Abstract: An RF amplifier for a phase and envelope varying signal employs a class C operated device for high efficiency. In order to improve the linearity of the class C operated device, a signal corresponding to the envelope of the amplifier output is formed and a portion thereof is fed back to an envelope modulation element such as a pulse width modulator connected to the class C operated device to reduce distortion at the amplifier output.

Abstract: A feed forward circuit receives an input signal having at least one carrier therein in a prescribed frequency range. The input signal is applied to a first circuit path having a power amplifier that produces an output signal with a distortion component and to a second circuit path that delays the input signal without distortion. The output signal of the first circuit path is combined with the output signal of the second circuit path to form a signal representative of the distortion component of the first circuit path output signal and the distortion component representative signal is subtracted from the output signal of the first circuit path to cancel the distortion component therein. The prescribed frequency range of the first circuit path output is scanned to detect a carrier signal and the amplitude and phase of the signal in the first circuit path is modified to minimize the magnitude of the detected carrier in the distortion representative signal.

Abstract: A QDPSK communication receiver includes a frequency source, apparatus for translating a received QDPSK signal having inphase I and quadrature phase Q components to baseband and a baseband demodulator. For each symbol period of the baseband QDPSK signal, a signal (I.sub.diff) representative of the inphase component of the phase different between immediately successive received symbols and signal (Q.sub.diff) representative of quadrature phase component of the phase difference between immediately successive received symbols is formed. In order to synchronize the frequency of the receiver frequency source to carried frequency of the received QDPSK signal, a preamble interval is defined during which a sequence of identified symbols is received.

Abstract: A distortion compensation circuit for power amplifier producing a prescribed distortion component receives an input signal having at least one carrier therein in a prescribed frequency range. The input signal is applied to a first circuit path having an amplifier that produces an amplified signal with the prescribed distortion component and to a second circuit path that delays the input signal without distortion. The output signals of the first and second circuit paths are combined in a first combiner to form a signal representative of the prescribed distortion component. A second combiner forms a signal having an amplified input signal component and inverted phase prescribed distortion component responsive to the output of the first combiner and the output the first circuit path.

Abstract: An automatic gain control circuit for an amplifier operating over a prescribed frequency range detects the output level of the amplifier; and couples a repeated predetermined waveform occurring at a rate greater than the reciprocal of twice the upper frequency of the prescribed frequency range to the output level signal. The waveform varying level signal is compared to a reference threshold to control the gain of the amplifier through a switched resistive elemement in the amplifier feedback path. The repeated waveform variations about the amplifier output level causes the value of the switched resistance to vary as a function of the output level. A low pass filter connected to the amplifier output removes switching transients resulting from the high frequency changes in the switched resistive element. The gains of a plurality of amplifiers may be determined by a common control for accurate tracking over a wide dynamic range.

Abstract: An opto-electronic organizer on a printed wiring card includes a plurality of opto-electronic devices each having electrical leads and at least one optical fiber extending therefrom and an optical fiber channel in the form of a closed loop for directing optical fibers. The opto-electronic devices are attached to the optical fiber closed loop channel at predetermined locations therealong and the optical fibers extending from the devices are directed into the closed loop channel wherein they are selectively interconnected. The closed loop channel has first and second portions and at least one channel joining the first and second portions so that optical fiber passing therethrough can reenter the closed loop either clockwise or counterclockwise. The organizer is affixed to the printed circuit card in predetermined alignment whereby the electrical leads extending from the opto-electronic devices are connected to prescribed electrical elements on the printed circuit card.

Abstract: A speech analyzer is adapted to produce speech parameter signals from a Pth order autocorrelation analysis of a speech pattern in a digital signal processor. The analyzer includes a plurality of memories of predetermined arrangement to store feature vector signals used in the analysis, a single set of coded signals for controlling the analysis, and a memory address processor for addressing the feature vector signal memories. In each iteration of the analysis, at least one speech parameter signal is produced by the digital signal processor responsive to the same set of control signals and the feature vector memory addressing signals.

Abstract: An arrangement for modifying an information carrying radiant energy beam array in which occurrences of a first prescribed pattern of radiant energy beams in the array are detected by producing images of said beam array and shifting the images relative to each other responsive to a first prescribed pattern. The shifted images are superimposed and a radiant energy beam array is formed that identifies the occurrences of first prescribed patterns in the superimposed images. A plurality of images of the identifying beam array are produced and shifted relative to each other in accordance with a second prescribed pattern. The shifted images of said occurrence identifying beam array are superimposed to form the modified beam array. The modifications may comprise arithmetic processing, pattern or image processing or Turing machine type processing.

Abstract: An optical fiber organizer and splicing arrangement permits storage of variable lengths of surplus fiber. The organizer has a pair of separated cylinders extending from a first rectangular section of a base plate and a splice tray having opposite entrance sides for optical fiber in a second rectangular section. Each cylinder has a prescribed height permitting wrapping of multiple loops of fiber around the cylinder circumference and a diameter determined by the fiber bend radius restriction. The splicing tray is spaced from the base plate to permit passage of optical fiber underneath the splicing tray. The surplus fiber is directed around one or both cylinders and underneath the splicing tray through a plurality of different length passageways so that the varying lengths of optical fiber are stored. Clockwise, counter clockwise and figure eight loops are used so that each optical fiber end is directed to predetermined entrance side of the splicing tray without exceeding the fiber bend radius restriction.

Abstract: A skew compensation circuit removes skew between a data stream and the clock of a processing module to which the data stream clocked at the same frequency is applied. A delayed data stream is generated. Either the data stream or the delayed data stream is selected to be clocked in the processing module. The selected data stream and a delayed version of the selected data stream are compared at prescribed transitions of the processing module clock to detect differences between the state of the selected data stream signal at the clock transition and the state of the delayed selected data signal. In the event of a detected difference in states, the other of the input data stream and the delayed data stream is selected for clocking in the processing module.

