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Pulse or digital communications

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Class / Patent application numberDescriptionNumber of patent applications / Date published
375240000 BANDWIDTH REDUCTION OR EXPANSION 6426
375259000 SYSTEMS USING ALTERNATING OR PULSATING CURRENT 3025
375316000 RECEIVERS 2692
375295000 TRANSMITTERS 1684
375130000 SPREAD SPECTRUM 1393
375219000 TRANSCEIVERS 1278
375224000 TESTING 923
375354000 SYNCHRONIZERS 862
375229000 EQUALIZERS 746
375257000 CABLE SYSTEMS AND COMPONENTS 276
375211000 REPEATERS 171
375238000 PULSE WIDTH MODULATION 81
375242000 PULSE CODE MODULATION 52
375286000 MULTILEVEL 50
375239000 PULSE POSITION, FREQUENCY, OR SPACING MODULATION 32
375216000 APPARATUS CONVERTIBLE TO ANALOG 14
375256000 PULSE TRANSMISSION VIA RADIATED BASEBAND 6
375218000 EARTH OR WATER MEDIUM 4
20080240209Sub-Surface communications system and method - A communications system including: a plurality of sub-surface portable transceivers each including: a digital data source, a modulator coupled to the digital data source, a power amplifier coupled to the modulator and a loop antenna inductively coupled to the power amplifier; and a base transceiver including: an electrically insulated ferrite core antenna for receiving magnetic signals, an electric di-pole antenna for receiving ambient noise, a noise canceller coupled to the insulated ferrite core antenna and electric dipole antenna and responsive to the electric-dipole antenna to filter noise from signals received via the insulated ferrite core antenna, a demodulator coupled to the noise canceller and a decoder coupled to the demodulator.10-02-2008
20100322293COMMUNICATION BETWEEN SUBMERGED STATION AND AIRBORNE VEHICLE - The present invention discloses a system for digitally modulated radio communication directly between a submerged underwater station and an airborne station. Each of the underwater station and the airborne station has or is associated with a radio communications antenna. Suitable radio communications antennas include loop antennas, solenoid antennas, stacked multiple loop antennas, planar arrayed loop antennas, a multiple resonant loop antennas. In some embodiments, the communications antennas of the submerged underwater station and the airborne station are each deployed horizontally thereby improving the efficiency of the signal transfer between the submerged underwater station and the airborne station.12-23-2010
20120076178Portable Wireless Through-The-Earth Communication System - A portable wireless through-the-earth bi-directional communication system for sending and receiving text data using ultra-low-frequency electric current and the earth as the conductive media. A surface controller which executes application software which controls the communication functions of the system. A surface receiver and surface transmitter are connected to sets of electrodes which provide the electric current, and are in communication with the surface controller. Text data are encoded into data packets, modulated onto ultra-low-frequency electric carrier waves, and transmitted through the earth by the surface electrodes to a subsurface transceiver. The subsurface transceiver demodulates, converts and displays incoming signals into text messages. The subsurface transceiver has a user interface to allow subsurface users to submit text data to the surface receiver. The transceiver converts the text data into analog data packets, modulates the packets onto ultra-low-frequency carrier waves, and transmits the signal to the surface receiver.03-29-2012
20130208768UNDERWATER ACOUSTIC MULTIPLE-INPUT/MULTIPLE-OUTPUT (MIMO) COMMUNICATION SYSTEMS AND METHODS - Methods and systems for acoustic multiple-input/multiple-output (MIMO) communication in an underwater environment. The method includes: a) receiving signals at multiple receivers representing transmitted signals from multiple transmitters, b) estimating channel responses between the multiple receivers and the multiple transmitters, c) performing an initial demodulation process on the received signals using the estimated channel responses to remove inter-symbol interference (ISI), and d) performing at least one subsequent demodulation process on the received signals. The subsequent demodulation process: i) removes co-channel interference (CoI) using the estimated channel responses and demodulated signals from an immediately preceding demodulation process to form interference cancelled signals and ii) removes ISI from the interference cancelled signals. In the initial and subsequent demodulation processes, ISI removal includes a time reversal combining process followed by a single-channel decision feedback equalization (DFE) process.08-15-2013
