Abstract: An orthogonal code division multiple-access communications system comprised of a plurality of transceivers respectively employing orthogonal noise code mate pairs of a type having autocorrelation functions upon detection which when linearly added together compress into a lobeless impulse and wherein the same single time slot is utilized by all of the users in the system. Each user is assigned a different unique noise code pair consisting of code mate pairs that are selected from a subset of multiplexed noise codes whose cross-correlation function value is equal to zero at a time when all the code mate pairs compress to an impulse, i.e. τ=0. The described arrangement enables random access, or direct call-up, to be accomplished with no interference between the users while using different noise codes for each user.

Abstract: An MOS dynamic RAM organized in a byte-wide arrangement is described. An internal bus is used for multiplexed column address signals and data. Other multiplexing reduced the lines associated with the input/output circuits. A unique power-on circuit automatically resets clock generators if they are not operative after power is applied.

Abstract: Recently, emphasis has been placed on integrated communication facilities capable of handling both line-switching and packet-switch-ing digital traffic. The problem of dynamically allocating the bandwidth of a trunk to both types of traffic is formulated as a Markovian decision process. Line switching is modeled as a time division multiplexing loss scheme over a varying portion of a fixed time frame. Packet-switching traffic is served through the remaining portion of the frame and requires queueing at the multiplexer-concentrator. Two different cost criteria are examined involving probability of blocking for line switching and average queueing delay for packets. The corresponding optimization problems are presented under reasonable simplifying assumptions. The movable boundary scheme suggested for commercial implementation of integrated multi-plexers is shown to offer optimal or near-optimal performance.

Abstract: A seismic array containing a large number of seismic sensors, which may be optical hydrophones, has successive sections, each of which contains a subarray of sensor channels, interconnected by a fiber optic signal transmission line via telemetry modules. Synchronizing signals for initiating successive scans of the sensors in the array and timing the multiplexing of the channels are transmitted along the signal transmission line from the tail end of the line through telemetry modules to the head end. Equipment for receiving, demultiplexing and processing the seismic data is provided at the head end. The array may be towed as a seismic streamer and the head end equipment located topside on the towing vessel. The telemetry modules provide hybrid optical/electrical operation such that array sections including the optical hydrophones and fiber optic links are coupled to each other exclusively by electrical connectors. Submultiplexing of each subarray of sensors (hydrophones) is carried out by the telemetry module under control of scan synchronizing and timing signals so as to avoid the need for anti-aliasing filters and sample and hold circuits associated with the hydrophones in the array, while improving the signal to noise ratio of the seismic data signals derived from the array, in spite of shot or photon noise and also minimizing timing skew errors.

Abstract: The method allows voice and data information to be concentrated over a reduced number of telephone lines. It consists mainly in processing each voice signal to extract therefrom a so-called analog base band signal and digitally coded characteristic parameters. Said parameters are then multiplexed with pure data and submitted to a modulation operation. The analog signal resulting from the modulation is then added to the base band before being transmitted over a telephone line.

Abstract: The intrinsic low-dispersion and low-attenuation properties of single-mode fibers between 13 and 16 μm make them attractive for use in high-capacity, long-haul digital systems In this paper we discuss some fundamental performance limitations — such as attenuation, bandwidth, mode-partition noise, burst-type error, and receiver sensitivities — for systems with bit rates above 274 Mb/s Also, we discuss the maximum capacity achievable by either using a single channel at the minimum-dispersion wavelength, or multiple wavelength-multiplexed channels with equal, but necessarily lower, bit rates We conclude that the characteristics of present laser diodes limit repeater spacing to lengths far less than the potential capacity expected from single-mode fibers For total capacity of bit rates less than 1 Gb/s, wavelength multiplexing is found to offer longer repeater spacings than single-wavelength systems

Abstract: Since more advanced transmultiplexer concepts have to compete with elementary alternative solutions derived from simple back-to-back connections, they have to aim at high efficiency and robust performance, the latter meaning that they should be quite insensitive against disturbances inherent to the type of technology adopted. Three solutions satisfying these requirements are reviewed, one for a more conventional technology, one for digital technology, and one for switched-capacitor technology. The first one of these is based on the use of efficient conversion circuits operating primarily in the continuous-time analog domain and the second one on a multistep single-path multiplier-free conversion scheme of a type which is particularly suitable for employing wave digital filters, including branching filters of that type. The third one makes use of an alternative of the second one which does not involve branching filters.

