Inphi Corporation

Clariphy Communications, Inc.

Marvell Asia Pte., Ltd.

Fundacion Tarpuy

Mario Rafael Hueda

Oscar Ernesto Agazzi

Diego Ernesto Crivelli

Hugo Santiago Carrer

Damian Alfonso Morero

Mario Alejandro Castrillon

Norman L Swenson

Martin Ignacio Del Barco

Ramiro Rogelio Lopez

Alfredo Javier Taddei

Matias German Schnidrig

Federico Nicolas Paredes

Mauro Marcelo Bruni

Elvio Adrian Serrano

Carl Grace

Martin Carlos Asinari

Vadim Gutnik

Paul Voois

Jorge Manuel Finochietto

German Cesar Augusto Luna

Seyedmohammadreza Motaghiannezam

Martin Serra

Facundo Abel Alcides Ramos

José Correa

Ariel Pola

Cristian Cavenio

Ramiro Matteoda

Gabriel Infante

Roman Antonio Arenas

Pablo Gianni

Pablo Gustavo Quiroga

Alejandro Javier Schwoykoski

Shih Cheng Wang

Adrián Ulises Morales

German C Luna

Damián Alfonso Morero

Geoffrey O Hatcher

Shu Hao Fan

Jeffrey Zachan

Michael Yeo

Andre Chartrand

María Laura Ferster

Nestor D Campos

Lucas Javier Yoaquino

José L Correa Lust

Thomas A Lindsay

Jinwoo Cho

Daniel A Tauber

Mario Alejandro Castrillion

Damián A Morero

Maria Laura Ferster

Néstor D Campos

Franco Paludi

Ulises Morales

Laura Maria Ferster

Cesar Sanchez Peñak

Teodoro Ariel Goette

Alejandro Castrillon

Genaro Bergero

Teodoro Goette

A decoder for a receiver in a communication system includes an interface configured to receive encoded input data via a communication channel. The encoded input data includes forward error correction (FEC) codewords. A processor is configured to decode the FEC codewords using low density parity check (LDPC) codes defined by a parity check matrix. The parity check matrix is defined by both regular column partition (RCP) constraints and quasi-cyclic (QC) constraints. An output circuit is configured to output a decoded codeword based on the FEC codewords decoded by the processor.

Decoding FEC codewords using LDPC codes defined by a parity check matrix which is defined by RPC and QC constraints

A method and structure for probabilistic shaping and compensation techniques in coherent optical receivers. According to an example, the present invention provides a method and structure for an implementation of distribution matcher encoders and decoders for probabilistic shaping applications. The techniques involved avoid the traditional implementations based on arithmetic coding, which requires intensive multiplication functions. Furthermore, these probabilistic shaping techniques can be used in combination with LDPC codes through reverse concatenation techniques.

Probabilistic shaping techniques for high performance coherent optical transceivers

A coherent optical receiver includes equalizer circuitry having a plurality of taps, the equalizer circuitry being configured to receive an input signal and compensate for polarization mode dispersion affecting the input signal to generate a compensated input signal. The coherent optical receiver further includes error evaluation circuitry configured to calculate a determinant of a frequency-domain (FD) coefficient-based matrix using a plurality of tap signals from among the plurality of taps, adjust an error of convergence of the compensated input signal to generate an adjusted input signal, and iteratively adjust the determinant of the FD coefficient-based matrix based on the adjusted input signal to minimize the error of convergence.

Tap centerer method and structure for coherent optical receiver

A decoder circuit includes first and second decoders. The first decoder is a first type of decoder configured to receive data encoded with an error correction code and decode and eliminate errors from a first subset of codewords of the data. The second decoder is a second type of decoder configured receive the data encoded with the error correction code and decode and eliminate errors from a second subset of codewords of the data, different from the first subset of the codewords, without attempting to decode and eliminate errors from the first subset of the codewords.

Decoder circuit including decoders with respective performance and power levels and decoding respective subsets of codewords of received data

A method and device for energy-efficient decoders. The decoder device can include a plurality of decoder modules configured to process an input data signal having a plurality of forward error correction (FEC) codewords. This plurality of decoder modules can include at least a first decoder followed by a second decoder. The first decoder can be low-power to first eliminate most of the errors of the codewords and the second decoder can be high-performance to correct the remaining errors. Alternatively, the first decoder can be high-performance to correct the codewords until the low-power decoder can correct the remaining errors. A classifier module can be included to determine portions of the codewords to be directed to any one of the plurality of decoder modules. These implementations can be extended to use additional decoders with different decoding algorithms and optimized to maximize decoder performance given a maximum power constraint.

