Keying Circuits Patents (Class 375/309)
  • Patent number: 10054621
    Abstract: An RF processing module that when coupled to a computer having appropriate signal processing software will function as a spectrum analyzer. The RF processing module has a first stage mixer and a switch that allows either port of the first stage mixer to be selected as the input and receive the RF signal. The RF processing module has a sample packing buffer that packs digitized signal samples into a fewer number of longer words and loads the words into a circular buffer and from then to one of two DMA channels on a USB link. The circular buffer can be emptied faster than it can be filled, allowing the sample packing buffer to create time intervals for a USB controller to switch DMA channels. LO leakage through the mixer-to-IF path is used to self-calibrate the filter's frequency response as temperature and other environmental factors change.
    Type: Grant
    Filed: June 11, 2015
    Date of Patent: August 21, 2018
    Assignee: Test Equipment Plus, Inc.
    Inventor: Justin Crooks
  • Patent number: 8948307
    Abstract: According to one embodiment, an ASK signal generator includes a differential oscillator, a first modulator, a second modulator, a first transmission line, a second transmission line and an impedance adjustment circuit. The differential oscillator generates first and second signals having an opposite phase, and outputs the first and second signals from first and second output terminals. The first modulator connected to the first output terminal is set in the normally off state. The second modulator connected to the second output terminal is turned on or off according to a digital signal. The first and second transmission lines connected to the first and second output terminals have a length equal to a ¼ wavelength of the oscillation frequency of the differential oscillator. The impedance adjustment circuit is operated together with the second modulator according to the digital signal.
    Type: Grant
    Filed: February 28, 2013
    Date of Patent: February 3, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Ryuichi Fujimoto
  • Patent number: 8903018
    Abstract: A communication system includes a baseband processor, an RF (Radio Frequency) transceiver, a power amplifier, an antenna, and a control circuit. The power amplifier generates an amplified signal. The control circuit includes a coupler, an AC-to-DC (Alternating Current to Direct Current) converter, a comparator, and an attenuator. The coupler generates a transmission signal and a coupling signal according to the amplified signal. The AC-to-DC converter is coupled to the coupler, and converts the coupling signal into a DC (Direct Current) signal. The comparator compares a DC voltage of the DC signal with a reference voltage so as to generate a control signal. The attenuator is coupled between the coupler and the antenna, and attenuates or does not attenuate the transmission signal according to the control signal.
    Type: Grant
    Filed: September 6, 2012
    Date of Patent: December 2, 2014
    Assignee: Wistron Corp.
    Inventor: Yin-Tsai Wang
  • Patent number: 8861643
    Abstract: A signal transmitting device and a method for transmitting via a signal transmitting device is disclosed. In one embodiment the transmitting device comprises a first resonant circuit with a resonant circuit inductance and a resonant circuit capacitance and a second resonant circuit with a resonant circuit inductance and a resonant circuit capacitance, a coupling element which couples the first resonant circuit to the second resonant circuit, a first excitation circuit, coupled to the first resonant circuit, and at least one further excitation circuit coupled to the second resonant circuit.
    Type: Grant
    Filed: May 14, 2013
    Date of Patent: October 14, 2014
    Assignee: Infineon Technologies AG
    Inventor: Martin Feldtkeller
  • Patent number: 8842745
    Abstract: In the transmitter, receiver and interface system capable of selective adoption of a differential current driving scheme and a differential voltage driving scheme, a differential current driving scheme and a differential voltage driving scheme can be selectively adopted in one semiconductor chip depending upon the states of the transmission lines, so that effective data transmission is possible and common parts can be shared, whereby a design time can be shortened and a layout area can be reduced.
    Type: Grant
    Filed: December 3, 2009
    Date of Patent: September 23, 2014
    Assignee: Silicon Works Co., Ltd.
    Inventors: Ju-Pyo Hong, Jun-Ho Kim, Jung-Hwan Choi
  • Patent number: 8842768
    Abstract: A radio communication system has a plurality of transmission formats available for transmitting data signals, and a pilot signal is transmitted during the transmission of data to enable channel estimation. The transmit power of the pilot signal is varied depending on the current transmission format of the data, and is reduced in the periods between data transmissions.
