Abstract: An AC plasma panel display (100) is described with selective row and column shifting capability. The column conductors (C.sub.2, C.sub.4 . . . , C.sub.512) are common between a staging area (11) and an exhibiting area (12) while the other column conductors (C.sub.1, C.sub.3 . . . , C.sub.511) are terminated at the boundary between the two areas. The row shifting is accomplished in the staging area to enter display data on the panel. Column shifting is used between the two areas to transport display data onto the exhibiting area from the staging area. The modified display panel requires a minimum number of drivers and intrinsically isolates column and row shifting during operation.

Abstract: An interlock arrangement utilizes a modification of printing circuit boards (11 and 41) and spring loaded locking levers (23 and 24). One printed circuit board (11) includes notches or detents (25 and 26) in which the locking levers rest to prevent the removal of the board after being inserted into its connectors (13-15). In order to remove the board, another printed circuit board (41) is utilized which has tapered portions (42 and 43) that displace the locking pins from the detents in the process of being inserted into auxiliary connectors (44 and 46). Thus, the first board may be removed while the second board provides a predetermined circuitry status via the interconnection of the two sets of connectors.

Abstract: An errorless line protection switching system utilizes a variable delay (29) in the spare channel (21-24, 26-29, 31-33) adjusted to provide data signal alignment with an impaired regular channel before substituting the spare channel for the regular channel. This switching system is able to provide bit error free channel substitution between the spare and any regular channel in a digital radio system by virtue of the data signal alignment capability. Data signal alignment is provided by first aligning clocking signals in fine incremental steps with each clocking signal derived from one of the two channels undergoing the substitution. Data signal alignment is then provided by shifting the spare channel in full bit positions until data alignment is indicated by a detector (119). Data signal alignment is also utilized to restore service to a regular channel so the spare channel may be removed from service.

Abstract: Various implementations of a technique are presented for capitalizing on signal correlation in a manner for providing usable frequency information. In a specific embodiment, a filter (51) is adapted to a signal component of an input signal using a variable generated by an adapter 58. The variable has a prescribed relationship to the frequency of the signal component. The variable is used to weight a combination of signal values derived from past signal history to form a prediction of a future signal. An adder 56 combines the new signal value with the prediction to form an error signal which is used by the filter (51) and the adapter (58). When the filter converges, a frequency indicator (59) using the variable provides an output signal indicative of the frequency of the signal component.

Abstract: An errorless line protection switching system utilizes a variable delay (29) in the spare channel (21-24, 26-29, 31-33) adjusted to provide data signal alignment with an impaired regular channel before substituting the spare channel for the regular channel. This switching system is able to provide bit error free channel substitution between the spare and any regular channel in a digital radio system by virtue of the data signal alignment capability. Data signal alignment is provided by first aligning clocking signals in fine incremental steps with each clocking signal derived from one of the two channels undergoing the substitution. Data signal alignment is then provided by shifting the spare channel in full bit positions until data alignment is indicated by a detector (119). Data signal alignment is also utilized to restore service to a regular channel so the spare channel may be removed from service.

Abstract: A speech detector uses a signal classifier (19) to identify portions of a representation of the average magnitude of a group of signal samples indicative of either speech or noise. A controller (33) in the signal classifier follows a four state sequence using appropriate time constants for signal measures in a variety of signal conditions in defining the speech and noise portions of the representation. A level estimator (21) uses selectively obtained signal measures from the defined portions of the representation to provide adaptively variable decision levels. A speech definer (16) compares the representation to a first decision level and the signal samples to a higher decision level to indicate the occurrence of speech signal activity when either decision level is exceeded. In a two way transmission arrangement, a receive trunk speech detector uses a stretcher (133) to prevent adaptation of the transmit speech detector thresholds when echo signals are present.

Abstract: A frequency multiplier which employs a step recovery diode operated in a double pulse mode for each period of the cycle of the input frequency signal provides efficient and high order harmonic generation. The bias circuitry for the diode and impedance characteristics of the input and output bandpass filters are selected to provide stable operation.