Abstract: An invention is disclosed in which a fluidic counter generates fluidic switching signals in response to a fluidic oscillator for sequentially activating a plurality of fluidically activated electrical switches for multiplexing a plurality of electrical conductors into a single conductor.

Abstract: The time compression multiplexing (TCM) technique offers a solution to the problem of achieving digital penetration of the two-wire loop plant. TCM is planned to provide the digital loop transmission in the new circuit switched digital capability of the Bell System, so that a full-duplex 56 khit/s digital connection is obtained between subscriber's premises and the serving central office. Herein, the concept of TCM and its parameters are described. Tradeoffs leading to determination of system parameters such as burst frequency, burst length, guard time, and delay as they affect the range of the system are discussed. Also, the performance of the digital loops in terms of eye diagrams, system range limitations due to crosstalk and impulse noise, and percentage of loops covered are summarized. In addition, the circuit implementation using both analog and digital technologies is described. Experiences with various digital architectures to implement TCM and tradeoffs leading to a low-power digital architecture suitable for VLSI are discussed.

Abstract: A digital television receiver includes an analog-to-digital converter having a controllable scaling factor and offset. To improve resolution of the digital samples, the scaling factor is increased and the offset is changed when the synchronizing and color reference burst portions of the composite video signal are being converted. In addition, the scaling can be greatly increased at selected times so that the phase of the color reference burst can be more accurately determined.

Abstract: PURPOSE:To enable transmission of a digital signal in a CATV system, by transmitting with multiplexing the digital audio signals belonging at least to a channel and other digital signals in a transmission band equivalent to a channel of a TV. CONSTITUTION:Programs P1-P6 are supplied to input terminals 1-6 respectively, and analog audio signals given from input terminals 1-4 are converted into digital signals. While facsimile signals supplied from input terminals 5 and 6 are supplied to a multiplexer 13. The output signal of the multiplexer 13 is supplied to a quadruple level converting circuit 15 through a BTF14 and converted into a base band signal of a quadruple level. The output signal of the circuit 15 is supplied to an AM modulator 16, and the carrier supplied from an oscillator 17 is modulated by the output signal of the circuit 15. This modulated signal is supplied to a mixing circuit 19 through a residual side band wave filter 18 to be mixed with a signal of oscillating frequency f1 supplied from a local oscillating circuit 20. Then a signal of a frequency f1-fif is extracted at the output side of the circuit 20.

Abstract: Two new digital transmultiplexers intended for commercial use have been developed. One transmultiplexer performs a bilateral conversion between two 12-channel FDM group signals and a 24-channel PCM carrier signal. The other mutually connects two 60Channel FDM supergroup signals and five 24-channel or four 30channel PCM signals. Both exploit a block processing digital SSBFDM multiplex/demultiplex scheme employing a cascade of an FFT processor and a set of complex coefficient digital filters. They have been built using newly developed high-level DSP LSI chips. Algorithmic considerations, developed LSI architecture, and equipment configuration are described as well as digital processor design details and measured performance.

Abstract: The D4 channel bank is the most recent Western Electric product in an evolution of time-division multiplex terminals for digital transmission facilities. D4 incorporates many technical innovations relative to the earlier developed D1D, D2, and D3 channel banks but is fully compatible with these earlier banks. D4 banks may be operated in any of five different modes as required to connect to a particular digital carrier facility (T1, T1C, T2, or FT2). The D4 channel bank is partitioned into common equipment and channel units. The common equipment provides digital line interface, pulse code modulation coding and multiplexing, alarms, trunk processing power, power fusing, and distribution. Individual channel units provide the circuits that interface to external circuits. There are many different versions of channel units including standard interoffice voice-frequency trunk types and those supplying data and special services.

