Ciena Corporation

Blackberry Corporation

Research in Motion Corporation

Apple Inc.

Timothy James Creasy

Wen Tong

Naim Ben-Hamida

Ahmad Abdo

Lukas Jakober

Zhijun Cai

Mo-Han Fong

Peiying Zhu

Ming Jia

Sadok Aouini

Shahab Oveis Gharan

Jason Robert Duggan

Andrew Mark Earnshaw

Mahdi Parvizi

Tung Trong Nguyen

Sebastien Gareau

Jianfeng Weng

Yalmez M A Yazaw

Hua Xu

Youn Hyoung Heo

Jun J Li

Mark Earnshaw

James St Harley

Christian Dubuc

James St Leger Harley

Blake Toplis

Jun Li

Mark Eamshaw

Lukas Jakpber

Systems and methods include receiving () a plurality of symbols that are part of a defined Digital Signal Processing (DSP) frame for coherent optical communication, wherein the DSP frame structure has a messaging channel incorporated therein that includes a subset of the plurality of symbols; capturing () multiple samples of the messaging channel; and determining () a message in the messaging channel based on analysis of the multiple samples. The method can further include transmitting (), in the messaging channel, a reply to the message with the reply being repeated multiple times. The analysis is performed prior to Forward Error Correction (FEC) decoding on the data path.

Messaging channel in a coherent optical DSP frame

An optical system includes a transmitter including transmitter circuitry configured to cause transmission of a transmitted optical signal over a fiber link on an X polarization and a Y polarization; and a receiver including receiver circuitry configured to receive a received optical signal from the fiber link on the X polarization and the Y polarization, wherein the transmitter circuitry is configured to cause State of Polarization (SOP) changes on the X polarization and the Y polarization for a test of the fiber link. The transmitter circuitry and the receiver circuitry are built-in with the transmitter and the receiver, respectively, for performance of the test.

Built-in jitter loading and state of polarization generation to characterize optical transceivers

Systems and methods include receiving a plurality of symbols that are part of a defined Digital Signal Processing (DSP) frame for coherent optical communication, wherein the DSP frame structure has a messaging channel incorporated therein that includes a subset of the plurality of symbols; capturing multiple samples of the messaging channel; and determining a message in the messaging channel based on analysis of the multiple samples. The method can further include transmitting, in the messaging channel, a reply to the message with the reply being repeated multiple times. The analysis is performed prior to Forward Error Correction (FEC) decoding on the data path.

A method at a receiver comprises receiving a signal conveying symbols at respective positions within a clock cycle, the symbols comprising a data set consisting of data symbols and a pilot set consisting of pilot symbols; determining detected phases of the symbols based on the signal; generating first phase estimates based on the detected phases of a subset of the pilot set, and reference phases of the subset of the pilot set, the first phase estimates being associated with the positions of the pilot set; and generating second phase estimates based on the detected phases of the pilot set, reference phases of the pilot set, and the first phase estimates, the second phase estimates being associated with the positions of the pilot set and of at least a subset of the data set; and applying rotations to the detected phases of the symbols based on the second phase estimates.

Modular carrier recovery

Upon receiving a communications signal conveying symbols at a symbol period T, a receiver applies filter coefficients to a digital representation of the communications signal, thereby generating filtered signals having a shape in the frequency domain characterized by a bandwidth expansion factor &#x3b1;, where components of the filtered signals correspond to angular frequencies The receiver calculates first-order components from a first phase derivative of the components at a first differential distance, second-order components from a second phase derivative of the first-order components at a second differential distance, and composite second-order components from an average of the second-order components over multiple time intervals. Using the composite second-order components, the receiver calculates at least one of (i) an estimate of residual chromatic dispersion (CD) associated with the filtered signals, and (ii) an estimate of carrier frequency offset (CFO) associated with the filtered signals.