Abstract: Bandstop (FIGS. 1-3) and bandpass (FIGS. 4, 5) filters are presented utilizing broad and narrow wall resonator coupling in a rectangular waveguide (11 and 37) at a common cross sectional reference plane. For the bandstop filter, the resonators (12, 13) are resonant at a common frequency f.sub.0 to provide a two-pole bandstop response in a filter of minimal longitudinal dimensions. For the compact bandpass filter, each tone rejection is provided by a pair of resonators (31, 35) coupling to the electromagnetic field signal at two points one from a broad wall and the other from a narrow wall of the waveguide (37) but displaced by some multiple of a half wavelength. Another pair of resonators (33, 34) are in common cross sectional plane relationship to the first pair but located on a wall of different width to provide rejection of a tone at the other end of the passband. The use of resonators with different resonant frequencies at a common cross sectional plane avoids possible interresonator coupling.

Abstract: An adaptive phase-jitter compensator, which is frequency selective, is disclosed for use in data receivers. The filter section (28) of the adaptive compensator receives a derived phase error signal and its own weighted sum output to provide the difference between them as selective noisy estimates of the actual phase via taps of a delay line (52-1 to 52-L). A multiplier (57) accepts each tap signal and the phase error to form a product used to update the coefficients or tap weights used in the filter section. An upmodulator (29) impresses the weighted sum output on a carrier signal whose output is used by a lookup table (31) to form components to be compatible with the received data signal. A complex multiplier, (23), multiplies the components and the data signal which has been previously split into components and equalized, to provide both demodulation and phase-jitter compensation.

Abstract: A speech detector uses a signal classifier (19) to identify portions of a representation of the average magnitude of a group of signal samples indicative of either speech or noise. A controller (33) in the signal classifier follows a four state sequence using appropriate time constants for signal measures in a variety of signal conditions in defining the speech and noise portions of the representation. A level estimator (21) uses selectively obtained signal measures from the defined portions of the representation to provide adaptively variable decision levels. A speech definer (16) compares the representation to a first decision level and the signal samples to a higher decision level to indicate the occurrence of speech signal activity when either decision level is exceeded. In a two way transmission arrangement, a receive trunk speech detector uses a stretcher (133) to prevent adaptation of the transmit speech detector thresholds when echo signals are present.

Abstract: A shift-keyed modulator utilizes a lookup table (41) to provide a binary sequence of digits one at a time. Since the binary digits are selected so that their accumulation represents the amplitudes of a series of points on a theoretical sinusoidal wave, a low-pass filter (51) acting as an integrator is able to provide a sinusoidal wave signal. Furthermore, the low-pass filter includes gates that operate in push-pull fashion to form a balanced configuration for cancelling even ordered harmonic distortion. The modulator has a rate multiplier (11) responsive to space/mark signaling for controlling the rate the the binary digits are produced by the lookup table. A second group of binary digits is stored in the lookup table and is read out concurrently with the first sequence. Alternate pairs of gates (52 and 53 or 54 and 55) are enabled in the low-pass filter to provide binary data signals for either of the frequency bands used in duplex data signaling circuits.

Abstract: An associative information retrieval system accepts information from a user and generates a query mask utilizing nested superimposed code words to search through and to find partial matches with the content of an auxiliary store. The auxiliary store contains similarly generated code words each produced from attribute values of records on a central store. The user information is put through the system on a character-by-character basis and the user is fed back information on the number of possible matches. The feedback informs the user on the incremental progress of the search produced in response to each newly entered character and also as part of a sequence that it may form with previously entered characters. The feedback information helps the user direct the search which the person does by supplying additional characters.

Abstract: A quadrature amplitude-modulated (QAM) data signal receiver employs a phase compensation arrangement (16, 31, 33) before the equalizer (17). The arrangement utilizes the assumption that the frequency components typically present in the phase perturbance are power-line related. This enables an effective phase compensator to be of relatively low complexity compared to the equalizer (17). Since the compensator is "pretuned", only the phase and amplitude of the frequency components need be adaptively found. This makes for a relatively stable arrangement with a suitable convergence rate. In an alternative arrangement, a phase compensator (216, 233, 240) is provided for use after the equalizer (217).

