 8. Unfortunately, the most useful codes have denominators starting at a size of q equals 32. This called for a novel approach to synchronisation. One device that shows much potential is the new Massey-Hodgart coherent MSK demodulator. In a significant departure from standard quadrature structures, this MSK demodulator uses matched filter detection with a pair of reference signals at the two MSK signaling frequencies; an optimal maximum-likelihood bit decision is then formed over two bit intervals. The reference signals are recovered by a pair of decision-switched Costas loops, which are tightly integrated with the demodulator structure. The goal was to modify the Massey-Hodgart MSK demodulator into a Multi-h synchroniser that contained matched filter detection for all the frequencies in the Multi-h signal. The reference frequencies would still be decision switched and recovered by Costas loops."],"dc:identifier.uri":["http://hdl.handle.net/11427/9471"],"dc:language.iso":["eng"],"dc:publisher.department":["Department of Electrical Engineering"],"dc:publisher.institution":["University of Cape Town"],"dc:title":["Multi-h synchronisation for codes with long constraints-length"],"dc:type":["Master Thesis"],"dc:type.qualificationlevel":["Masters"],"dc:type.qualificationname":["MSc"]},"updated_at":"2026-07-24T01:34:19Z"}