| 5375171 |
Transmission system, and transmitter and receiver used in the transmission system for transmitting and receiving digital signals containing modulated bit allocation information |
| Dec-20-1994 |
Transmission system, and transmitter and receiver for use in the transmission system for transmitting and receiving digital signals containing modulated bit allocation information. The transmitter encodes... |
| 5369703 |
Command and control signalling method and apparatus |
| Nov-29-1994 |
A local communication apparatus (e.g., a modem) is arranged to detect when a remote communication apparatus desires to switch from the data mode and enter a command/control mode. To accomplish mode switching,... |
| 5355415 |
Parallel distributed sample scrambling system |
| Oct-11-1994 |
A parallel distributed sample scrambling and descrambling system for fixed-sized packet transmission comprising a parallel scrambler and a parallel descrambler. The scrambler includes; a parallel shift... |
| 5333197 |
System to prevent a scrambler from generating undesired symbols |
| Jul-26-1994 |
A communication system is described in which data characters are each repeatedly encoded in an encoder (3) until an encoded character occurs which is not one of a predetermined set of characters, e.g.... |
| 5323463 |
Method and apparatus for controlling the spectral content of a data stream |
| Jun-21-1994 |
An FDDI transmitting apparatus employs a scrambler to scramble input NRZ data which in turn is input to an NRZI-to-NRZ pre-encoder. This is in turn coupled in series with an NRZ-to-NRZI encoder to produce... |
| 5321754 |
Sequence synchronization |
| Jun-14-1994 |
A data sequence is transmitted from a transmitter to a receiver, being scrambled at the transmitter by adding a pseudo random sequence (PRS) thereto. At the receiver the received data is unscrambled by... |
| 5283831 |
Method of synchronizing the pseudo-random binary sequence in a descrambler |
| Feb-1-1994 |
In a data communication system a signal is coded with n-bit codewords, wherein n is an integer. The codewords are converted to a serial bit-stream and scrambled using a PRBS (Pseudo-Random Binary Sequence)... |
| 5278906 |
System for encoding data presented with a first coding device and for decoding encoded data with a second coding device, and coding device for use in the system |
| Jan-11-1994 |
In a system for de-/encoding data using (de)coding devices at either end of a transmission channel, the data sometimes comprise additional synchronisation information which is used to reduce the effect... |
| 5268961 |
Error control apparatus for a digital video signal processing system |
| Dec-7-1993 |
In a system for coding and decoding a digital television signal, a signal representing residual image information is transformed into plural subband signals representing vertical and horizontal frequencies,... |
| 5267316 |
Synchronous system for parallel data scrambling |
| Nov-30-1993 |
Of the type formed by a pseudorandom code generator and a block that performs the synchronizing and the scrambling in parallel which, in addition to the initialization signal, receives as inputs the set... |
| 5245661 |
Distributed sample scrambling system |
| Sep-14-1993 |
A distributed sample scrambling system comprising scrambler and a descrambler. The scrambler includes a first shift register generator (SRG) 2 for generating scrambler SRG sequence, an exclusive OR gate... |
| 5241602 |
Parallel scrambling system |
| Aug-31-1993 |
A parallel scrambling system comprises an M-bit (M>1) interleaved parallel scrambler for parallel scrambling input signals and an M-bit interleaved multiplexer for multiplexing output signals from the... |
| 5235645 |
Scrambler/descrambler system for data transmission |
| Aug-10-1993 |
A scrambler system is provided for the detection and separation of synchronization signals from data signals, and for the scrambling of the data signals such that no long and repeatable series of one's... |
| 5231667 |
Scrambling/descrambling circuit |
| Jul-27-1993 |
A scrambling/descrambling circuit that may be manufactured as a CMOS arrangement in LSI format and free of constraints on the degree of the generating polynomial involved. Scrambled (or descrambled) "m"... |
| 5222141 |
Apparatus and method for encoding data |
| Jun-22-1993 |
A first bit of the communication signal is encrypted and forwarded to a CRC where it is processed in parallel with the encryption of the second bit. The first bit is then passed to the scrambler and the... |
| 5216714 |
Method and apparatus for controlling the spectral content of a data stream |
| Jun-1-1993 |
An FDDI transmitting apparatus employs a scrambler to scramble input NRZ data which in turn is input to an NRZI-to-NRZ pre-encoder. This is in turn coupled in series with an NRZ-to-NRZI encoder to produce... |
| 5197097 |
Cell signal processing circuit and optical switch apparatus using the same |
| Mar-23-1993 |