Blind estimation of residual chromatic dispersion and carrier frequency offset

Clock circuits, components, systems and signal processing methods enabling digital communication are described. A phase locked loop device derives an output signal locked to a first reference clock signal in a feedback loop. A common phase detector is employed to obtain phase differences between a copy of the output signal and a second reference clock signal. The phase differences are employed in an integral phase control loop within the feedback loop to lock the phase locked loop device to the center frequency of the second reference signal. The phase differences are also employed in a proportional phase control loop within the feedback loop to reduce the effect of imperfect component operation. Cascading the integral and proportional phase control within the feedback loop enables an amount of phase error to be filtered out from the output signal.

High-order phase tracking loop with segmented proportional and integral controls

Upon receiving a communications signal conveying symbols at a symbol period T, a receiver applies filter coefficients to a digital representation of the communications signal, thereby generating filtered signals characterized by a substantially raised cosine shape in the frequency domain with a roll-off factor &#x3b1;, where components of the filtered signals correspond to angular frequencies The receiver calculates first-order components from a first phase derivative of the components at a first differential distance, second-order components from a second phase derivative of the first-order components at a second differential distance, and composite second-order components from an average of the second-order components over multiple time intervals. Using the composite second-order components, the receiver calculates at least one of (i) an estimate of residual chromatic dispersion (CD) associated with the filtered signals, and (ii) an estimate of carrier frequency offset (CFO) associated with the filtered signals.

Managing clock-data recovery for a modulated signal from a communication channel comprises: receiving the modulated signal and providing one or more analog signals, providing one or more digital input streams from samples of the analog signals, and processing the digital input streams to provide decoded digital data. The processing comprises: determining the decoded digital data based on information modulated over a plurality of frequency elements associated with the modulated signal, based at least in part on transforms of the digital input streams; a clock signal based on clock recovery from the digital input streams; and determining a clock phase error estimate associated with the determined clock signal based at least in part on a sum that includes different weights multiplied by different respective summands corresponding to different sets of frequency elements.

Estimating clock phase error based on channel conditions

A system includes an optical transmitter including a transmitter Phase Lock Loop (PLL) circuit; an optical receiver connected to the optical transmitter and including a receiver PLL circuit; and circuitry configured to inject a test stimulus to a clock causing jitter in one of the transmitter PLL circuitry and the receiver PLL circuit, wherein the test stimulus is set for characterizing the jitter tolerance of optical receiver. As well, a circuit that injects SOP transient at the transmitter is included. It is configured to test the tolerance of optical receiver to handle fast change in the SOP state. The optical receiver is configured to determine if the system is operational at a jitter value due to the test stimulus based on compliance to one or more thresholds including any of a target Bit Error Rate, a Forward-Error-Correction (FEC) hit, and a jitter Root Mean Square (RMS).

A method and device for performing Hforward error (FEC) correction avoidance based upon predicted block code reliability in a communications device is provided. An avoidance unit comprising a metric computation unit and a decision unit generates a reliability metric based upon a received code block. The reliability metric is compared to a reliability threshold, and the forward error correction decoder in the communications device is disabled if the metric is below or equal to the threshold.

Forward error correction decoding avoidance based on predicted code block reliability

A method and device for performing forward error (FEC) correction avoidance based upon predicted block code reliability in a communications device is provided. An avoidance unit comprising a metric computation unit and a decision unit generates a reliability metric based upon a received code block. The reliability metric is compared to a reliability threshold, and the forward error correction decoder in the communications device is disabled if the metric is below or equal to the threshold.

Methods and apparatus to perform antenna management are described herein. One example method of establishing communication between user equipment and a network includes receiving a control channel message, decoding the control channel message, and sending an indication of whether interoperability of receiving signals from a first number of antennas is certified for the user equipment. Other examples are shown and described.

Methods and apparatus to perform antenna management

Aspects of the present application include using adaptive measurement intervals to improve RSSI scan accuracy. A method may involve determining a first power value in respect of a first measurement time interval, determining whether or not the first power value meets at least one criterion, when the first power value does not meet the at least one criterion, determining at least one additional power value, selecting at least one power value from a set of power values that have been determined, the set including the first power value and the at least one additional power value, and determining the power value for use in cell selection or cell re-selection based on the selected at least one power value. The methods may be applied to any cell selection or re-selection scheme for which an adaptive measurement interval may be beneficial.

Growing community of inventors

Manotick, Canada

Timothy James Creasy