Abstract: The horizontal sync signal contained in the video signal from a video apparatus sometimes undergoes phase jump, resulting in failure of multiplexing of audio and video signals based on the horizontal sync signal. A sync signal switching circuit is adapted to produce a modified sync signal by switching the sync signal to a local sync signal upon occurrence of the phase jump, thereby assuring the multiplexing of audio and video signals.

Abstract: A transformation method is introduced for enabling filters of the extracted-pole variety to be match-multiplexed onto a manifold using standard waveguide multiplexer computer programs. Thus the advantages that accrue from the extracted-pole realization for filters may now be extended to multiplexers, which will be particularly useful in narrow-band high-power low-loss multiplexing applications. The measured performance of a 12-GHz contiguous-channel quadraplexer comprising TE/sub 011/ cavity extracted-pole elliptic filters is presented, demonstrating the very low insertion losses attainable with this form of realization. Since the majority of applications envisaged for this type of multiplexer is in high-power output circuitry, a discussion on thermal aspects is included.

Abstract: A concept for a digital customer access to an integrated services digital network (ISDN) is proposed. It is based on a passive bus which conveys information by means of two circuit switched B channels and a D channel to support associated signaling (outslot channel) dynamically multiplexed with slow speed packetized data and telemetry. The customer access can support multiple terminal arrangements with simultaneously active users. Information to be conveyed by the D channel is transferred in the form of messages, each associated with a logical link which has to coexist with other logical links on the common physical D channel. Access to that channel is regulated by level 1 arbitration with collision avoidance. It is possible to connect one X.25 DTE with minimum adaptation to the customer installation.

Abstract: The development and design of high power manifold type output multiplexer are described. The results obtained on Invar multiplexers with up to 450-W input power per channel are reported. The multiplexer are equipped with heat pipes in order to remove the heat generated in the filters.

Abstract: In a variable configuration multiplex transmission method, correct sending of data to their respective addressees (terminals 22, 24, 26 and/or 28) supposes that reception station (34) can determine which is the channel configuration from amongst configurations (A, B, C and/or D) that is active. This invention is adapted to proceed to such a channel determination by multiplexing a predetermined particular character from the active channels, directly transmitting over transmission channel (32) the multiplexed predetermined character burst, receiving (34) the multiplexed character burst, and using the received character burst in order to read a pre-registered table which directly gives out that channel configuration which has active channels.

Abstract: A statistical multiplexer employing split band encoding in which each port has associated with it a sub-bank of filters (110F-130F) and a sub-bank of quantizers (110Q-130Q). The common equipment assigns the coding resource across all the ports rather than only within a single port. This equipment includes a power level measurement device (170) which is separately responsive to the output of each of the filters and provides an input to a signalling control and multiplexing equipment (180) and to a bit allocation device (171) which provides a control signal to each of the quantizers providing to each of them a bit allocation out of the pool of bit capacity for the entire multiplexer.

Abstract: This paper describes various methods to compress the bandwidth of a National Television System Committee (NTSC) color TV signal. The methods are based on taking differences between adjacent or successive scan lines and then performing time companding on these differential signals. In the three specific methods outlined, a 4.2-MHz TV signal can be bandwidth-reduced to 3.34 MHz, 2.9 MHz, and 2.5 MHz, respectively, without loss of picture quality. When these techniques are used with time-compression multiplexing in satellite transmissions, high spectral efficiency can be obtained. Examples are shown where the transmission of two or three broadcast-quality TV's per 36-MHz transponder are possible with existing technology.

Abstract: In an optical transmission system in which a plurality of optical signal channels is multiplexed before transmission along a common optical path to a receiver, each channel is produced by means of a respective multimode injection laser, the overall cavity length of each laser being arranged to provide a multimode spectral output with a respective intermode spacing which differs from that provided by the other lasers for channel discrimination purposes. Comb filters are employed for demutliplexing.