    Type: Grant
    Filed: September 15, 2005
    Date of Patent: September 23, 2014
    Assignee: Koninklijke Philips N.V.
    Inventors: Timothy J. Moulsley, Matthew P. J. Baker
  • Publication number: 20140254696
    Abstract: A communication system that uses keyed modulation to encode fixed frequency communications on a variable frequency power transmission signal in which a single communication bit is represented by a plurality of modulations. To provide a fixed communication rate, the number of modulations associated with each bit is dynamic varying as a function of the ratio of the communication frequency to the carrier signal frequency. In one embodiment, the present invention provides dynamic phase-shift-keyed modulation in which communications are generated by toggling a load at a rate that is a fraction of the power transfer frequency. In another embodiment, the present invention provides communication by toggling a load in the communication transmitter at a rate that is phase locked and at a harmonic of the power transfer frequency. In yet another embodiment, the present invention provides frequency-shift-keyed modulation, including, for example, modulation at one of two different frequencies.
    Type: Application
    Filed: April 4, 2014
    Publication date: September 11, 2014
    Applicant: Access Business Group International LLC
    Inventors: Matthew J. Norconk, Joshua K. Schwannecke, Colin J. Moore, Joshua B. Taylor, Neil W. Kuyvenhoven, Dale R. Liff, Jason L. Amistadi, Robert D. Gruich, Arthur Kelley, Kenneth C. Armstrong
  • Patent number: 8831160
    Abstract: An apparatus includes a first clock source, a second clock source and circuitry configured to supply a clock signal to a circuit. The circuitry operates to change the clock signal from one frequency to another different frequency. This change is made in a manner whereby no clock signal is supplied during a period of time when the change from the one frequency to the another different clock frequency is being made.
    Type: Grant
    Filed: January 17, 2013
    Date of Patent: September 9, 2014
    Assignees: STMicroelectronics (Research & Development) Limited, STMicroelectronics (Grenoble 2) SAS
    Inventors: Andrew Ferris, Ignazio Antonino Urzi
  • Patent number: 8699617
    Abstract: According to an embodiment, a transmitter is described comprising an input configured to receive a plurality of symbols to be transmitted and a timing circuit configured to associate each symbol with a symbol transmission period of a predefined sequence of symbol transmission periods, wherein the symbol transmission periods of the sequence of symbol transmission periods are at least partially different.
    Type: Grant
    Filed: March 28, 2011
    Date of Patent: April 15, 2014
    Assignee: Infineon Technologies AG
    Inventor: Ljudmil Anastasov
  • Patent number: 8660206
    Abstract: The present invention forms, in UWB communications in which a pulse of short duration is transmitted, a transmission signal with a desired frequency characteristic by adjusting the shape of a pulse signal used in data transmissions. As a result, radio interference with other wireless systems in UWB communications is reduced. As aspects for adjusting the pulse signal, the present invention comprises an aspect for generating a pulse signal having a desired frequency characteristic by adjusting the shape of a single pulse itself, an aspect for generating a pulse signal having a desired frequency characteristic by combining a plurality of pulses, and an aspect for finding a combination of pulse signals from the frequency characteristic of an object transmission signal.
    Type: Grant
    Filed: December 16, 2003
    Date of Patent: February 25, 2014
    Assignees: Yokohama TLO Company, Ltd.
    Inventor: Ryuji Kohno
  • Patent number: 8611437
    Abstract: One embodiment of the present invention sets forth a mechanism for transmitting and receiving ground-referenced single-ended signals. A transmitter combines a direct current (DC) to DC converter including a flying capacitor with a 2:1 clocked multiplexer to drive a single-ended signaling line. The transmitter drives a pair of voltages that are symmetric about the ground power supply level. Signaling currents are returned to the ground plane to minimize the generation of noise that is a source of crosstalk between different signaling lines. Noise introduced through the power supply is correlated with the switching rate of the data and may be reduced using an equalizer circuit.
