Abstract: A common pressure vessel type Ni--H.sub.2 storage battery having an outer pressure vessel that contains a stack of compartments. Each of the compartments including at least one battery cell, a heat transfer member, and a cell spacer for maintaining a relatively constant distance between adjacent compartments. The heat transfer members include a fin portion, which is in thermal contact with the battery cell, and a flange portion which extends longitudinally from the fin portion and is in tight thermal contact with the inner wall of the pressure vessel. The heat transfer member serves to transfer heat generated from a battery cell radially outward to the pressure vessel, which is capable of dissipating the heat into the surrounding atmosphere.

Abstract: A coding technique for high-definition television signals involves splitting the luminance signal into four sub-bands using a sub-band encoder and separately encoding each sub-band using a simplified vector quantization technique. The characteristics of each respective simplified vector quantization encoder can be matched to the characteristics of the respective sub-bands.

Abstract: An intercell connector for electrically interconnecting a plurality of battery cells, each of the battery cells including a plurality of spaced apart positive and negative electrode plates encased in a plastic casing. The intercell connector includes first and second buss bars disposed in spaced apart relation to each other and each including a base portion and an electrode connecting portion extending from the base portion, the base portions of the first and second buss bars respectively including first and second electrode terminals aligned with each other; and an insulator for insulating the first and second buss bars from each other. The connector is disposed in the casing of each of the cells so as to extend transversely to the electrode plates with the casing being bonded to a portion of the insulator such that only the electrode terminals are exposed outside the casing.

Abstract: A speech codec operating at low data rates uses an iterative method to jointly optimize pitch and gain parameter sets. A 26-bit spectrum filter coding scheme may be used, involving successive subtractions and quantizations. The codec may preferably use a decomposed multipulse excitation model, wherein the multipulse vectors used as the excitation signal are decomposed into position and amplitude codewords. Multipulse vectors are coded by comparing each vector to a reference multipulse vector and quantizing the resulting difference vector. An expanded multipulse excitation codebook and associated fast search method, optionally with a dynamically-weighted distortion measure, allow selection of the best excitation vector without memory or computational overload. In a dynamic bit allocation technique, the number of bits allocated to the pitch and excitation signals depend on whether the signals are "significant" or "insignificant".

Abstract: The correct sampling timing phase is obtained by a digital data receiver by averaging samples of the preamble of a received data burst and using the computed averages as addresses to a memory which stores correction values for the timing phase. The output of the memory is sent to a phase correction circuit for correcting the phase of the presently received data burst.

Abstract: A linear predictive speech codec arrangement including: a spectrum synthesizer for providing reconstructed speech generation in response to excitation signals; a distortion analyzer for comparing the reconstructed speech with an original speech, and providing a distortion analysis signal in response to such comparison; and an excitation model circuit for providing excitation signals to the spectrum synthesizer, with the excitation model circuit receiving and utilizing the distortion analysis signal in an analysis-by-synthesis operation, for determining ones of excitation signals which provide an optimal reconstructed speech. The excitation model circuit can include: a voiced excitation generator and a Gaussian noise generator, both of which should optimally provide a plurality of available excitation signal models.

Abstract: A compression and decompression system for transmitting facsimile images in which the facsimile image is compressed in a vertical and a horizontal direction. The compressed facsimile image is decompressed by selecting a reference bit in the decompressed facsimile image and expanding the bit in a vertical and a horizontal direction in accordance with a binary value of bits near the selected reference bit.

Abstract: A compound time-multiplexed video transmission processing system transmitting and receiving a signal corresponding to luminance signal for driving a video display includes a transmit processor for processing a received luminance signal to produce a time-multiplexed mixed field signal based on a high frequency signal corresponding to a high frequency portion of the input luminance signal received during a previous field and a half bandwidth signal received during a current field, and a receive processor for processing the mixed field signal to produce an output luminance signal based on the high frequency portion and the half bandwidth signal. The transmit processor includes circuitry for storing the high frequency portion of the input luminance signal from the previous field. The system produces an artifact in the mixed field signal, which is evenly distributed in the output luminance signal in a predetermined processing sequence. A method for processing luminance signals is also disclosed.

Abstract: A low-bit-rate, low-cost, all-digital preambleless demodulator for maritime and mobile data communications operates under severe high noise conditions, fast Doppler frequency shifts, large frequency offsets, and multipath fading. Sophisticated algorithms, including an FFT-based burst acquisition system, a cycle-slip resistant carrier phase tracker, an innovative Doppler tracker, and a fast acquisition symbol synchronizer, provide reliable burst reception. The compact DSP-based demodulator includes an input buffer receiving a complex sampled baseband input signal and providing a baseband output to a coarse frequency estimator fast Fourier transform (FFT) or discrete Fourier transform (DFT) module which produces a first estimation of the carrier frequency. A fine frequency estimator FFT or DFT module receives the first estimation and provides a second estimation of the carrier frequency. An extra coarse frequency estimator FFT or DFT module may be provided between the buffer and the coarse frequency estimator.

