Synchronization of spread spectrum communication systems using signal design |
Posted on:1999-07-29 | Degree:Ph.D | Type:Dissertation |
University:University of Rochester | Candidate:Osadciw, Lisa Ann | Full Text:PDF |
GTID:1468390014468933 | Subject:Engineering |
Abstract/Summary: | |
This dissertation addresses the problem of synchronization in a multi-user communication system using a signal design approach. Spread spectrum signal design is used to take advantage of a unique narrowband auto-ambiguity function property, traceability, which can be used to reduce the synchronization time and the number of false synchronization events. Traceability as a narrowband auto-ambiguity function property is fully developed and measured for a variety of spread spectrum signals. Frequency hop spread spectrum signals demonstrate traceability by allowing for direct control over their narrowband auto-ambiguity function properties. Phase modulation techniques such as direct sequence can not be used to control the energy spreading in the narrowband auto-ambiguity function.;The research is comprised of developing the traceability concept, analyzing the traceability of various spread spectrum signals, and quantifying the improvement in synchronization performance of a simple tracing search algorithm. The traceability property is defined using an approximation of the narrowband auto-ambiguity function. The traceability of various frequency hopped and direct sequence spread spectrum signals is evaluated. The linear congruence code family is found to be maximally traceable. A synchronization scheme that takes advantage of traceability is developed and simulated to determine the effectiveness of traceability. Performance results show that the synchronization time is reduced by a factor of 2 and false synchronization events by a factor of 10. Synchronization time can be further reduced by a factor of 10 if the local oscillator error budget is carefully specified in a communications system. |
Keywords/Search Tags: | Spread spectrum, Synchronization, Signal, Using, Narrowband auto-ambiguity function, Traceability |
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