Method and device for energy-efficient decoders

A method and structure for tap centering in a coherent optical receiver device. The center of gravity (CG) of the filter coefficients can be used to evaluate a proper convergence of a time-domain adaptive equalizer. However, the computation of CG in a dual-polarization optical coherent receiver is difficult when a frequency domain (FD) adaptive equalizer is adopted. In this case, the implementation of several inverse fast-Fourier transform (IFFT) stages is required to back time domain impulse response. Here, examples of the present invention estimate CG directly from the FD equalizer taps and compensate for an error of convergence based off of the estimated CG. This estimation method and associated device architecture is able to achieve an excellent tradeoff between accuracy and complexity.

A method and structure for a coherent optical receiver device. Timing recovery (TR) is implemented after channel dispersion (i.e., chromatic dispersion (CD) and polarization mode dispersion (PMD)) compensation blocks. This architecture provides both improves performance and reduces power consumption of the device. Also, a TR loop is provided, enabling computing, by an error evaluation module, a first sampling phase error (SPE) and computing, by a timing phase information (TPI) module coupled to the error evaluation module, a second SPE from a plurality of CD equalizer taps PMD equalizer taps. The first and second SPE are combined into a total phase error (TPE) in a combining module, and the resulting TPE is filtered by a timing recovery (TR) filter coupled to an interpolated timing recovery (ITR) module and the combining module. The ITR module then synchronizes an input signal of the coherent optical receiver according to the TPE.

Tap stabilizer method and structure for coherent optical receiver

A communication system includes a transmitter having an encoder configured to encode input data using FEC codewords and a receiver including a decoder configured to decode the FEC codewords using a parity check matrix. The decoder includes check node processing units each configured to perform a check node computation on an FEC codeword using a different row of the parity check matrix. Each of the check node processing units includes an input computation stage configured to compute initial computation values, a pipelined message memory configured to shift the initial computation values at a predefined clock interval, an output computation stage configured to generate a plurality of check node output messages, a plurality of variable node processing units each configured to perform variable node update computations to generate the variable node messages, and an output circuit configured to generate a decoded codeword based on the variable node messages.

Non-concatenated FEC codes for ultra-high speed optical transport networks

A method and structure for equalization in coherent optical receivers. Block-based LMS (BLMS) algorithm is one of the many efficient adaptive equalization algorithms used to (i) increase convergence speed and (ii) reduce implementation complexity. Since the computation of the equalizer output and the gradient of the error are obtained using a linear convolution, BLMS can be efficiently implemented in the frequency domain with the constrained frequency-domain BLMS (FBLMS) adaptive algorithm. The present invention introduces a novel reduced complexity constrained FBLMS algorithm. This new approach replaces the two discrete Fourier transform (DFT) stages required to evaluate the DFT of the gradient error, by a simple frequency domain filtering. Implementation complexity can be drastically reduced in comparison to the standard constrained FBLMS. Furthermore, the new approach achieves better performance than that obtained with the unconstrained FBLMS in ultra-high speed coherent optical receivers.

Reduced complexity constrained frequency-domain block LMS adaptive equalization for coherent optical receivers

A method and structure for compensation techniques in coherent optical receivers. The present invention provides a coherent optical receiver with an improved 8&#xd7;8 adaptive MIMO (Multiple Input, Multiple Output) equalizer configured within a digital signal processor (DSP) to compensate the effects of transmitter I/Q skew in subcarrier multiplexing (SCM) schemes. The 8&#xd7;8 MIMO equalizer can be configured such that each of the 8 outputs is electrically coupled to 3 of 8 inputs, wherein each of the input-output couplings is configured as a filter. The method includes compensating for impairments to the digital conversion of an optical input signal via the 8&#xd7;8 MIMO equalizer following other signal processing steps, such as chromatic dispersion (CD)/polarization-mode dispersion (PMD) compensation, carrier recovery, timing synchronization, and cycle slip correction.

Impairment compensation techniques for high performance coherent optical transceivers

A method and structure for signal propagation in a coherent optical receiver device. Asynchronous equalization helps to reduce complexity and power dissipation, and also improves the robustness of timing recovery. However, conventional devices using inverse interpolation filters ignore adaptation algorithms. The present invention provides for forward propagation and backward propagation. In the forward case, the filter input signal is forward propagated through a filter to the adaptation engine, while, in the backward case, the error signal is backward propagated through a filter to the asynchronous domain. Using such forward and backward propagation schemes reduces implementation complexity while providing optical device performance.

Forward and backward propagation methods and structures for coherent optical receiver

Growing community of inventors

Cordoba, Argentina

Mario Rafael Hueda