Lucent Technologies Inc.

Alcatel-lucent USA Inc.

Alcatel Lucent

Jeffrey H Sinsky

Andrew Adamiecki

Theodore Sizer

Liming Zhang

Weiguo Yang

Sebastian A Randel

Chia-Ming Chang

Don Taylor

Lawrence Buhl

Andrew L Adamiecki

We disclose an optoelectronic circuit that is configurable to operate as an FIR filter, in which the tapping and the weighting of the signal that is being equalized are performed in the optical domain, whereas the summation of the weighted signals is performed in the electrical domain after the corresponding optical signals are converted into electrical form using an array of photodetectors. Photodetectors in the array are arranged such that some of them contribute to the equalized electrical signal with a positive polarity and the others contribute to the equalized electrical signal with a negative polarity. As a result, at least some of the tap weights used in the FIR filter can be made variable between a positive value and a negative value.

Optoelectronic equalizer circuit

Disclosed is a polybinary-signal generator in which correlative coding is applied to a plurality of fractional-bit-rate signals instead of being applied to a corresponding multiplexed full-bit-rate signal. The resulting coded fractional-bit-rate signals are variously delayed with respect to one another and then summed to generate a polybinary output signal. One beneficial feature of this architecture is that most circuit components of the polybinary-signal generator operate at the fractional bit rate, which helps to alleviate at least some of the technical difficulties associated with the design of radio-frequency circuits intended for relatively high bit rates. Another beneficial feature of this architecture is that the polybinary-signal generator also serves as a signal multiplexer.

Generation of multilevel signals using correlative coding

Disclosed herein are various embodiments of a time-domain reflectometer having a transmitter configured to apply, to a system under test (SUT), an intensity-modulated probe signal generated based on a periodic pseudo-random bit sequence. The reflectometer further has a receiver configured to receive, back from the SUT, a reflected signal corresponding to the probe signal. The receiver converts the received reflected signal into a binary bit sequence using a relatively simple slicer circuit, and without the use of complex analog circuits and/or multi-bit analog-to-digital converters. The binary bit sequence is then compared with the original pseudo-random bit sequence to obtain a measure of the impulse response of the SUT. In some embodiments, the reflectometer has a controllable noise generator that can be used, e.g., to optimize the obtained measure for the detection of multiple SUT defects having significantly differing reflection characteristics.

Stochastic reflectometer

A novel 100+ Gbit/s opto-electronic receiver uses hybrid integration of a photodiode and a demultiplexer. The photodiode converts a high speed optical data stream to an electrical data stream that is input to an electronic demultiplexer. The photodiode and the demultiplexer are connected together by a novel planar microwave transmission structure.

High speed optoelectronic receiver

A (binary) signal is transmitted through an electrical backplane, and the received signal is interpreted as a duobinary signal. In order to ensure that the received signal can be properly interpreted as a duobinary signal, the data signal is preferably filtered prior to being interpreted. The filter is preferably designed such that the combination of filter and the backplane approximates a binary-to-duobinary converter. In one embodiment, an (FIR-based) equalizing filter is applied to the data signal prior to transmission to emphasize the high-frequency components and flatten the group delay of the backplane. The resulting, received duobinary signal is converted into a binary signal by (1) splitting the duobinary signal, (2) applying each copy to a suitably thresholded comparator, and (3) applying the comparator outputs to a suitable (e.g., XOR) logic gate. The transmission system enables high-speed data (e.g., greater than 10 Gb/s) to be transmitted over relatively inexpensive electrical backplanes.

Electrical backplane transmission using duobinary signaling

An optoelectronic integrated circuit (OEIC) having an optical core coupled to first and second interface circuits. The first interface circuit is adapted to convert an electrical input signal into an optical signal; the optical core is adapted to process the optical signal in the optical domain; and the second interface circuit is adapted to convert the processed optical signal into an electrical output signal. In one embodiment, an OEIC of the invention is fabricated using a single wafer, has only electrical inputs/outputs, does not have any external optical interfaces, and is not adapted to receive any external optical signals. Advantageously, due to the signal processing being in the optical domain, a circuit of the invention carries out its functionality, with little or no performance degradation, over a relatively wide frequency range. In addition, this circuit has a relatively small size and can be relatively inexpensive.

Integrated circuit having an optical core

A device and technique for aligning an optical carrier signal (e.g., a soliton pulse train) with a data signal in a transmitter. According to the invention, the device is configured to analyze the radio frequency (RF) spectrum of the transmitter's output. In one implementation, the device evaluates the amount of energy in a certain frequency band located near a selected null of the RF spectrum. In another implementation, the device examines the shape of the RF spectrum within that frequency band. In either case, based on the analysis, the device adjusts the phase of the clock signal driving an electro-optic (E/O) modulator in the transmitter. Such adjustment reduces misalignment between the optical carrier signal and data resulting, e.g., from thermal effects in the E/O modulator. The device may be used, e.g., in long-haul optical transmission systems operating at 10 GBit/s.

Correcting misalignment between data and a carrier signal in transmitters

A technique for performance-monitoring of a standard SONET signal involves first converting the optical signal to an electrical signal, removing in the framing signal time slot the framing signal for leaving only the framing signal noise in such time slot, and separating the framing signal noise from the data signal for viewing as a measure of the quality of the SONET signal.

Technique for monitoring SONET signal

A method, controller, system, and computer program for generating data points by measuring the power of the transmitted/received signal while each antenna element is rotated through a series of phase angles. Thereafter, a pairwise comparison of these data points is performed in order to determine the phase and amplitude corrections needed for each antenna element. This pairwise analysis uses as few as three signal measurements for each antenna element, made at sparse, arbitrarily spaced phase angles. Further, the method includes smart data selection to ignore bad data points resulting from anomalies or noise bursts.

Phased array calibration using sparse arbitrarily spaced rotating electric vectors and a scalar measurement system

An electromechanical phase shifter for a microstrip microwave transmission line includes a conductive base plate and a pair of microstrip transmission line segments supported parallel to each other and parallel to and spaced from the base plate. A movable microstrip transmission line bridges the pair of transmission line segments and is movable therealong to provide a short circuit therebetween. A movable ground element is coupled to the bridging transmission line for movement therewith and is in contact with the pair of transmission line segments and the base plate. The spacing between the movable bridging transmission line and the ground element is maintained at one quarter wavelength of the center frequency of the signal frequency band.

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Marlboro, NJ, United States of America

Jeffrey H Sinsky