US 4,792,964 AGranted

Adaptive jitter canceller having sinusoidal accentuator and jitter prediction filter

AssigneeNEC Corporation

InventorAtsushi Yoshida

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Abstract

A signal representative of the carrier phase of a received digitally modulated signal is supplied to a first low-pass filter for band-limiting frequencies of the carrier phase signal below 1/(2NT), where N is an integer equal to or greater than two and T is a unit delay time. The band-limited signal is sampled at intervals NT and fed to a digital sinusoidal accentuator for accentuating the signal at intervals NT. An interpolator converts the output of accentuator to a series of samples spaced at intervals 1/T by inserting zero-bit samples between adjacent input samples. A second low-pass filter band-limits the frequencies of the output of the interpolator below 1/(2NT). A prediction filter receives the output of the second low-pass filter to produce a cancelling signal which is combined with the received signal to cancel the phase jitter.

Claims4

Dependent claims

An adaptive jitter canceller comprising:

means for detecting a signal representative of the carrier phase of a received digitally modulated signal;
first low-pass filter means for band-limiting said carrier phase signal to frequencies below 1/(2NT), where N is an integer equal to or greater than two and T is a unit delay time;
sampling means for sampling an output signal from said first low-pass filter means at intervals NT;
digital sinusoidal accentuator means for accentuating an output signal from said sampling means at intervals NT;
interpolator means for interpolating an output signal from said sinusoidal accentuator means and generating a series of smmples spaced at intervals 1/T;
second low-pass filter means for band-limiting an output signal from said interpolator means to frequencies below 1/(2NT);
prediction filter means for receiving an output signal from said second low-pass filter means;
and
means for cancelling phase jitter contained in said received signal with an output signal from said prediction filter means.

6 more elements

Dependencies are inferred from the claim text.