A cell signal processing circuit is provided which is capable of precisely extracting a timing signal and a cell synchronizing signal. The cell signal processing circuit is principally composed of a signal... |
| 5163092 |
Parallel scrambler used in sonet data transmission |
| Nov-10-1992 |
A data scrambler circuit which adds the SONET polynomial 1+X.sup.6 +X.sup.7 to data in a parallel format to thereby reduce circuitry clock rates to one-eighth the line rate, which reduces power consumption... |
| 5144669 |
Method of communicating digital signals and receiver for use with such method |
| Sep-1-1992 |
A receiver (2) for selectively extracting one of two or more time division multiplexed channels of digital signals, which channel has been scrambled before multiplexing using a predetermined digital sequence... |
| 5086470 |
Scrambling in digital communications network using a scrambled synchronization signal |
| Feb-4-1992 |
A passive, all optical communications network is provided in which a single optical source in a central station serves many outstations (e.g. telephones in customers' premises). Time division multiplexed... |
| 5063595 |
Optical communications network |
| Nov-5-1991 |
A passive, all optical communications network is provided in which a single optical source in a central station serves many outstations (e.g., telephones in customers' premises). Time division multiplexed... |
| 5063571 |
Method and apparatus for increasing the data rate for a given symbol rate in a spread spectrum system |
| Nov-5-1991 |
A method and apparatus for transmitting a stream of data bits in a spread spectrum format is disclosed. The inventive method comprises providing 2.sup.N predetermined spreading sequences, where N is equal... |
| 5046095 |
Digital data processor having data-unscrambling function |
| Sep-3-1991 |
A data processor includes a data unscrambling unit. The unit includes a memory circuit for storing data supplied thereto in a scrambled form, the data stored in the memory circuit being thereafter read... |
| 5040211 |
Reliable television transmission through analog channels |
| Aug-13-1991 |
The presence of random noise, interference, multipath, and imperfect frequency response in terrestrial broadcasting channels, and of pervasive low-level reflections in cable systems, degrades the quality... |
| 4977596 |
Cryptographic synchronization recovery by measuring randomness of decrypted data |
| Dec-11-1990 |
The invention relates to synchronization of encrypted data communication systems and a method which looks for any lack of pattern or intelligent information in the received data and triggers a resynchronization... |
| 4965881 |
Linear feedback shift registers for data scrambling |
| Oct-23-1990 |
A linear feedback shift register for use as a SONET data scrambler, operating in accordance with a generating polynomial of order n corresponding to an n by n transition matrix T, comprises k storage cells,... |
| 4930139 |
Spread spectrum communication system |
| May-29-1990 |
The spread spectrum digital communication system includes data input devices for generating digital information signals to be transmitted using radio signals. A chip stream generator converts the data... |
| 4864617 |
System and method for reducing deadlock conditions caused by repeated transmission of data sequences equivalent to those used for inter-device signalling |
| Sep-5-1989 |
A system and method for reducing the probability of deadlock conditions caused by the repeated transmission of data frames containing data sequences equivalent to those used by serial data communications... |
| 4827514 |
Method and apparatus to detect and recover a pseudo-random sequence |
| May-2-1989 |
A synchronization detector is disclosed wherein a portion of the received data stream is parallel loaded into a sequence generating means. The sequence generating means provides a local synchronization... |
| 4817147 |
Intelligent synchronous modem and communication system incorporating the same |
| Mar-28-1989 |
An intelligent synchronous modem and data communication systems utilizing the intelligent synchronous modem are provided. The modem comprises: at least one connector having a first and a second port for... |
| 4817148 |
Signal scrambling transmission system |
| Mar-28-1989 |
There is disclosed a signal scrambling transmission system in which the data is scrambled at the transmit end by logically combining the data with a pseudo random sequence generated by a ROM prior to transmission.... |
| 4790013 |
Receiver capable of quickly establishing stable frame synchronization |
| Dec-6-1988 |
In a receiver responsive to an input signal comprising information signals following frame synchronization signals, respectively, frame synchronization is established by a frame synchronization pulse generator... |
| 4775984 |
Synchronous digital cable transmission system |
| Oct-4-1988 |
A synchronous digital cable transmission system comprises a transmitting terminal, intermediate regenerative repeaters and a receiving terminal. The transmitting terminal includes a data scrambler and... |