Abstract: A novel approach to frequency multiplexing of images is presented. By modulating each image pixel at a different (temporal) frequency, the entire image can be transformed into an electrical signal utilizing a single detector. The electrical current of the detector is proportional to the spatial Fourier transform of the image, allowing one to perform spatial frequency manipulations in the time domain. The multiplexing is obtained by using a two-dimensional array of piezoelectric-elasto-optic modulators. By utilizing these effects one makes use of the mechanical resonance of the crystals simplifying the electrical signals needed for excitation. It is shown that a similar (or the same) modulator can be used for image reconstructions; i.e. performing the inverse Fourier transform. Preliminary results obtained with quartz crystals prove the feasibility of this approach.

Abstract: Measured data of a 5-Channel 11GHz Contiguous Band Multiplexer meeting INTELSAT VI requirements is presented. No compensating networks or dummy channels are used in the physical realization of the multiplexer, thus advancing the state-of-the-art.

Abstract: Display power consumption is calculated as a function of the physical display parameters for a five-voltage, line-at-a-time drive scheme. It is found that at high multiplexing levels the power varies as the product of the number of columns and the square of the number of rows, assuming that the rows are strobed. Typical power for a small 128 character display multiplexed at 1/28 duty cycle is expected to be 140 µW.

Abstract: A very small, high-quality, full-duplex 2.4 kbps channel vocoder based on the JSRU Belgard design has been implemented with commercially available integrated circuits. This fully digital realization is based on a distributed signal processing architecture employing six (6) Nippon Electric Company (N.E.C.) µPD7720 Signal Processing Interface (SPI) single chip microcomputers. Three of the µPD7720s implement a Belgard-type analysis filter bank by dividing the 19 channels into groups of 6, 6, and 7 channels. Similarly, a Belgard synthesizer including excitation generation is realized by two SPI's which process and combine the 10- and 9-channel subbands comprising the output speech. A one-chip implementation of the Gold pitch and voicing decision algorithm is achieved with the sixth µPD7720. An intel 8085-based 8-bit microcomputer is used for data transfer, control and multiplexing functions, and communications with the host terminal. Finally, the design features a compact analog subsystem based on a telecommunications industry LSI CODEC-with-filters chip. A total of 26 integrated circuits is required with a power dissipation of 11.5 watts and occupying about 70% of a 7" × 7" wirewrap board (excluding power supply). A very compact, full-duplex 2.4 kbps LPC vocoder has also been designed based on the same architecture as the channel vocoder but requires only three µPD7720s. A total of 16 integrated circuits are used in the LPC vocoder with a power dissipation of 8.6 watts, occupying one-half of a 7" × 7" wirewrap board.

Abstract: A sequencer control for controlling the time sequencing of the energization of controlled elements includes a microprocessor unit A large number of input lines and output lines are uniquely multiplexed into a relatively small number of I/O terminals on the microprocessor The multiplexing, the sequencing and all of the delays are effectively controlled by the microprocessor

Abstract: A novel method and system are disclosed for multiplex addressing of the electrochromic elements in a matrix array which substantially eliminates cross talk. The method comprises reverse addressing, i.e. supplying erase information to the off points of the matrix, while addressing the on points, i.e. providing write information to the points desired to be colored. The electrochromic elements are arranged in columns and rows to form the matrix and appropriately controlled drivers supply the desired write and erase voltages to the elements.

Abstract: A process for time-sequenced multiplexing of telephone data, PCM coded, on a transmission medium, and more specifically a process for multiplexing three 10-channel systems to form a standard 30-channel system, wherein: frames and multiframes are identical in structure for all 10-channel systems; each 10-channel frame contains 11 time intervals of the same length, the first of which contains auxiliary data, for synchronization, channel signalling, etc., and the last ten carrying information to be transmitted, coded by the pulse modulation and coding technique; each multiframe comprises the same number of frames as the 30-channel system; signalling and synchronization data is distributed among the first time intervals in the different frames, such distribution ensuring reliable synchronization and minimum delay, during the change from 10 to 30 channels and vice versa.