US 7,254,185 B2Granted

Method for recovering a digital data content in a communication system and apparatus for performing the same

AssigneeMediatek Incorporation

InventorsMao-Ching Chiu, Chi-Chao Chao, Chao-Ming Chang, Tai-Yuan Cheng, Hung-Kun Chen

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Abstract

A method is directed to recovering a digital data content in a communication system, wherein the digital data content has been converted into an analog signal based on a primary clock, at a transmitter for transmitting to a receiver. The method comprises receiving the analog signal by the receiver. The analog signal is converted into a digital signal, based on a clock of the receiver. The digital signal is interpolated at the desired interpolation point, if digital signal in time has been shifted by an amount equal to or larger than a predetermined time length. The interpolated digital signal is recovered back to the digital data content, with the assist of an estimated channel impulse response. The channel impulse response is retrained every time when the interpolation point is significantly changed.

Claims12

Dependent claims

A method for recovering a digital data content in a communication system, wherein the digital data content has been converted into an analog signal for transmitting from a transmitter to a receiver through a communication channel, the method comprising:

receiving the analog signal by the receiver, converting the analog signal into a sampled digital signal, based on a local sampling clock;
performing a interpolation process to interpolate the sampled digital signal at an interpolation point for generating an interpolated digital signal;
performing a timing tracking process to determine the interpolation point where the interpolation is to be taken at and determine whether or not the interpolation point is changed and different from the previous determined interpolation point;
estimating a channel impulse response described by a set of coefficients based on the interpolated digital signal when the interpolation point is changed;
detecting the digital data content from the interpolated digital signal and the estimated coefficients of channel impulse response;
performing an update process if the interpolation point has been changed, wherein the update process comprises:
updating the filter coefficients used in the interpolation process according to the interpolation point;
performing a retraining process to update the set of coefficients of the channel impulse response, according to the interpolated digital signal, wherein the timing tracking process is simultaneously paused as the interpolation point is changed, and the timing tracking process is simultaneously awakened as the retraining process is accomplished.

5 more elements

An apparatus for recovering a digital data content in a communication system, used in a receiver, wherein the digital data content has been converted into an analog signal at a transmitter for transmission to the receiver through a communication channel, the apparatus comprising:

an analog-to-digital converter (ADC), used to receive the analog signal and convert into a sampled digital signal according to a local sampling clock;
an interpolation unit, receiving the sampled digital signal from the ADC, wherein interpolation unit is used to interpolate the sampled digital signal at an interpolation point and output an interpolated digital signal;
a channel estimator, receiving an output of the interpolation unit and a refraining signal, wherein the channel estimator produces a set of coefficients for representing a shape of the channel impulse response, and perform a retraining process to update the coefficients when a refraining signal is received;
a data detector, receiving the interpolated digital signal from the interpolation unit and an information from the channel estimator, including the set of coefficients for the channel impulse response, so as to recover the interpolated digital signal back to the current actual digital data content;
and
a timing tracking unit, used to determine the interpolation point, and generate the retraining signal when the interpolation point is changed and different from the previous determined interpolation point,
wherein the timing tracking unit is simultaneously paused to perform retraining process while the interpolation point is changed, and the timing tracking unit is simultaneously awakened as the channel estimator finishes the refraining process.

4 more elements

Dependencies are inferred from the claim text.