Abstract: An arrangement for processing a speech message which uses arbitrary value codes to form time frame excitation signals. The arbitrary value codes, e.g., random numbers, are stored as well as signals indexing the codes and transform domain signals corresponding to the arbitrary codes are generated. The speech message is partitioned into time frame interval speech patterns and a first signal representative of the transform domain speech pattern of each successive time frame interval is formed responsive to the partitioned speech message. A plurality of second signals representative of time frame interval patterns corresponding to the transform code signals are generated responsive to said set of transform signals. One of the arbitrary code signals is selected jointly responsive to the first and second signals of each successive time interval to represent the time frame speech signal excitation, and the index signal corresponding to said selected arbitrary code signal is output.

Abstract: Splices between conductors in of an aerial telephone cable are covered by a closure located within a terminal. The closure has a large central section connected via tapered joints to two end sections. A settable liquid encapsulant is received in the central section. The closure has two halves joined by a flexible hinge that runs lengthwise along a first longitudinal edge. Two rigid tabs of nonuniform thickness running lengthwise along a second longitudinal edge are secured by snaps through apertures in the tabs. The snaps have tapered sections that clamp the varying thickness rigid tabs along their lengths to prevent leakage of liquid encapsulant. The end sections have open cell foam strips fitting snugly between the cable and the end section walls which are fixed with the liquid encapsulant. The encapsulant sets within the open cell foam to form a barrier to passage of contaminants into the central section.

Abstract: A sound processing arrangement couples sound from a prescribed environment through a fixed microphone array to a signal processing arrangement having a specifiable preferred sound source location. The microphone pickup signals are combined with a set of weighting signals to adjust the directional response pattern in successive analysis time intervals. The weighting signals are modified in each analysis time interval so that the total acoustic signal power of the signal processing arrangement output signal is decreased toward a minimum while substantially unity power transfer of sound signals from said preferred location is maintained at all frequencies over a prescribed frequency range. In this way, the preferred source location is in the main beam while unwanted sound source locations are at the null points of the adjusted directional response pattern.

Abstract: In a speech signal recognition system, signals are data-reduced by eliminating highly-transient intervals: each successive time frame is temporarily identified as an anchor frame and compared to m preceding and m succeeding frames, whereby defined uniform time intervals of 2m+1 frames having a prescribed similarity are retained, and highly-transient 2m+1 intervals are discarded.

Abstract: Operation of a decision feedback equalizer is enhanced by measuring the intersymbol interference precursor effect on each symbol decision output and utilizing that measurement information to update equalizer, transversal filter, tap multiplier coefficients in a direction to reduce the precursor and postcursor effects. In one embodiment, the updated coefficient information is further utilized to adjust equalizer input signal sampling phase toward a time of maximum data signal eye opening.

Abstract: A speech recognizer identifies an unknown utterance as a variable length string of stored reference patterns in a single pass through the time frame sequence of utterance feature signals. A plurality of reference pattern levels are used to permit strings of varying lengths. As each utterance time frame portion is received, its acoustic feature signals are time registered with the reference pattern feature signals at each reference pattern level to form reference pattern endframe registration path and registration path correspondence signals. Responsive to the plurality of level reference pattern end frame registration path signals, reference pattern strings are selected for the current utterance frame. The utterance is identified as the selected reference string with the best correspondence to the utterance from the registration path signals of the reference levels of the last utterance time frame.

Abstract: A radiant energy logic element includes first and second reflecting devices and a radiant energy nonlinear medium between said first and second reflecting devices and in contact therewith. Radiant energy beams of first and second wavelengths are applied to the reflecting devices. The first reflecting device is transmissive at said second radiant energy beam wavelength and reflective at said first radiant energy beam wavelength, and said second reflecting device is reflective at said first and second radiant energy beam wavelengths. The nonlinear medium of the logic element is responsive to radiant energy beams applied to the first reflecting device but insensitive to radiant energy beams applied to the second reflecting device.

Abstract: There are disclosed speech encoding methods and arrangements, including among others a speech synthesizer that reproduces speech from the encoded speech signals. These methods and arrangements employ a reduced bandwidth encoding of speech for which the bandwidth more nearly than in prior arrangements approaches that of the rate of occurrences of the individual sounds (equivalently, the articulatory movements) of the speech by locating the centroid of the individual sound, for example, by employing the zero crossing of a single (v(L)) representing the timing of individual sounds, which is derived from a .phi. signal which is itself produced from prescribed linear combination of acoustic feature signals, such as log area parameter signals. Each individual sound is encoded at a rate corresponding to its bandwidth. Accuracy is ensured by generating each individual sound signal from the linear combinations of acoustic feature signals for many times frames including the time frame of the centroid.

Abstract: Wideband digital signals, such as video program signals, are distributed to multiple customer locations by providing the wideband digital signals to all customer line interface units in an intermediate selection terminal which is remote from a central wideband signal distribution office. The individual signals are made available to all line interface circuits by way of nonreflectively terminated transmission lines and high-input-impedance signal tapping circuits. Control signals from customer terminals are used at the corresponding line interface circuit to control digital selection of channels for customer use, any number of customers being able to select simultaneously a common one of said transmission lines. Other control signals from the central office are used to limit customer access to all wideband signals.

Abstract: Partial response signal processing is applied to samples of an analog signal quantized in an amplitude range having a sufficient number of levels that a sample amplitude error of a small percentage of the total levels of the range is not readily perceptible to the human auditory function and that it exhibits tolerable quantizing noise. Samples received into the processing in a transmitting station are sample masked for privacy enciphering. Complementary processing is employed for a receiving station.