PN code synchronization is a common and essential task at the receiver in CDMA communication systems. In most literatures, there usually exists assumption of synchronization between the received spreading sequence and a locally generated replica. Few practical and detail synchronization schemes are showed in literatures. Moreover, there are no sufficient knowledge about operation characteristics of loop elements and operation strategies. Hence, in this thesis we propose some schemes about PN code synchronization and then do some analysis to compare performance of those schemes in AWGN channel.
Code synchronization at DSSS receivers is performed in two steps. One is code acquisition and the other is code tracking. In acquisition process, we propose so called some ¡§auxiliary decision criterions¡¨ in multiple-dwell detection strategies. Analytical results are validated with computer simulations. By use of auxiliary decision criterions, the acquisition process is outperforms the conventional multiple-dwell and single-dwell detection strategies in AWGN channel. In code tracking process, we use coherent DLL. Loop filter parameters are tuned by observing phase-plane trajectories to acquire stable lock points and convergence property. In addition, we proposed a coherent DLL chip implementation, and accomplish the design flow that includes verification, synthesis, place and route, and simulation.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0626102-130501 |
| Date | 26 June 2002 |
| Creators | Tsai, Cheng-Jung |
| Contributors | none, none, Shiunn-Jang Chern, Ju-Ya Chen, none |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0626102-130501 |
| Rights | unrestricted, Copyright information available at source archive |
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