Method and apparatus for demodulating amplitude-shift keyed data signals

申请公布号：US6496549(B1)

申请号：US19990352428

申请日期：1999.07.13

申请公布日期：2002.12.17

申请人：

HEWLETT-PACKARD COMPANY

发明人：CRAWFORD RICHARD D.

分类号：H04B10/00;H03D1/18;H04L27/06;(IPC1-7):H03D1/24

主分类号：H04B10/00

摘要：An approved demodulator is disclosed for demodulating optical ASK data signals whose data bits are each characterized by either an absence of pulses or a burst of pulses at a predetermined frequency. The demodulator includes an amplifier tuned to this predetermined frequency, and it further includes an edge detector that produces an envelope of the amplified signal. A comparator then compares the envelope signal with a prescribed threshold, to produce a pulse signal for each received burst of pulses. The duration of this pulse signal is then stretched so as to correspond to the pulse burst's expected nominal duration. The demodulator is specially configured such that it can properly demodulate ASK data signals having power levels that vary over a range of several orders of magnitude.