    Type: Grant
    Filed: January 26, 2012
    Date of Patent: December 17, 2013
    Assignee: NVIDIA Corporation
    Inventors: John W. Poulton, Thomas Hastings Greer, III, William J. Dally
  • Patent number: 8588330
    Abstract: A communications device may include In-phase (I) power amplifiers configured to respectively generate I amplified signals, Quadrature (Q) power amplifiers configured to respectively generate Q amplified signals, I antennas respectively coupled to the I power amplifiers, and Q antennas respectively coupled to the Q power amplifiers. The communications device may also include an I controller coupled to the I power amplifiers and configured to selectively enable some of the I power amplifiers, and a Q controller coupled to the Q power amplifiers and configured to selectively enable some of the Q power amplifiers.
    Type: Grant
    Filed: March 16, 2011
    Date of Patent: November 19, 2013
    Assignee: BlackBerry Limited
    Inventor: Khurram Muhammad
  • Patent number: 8553802
    Abstract: A communications device may include an In-phase (I) power amplifier configured to generate an I amplified signal, a Quadrature (Q) power amplifier configured to generate a Q amplified signal, an I digital-to-analog converter (DAC) configured to generate an I signal, and a Q DAC configured to generate a Q signal. The communications device may also include an I power supply circuit coupled to the I power amplifier and to the I DAC and configured to cause the I power amplifier to modulate an I carrier signal into the I amplified signal based upon the I signal, a Q power supply circuit coupled to the Q power amplifier and to the Q DAC and configured to cause the Q power amplifier to modulate a Q carrier signal into the Q amplified signal based upon the Q signal, and at least one antenna coupled to the I and Q power amplifiers.
    Type: Grant
    Filed: March 16, 2011
    Date of Patent: October 8, 2013
    Assignee: Blackberry Limited
    Inventor: Khurram Muhammad
  • Patent number: 8462880
    Abstract: A device for Electro-Magnetic Interference (EMI) reduction in an Ethernet system has an Ethernet compatible device. The Ethernet compatible device has a filter for adjusting a signal outputted by the Ethernet compatible device for EMI reduction.
    Type: Grant
    Filed: August 26, 2009
    Date of Patent: June 11, 2013
    Assignee: MICREL, Inc.
    Inventors: Sheng Lin, Menping Chang
  • Patent number: 8432977
    Abstract: There is provided an information processing apparatus including an encoding unit that represents input data containing mutually different first and second bit values by a plurality of first amplitude values for the first bit value and a second amplitude value that is different from the first amplitude values for the second bit value, does not take an identical value consecutively, and perform encoding so that polarity of the amplitude value is reversed for each cycle, and a transmission unit that transmits a signal encoded by the encoding unit through a predetermined transmission line.
    Type: Grant
    Filed: April 22, 2009
    Date of Patent: April 30, 2013
    Assignee: Sony Corporation
    Inventor: Kunio Fukuda
  • Patent number: 8385456
    Abstract: A differential radio frequency signal transmitter is provided. The differential radio frequency signal transmitter includes an oscillator, a modulator and an amplifier module. The oscillator generates a pair of differential oscillation signals. The modulator generates a pair of differential modulated signals according to an input signal and the pair of differential oscillation signals. The input signal is a digital signal. When the input signal is at a first state, the modulator outputs the pair of differential oscillation signals as the pair of differential modulated signals, and when the input signal is at a second state, the modulator outputs a constant voltage signal as the pair of differential modulated signals. The amplifier module receives and amplifies the pair of differential modulated signals and generates a pair of differential radio frequency signals, accordingly.
    Type: Grant
    Filed: October 1, 2009
    Date of Patent: February 26, 2013
    Assignee: National Taiwan University
    Inventors: Jr-I Lee, Yen-Lin Huang, Yen-Tso Chen, Chia-Jung Chang
  • Patent number: 8259851
    Abstract: Briefly, a method and apparatus to calculate cross-correlation values of complex binary sequences are provided. The apparatus may include a transformation unit and a cross-correlator. The cross-correlator may include a cross-correlation controller to provide, based on a type bit and a sign bit, a real component and/or an imaginary component of signals of complex binary sequences to a real accumulator and/or to an imaginary accumulator.
    Type: Grant
    Filed: November 11, 2008
    Date of Patent: September 4, 2012
    Assignee: Marvell World Trade Ltd.
