Abstract: In accordance with the present invention, a communications system transmits a predetermined signal, from a first, sending, end of a communications system to a second, receiving, end of a communications system. The predetermined signal is distorted by the communication system and is received as a distorted signal that is compared to a known version of the originally transmitted signal. A comparison signal related to the difference between the originally transmitted signal (as represented by the known version of the originally transmitted signal) and the distorted predetermined signal as received at the receiving end is employed to adjust the transfer characteristic of a programmable converter to compensate for the distortion introduced by the communication system.

Abstract: A method of training a TTS or other system to assign intonational features, such as intonational phrase boundaries, is described. The method of training involves taking a set of predetermined text (not speech or a signal representative of speech) and having a human annotate it with intonational feature annotations. This results in annotated text. Next, the structure of the set of predetermined text is analyzed to generate information. This information is used, along with the intonational feature annotations, to generate a statistical representation. The statistical representation may then be stored and repeatedly used to generate synthesized speech from new sets of input text without training the TTS system further.

Abstract: There is disclosed, a converter for converting an input signal from one form to another. The converter includes a slicing circuit adapted to slice a signal into levels. The slicing circuit includes at least one threshold for establishing slicing levels. Dither is employed to vary at least one slicing level in the slicing circuit.

Abstract: An acoustic signature recognition and identification system receives signals from a sensor placed on a designated piece of equipment. The acoustic data is digitized and processed, via a Fast Fourier Transform routine, to create a spectrogram image of frequency versus time. The spectrogram image is then normalized to permit acoustic pattern recognition regardless of the surrounding environment or magnitude of the acoustic signal. A feature extractor then detects, tracks and characterizes the lines which form the spectrogram. Specifically, the lines are detected via a KY process that is applied to each pixel in the line. A blob coloring process then groups spatially connected pixels into a single signal object. The harmonic content of the lines is then determined and compared with stored templates of known acoustic signatures to ascertain the type of machinery. An alert is then generated in response to the recognized and identified machinery.

Abstract: An optical mirror switch is formed by utilizing a pair of walk-off devices separated by a polarization switch. A first signal port is coupled to the first walk-off device and a second signal port is coupled to the second walk-off device. A reflective surface is also disposed beyond the output of the second walk-off device. In a first, “pass through” state of the switch, an optical signal applied as an input at the first signal port will propagate through the switch and exit at the second signal port. In a second, “reflective” state of the switch, an optical signal applied as an input at the first signal port will propagate through the switch, impinge the reflective surface and be re-directed back through the switch and exit through the first port. The “state” of the switch is controlled by the “state” of the polarization switch (which either exchanges the polarization states of the orthogonal components passing through, or maintains them).

Abstract: An optical attenuator for use in optical power regulation uses a shutter to control the insertion loss of a gap in a pair of substantially coaxially aligned waveguides, for example a pair of optical fibers. The shutter is part of a MEMS accuator device and is coupled to the movable one of a pair of spaced plates, the movable plate being movable by a voltage applied between the pair of plates. To regulate the power, a small portion of the optical power is abstracted and used to derive a control voltage that is applied to the optical attenuator for varying the attenuation inserted in the optical wave path.

Abstract: A line-driver receives as an input a Manchester-encoded digital data signal, which is then converted into an analog signal by a wave-shaping circuit. The wave-shaping circuit comprises a bank of current sources with a combined output, each current source being actuated by a switch controlled by a switching signal. The current sources are each scaled by a coefficient, and are actuated in a selected sequence during each input data pulse, thereby generating as a combined output a staircase pulse signal with n steps for each input data pulse.

Abstract: A preferred embodiment of the cable of the present invention incorporates a core, an outer jacket surrounding the core, and a tape disposed between the core and the outer jacket. The tape includes a first layer and superabsorbent polymers (SAPs) which are applied to the first layer. Preferably, the first layer is formed of spun bonded non-woven polyester material, nylon spun bonded fabric, non-woven glass, polypropylene melt blown non-woven fabric, polyurethane spun bonded fabric, or TCF cellulose fabric, among others. Additionally, the SAPs preferably are provided with a moisture content of greater than approximately 2 percent, by weight, thereby improving the flame-retarding characteristics of the tape.

Abstract: A system and method for translating a non-logic-family signal level into a logic-family signal level, the system comprising: a source of a non-logic-family signal that can assume a first and a second non-logic-family state; and a translator for determining whether the signal is in the first non-logic-family state, and if so, providing a translated signal having a first-logic family level. The translator can take the form of a comparator controlling an output transistor tied to a pull-up resistor, or a programmed processor. Examples of the logic-families include transistor-transistor logic (TTL) and complimentary metal oxide semiconductor (CMOS) logic. Examples of sources of non-logic-family signals includes a light emitting diode, a buzzer and a beeping device.

