Quellan, Inc.

Sanjay Bajekal

Andrew Joo Kim

Vincent Mark Hietala

Michael Gerald Vrazel

Charles E Summers

Stephen E Ralph

Processing a signal comprising signal distortions with filters. The filters comprise a first filter configured to a first time scale to compensate for signal distortions within respective symbols of the signal and a second filter configured to a second time scale to compensate for signal distortions among symbols of the signal. A probability estimate is produced based on an output of at least one of the first and second filters. At least one of the first and second time scales is adjusted according to the probability estimate.

Adaptive noise filtering and equalization

A Signal Conditioning Filter (SCF) and a Signal Integrity Unit (SIU) address the coupled problem of equalization and noise filtering in order to improve signal fidelity for decoding. Specifically, a received signal can be filtered in a manner to optimize the signal fidelity even in the presence of both significant (large magnitudes of) ISI and noise. The present invention can provide an adaptive method that continuously monitors a signal fidelity measure. Monitoring the fidelity of a multilevel signal can be performed by external means such as by the SIU. A received signal y(t) can be 'conditioned' by application of a filter with an electronically adjustable impulse response g(t). A resulting output z(t) can then be interrogated to characterize the quality of the conditioned signal. This fidelity measure q(t) can be used to adjust the filter response to maximize the fidelity measure of the conditioned signal.

Adaptive noise filtering and equalization for optimal high speed multilevel signal decoding

A method and system using the principle of generalized maximum likelihood estimation to resolve sample timing uncertainties that are associated with the decoding of communication signals. By using generalized maximum likelihood estimation, sample timing uncertainty can be resolved by taking multiple samples of the received signal within a symbol period and determining which sample best corresponds to the optimal sample timing. The sample which best corresponds to the optimal sample timing can be determined from a timing index which can be calculated from ambiguity indicators that are based on the samples of the received signal.

High-speed communication channel techniques with improved robustness to timing uncertainty

Signals propagating in one communication channel can generate crosstalk interference in another communication channel. A crosstalk cancellation device can process the signals causing the crosstalk interference and generate a crosstalk cancellation signal that can compensate for the crosstalk when applied to the channel receiving crosstalk interference. The crosstalk cancellation device can include a model of the crosstalk effect that generates a signal emulating the actual crosstalk both in form an in timing. The crosstalk cancellation device can include a controller that monitors crosstalk-compensated communication signals and adjusts the model to enhance crosstalk cancellation performance. The crosstalk cancellation device can have a mode of self configuration or calibration in which defined test signals can be transmitted on the crosstalk-generating channel and the crosstalk-receiving channel.

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Marietta, GA, United States of America

Sanjay Bajekal