Pulse or digital communications – Receivers – Angle modulation
Reexamination Certificate
2005-04-12
2005-04-12
Liu, Shuwang (Department: 2634)
Pulse or digital communications
Receivers
Angle modulation
C375S376000, C375S344000, C329S310000, C329S306000, C327S156000
Reexamination Certificate
active
06879646
ABSTRACT:
A QAM demodulator comprises a timing synchronizer whose output is supplied via an adaptive equalizer to a carrier synchronizer, all of which are controlled by a controller. The timing synchronizer resamples the incoming signal in the digital domain with a sampling period which, during an acquisition mode, sweeps between limit values at different rates. The controller begins an acquisition cycle at the highest rate and monotonically lowers the sweep rate until timing lock is achieved. The sampling rate is then fixed at the correct value. Similarly, the controller sweeps the local oscillator of a phase locked loop in the carrier synchronizer initially at a highest rate and at progressively lower rates until the carrier synchronizer locks to the phase of the incoming signal.
REFERENCES:
patent: 5588027 (1996-12-01), Lim
patent: 5636250 (1997-06-01), Scarpa
patent: 5754591 (1998-05-01), Samueli et al.
patent: 6016069 (2000-01-01), Sadowski
patent: 6696886 (2004-02-01), Ke et al.
patent: 827 311 (1998-03-01), None
patent: 2221861 (1974-11-01), None
Great Britain Search Report for Application No. GB 0009302.1, Issued Nov. 1, 2000.
Liu Shuwang
Thompson Hine LLP
Zarlink Semiconductor Limited
Zheng Eva
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