Matches 201 - 250 out of 257 < 1 2 3 4 5 6 >
Match Document Document Title
4220816 Digital duplex transmission system  
A digital duplex transmission system for use in a local area uses a modified dipulse code from the exchange terminal to the subscriber terminal and either a different modified dipulse code or a...
4217467 Amplitude and periodic phase modulation transmission system  
A carrier is amplitude modulated in an amplitude modulator by a train of unipolar signals which alternately assume a definite voltage level and an arbitrary amplitude of one polarity. Either the...
4217572 Arrangements for transmitting electrical signals between two devices which are connected by contacts  
A system for transmitting digital signals between a fixed transmitter and a portable receiver which are temporarily interconnected by physical contacts which employs a single pair of contacts and a...
4206320 High speed modem suitable for operating with a switched network  
A modem capable of achieving essentially 9600 bit per second information transfer rate through the switched telephone network. The high bit rate is achieved notwithstanding the variations in the...
4184052 AM/FM time division surface wave device transmitter  
A device for sample modulating electronic information signals which includes mixing circuitry having a first input coupled to receive information signals, a second input for receiving electrical...
4087677 Digital PSK modem  
In the transmitter portion a multiplexer multiplexes first digital data and first teletype signals to provide first digital data signals. The first digital data signals are converted into second...
4079203 Method and apparatus for transmitting auxiliary channel over digital communications system  
An auxiliary channel, for example, an engineering orderwire, is derived on n existing time-division multiplex carrier system by modulating the pulse repetition rate of the digital bitstream. The...
4075429 Transmultiplexer  
A transmultiplexer, in which after a pulse code modulated, time division multiplex signal of the voice band signal is converted into an analog signal, the analog signal is separated by filters into...
4070550 Quantized pulse modulated nonsynchronous clipped speech multi-channel coded communication system  
1. A quantized pulse-modulated nonsynchronous clipped speech multi-channel oded communication system comprising transmitter terminals and receiver terminals; said transmitter terminals comprising a...
4041392 System for simultaneous transmission of several pulse trains  
A main pulse train at a main frequency and at least two derived pulse tra at submultiples of the main frequency are transmitted over a transmission path, from a transmitter to a receiver, in the...
3908114 Digital Hilbert transformation system  
A multiplex mechanization of a Hilbert transformation system is disclosed wherein, in a preferred embodiment, digital sine and cosine signal samples from a reference generator are selectively...
3887873 Pulse amplitude modulation, frequency modulation telemetric data transmitter  
A data signal telemetry system having a pulse amplitude modulation subsys, a video doppler subsystem, and a switchable external and internal power subsystem coupled and coacting to produce a...
3873771 SIMULTANEOUS TRANSMISSION OF A VIDEO AND AN AUDIO SIGNAL THROUGH AN ORDINARY TELEPHONE TRANSMISSION LINE  
A communication system for simultaneously transmitting a video and audio signal through the same transmission line. The transmission line can be a standard telephone line, and the video signal can...
3860870 MICROWAVE RELAY SYSTEM HAVING AUXILIARY SIGNAL TRANSMISSION ARRANGEMENT  
A microwave heterodyne relay system transmitting a main carrier, angle-modulated wave in combination with an auxiliary signal transmission system is disclosed. The auxiliary signal transmission is...
3849595 FACSIMILE SIGNAL TRANSMISSION SYSTEM  
A facsimile transmission system is disclosed which uses both amplitude and phase modulation. The amplitude and phase of the transmitted signal are selected in correspondence with the binary values...
3764731 COLOR SIGNAL RECORDING AND DECODING APPARATUS  
Apparatus for converting two independent functions of color saturation and hue into pulses varying in width and frequency each in accordance with one of said functions. Apparatus for scanning a...
3754101 FREQUENCY RATE COMMUNICATION SYSTEM  
A communication system for transmitting a plurality of analog or digital information signals to a receiver with an improvement in band width utilization over conventional systems. A system with a...
3742149 A FREQUENCY DIVISION MULTIPLEX MICROWAVE COMMUNICATION SYSTEM USING POLARIZATION DIVISION MULTIPLEX TECHNIQUE  
A signal transmission and reception system which includes means for transmitting a plurality of information signals each of which occupies a different frequency band. The information signals, which...