Abstract: The present invention is directed to reducing the number of components required to minimize intermodulation distortion within the wide transmission frequency band used by a satellite communications repeater system. In particular, at least two TM.sub.010 mode cavity is cascaded to a plurality of TE.sub.113 mode cavities to form a narrow band-pass, wide band-stop filter for receiving and outputting channel signals to the multiplexer manifold of a satellite repeater. The filter thus constructed realizes the narrow band-pass response required in microwave communications, while eliminating the spurious resonance frequencies normally eliminated by additional filter components. In this manner, the size and weight considerations of the satellite system are improved without loss in performance.

Abstract: A low-rate encoding/digital speech interpolation (LRE/DSI) system architecture is organized to eliminate the LRE mistracking problem normally associated with DSI-induced speech clipping, to reduce the number of LRE codes required and to provide a mechanism for gradually introducing overload.

Abstract: A "modified rearrangeable" switch matrix combines both .beta. switching elements and crossbar switch matrices in a single switch configuration, with .beta. switching elements used at the input and output and at least one crossbar switch matrix in the middle to receive its inputs from .beta. switching elements and provide its outputs to .beta. switching elements.

Abstract: Predetection noise bandwidth reduction is effected by a pre-averager capable of digitally averaging the samples of an input data signal over two or more symbols, the averaging interval being defined by the input sampling rate divided by the output sampling rate. As the averaged sample is clocked to a suitable detector at a much slower rate than the input signal sampling rate the noise bandwidth at the input to the detector is reduced, the input to the detector having an improved signal to noise ratio as a result of the averaging process, and the rate at which such subsequent processing must operate is correspondingly reduced. The pre-averager forms a data filter having an output sampling rate of one sample per symbol of received data. More specifically, selected ones of a plurality of samples accumulated over two or more symbol intervals are output in response to clock signals at a rate of one sample per symbol interval.

Abstract: An apparatus for obtaining carrier synchronization acquisition in a digital burst mode communication system is provided. An accurate estimate of the carrier phase of the unmodulated preamble, .theta., is obtained by determining which of 256 intervals X.sub.o.sup.2 +X.sub.e.sup.2 fall into, and by evaluating which of 256 intervals Y.sub.o.sup.2 +Y.sub.e.sup.2 fall into. A quantized value is assigned to the generated output code for both X and Y inputs. The square root and arc tangent are evaluated to determine the value .theta..

Abstract: A residual signal quantization technique used in the adaptive predictive coding of speech signals is based in the frequency domain. In predictive coders, a residual signal that results after redundancies are removed from the input signal using linear prediction techniques is quantized. The technique invented involves a transformation of the residual signal to the frequency domain and a quantization of the frequency domain coefficients. Further, the number of bits used to quantize each frequency coefficient is determined by an estimate of the power of the input signal at that frequency. Once the number of bits to be used for quantization is determined, the quantization noise power spectrum is shaped, and can be selectively shaped so as to form a desired reconstruction noise power distribution.

Abstract: A planar doped valley field effect transistor (PDVFET), which positions more than one two-dimensional electron gas (2DEG) layer within a homo-structure (GaAs), in order to improve the FET's power output. The FET includes two 2DEG donor planes with an undoped GaAs layer therebetween, and a n-doped GaAs layer on the other side of each donor plane. The FET also includes a 2DEG acceptor plane below the n-doped GaAs layer, which is furthest from the contacts. This 2DEG plane combination forms a deep and wide valley in the FET's conduction band, which improves the FET's power output.

Abstract: Electrical devices are characterized by optically triggering an electrical signal onto the device and then optically sampling the electrical signal waveform on the device.

Abstract: A carrier frequency lock detection circuit receives a baseband signal from a tuning control loop of a receiver. The baseband signal is sent to a comb-filter network which has a plurality of bandpass filters, each receiving a specific sideband frequency. The output power of each filter of the comb-filter network is added up by an adder, filtered by a multiple low-pass filter to reject noise components, and finally converted to a voltage. The thus converted voltage is compared to a preset threshold voltage in order to determine whether the carrier signal has passed through one of the filters of the comb-filter network intended for a sideband, thus indicating that the tuning control loop of the receiver is locked onto a sideband frequency. If such a situation exists, a break-lock indication is sent to the receiver.

Abstract: A compact multi-layer flat antenna structure incorporating a low noise block down-converter on the power divider network layer of the antenna. RF circuit losses are reduced, and the antenna/receiver combination is made more compact, for flush mounting. The antenna/receiver combination finds particular utility in direct broadcast satellite (DBS) applications for single or dual orthogonal polarizations. The connection between the antenna and receiver may be implemented in stripline/coplanar waveguide, or other known technologies such as microstrip, slotline, and finline.

Abstract: A pay television subscriber pays for viewing credits which are transmitted to the subscriber equipment from a central office. Each program is associated with a pulse having a rate corresponding to the charge per unit time for that program, and the viewing credits are debited appropriately.