Characteristics of multi-h coded modulation

 

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dc.contributor.advisor Braun, Robin M en_ZA
dc.contributor.author Crawford, Brian Patrick en_ZA
dc.date.accessioned 2014-11-15T19:35:53Z
dc.date.available 2014-11-15T19:35:53Z
dc.date.issued 1994 en_ZA
dc.identifier.citation Crawford, B. 1994. Characteristics of multi-h coded modulation. University of Cape Town. en_ZA
dc.identifier.uri http://hdl.handle.net/11427/9646
dc.description Includes bibliographical references (leaves 74-75). en_ZA
dc.description.abstract Multi-h Coded Continuous-Phase Frequency Shift Keying (Multi-h CPFSK) has gained interest in recent years because it offers an additional degree of freedom in the coding of CPFSK. Similar to Trellis Coded Modulation (TCM), it does not use redundancy to achieve coding gain. Hence with properly chosen modulation indices, impact to spectral occupancy is kept to a minimum. While there has been less attention given of this method as compared with TCM, this method can also be used with data coding. In cases where data coding is to be implemented, simultaneous use of Multi-h coding can be implemented with very little increase in complexity. In this thesis, a thorough mathematical review of this technique is made. A multi-oscillator multih coded modulator is shown similar to one presented by Massey for MSK. A unique analytical tool called a multi-oscillator trellis is presented. This considers the phase transitions with respect to each of the signalling frequencies instead of the center frequency, f₀. The multi-oscillator trellis is used to determine the state machine that will switch a bank of oscillators. The purpose of the state machine is to maintain continuous phase at the multi-oscillator output while generating the proper signal frequencies according to the data and modulation index. The Maximum Likelihood Detection process at the receiver is shown as a partition of an uncoded CPFSK signal. Finally, an analysis is made to determine if a modulator with a non-linear frequencyvoltage characteristic is suitable in a coherent multi-h coded application. Much of the literature on this topic has been comparative to PSK. It is the intent of this work to use FSK and MSK as the baseline to determine how existing structures may be extended to realize the benefits of multi-h coding. The application of this coding to an 8 Mbps 23 GHz CPFSK point-to-point terrestrial communications system is also a topic of this thesis. It is in this context that the analysis is made. en_ZA
dc.language.iso eng en_ZA
dc.subject.other Electrical Engineering en_ZA
dc.title Characteristics of multi-h coded modulation en_ZA
dc.type Master Thesis
uct.type.publication Research en_ZA
uct.type.resource Thesis en_ZA
dc.publisher.institution University of Cape Town
dc.publisher.faculty Faculty of Engineering and the Built Environment
dc.publisher.department Department of Electrical Engineering en_ZA
dc.type.qualificationlevel Masters
dc.type.qualificationname MSc en_ZA
uct.type.filetype Text
uct.type.filetype Image
dc.identifier.apacitation Crawford, B. P. (1994). <i>Characteristics of multi-h coded modulation</i>. (Thesis). University of Cape Town ,Faculty of Engineering & the Built Environment ,Department of Electrical Engineering. Retrieved from http://hdl.handle.net/11427/9646 en_ZA
dc.identifier.chicagocitation Crawford, Brian Patrick. <i>"Characteristics of multi-h coded modulation."</i> Thesis., University of Cape Town ,Faculty of Engineering & the Built Environment ,Department of Electrical Engineering, 1994. http://hdl.handle.net/11427/9646 en_ZA
dc.identifier.vancouvercitation Crawford BP. Characteristics of multi-h coded modulation. [Thesis]. University of Cape Town ,Faculty of Engineering & the Built Environment ,Department of Electrical Engineering, 1994 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/9646 en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Crawford, Brian Patrick AB - Multi-h Coded Continuous-Phase Frequency Shift Keying (Multi-h CPFSK) has gained interest in recent years because it offers an additional degree of freedom in the coding of CPFSK. Similar to Trellis Coded Modulation (TCM), it does not use redundancy to achieve coding gain. Hence with properly chosen modulation indices, impact to spectral occupancy is kept to a minimum. While there has been less attention given of this method as compared with TCM, this method can also be used with data coding. In cases where data coding is to be implemented, simultaneous use of Multi-h coding can be implemented with very little increase in complexity. In this thesis, a thorough mathematical review of this technique is made. A multi-oscillator multih coded modulator is shown similar to one presented by Massey for MSK. A unique analytical tool called a multi-oscillator trellis is presented. This considers the phase transitions with respect to each of the signalling frequencies instead of the center frequency, f₀. The multi-oscillator trellis is used to determine the state machine that will switch a bank of oscillators. The purpose of the state machine is to maintain continuous phase at the multi-oscillator output while generating the proper signal frequencies according to the data and modulation index. The Maximum Likelihood Detection process at the receiver is shown as a partition of an uncoded CPFSK signal. Finally, an analysis is made to determine if a modulator with a non-linear frequencyvoltage characteristic is suitable in a coherent multi-h coded application. Much of the literature on this topic has been comparative to PSK. It is the intent of this work to use FSK and MSK as the baseline to determine how existing structures may be extended to realize the benefits of multi-h coding. The application of this coding to an 8 Mbps 23 GHz CPFSK point-to-point terrestrial communications system is also a topic of this thesis. It is in this context that the analysis is made. DA - 1994 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 1994 T1 - Characteristics of multi-h coded modulation TI - Characteristics of multi-h coded modulation UR - http://hdl.handle.net/11427/9646 ER - en_ZA


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