3737776 TWO CARRIER COMMUNICATION SYSTEM WITH SINGLE TRANSMITTER  
A pulse-code modulated communication system is disclosed for transmitting two subcarrier-modulated carriers from a single transmitter comprising two channels for phase modulating the two carriers...
3715510 METHOD AND APPARATUS FOR HANDLING DATA FROM A PLURALITY OF CHANNELS  
A time-multiplexing system wherein a frequency-modulated signal contains the data from a plurality of channels in time-sequential order. Each channel is represented by the same integral number of...
3706842 METHOD TO DOUBLE TRANSMISSION SPEED OF TELEPHONE NETWORK FACSIMILE  
Material to be sent is scanned two lines at a time and the information in the two lines is transmitted simultaneously. The first line of each pair is encoded and transmitted by a frequency or phase...
3689841 COMMUNICATION SYSTEM FOR ELIMINATING TIME DELAY EFFECTS WHEN USED IN A MULTIPATH TRANSMISSION MEDIUM  
A communication system for providing effective multipath transmission without intermodulation or other distortion effects normally arising from the transmission through a dispersive medium, such as...
3659053 METHOD AND APPARATUS FOR FREQUENCY-DIVISION MULTIPLEX COMMUNICATIONS BY DIGITAL PHASE SHIFT OF CARRIER  
A system is disclosed for subcarrier frequency multiplexing to separate independent pulse-code-modulated data streams on a common carrier by modulating the carrier in a digital-to-phase shift...
3626417 HYBRID FREQUENCY SHIFT-AMPLITUDE MODULATED TONE SYSTEM  
A two channel data transmission system using amplitude modulation of the frequency shifted carrier of one channel to transmit the data of the second channel. Both channels operate at the maximum...
3623105 FILTERED PULSE WIDTH MODULATION COMMUNICATION SYSTEM  
A communications system provides a practical means for transmitting a plurality of input information signals, such as television signals, over a single transmitter. The signals are combined or...
3603882 PHASE SHIFT DATA TRANSMISSION SYSTEMS HAVING AUXILIARY CHANNELS  
In a data transmission system utilizing phase shift modulation of a carrier signal to transmit pulse coded data from one station to another an auxiliary low frequency signal is transmitted between...
3601544 BASEBAND FREQUENCY MULTIPLEXING SCHEME  
A binary data multiplexing system is disclosed wherein data from a binary source is applied to two encoders. One encoder operates to impart a self-clocking coding to the data and to thus cause the...
3596001 FREQUENCY DIVISION MULTIPLEXING  
In a time division multiplex electrical signalling system having a main carrier modulated by a first group of subcarriers to produce signals in frequency bands of higher frequency than the main...
3553367 FACSIMILE MULTIPLEX COMMUNICATION SYSTEM  
A system for multiplexing facsimile transmission on an audio frequency carrier. The signals from a first transmitter are converted to serial digital data and used to synchronously amplitude...
3546386 SATELLITE COMMUNICATION SYSTEM AND METHOD  
3499992 HIDDEN CHANNEL COMMUNICATIONS SYSTEM  
3499995 FREQUENCY AND TIME DIVISION MULTIPLEX SIGNALLING SYSTEMS USING SUCCESSIVE CHANGES OF FREQUENCY BAND AND TIME SLOT  
3440346 METHOD OF MULTIPLEX REPRESENTATION OF SAMPLED DATA  
3406343 Pm/am multiplex communication  
3406344 Transmission of low frequency signals by modulation of voice carrier  
3403402 Fm isolation transformer coupling to dual frequency transmitter antenna  
3366882 Pam and pwm dual modulation arrangement for doubling channel capacity  
3337850 Digital phase transition detector  
3260964 Separate amplitude and frequency modulator channels for high and low signals to prevent distortion due to carrier suppression  
3188573 Dual modulation communication system  
3178515 Plural modulation communication system  
3160812 Composite transmission system utilizing phase shift and amplitude modulation  
3144609 Signal to noise enhancement technique for binary transmission  
3137821 Discriminators  
3132334 Mixed base code generation  
3032717 Method and apparatus for multiplexing and delaying normal and coherent video on one delay line  
3007042 Communication system  
2976363 Modulation of selected phases of carriers for simultaneous transmission through single delay means  
2935604 Long range communication system  
2912492 Multiplex transmission system  
Matches 201 - 250 out of 257 < 1 2 3 4 5 6 >