Abstract: A dual position mount is disclosed for mobile radio telephone sets. The base (11) of the mount is hollow and has an access port (28). The interior position (29) of the base serves as a secure receptacle for the mobile radio control unit when it is not being used. A lock (31) prevents removal of the control unit. For operation, the control unit is mounted on a connector plate (19) which is supported by means of an adjustable mechanical coupling (16 and 17) while a conductor (41) is fed through the center of the coupling to complete the circuitry between the control unit and the remaining portions of the mobile radio.

Abstract: In a disconnectable low-loss optical connector for optical fiber light guides, the fiber is precisely located in the body of the connector form in a molding die cavity. The portion of the cavity that forms the mating surface of the molded connector body corresponds to a frustum of a cone whose axis is a reference point for determining the exact location of the fiber. The fiber is placed in a sleeve-like member to form a subassembly around which the connector body is molded. One end of the member has a port located in the tip of the frustum of the molding cavity and aids in the precise formation of the mating surface. When the molding cavity is filled to form the molded connector body, gas pockets which form and produce voids in the molding material are accepted in a flow of filler material and prevented from interfering with the formation of the mating surface. The fiber which protrudes out of the tip of the mating surface is then cut and polished to form the junction end.

Abstract: A telephone station set has subscriber-interface elements associated with rotatable panel (11). Rotatable panel (11) is adapted to serve as a sunshade visor in an automobile. In panel (11), exterior cavity (14) readily accommodates handset (16) in either of two hangup positions. Handset (16) is compact and nonsymmetrical while the interior of cavity (14) completely contains the handset in either of the hangup positions. This arrangement provides the convenience of one handed operation by either hand of an operator. Coiled handset cord (27) emerges from a centrally located port (28) to provide the electrical connection compatible with this convenient operation.

Abstract: A versatile loop communication system is disclosed wherein recurring frames of the ring carrier signal are divided by a movable partition into a dynamically allocated time division channel portion and a data packet communication portion. A common signal channel, in the ring carrier frame, is used to logically connect and disconnect stations for either circuit or packet communication on a common bus extending from terminals located in the loop. The loop controller automatically forms a contiguous group of time division channels or signal bytes at one end of the ring carrier frame. The format of the time division multiplexing channels is such that dynamic time slot interchanges of signal bytes are produced by the controller without the necessity of counting circuitry in the terminals to identify specific channel locations.

Abstract: The luminance and two chrominance signals generated in a color video system are all translated into pulse code modulation signals by a plurality of analog-to-digital encoders. The luminance signal is then differentially encoded into variable length digital words and applied to a buffer. The encoded differences of the luminance signal are between the values of successive picture elements along horizontal scan lines. At least one of the chrominance signals is encoded using differences between corresponding picture element values in alternate horizontal scan lines. When the differences are large, the value of the corresponding picture element of the intermediate horizontal scan line is classified. If half the difference between the large transition of alternate picture element values does not correspond to the value of the intermediate picture element, another code word indicative of both intermediate picture element and alternate picture element is used.

Abstract: An improved noise loading arrangement and method are disclosed capable of measuring low intensity intermodulation distortion products, such as introduced in the operation of individual wideband transmission repeaters. The improved arrangement and method also have the further capability of resolving individual orders of distortion products. The arrangement utilizes a noise signal generator that produces a pseudorandom signal made of several spectral components providing high spectral density throughout a large bandwidth to simulate a broadband message load obtained by frequency multiplexing several independent signal sources. The noise signal is shifted in frequency before a quiet band is produced in the signal applied to the transmission apparatus to be tested. The orders of intermodulation distortion products appearing in the quiet band of the output signal of the transmission apparatus are individually measured to evaluate same.

Abstract: This invention pertains to a method and arrangements that provide automatic detection of sequences of signals which previously required listening by operators in telephone systems to identify them. In a telephone system, certain information is transmitted using preselected signal sequences of tone bursts and silent intervals. These signal sequences are subjected to interference by speech and noise occurring in the telephone system. An arrangement is disclosed which reliably recognizes and identifies these signal sequences notwithstanding the apparent modification thereof due to the interference. In the process of recognizing these signal sequences, a three-stage recognition test is utilized to classify the durations of tone bursts and silent intervals in the signal sequences that occur. The validity of the signal sequence is checked by detecting inconsistent durations within the sequences. This feature is also utilized to indicate faulty apparatus used to generate these signal sequences.