Abstract: An integrated laser/modulator (“ILM”) operating with reduced chirping is formed on a single semiconductor substrate. A reduction in chirping and any resultant wavelength dispersion is realized by precisely controlling the length of a window region incorporated in the ILM in order to isolate the ILM's active regions from any residual reflections.

Abstract: A feedforward linearizer includes a signal cancellation circuit and an error cancellation circuit. The signal cancellation circuit includes a tap delay line, that delay the input signal by a predetermined time delay so as to provide several delayed versions of the input signal. Each delayed version of the input signal is weighted by a tap coefficient. The weighted signals are then added together and fed to the power amplifier. The tap coefficients are derived such that the signals traveling through the upper and lower branch of the signal cancellation loop are aligned and that the output signal of the power amplifier is equalized.

Abstract: A door for an outdoor cabinet such as those used in telephony or CATV systems. The door has a first gasketed section to provide a first area of the cabinet with an airtight seal for protecting components housed therein from the outside environment. This first section of the door also includes a multi-point compression latch. The door has a second ungasketed section which ventilates gases around its unsealed perimeter from a second area of the cabinet housing batteries. This second section of the door includes a slam latch that is automatically engaged when the compression latch on the first door section is engaged.

Abstract: Various modem designs are described, along with systems that use the modem designs for communicating data between a large number of remote locations and one or more central locations preferably over CATV. One aspect features a modem having a transmitter which uses a state machine and digital waveform signals stored in a memory to create a modulated signal. Another aspect features a modem having a receiver which uses a digital correlator including an SRAM for detecting a bipolar phase shift keyed signal. Still another aspect features a modem comprising an oscillator circuit having a feedback loop, wherein the feedback loop utilizes a downlink signal, and a protection circuit which prevents a malfunction in the modem from causing system-wide shutdown.

Abstract: A multiplier contains an array of partial product generators, at least one new modified-Booth encoder. Corresponding to each new modified-Booth encoder, the partial product generator array includes a new adder cell. The partial product generator array receives inputs Y0 . . . YN with the Y0 receiving partial product generator being a new partial product generator for generating a partial product PP*(0,j). The new modified-Booth encoder receives multiplier bits and a multiplicand input Y0, and generates control signals and a carry in signal. The new adder cell is connected to the new modified-Booth encoder, the Y0 receiving new partial product generator and the (j−2) row Y2 receiving partial product generator and generates a partial product and an intermediate carry out signal so as to reduce the number of gate delay stages in the critical path of the multiplier.

Abstract: A method for efficiently updating as shared data structure in a multiprocessor environment comprises accessing a queue variable associated with time-based data events in the data structure. Information associated with the queue variable is used to determine the point of insertion of a new time-based data event. If a new time based data event is inserted, the data of the queue variable of a preceding time-based data event is altered to identify the new time-based data event. An embodiment employing a contention-free locking mechanism is also disclosed.

Abstract: A rate adaptive polling method sensitive to network congestion is used to monitor network resources. Initially, a baseline rate constraint is set based on desirable engineering factors. Unacknowledged polls are retransmitted with timeouts, successively increasing by a factor of 2. During each polling round, the rate is adapted in accordance with congestion feedback and changes in node status such as recently activated or deactivated nodes. Congestion feedback is estimated from a congestion metric computed as the average delay of all active nodes. Depending on the value of the congestion metric corresponding to polling round Rj, the minimum rate of polling for round Rj+1 is adapted accordingly.

Abstract: A clamp for holding at least one laser component during a facet coating process. The clamp includes a first elongate member for contacting a first side of the laser component(s) and a second elongate member for contacting a second side of the laser component(s). The clamp also includes a magnetic member overlying a third side of the laser component(s), and at least one magnet disposed adjacent to the magnetic member, so that the magnetic member is drawn towards the third side of the laser component(s). The first and second elongate members, the magnetic member and the at least one magnet hold the laser component(s) therebetween.

Abstract: A wavelength division multiplexed optical system utilizes a plurality of lasers each operating at a different wavelength. Each laser is directly modulated with independent data at an NRZ signal of a given bit rate frequency and their outputs are combined as a train of pulses in a single optical fiber in the WDM format. The train of pulses is passed through a Mach-Zehender modulator driven with a sine wave synchronized with the bit rate of the NRZ drive to the lasers.

Abstract: A test system in a communication system provides for a simulation of a test telephone call to a switching system under test. A test controller is integrated with the system under test for simulating the telephone call to the system under test. A high speed interface card with a processor is interfaced with the computer on the system under test through a computer bus interface for gathering call processing event data, A high speed interface communicates with the test controller to convey the simulated call processing event data to the controller computer.

Abstract: The specification describes a Mach-Zehnder electro-optic modulator device in which the ridge containing the waveguides in the interactive electro-optic regions have re-entrant sidewalls. This shifts the peak in the RF field profile to below the surface of the ridge and closer to the peak of the optical field, thereby producing a device with reduced drive voltage.