Effects of fading and data modulation on noncoherent m-sequence acquisition schemes
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Authors
Vincent, Patrick J.
Subjects
sequential acquisition
spread spectrum
communications
spread spectrum
communications
Advisors
Lam, Alex W.
Date of Issue
1992-03
Date
Publisher
Monterey, California. Naval Postgraduate School
Language
en_US
Abstract
In direct-sequence spread-spectrum systems, successful communications require phase synchronization of the m-sequence in the incoming signal with a locally generated m-sequence at the receiver. Many acquisition schemes which extract the phase of an incoming m-sequence have been studied, but most of them assume coherent demodulation (which is usually not available during acquisition) and or independent samples (which introduce a loss in the effective signal to noise ratio (SNR)). This thesis investigates the performance of two m-sequence acquisition schemes in the presence of fading and data modulation. A fixed sample size test and a truncated sequential test are studied without the usual assumptions of coherent demodulation or independent samples. The effects of fading and data modulation on our schemes' probability of false alarm, probability of detection and test length are thoroughly explored. We find that channel fading in effect induces a loss of signal SNR, but the desired power of the tests can be restored by suitable adjustments in the decision processor. We find that the effects of data modulation are less severe, but more problematic to correct
Type
Thesis
Description
Series/Report No
Department
Electrical Engineering
Organization
Naval Postgraduate School
Identifiers
NPS Report Number
Sponsors
Funder
Format
Citation
Distribution Statement
Approved for public release; distribution is unlimited.