    Inventors: Kobby Pick, Yona Perets
  • Patent number: 8249187
    Abstract: Communication is performed for a first communication device having a set of antenna elements. A quality-indication signal is received from a second communication device (e.g., a basestation). A complex weighting is calculated based on the quality-indication signal. A pre-transmission signal is modified based on the complex transmit diversity weighting to produce a set of modified-pre-transmission signals, wherein the modifications are symmetric by making approximately half the magnitude of the transmit diversity modification to one signal in a first direction, and approximately half the magnitude of the transmit diversity modification to the other signal in a second direction, opposite the first direction. Each modified pre-transmission signal from the set of modified-pre-transmission signals is uniquely associated with an antenna element from the set of antenna elements. The set of modified-pre-transmission signals is sent from the set of antenna elements to produce a transmitted signal.
    Type: Grant
    Filed: April 23, 2010
    Date of Patent: August 21, 2012
    Assignee: Google Inc.
    Inventors: Haim Harel, Phil F. Chen, Sherwin J. Wang, Eduardo Abreu
  • Publication number: 20110268202
    Abstract: In the transmitter, receiver and interface system capable of selective adoption of a differential current driving scheme and a differential voltage driving scheme, a differential current driving scheme and a differential voltage driving scheme can be selectively adopted in one semiconductor chip depending upon the states of the transmission lines, so that effective data transmission is possible and common parts can be shared, whereby a design time can be shortened and a layout area can be reduced.
    Type: Application
    Filed: December 3, 2009
    Publication date: November 3, 2011
    Applicant: SILICON WORKS CO., LTD
    Inventors: Ju-Pyo Hong, Jun-Ho Kim, Jung-Hwan Choi
  • Patent number: 8050360
    Abstract: Disclosed herein are exemplary techniques for power conservation in a wireless network. A wireless device identifies another wireless device suitable to act as a relay node. Uplink information is transmitted to the other wireless device, which is in turn relayed to an access point for transmission to its destination. Downlink information may be transmitted directly from the access point to the wireless device. The use of a relay node may reduce transmit power consumption as the relay node may be closer to, or support a higher transmit rate, than the access point with which the wireless device is associated.
    Type: Grant
    Filed: June 30, 2004
    Date of Patent: November 1, 2011
    Assignee: Intellectual Ventures I LLC
    Inventor: Menzo Wentink
  • Patent number: 7924907
    Abstract: there is provided a spreading apparatus using a child orthogonal variable spreading factor (OVSF) code pair, including: a channel condition information receiving unit for receiving channel condition information including a channel condition metric; a switch controlling unit for receiving the channel condition information from the channel condition information receiving unit and transferring data stream according to the received channel station information; a first spreading unit for receiving the data stream from the switching controlling unit, and spreading the data stream using a single OVSF code; and a second spreading unit for receiving the data stream from the switching controlling unit, and spreading the data stream using a child OVSF code pair.
    Type: Grant
    Filed: August 16, 2007
    Date of Patent: April 12, 2011
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Sung-Rae Cho, Seong-Su Park, Hoo-Sung Lee, Byung-Jo Kim
  • Publication number: 20110075763
    Abstract: A local wireless signal transmitting/receiving apparatus and method using digital RF processing technology. When the local wireless signal transmitting/receiving apparatus generates a local wireless signal to be transmitted, spreads the frequency of the generated local wireless signal and thereby generates a baseband signal, the local wireless signal transmitting/receiving apparatus converts the baseband signal of the local wireless signal into phase information, converts the phase information into an RF signal by means of a polar modulator, and transmits the RF signal.
    Type: Application
    Filed: May 19, 2009
    Publication date: March 31, 2011
    Applicant: SK TELECOM CO., LTD.
    Inventors: Woo Jin Shim, Young Woo Kim, Jae Hwang Yu, Sung Cheol Hong, Se Hyun Oh
  • Patent number: 7860188
    Abstract: A digital modulator in a radio transmitter includes circuitry for switching between Gaussian Minimum Shift Keying (GMSK) and Phase-Shift Keying (PSK) while maintaining spectral mask requirements. The digital modulator of the present invention includes both GMSK and PSK symbol mappers that produce PSK in-phase and quadrature symbols and GMSK symbols, respectively, to a pulse shaping block. Based on opposite phases of a modulation control signal, the symbol mappers produce either modulated data or a steam of logic zeros to the pulse shaping block. The pulse shaping block filters the received data and multiplexes the data so that each modulated data stream receives non-zero data during a guard time to avoid abrupt changes in the modulated signal that would violate the spectral mask requirements.
