Marvell International Limited

Solarflare Communications, Inc.

Gavin D Parnaby

George Zimmerman

William W Jones

Chris Pagnanelli

George A Zimmerman

A crosstalk cancellation system and method is disclosed for use in a multi-channel communication system. Crosstalk which couples between channels is cancelled through use of an in-line FFE filter and in-line delay. A cross-connect system associated with each channel includes a cross-connect delay and cross-connect filter. The cross-connect system generates a cancellation signal for each of the channels, which is routed into a junction. The junction subtracts the cancellation signal from the received signal, which has also been delayed and filtered, to remove unwanted cross-talk. During training, cancellation magnitude is monitored at various delay offsets to determine which offset and corresponding filter coefficients, for each delay, maximizes cancellation. The filters are set with filter coefficients that maximize cancellation. The cross-connect delay with the maximum offset is set to zero and its calculated offset amount is established as the in-line delay offset. The other cross-connect delay offsets are adjusted accordingly.

Crosstalk cancellation using sliding filters

A cancellation system is disclosed for processing incoming and outgoing signals in a transform domain to create a cancellation signal for reducing or removing unwanted interference. Data is ordered based on Good-Thomas indexing into a two dimensional array in a buffer. The two dimensional array may have lrows and lcolumns. From the buffer, the columns of data undergo a Winograd small transform. The rows of data undergo a Cooley-Tukey operation to complete the transform operation into the frequency domain. Multipliers scale the transformed data to generate a cancellation signal in the frequency domain. Inverse (Cooley-Tukey) and Winograd transforms perform inverse processing on the cancellation signal to return the cancellation signal or data to the time domain. Re-ordering the data and combination of the cancellation signal or data with incoming or outgoing signals achieve interference cancellation.

Frequency domain echo and next cancellation

A method comprises receiving data, modulated according to a first modulation scheme, from a transmitter via an Ethernet link while the receiver is in a first mode. The first mode corresponds to a first power consumption level of the receiver. The method also includes receiving a sleep signal, and, in response, transitioning the receiver to a second mode. The second mode corresponds to a second power consumption level lower than the first power consumption level. The method also includes detecting an expiration of a predetermined time interval, and, in response, transitioning the receiver to a third mode. The third mode corresponds to a third power consumption level greater than the second power consumption level. The method also includes receiving a refresh signal modulated according to a different, second modulation scheme, synchronizing the receiver to the transmitter based on the refresh signal, and transitioning the receiver back to the second mode.

Method of synchronization for low power idle

A method of synchronizing a first transceiver with a second transceiver during a low power idle mode is disclosed for use in network communication devices. A LDPC counter, which initiates a count operation upon transition to PAM16 mode, serves as a master counter to determined when, based on predetermined count values, each channel reactivates from low power idle mode to active mode to generate and send a refresh signal. The transmitter and associated remote receiver both reactivate at the predetermined refresh period to process the refresh signal. Each transmitter/receiver pair has predetermined refresh periods during low power idle mode. The refresh signal is processed for maintain clock synchronization and for filter and equalizer adaptation.

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Irvine, CA, United States of America

Gavin D Parnaby