Nortel Networks Corporation

Texas Instruments Corporation

Jianzhong Xu

Kim Bryon Roberts

Chandra Sekhar Bontu

Han Henry Sun

Kuang Tsan Wu

Slobodan Jovanovic

Bogdan R Kosanovic

Echo cancellation is provided in a telephone device by calculating a metric value indicative of a similarity between a representation of an incoming signal from a far end talker and a representation of an outgoing signal from a near end talker. A threshold value is derived based on the metric value. A portion of the outgoing signal is removed by using the threshold value to determine an amount to remove from the outgoing signal with continuous, real-time updating of the threshold value.

Clipping based on cepstral distance for acoustic echo canceller

A method of recovering a clock signal from an optical signal received through an optical communications system. A digital sample stream is processed to generate a dispersion compensated signal. The dispersion compensated signal is then tapped to obtain upper side band and lower side band signals of each received polarization of the optical signal. The upper side band and lower side band signals are then processed to compensate polarization dependent impairments, and the clock recovered from the resulting optimized.

Clock recovery from an optical signal with dispersion impairments

A method of recovering a clock signal from an optical signal received through an optical communications system. A digital sample stream is processed to generate a dispersion compensated signal. The dispersion compensated signal is then tapped to obtain upper side band and lower side band signals of each received polarization of the optical signal. The upper side band sand lower side band signals are then processed to compensate polarization dependent impairments and the clock recovered from the resulting optimized.

Clock recovery from an optical signal with polarization impairments

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Gaithersburg, MD, United States of America

Jianzhong Xu