Celight, Inc.

Agere Systems Inc.

Lucent Technologies Inc.

Alper Demir

Isaac Shpantzer

Aviv Salamon

Peter Feldman

Peter R Kinget

Pak Shing Cho

Jaijeet S Roychowdhury

Michael Tseytlin

Nagendra Krishnapura

Olga Ritterbush

Yehouda Meiman

Jaijeet Roychowdhury

Jacob B Khurgin

Vladimir S Grigoryan

Nadejda Reingand

Yaakov Achiam

Israel Smilanski

Joseph Schwarzwalder

Charles Sciabarra

Amit Mehrotra

Li Guoliang

The present invention relates to a method for transmitting data. An optical pulse stream comprising a plurality of return-to-zero optical pulses is prepared by modulating a phase of light output by an optical source to thereby encode data from a data source. The light of the optical pulse stream has a wavelength. The optical pulse stream is transmitted along an optical fiber of an optical network. Optical pulse streams of the invention enhance transmission performance at least in part by reducing noise at the receiver caused by fiber non-linearities.

Method and system for mitigating nonlinear transmission impairments in fiber-optic communications systems

A system for optical communication forms a family of orthogonal optical codes modulated by a data stream. The orthogonal codes are formed by creating a stream of evenly spaced-apart pulses using a pulse spreader circuit and modulating the pulses in amplitude and/or phase to form a family of orthogonal optical code words, each representing a symbol. A spreader calibration circuit is used to ensure accurate timing and modulation. Each code word is further modulated by a predetermined number of data bits. The data modulation scheme splits a code word into H and V components, and further processes the components prior to modulation with data, followed by recombining with a polarization beam combiner. The data-modulated code word is then sent, along with others to receiver. The received signal is detected and demodulated with the help of a symbol synchronization unit which establishes the beginning and end of the code words. A polarization mode distortion compensator at the receiver cooperates with a state of polarization compensator at the transmitter to mitigate polarization distortion in the fiber.

System and method for code division multiplexed optical communication

A system for optical communication send optical signals over a plurality of wavelength channels. Each wavelength channel comprises a number of orthogonal subchannel frequencies which are spaced apart from one another by a predetermined amount. Each of the subchannel frequencies is modulated with data from a data stream. The data modulation scheme splits a subchannel frequency code into H and V components, and further processes the components prior to modulation with data. The various data-modulated subchannels are then combined into a single channel for transmission. The received signals are detected and demodulated with the help of a symbol timing recovery module which establishes the beginning and end of each symbol. A polarization mode distortion compensation module at the receiver is used to mitigate the effects to polarization more distortion in the fiber.

System and method for orthogonal frequency division multiplexed optical communication

The present invention is for a method and apparatus for analyzing the effect of a plurality of noise sources in a circuit, wherein each one of the noise sources is associated with a discrete stochastic process defined on a state-set of Markov chains. Each discrete stochastic process is modulated with a set of continuous signals that represents the noise generated by the corresponding noise source at each noise generating event. A spectral power density of the signals resulting from the modulation is computed and transferred through a linear system that represents a platform that supports the circuit. The output of the linear system comprises the spectral power density of interference signals at the points of interest and their correlations.

Method and apparatus for evaluating effects of switching noise in digital and analog circuitry

The phase noise of an oscillator described by a known set of differential algebraic equations (DAEs) can be predicted by a) finding the steady state waveform of the oscillator, e.g., by using harmonic balance techniques or so-called &ldquo;shooting&rdquo; techniques, either of which involves developing a mathematical quantity known as the augmented Jacobian matrix; b) solving a prescribed linear system of equations that uses the augmented Jacobian matrix, the solution being called a perturbation projection vector (PPV), c) plotting a graph of the phase noise of the oscillator as a Lorentzian function of the solution of the prescribed linear system of equations. The prescribed linear system of equations which is used is the system of equations formed by setting a matrix product equal to a unit vector.

Oscillator phase noise prediction

A nonlinear analysis for characterizing phase noise and timing jitter in oscillators is disclosed. The method and apparatus utilize a nonlinear differential equation to characterize the phase error of a given oscillator. A precise stochastic characterization of timing jitter and spectral dispersion is also disclosed based on the nonlinear differential equation. Representative time and frequency domain computational techniques are disclosed for characterizing the phase noise and timing jitter of circuits. In addition, a single scalar constant, c, is utilized to describe jitter and spectral spreading in a noisy oscillator.

Method and apparatus for characterizing phase noise and timing jitter in

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Alper Demir