375237000 PULSE NUMBER MODULATION 4
20080267279RFID receiver for miller-encoded signals - A method for decoding a Miller-encoded signal having first and second quadrature components is provided. A Miller sub-carrier signal, synchronized with the Miller-encoded signal, is recovered from the quadrature components. A first, a second, a third, and a fourth half-bit correlation coefficient are calculated from at least one quadrature component and the Miller sub-carrier signal. A cross-correlation result of the first, the second, the third, and the fourth half-bit correlation coefficient is calculated. A value for an output bit is determined from the inverse sign of the cross-correlation result.10-30-2008
20120275508Constellation-Multiplexed Transmitter and Receiver - A device of dynamic communication of information allows, on the average, non-integer bits per symbol transmission, using a compact code set or a partial response decoding receiver. A stream of selectable predetermined integer bits, e.g., k or k+1 data bits, is grouped into a selectable integer number of bit vectors which then are mapped onto corresponding signal constellations forming transmission symbols. Two or more symbols can be grouped and further encoded, so that a symbol is spread across the two or more symbols being communicated. Sequence estimation using, for example, maximum likelihood techniques, as informed by noise estimates relative to the received signal. Each branch metric in computing the path metric of a considered sequence at the receiver is weighted by the inverse of the noise power. It is desirable that the constellation selection, sequence estimation and noise estimation be performed continuously and dynamically.11-01-2012
20110310953Managing Spectra of Modulated Signals in a Communication Network - Information is modulated onto frequency components of a signal. The resulting modulated signal includes at least some redundancy in frequency enabling a portion of the information modulated onto selected frequency components to be recovered from fewer than all of the selected frequency components. Controlling the spectrum of the modulated signal includes enabling the amplitude of at least some frequency components of the modulated signal to be set below a predetermined amplitude used for modulating the information.12-22-2011
20130208783TRANSMITTER AND RECEIVER FOR PULSE DENSITY MODULATED SIGNALS AND SIGNAL PROCESSING METHOD - A transmitter (TX) for transmitting a pulse density modulated signal comprises means (SDM) for generating a pulse density modulated input signal (SI) and an encoder (ENC). The encoder (ENC) comprises a first input for receiving the pulse density modulated input signal (SI) and a second input for receiving additional information (AI) comprising at least one data bit. The encoder (ENC) is configured to generate a multi-bit telegram (TG) on the basis of the additional information (AI), the telegram (TG) comprising a predefined bit-sequence, and to replace an appropriate number of consecutive bits of the input signal (SI) with the telegram (TG) in order to generate an output signal (SO).08-15-2013
375353000 PULSE AMPLITUDE MODULATION 1
20110311008APPARATUS AND METHOD THEREOF FOR CLOCK AND DATA RECOVERY OF N-PAM ENCODED SIGNALS USING A CONVENTIONAL 2-PAM CDR CIRCUIT - An interface circuit for enabling clock and data recovery (CDR) of N-level pulse amplitude modulation (N-PAM) modulated data streams using a 2-PAM CDR circuit. The circuit comprises a number of N−1 comparators for comparing an input data stream to N−1 configurable thresholds, the input data stream is N-PAM modulated and the N−1 configurable thresholds are N−1 different voltage levels; a number of N−1 of edge detectors respectively connected to the N−1 comparators for detecting transitions from one logic value to another logic value, N is a discrete number greater than two; and a determination unit for determining if the detected transitions is any one of a major transition and a minor transition and asserting a transition signal if only a major transition or a minor transition has occurred, the transition signal is fed into a 2-PAM CDR circuit and utilized for recovering a clock signal of the input data stream.12-22-2011

Patent applications in all subclasses Pulse or digital communications