    Type: Grant
    Filed: February 24, 2009
    Date of Patent: December 28, 2010
    Assignee: Broadcom Corporation
    Inventor: Henrik T. Jensen
  • Patent number: 7822140
    Abstract: A receiver operatively coupled to an antenna structure capable of receiving a first plurality of RF signals is disclosed herein. The receiver includes an RF processing network operative to perform weighting and combining operations within the RF domain using the first plurality of RF signals so as to produce a second plurality of RF signals. Also provided is a downconverter configured to downconvert the second plurality of RF signals into a second plurality of down-converted signals. In alternate implementations certain of the weighting and combining operations are performed at baseband and the remainder effected within the RF domain. A transmitter of corresponding architecture is also disclosed.
    Type: Grant
    Filed: March 16, 2004
    Date of Patent: October 26, 2010
    Assignee: Broadcom Corporation
    Inventors: Severine Catreux, Vinko Erceg, Pieter Roux, Pieter Van Rooyen, Jack Winters
  • Patent number: 7817644
    Abstract: Methods and apparatus for an ATM network for implementing a fair servicing of all connections during a back-logged condition through the use of a weighted fair queuing technique. The system is particularly suited for systems where the packets/cells are of a fixed size. Although some important approximations are made in the proposed implementation, all of the properties of an ideal weighted fair queuing algorithm are preserved. The sorting methods and apparatus are advantageous in that it is possible to maintain appropriate servicing of connections without sorting all of the individual connections. This may be accomplished by pre-sorting each of the individual virtual circuit connections into a finite number of predetermined bins according to a weight associated with the connection. Thereafter, only the bins need be sorted without having to sort each of the individual connections.
    Type: Grant
    Filed: November 12, 2004
    Date of Patent: October 19, 2010
    Assignee: Alcatel-Lucent USA Inc.
    Inventors: Chien Chen, Linhai He, Albert Kai-sun Wong
  • Patent number: 7792198
    Abstract: A burst control pulse generating circuit which generates a pulse signal used to provide communication includes a timing generating circuit containing a ring oscillation circuit which oscillates a periodic signal based on a burst signal for controlling the ON and OFF condition of the communication to output a plurality of timing signals based on the periodic signal, and a pulse generating logic circuit which generates the pulse signal based on the plural timing signals. The burst control pulse generating circuit generates the pulse signal one or more times when the burst signal is in an ON condition, and stops generation of the pulse signal when the burst signal is in an OFF condition.
    Type: Grant
    Filed: September 6, 2007
    Date of Patent: September 7, 2010
    Assignee: Seiko Epson Corporation
    Inventor: Izumi Iida
  • Patent number: 7769105
    Abstract: A method for transmitting low data rate symbols from a burst radar transceiver is disclosed. The method includes dividing a symbol having a symbol period into a plurality of symbol sections. Each symbol section has a symbol section interval that is less than or equal to a burst interval of the radar transceiver. At least two symbol sections can be transmitted with the burst radar transceiver. Symbol energy can be accumulated from the at least two symbol sections at the communications terminal. Information in the received symbol sections can be identified based on characteristics of the accumulated symbol energy.
    Type: Grant
    Filed: November 3, 2006
    Date of Patent: August 3, 2010
    Assignee: L-3 Communications, Corp.
    Inventors: William K. McIntire, Larry S. Thomson, David H. Robbins, James J. Boesch
  • Patent number: 7756219
    Abstract: A WLAN transmitter capable of transmitting data signals modulated in accordance with an individual one of at least two different modulation schemes and corresponding methods and integrated circuit chips are provided. The WLAN transmitter contains a front end section having a low-IF topology and including a digital front end unit and an analog front end unit. The digital front end unit contains a first signal processing branch for processing transmission data signals modulated in accordance with a first one of said at least two different modulation schemes. The digital front end unit further contains a second signal processing branch for processing transmission data signals modulated in accordance with a second one of said at least two different modulation schemes. The analog front end unit contains one single signal processing branch for processing transmission data signals modulated in accordance with any one of said at least two different modulation schemes.
