Fonseka, John Priyantha (1985) Detection of continuous phase frequency shift keyed signals. Masters thesis, Memorial University of Newfoundland.
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In this thesis, the performance of Limiter Discriminator (LD) receiver, Differentially Coherent (DC) receiver and Coherent Detection-Differential Decoding (CD-DD) receiver is analyzed for the detection of M-ary CPFSK signals under various signal impairments. -- The analysis is first carried out for the detection of M-ary CPFSK with modulation index -- [special characters omitted] -- in wideband channels. The effect of symbol timing errors and baseband symbol pulse shaping is considered. It is shown that CD-DD detection has better performance and less sensitivity to timing errors than LD detection and DC detection whereas LD detection and DC detection yield approximately the same performance both in the presence and in the absence of symbol timing errors. -- The bandlimiting effect of the front-end filter of the three receivers is then considered. An effective methodology is developed to take into account the effect of Intersymbol Interference (ISI). As in wideband channels, it is shown that even in bandlimited channels, CD-DD detection yields better performance and has less sensitivity to ISI than LD detection and DC detection whereas the latter two detection schemes have almost identical performance and sensitivities. -- The performance evaluation of LD detection of M-ary CPFSK with arbitrary modulation index, in both wideband and bandlimited channels, is also considered in order to determine the optimum modulation index which minimizes the error probability. It is shown that the performance of LD detection can be improved by increasing the modulation index above -- [special characters omitted] -- . A variable delay differential detection technique which employs a delay interval dependent on the modulation index is analyzed for the detection of binary CPFSK signals with arbitrary modulation index in bandlimited channels. The performance of the variable delay differential detector is shown to be comparable with the performance of LD detector. -- Finally, the numerical results obtained for the detection of quaternary CPFSK and octonary CPFSK in bandlimited channels are verified by digital computer simulation.
|Item Type:||Thesis (Masters)|
|Additional Information:||Bibliography: leaves 138-141.|
|Department(s):||Engineering and Applied Science, Faculty of|
|Library of Congress Subject Heading:||Frequency modulation detectors; Signal processing--Digital techniques; Phase shift keying; Signal detection; Demodulation (Electronics)|
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