US 7,254,345 B2 · Receiver and receiving method capable of detecting an eye aperture size formed by reception data signals

Abstract

In a receiver operable in response to a data signal, an eye aperture size is detected along a time axis by an eye aperture detection circuit and is controlled by a control circuit so that it becomes a maximum. The eye aperture detection circuit determines different decision time points of the same level arranged along a time axis and judges whether or not an error is caused to occur at each of the decision time points, so as to detect the eye aperture size and to produce detection results. The control circuit processes the detection results in accordance with a predetermined algorithm to successively vary the eye aperture size and to keep the data signal at an optimum amplitude.

Claims36

Dependent claims

An optical receiver operable in response to a light signal and comprising:

a clock and data recovery circuit (CDR) for recovering a sequence of clocks and a sequence of data signals in response to an intermediate data signal obtained from the light signal, with reference to a threshold control signal used for recovering the data signal sequence;
a controller, responsive to the intermediate data signal and the threshold control signal, for detecting an eye pattern of the intermediate data signal that includes an eye aperture to control an eye aperture size;
and
a waveform equalizer, responsive to an electric signal converted from the light signal and an internal control signal, for reshaping a waveform of the electric signal into a waveform-shaped signal in accordance with the internal control signal to supply the waveform-shaped signal to the clock and data recovery circuit as the intermediate data input signal,
wherein said waveform equalizer comprises:
a single bit delay circuit that delays the electric signal by one bit;
a variable gain amplifier that controls an amplitude of the delayed electric signal in response to the internal control signal from the controller;
and
a subtracter that subtracts the amplitude controlled and delayed electric signal, which is received from the variable gain amplifier, from the electric signal converted from the light signal.

6 more elements

An optical receiver operable in response to a light signal and comprising:

a clock and data recovery circuit (CDR) for recovering a sequence of clocks and a sequence of data signals in response to an intermediate data signal obtained from the light signal, with reference to a threshold control signal used for recovering the data signal sequence;
a controller, responsive to the intermediate data signal and the threshold control signal, for detecting an eye pattern of the intermediate data signal that includes an eye aperture to control an eye aperture size;
and
a waveform equalizer, responsive to an electric signal converted from the light signal and an internal control signal, for reshaping a waveform of the electric signal into a waveform-shaped signal in accordance with the internal control signal to supply the waveform-shaped signal to the clock and data recovery circuit as the intermediate data input signal,
wherein said waveform equalizer comprises:
a single bit delay circuit that delays the electric signal by one bit;
and
a variable gain amplifier that controls an amplitude of the delayed electric signal in response to the internal control signal from the controller,
wherein the controller comprises:
an eye aperture detection circuit, responsive to the intermediate data signal and the threshold control signal, for detecting the eye aperture size to produce a result of detection as a detection signal representative of the result of detection;
and
a processing circuit for processing the detection signal to supply the eye control signal as the internal control signal to the waveform equalizer so that the eye aperture is widened along a time axis.

9 more elements

An optical receiver operable in response to a light signal and comprising:

a clock and data recovery circuit (CDR) for recovering a sequence of clocks and a sequence of data signals in response to an intermediate data signal obtained from the light signal, with reference to a threshold control signal used for recovering the data signal sequence;
a controller, responsive to the intermediate data signal and the threshold control signal, for detecting an eye pattern of the intermediate data signal that includes an eye aperture to control an eye aperture size;
a photoelectric converter for converting the light signal sequence into an electric signal;
and
a waveform equalizer, responsive to the electric signal and an internal control signal, for reshaping a waveform of the electric signal into a waveform-shaped signal in accordance with the internal control signal to supply the waveform-shaped signal to the clock and data recovery circuit as the intermediate data input signal;
the controller producing an eye control signal for controlling the eye aperture size and supplying the waveform equalizer with the eye control signal as the internal control signal,
wherein the controller comprises:
an eye aperture detection circuit, responsive to the intermediate data signal and the threshold control signal, for detecting the eye aperture size to produce a result of detection as a detection signal representative of the result of detection;
and
a processing circuit for processing the detection signal to supply the eye controls signal as the internal control signal to the waveform equalizer so that the eye aperture is widened along a time axis,
wherein the processing circuit controls the eye aperture size in accordance with an algorithm that defines a relationship between each amplitude of the intermediate data signal and the eye aperture size,
wherein the algorithm uses a variation of the eye aperture size that appears when an amplitude of a single bit delayed data signal is varied by a unit quantity.

9 more elements

A receiver responsive to a sequence of data signals specified by an eye pattern to produce a sequence of output data signals representative of reproductions of the data signals, comprising:

an eye aperture detection circuit for detecting an eye aperture size in the eye pattern from the data signal sequence to produce a detection signal representative of a result of detection;
a processing circuit for processing the detection signal to produce a control signal for controlling the eye aperture size;
and
a waveform equalizer for reshaping the data signal sequence into a sequence of waveform-shaped signals to supply the wave-formed shaped signals to the eye aperture detection circuit;
the control signal being supplied from the control circuit to the waveform equalizer as an internal control signal while the waveform equalizer delays the data signal sequence in response to the internal control signal and shapes the data signal sequence,
wherein the waveform equalizer comprises:
a delay circuit for delaying the data signal sequence by a single bit to produce a sequence of single bit delayed data signals;
a variable gain amplifier, responsive to the single bit delayed data signals and the internal control signal, for controlling a gain in accordance with the internal control signal to produce a sequence of gain controlled data signals;
and
a subtracter for subtracting the gain controlled data signal sequence from the data signal sequence.

7 more elements

Dependencies are inferred from the claim text.

Receiver and receiving method capable of detecting an eye aperture size formed by reception data signals

Life of this patent

Receiver and receiving method capable of detecting an eye aperture size formed by reception data signals

Life of this patent

Abstract

Claims36