    Type: Grant
    Filed: July 14, 2005
    Date of Patent: July 13, 2010
    Assignee: GLOBALFOUNDRIES Inc.
    Inventors: Sascha Beyer, Wolfram Kluge, Michael Schmidt
  • Patent number: 7697629
    Abstract: An apparatus comprising a first circuit, a second circuit, a third circuit and a fourth circuit. The first circuit may be configured to generate a demodulated signal in response to (i) a modulated signal and (ii) a seed value. The second circuit may be configured to generate a first control signal in response to the demodulated signal. The third circuit may be configured to generate a second control signal in response to (i) the first control signal and (ii) a compensation signal. The fourth circuit may be configured to generate the seed value in response to the second control signal.
    Type: Grant
    Filed: June 6, 2008
    Date of Patent: April 13, 2010
    Assignee: LSI Corporation
    Inventor: Dean L. Raby
  • Patent number: 7693235
    Abstract: A concatenated coding scheme, using an outer coder, interleaver, and the inner coder inherent in an FQPSK signal to form a coded FQPSK signal. The inner coder is modified to enable interative decoding of the outer code.
    Type: Grant
    Filed: August 31, 2006
    Date of Patent: April 6, 2010
    Assignee: California Institute of Technology
    Inventors: Marvin K. Simon, Dariush Divsalar
  • Publication number: 20100046670
    Abstract: Methods and apparatus for encoding data for wireless transmission are disclosed in which a data message may be encoded into a transmission code as a first coding format and a second coding format. The first coding format characterized by a first bit representation and the second coding format characterized by a second bit representation different from the first bit representation. The transmission code may be transmitted having the first and second coding formats.
    Type: Application
    Filed: November 7, 2008
    Publication date: February 25, 2010
    Inventors: Gallen Ka Leung Tsui, Philip Y.W. Tsui
  • Patent number: 7613239
    Abstract: A digital signal offset adjusting apparatus has a capacitor causing an output terminal to pass a high frequency band of an input digital signal. A first coil has one end connected to an input terminal and a second coil has one end connected to an output. An operational amplifier has an input connected to another end of the first coil, a second input connected to a direct current voltage generator and an output connected to another end of the second coil. The operational amplifier outputs a signal obtained by subtracting and combining the low frequency band, the direct current component and a direct current bias voltage. A frequency characteristic compensating circuit is connected between a reference point and the second input of the operational amplifier. The gain of the operational amplifier increases with a component having a higher frequency from among low frequency bands of the input digital signal.
    Type: Grant
    Filed: September 29, 2005
    Date of Patent: November 3, 2009
    Assignee: Anritsu Corporation
    Inventors: Satoru Shiratsuchi, Kazuhiro Fujinuma, Sumio Saito
  • Patent number: 7606321
    Abstract: The system and method enable simpler analog processing in a transmitter by reducing the number of bits in a digital signal through delta sigma modulation. Selection of current sources in a digital to analog converter of the transmitter is done using a randomization circuit.
    Type: Grant
    Filed: June 29, 2004
    Date of Patent: October 20, 2009
    Assignee: Broadcom Corporation
    Inventor: Meng-An Pan
  • Patent number: 7376883
    Abstract: An approach is provided for generating Low Density Parity Check (LDPC) codes. An LDPC encoder generates a LDPC code with an outer Bose Chaudhuri Hocquenghem (BCH) code. For ? rate, the relevant parameters are as follows: q=120, nldpc=64,800, kldpc=nBCH=21600, kBCH=21408 (12 bit error correcting BCH). For ¼ rate, the LDPC code has the following relevant parameters: q=135, nldpc=64,800, kldpc=nBCH=16200, kBCH=16008 (12 bit error correcting BCH). For ? rate, the following parameters exist: q=108, nldpc=64800, kldpc=nBCH=25920, kBCH=25728 (12 bit error correcting BCH). The above approach has particular application in digital video broadcast services over satellite.
    Type: Grant
    Filed: October 22, 2004
    Date of Patent: May 20, 2008
    Assignee: The DIRECTV Group, Inc.
