Xieon Networks S.a.r.l.

Alcatel Lucent

Nokia Siemens Networks Gmbh & Co Kg

Nokia Siemens Networks Oy

Fabian N Hauske

Berthold Lankl

Bernhard Spinnler

Maxim Kuschnerov

Kittipong Piyawanno

Noriaki Kaneda

Joseph K Kakande

Ernst-Dieter Schmidt

Sebastian A Randel

Changsong Xie

We disclose demultiplexing processing for an adaptive MIMO equalizer of a receiver of multiplexed communication signals implemented in a manner that significantly reduces the occurrence of singularities at the equalizer output without a significant concomitant increase in the required computational power. The receiver includes an equalizer controller that operates to dynamically track the degree of correlation of one or more pairs of equalized signals outputted by the MIMO equalizer and to use the tracking results to configure the MIMO equalizer in a manner that substantially prevents any two outputs of the MIMO equalizer from converging to the same state. In an example embodiment, the degree of correlation can be determined in a computationally efficient manner by identifying and comparing quadrants in which complex values produced at the different outputs of the MIMO equalizer are located over a plurality of time slots.

Demultiplexing processing for a receiver

A received optical signal is coherently demodulated and converted into electrical complex samples (p(n); (px(n), py(n)), which are dispersion compensated in a compensation filter (). A control circuit () calculates comparison values (R, R) from corrected samples q(n) and an estimated error value (&#x3b5;). A plurality of compensation function (T(M)) is applied according to a predetermined dispersion (CD) range and after a second iteration is the compensation filter () set to an optimum compensation function (T(M)).

Method and arrangement for adaptive dispersion compensation

An optical receiver having an electronic dispersion-compensation module with two parallel signal-processing branches configured to provide a greater range of dispersion compensation than that provided by a prior-art device of comparable implementation complexity. In an example embodiment, each of the signal-processing branches includes a respective bank of finite-impulse-response filters that are configured in accordance with a different respective approximation of the group delay that needs to be compensated. The two group-delay approximations used by the filter banks rely on different respective step functions, each having a respective plurality of quantized steps, with the transitions between adjacent steps in one step function being spectrally aligned with the flat portions of the corresponding steps in the other step function. The filter banks may be further configured to apply different respective frequency-dependent phase-shift and/or amplitude-scaling profiles designed to reduce signal distortions associated with the transitions between adjacent steps in the step functions.

Optical receiver having a chromatic-dispersion compensation module with a multibranch filter-bank structure

A method and a device are provided for data processing. The data contains symbols and a control parameter is determined based on a correlation property of the symbols of the data. In this manner signal recovery is achieved that is robust against any kind of distortion and is fast enough to track time varying clocking disturbances. Further, a communication system is provided containing such a device.

Method and device for processing data and communication system comprising such device

A received optical signal is coherently demodulated and converted into electrical complex samples, which are dispersion compensated in a compensation filter. A control circuit calculates comparison values from corrected samples and an estimated error value. A plurality of compensation functions is applied according to a predetermined dispersion range and after a second iteration, the compensation filter is set to an optimum compensation function.

A method and a device are provided for phase recovery of at least two channels comprising the steps of (i) a phase is estimated for each channel; (ii) the phase estimated of each channel is superimposed by a coupling factor with at least one other phase estimated. Further, a communication system is suggested comprising such a device.

Method and device for phase recovery and communication system comprising such device

A receiver is provided for a quadrature-modulated signal, which can be divided into an inphase signal and a quadrature signal. The inphase signal is fed to first and third equalizers, and the quadrature signal is fed to second and fourth equalizers, wherein the first and second equalizers each perform a first equalization of the respective signal. An output of the first equalizer is connected to a second input of the fourth equalizer, which, by means of a second equalization of the quadrature signal, transmits an equalized quadrature signal as a function of the previously fed equalized inphase signal of the first equalizer. An output of the second equalizer is connected to the second input of the third equalizer, which, through a second equalization of the inphase signal, transmits an equalized inphase signal as a function of the previously fed equalized quadrature signal of the second equalizer.

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Woerthsee, Germany

Fabian N Hauske