Pulse or digital communications – Receivers – Angle modulation
Patent
1997-01-24
2000-03-14
Chin, Stephen
Pulse or digital communications
Receivers
Angle modulation
375340, 375347, 375371, 329304, H03D 322
Patent
active
060382678
ABSTRACT:
A digital demodulator compensates for frequency offset between modulated and unmodulated carrier signals by detecting the frequency offset during a preamble with a known modulation pattern. Samples obtained during the preamble are stored in a memory during clock recovery, and read from the memory after the recovered clock signal has become stable. Phase offset is detected from a histogram of the phase differences between the two carrier signals, calculated modulo a certain phase angle, and compensation for phase offset is applied. The maximum histogram value is found by comparisons made according to a single-elimination tournament plan. In a diversity receiver, the maximum histogram value is used to select the output data.
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Iguchi Yuji
Ishii Yoshiyuki
Oura Hideto
Chin Stephen
Fan Chieh M.
OKI Electric Industry Co., Ltd.
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