| 4771463 |
Digital scrambling without error multiplication |
| Sep-13-1988 |
The present invention describes a circuit which allows a data stream to be scrambled by continuously running uninterrupted Pseudo Random sequence without multiplying errors. This is accomplished by allowing... |
| 4760598 |
Coded data transmission system |
| Jul-26-1988 |
Disclosed is a scrambler/encryption system for randomizing an information-containing data signal for transmission and for reproducing the original information at a receiver. The information-containing... |
| 4755987 |
High speed scrambling at lower clock speeds |
| Jul-5-1988 |
Circuitry generates a plurality of differently-phased m-sequences (or pseudo-random sequences) for scrambling/descrambling of all tributary data signals at a multiplexer/demultiplexer. By scrambling/descrambling... |
| 4744104 |
Self-synchronizing scrambler |
| May-10-1988 |
A self-synchronizing scrambler for high bit rates has a number of scrambler stages supplied in parallel with bits of a signal to be scrambled, each scrambler stage having a series-connected pair of modulo-2... |
| 4736424 |
Data scrambling apparatus |
| Apr-5-1988 |
A data scrambler-descrambler combination is illustrated which stores previously modified received data and alters data passing through on the basis of certain of the previously stored data bits. Additionally,... |
| 4723246 |
Integrated scrambler-encoder using PN sequence generator |
| Feb-2-1988 |
Simplified method and apparatus for performing integrated scrambling and encoding or descrambling and decoding of block code digital transmissions is disclosed. The method involves setting the scrambling... |
| 4719624 |
Multilevel multiplexing |
| Jan-12-1988 |
A synchronous PCM digital transmission system including multilevel multiplexing wherein the higher order multiplexers interleave two or more tributary signals each of which comprises a multiplexed plurality... |
| 4716587 |
Broadband-signal broadcasting system |
| Dec-29-1987 |
A broadband signal broadcasting system comprising a circuit to encode video and audio signals forming a TV channel to be sent to a switching matrix, which is remotely operated by the subscriber; a circuit... |
| 4688218 |
Multiplex channels for continuous flow for numerical signal |
| Aug-18-1987 |
A digital data pack transmission system is especially--but not exclusiveluseful in videotex or teletext transmission (i.e. videotext or teletext data is transmitted during intervals between segments of... |
| 4663501 |
Self-synchronizing descrambler |
| May-5-1987 |
A self-synchronizing descrambler for high bit rates having a number of parallel operating descrambler stages each of which represents the series connection of first and second modulo-2 adders and at least... |
| 4621355 |
Method of synchronizing parallel channels of orthogonally multiplexed parallel data transmission system and improved automatic equalizer for use in such a transmission system |
| Nov-4-1986 |
A reference data sequence is transmitted and applied to a first automatic equalizer which is arranged in a reference channel. The transmitted reference data is used to establish an initial equalization... |
| 4599719 |
Full duplex data set with half-duplex emulation |
| Jul-8-1986 |
Half-duplex switched carrier operation is emulated in a full-duplex voiceband data transmission system by utilizing predetermined signal indications in each channel to signal the initiation and termination... |
| 4563546 |
Method for preventing "compromising radiation" |
| Jan-7-1986 |
A method of preventing "compromising radiation" when processing and transmitting secret data information in data processing and long-distance data transmission systems. In addition to direct, physical... |
| 4451916 |
Repeatered, multi-channel fiber optic communication network having fault isolation system |
| May-29-1984 |
A repeatered, multichannel fiber optic communication network includes a plurality of full duplex fiber optic channels and one or more auxiliary channels. In order to supervise and control the operation... |
| 4431865 |
Digital signal enciphering and deciphering apparatus and system |
| Feb-14-1984 |
A digital signal of n-bit words N.sub.i is enciphered into an enciphered signal of n-bit words R.sub.i. In an enciphering unit, a logic circuit delivers each enciphered word R.sub.i through a logic operation... |
| 4387460 |
Supplementary information transmitting arrangement for a digital data transmission system |
| Jun-7-1983 |
This invention relates to an arrangement for transmitting a digital supplementary information signal having a low rate with a digital data signal having a high rate. The insertion of the supplementary... |
| 4304962 |
Data scrambler |
| Dec-8-1981 |
Binary digital data signal patterns containing either no transitions, periodically recurring transitions or both are randomized by constructing a key signal from a summation of selected stored digits of... |