    Inventors: Mustafa Eroz, Feng-Wen Sun, Lin-Nan Lee
  • Patent number: 7003049
    Abstract: Digital I and Q (NRZ) data streams are generated by specially configured conversion circuits, the outputs of which are applied to a F-N synthesizer to modulate the synthesizer. All illustrative conversion circuit employs a system of comparators to detect the state of analog I and Q signals at each bit interval and to decode outputs of such comparators to determine the NRZ sequence that gave rise to detected states. Once so determined, these NRZ signals are applied to an F-N synthesizer in the same manner as NRZ signals. Advantageously, inputs to present inventive embodiments may be received either as analog or digital I and Q inputs, subject to selection between input modes using only a single binary input.
    Type: Grant
    Filed: June 12, 2001
    Date of Patent: February 21, 2006
    Assignee: RF Micro Devices, Inc.
    Inventor: Alex Wayne Hietala
  • Patent number: 6968014
    Abstract: A sinusoidal R.F. carrier is modulated for the transmission of digital binary datastreams through the deletion of carrier wavelets. These wavelets are defined between zero crossover positions representing zero energy locations. One or more wavelets are switched out of the carrier at the zero crossing positions to avoid sideband generation occasioned by electromagnetic energy disturbance. Transmissional amplification as well as receptional amplification is carried out with non-resonating amplifier architecture.
    Type: Grant
    Filed: February 23, 2000
    Date of Patent: November 22, 2005
    Assignee: XG Technology, LLC
    Inventor: Joseph A. Bobier
  • Patent number: 6882604
    Abstract: The invention is a modulation system that encodes symbols in accordance with a modulation code which, for a given communications channel, produces a signal that at the decoder includes maximized sample timing information in each encoded symbol. For systems that use PLLs to control a sample timing clock, the sample timing information is the average or squared slope. The modulation code used for a given system is selected based on the target response h(x) of the associated communications channel, such that h (x)*rk exceeds a predetermined threshold value, where “*” represents convolution and rk is a modulation code symbol. To reduce the bit overhead, or code rate, the inventive modulation system provides more modulation code symbols at the start of a data block, or sector, when system jitter is expected to be relatively high in response, for example, to the movement of a read head.
    Type: Grant
    Filed: September 17, 2001
    Date of Patent: April 19, 2005
    Assignee: Maxtor Corporation
    Inventors: Ara Patapoutian, Peter McEwen
  • Patent number: 6661850
    Abstract: According to the present invention, a maintenance operator can optionally or automatically test not only normality of a frequency shift keying (FSK) signal calling circuit but a specification, a transmission protocol and a standard of a signal length of FSK signal. An exchange system for transmitting information, such as a caller number, to a subscriber line circuit by employing a frequency shift keying signal, the exchange system comprising: a loop circuit for imitating a loop of a subscriber's telephone set; and a firmware for receiving a frequency shift keying signal and judging the normality of the frequency shift keying signal, wherein the firmware controls to open and close the loop circuit according to testing on On-Hook or Off-Hook protocol.
    Type: Grant
    Filed: October 8, 1998
    Date of Patent: December 9, 2003
    Assignee: Fujitsu Limited
    Inventor: Hisashi Amagasaki
  • Publication number: 20030165184
    Abstract: A transmitter encodes and a receiver decodes a signal using M-ary bi-orthogonal keying. The transmitter receives a stream of data bits and breaks a number of data bits off of the stream to form a bit sequence. The transmitter then chooses a code that corresponds the bit sequence, and transmits the chosen code. The receiver receives the code and correlates it with all possible codes to generate a plurality of correlation values. It then compares these correlation values to determine which code was sent, and therefore what the received bit sequence is. The codes are all mutually orthogonal, and preferable include a plurality of code words and an equal number of code word inverses. The code may be scrambled by multiplying it with a pseudo-random sequence at the transmitter, and descrambled by multiplying it by the same pseudo-random sequence at the receiver.
    Type: Application
    Filed: February 19, 2003
    Publication date: September 4, 2003
    Inventors: Matthew L. Welborn, John W. McCorkle
  • Publication number: 20030076898
    Abstract: A digital (de)modulation system uses a larger code set of M codes for N length codes, where M>N, to provide an increased data rate while maintaining the coding gain. For example, the system can use 16 different codes each having a length of 11 chips in a code set while the conventional M-ary keying systems use a code set size of 8 for 11-chip codes or 8-chip codes. By extending the code set size, the system increases the data rate of the system. With 16 codes and the ability to change the sign of the code to be transmitted, the system can encode 5 data bits on both I and Q, so a total of 10 data bits can be encoded per code symbol. In this embodiment, a code symbol contains an 11 chip code on a I modulation branch and an 11 chip code on a Q modulation branch. As such, using 11 chip codes and a chip rate of 11 Mhz, the system provides a data rate of 10 Mbps while conventional M-ary keying systems can only achieve 8 Mbps using the same code length and chip rate.
