Pulse or digital communications – Synchronizers – Synchronizing the sampling time of digital data
Reexamination Certificate
2006-03-16
2010-10-05
Fan, Chieh M (Department: 2611)
Pulse or digital communications
Synchronizers
Synchronizing the sampling time of digital data
C375S149000
Reexamination Certificate
active
07809097
ABSTRACT:
A frame timing synchronization technique for orthogonal frequency division multiplexing (OFDM) systems is presented. First, a coarse synchronization technique generates a coarse frame timing estimate. The coarse synchronization technique applies a sliding window differentiator to the output of a conventional auto-correlator to mitigate the plateau effect associated with conventional auto-correlation techniques. Second, a fine synchronization technique generates a fine frame timing estimate. The fine synchronization technique uses the coarse frame timing estimate to reduce the number of cross-correlation calculations. Additionally, the fine synchronization technique acquires a fine frame timing estimate based on a signal-to-interference ratio (SIR) metric, which is more robust to multi-paths and pseudo multi-paths caused by cyclic delay diversity (CDD) schemes than conventional cross-correlation synchronization techniques. A fine-tuning technique generates a desired frame timing estimate by searching a first signal path in a searching window around the fine frame timing estimate to further refine frame timing synchronization.
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Wang Dong
Zhang Jinyun
Buchanan & Ingersoll & Rooney PC
Fan Chieh M
Fotakis Aristocratis
Renesas Electronics Corporation
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