Multiplex communications – Communication techniques for information carried in plural... – Combining or distributing information via frequency channels
Reexamination Certificate
2000-04-13
2004-07-20
Chin, Wellington (Department: 2739)
Multiplex communications
Communication techniques for information carried in plural...
Combining or distributing information via frequency channels
C370S285000
Reexamination Certificate
active
06765931
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to telecommunications systems, and more particularly, to a system for interfacing telephony devices with DOCSIS compatible networks.
BACKGROUND
Traditional dial-up modems provide online access through the public telephone network at up to 56 Kbps (equal to 56,000 bits per second). A cable modem, on the other hand, provides users with high-speed Internet access through a cable television network. Cable modem is capable of providing data rates as high as 56 Mbps, and is thus suitable for high speed Internet access, digital television (such as pay-per-view) and digital telephony.
SUMMARY OF THE INVENTION
In one aspect of the present invention, a method of conditioning a composite signal, the composite signal being formed by introducing a first signal into a second signal, includes adaptively filtering the first signal, detecting the second signal in the composite signal, controlling filter adaptation of the first signal responsive to detecting the second signal in the composite signal, and conditioning the composite signal after the filter adaptation is controlled.
In another aspect of the present invention, a method of cancelling a far end echo from a near end signal includes adaptively filtering a far end signal based on adaptation coefficients, detecting whether voice is present on the near end signal, holding the adaptation coefficients constant when voice is present, and cancelling the echo from the near end signal after the adaptation coefficients are held constant.
In yet another embodiment of the present invention, a signal conditioner for conditioning composite signal, the composite signal being formed by introducing a first signal into a second signal, includes logic to detect the second signal in the composite signal, an adaptive filter to filter the first signal, wherein the logic controls filter adaptation responsive to detecting the second signal in the composite signal, a difference operator to subtract the filtered first signal from the composite signal, and a delay between the logic and the difference operator.
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Hartman David
Rabenko Theodore F.
Thi James C. H.
Broadcom Corporation
Chin Wellington
Christie Parker & Hale LLP
Schultz William
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