    Type: Application
    Filed: July 29, 2002
    Publication date: April 24, 2003
    Inventor: Richard D.J. van Nee
  • Patent number: 6449318
    Abstract: A method and system for transmitting data over twisted pair copper wires using a low frequency offset, differential voltage, on-off keying (OOK) transmission technique are described. According to one embodiment, an analog or digital signal is sent or received and converted, if necessary, into or from serial format onto or out of a twisted pair. The signal uses an OOK modulated sinusoidal offset signal with an associated differential voltage. A floating reference ground set positive or negative for the differential nature of the transmission may be required. The OOK modulated offset low frequency is being keyed to the floating ground reference that is set to a minimum signal to noise ratio (SNR) level. The SNR level may be set by adjusting the voltage separation between floating ground and the offset of the sinusoidal low frequency wave. The amplitude of the sinusoidal wave may be adjusted to provide increased transmission distance and better SNR.
    Type: Grant
    Filed: August 28, 2000
    Date of Patent: September 10, 2002
    Assignee: TeleNetwork, Inc.
    Inventor: Stephen Roy Rumbaugh
  • Patent number: 6434135
    Abstract: The invention reduces transient peaks in signals transmitted in CDMA communication systems. A plurality of spread spectrum data signals are combined into a combined signal having fluctuating power level corresponding to the combination of the data signals. The combined signal is modulated to produce an RF signal for transmission. The average power of the combined signal is measured over a selected time period. The combined signal power level is adaptively limited to a calculated power level based at least in part on the measured power.
    Type: Grant
    Filed: August 31, 1999
    Date of Patent: August 13, 2002
    Assignee: Interdigital Technology Corporation
    Inventors: Fatih M. Ozluturk, Brian Kiernan
  • Patent number: 6396355
    Abstract: A signal generator includes an oscillator, a phase locked loop and a fractional divider. The oscillator is configured to provide an output signal. The phase locked loop is configured to receive the output signal and to provide a tuning signal to the oscillator. The phase locked loop has a phase detector configured to receive the output signal, to compare the output signal to a reference signal, and to provide the tuning signal to the oscillator based on the comparison. The fractional divider is outside of the phase locked loop and is configured to generate the reference signal.
    Type: Grant
    Filed: April 12, 2000
    Date of Patent: May 28, 2002
    Assignee: Rockwell Collins, Inc.
    Inventor: Phillip J. Rezin
  • Patent number: 6314143
    Abstract: A circuit configuration for receiving an OOK-modulated signal, in particular for use in a data carrier of an identification system. The configuration has a demodulator circuit, a decoding circuit that is connected downstream of the latter and a sequential control for controlling in particular the reception, demodulation and processing of received data. A switching element that is driven by the sequential control is disposed between the demodulator circuit and the decoding circuit. An input of the switching element is connected to the output of the demodulator circuit and a first output of the switching element being connected to the input of the decoding circuit. The switching element has a second output that is connected to the reset input of the circuit configuration.
    Type: Grant
    Filed: January 31, 2000
    Date of Patent: November 6, 2001
    Assignee: Infineon Technologies AG
    Inventor: Robert Reiner
  • Patent number: 6301310
    Abstract: Circuitry for modulating the frequency of a carrier signal with data signals for high frequency radio transmission, which includes a MSK generator for generating a series of in-phase (I) signals and an associated series of quadrature (Q) signals corresponding to the data signals to be transmitted. A first shift register receives binary input from the I signals generated with the MSK generator, the binary input being indicative of the sign orientation of the generated I signals from the MSK generator. A second shift register receives binary input from the Q signals generated with the MSK generator, with the binary input being indicative of the sign orientation of the generated Q signals from the MSK generator.
    Type: Grant
    Filed: December 14, 1998
    Date of Patent: October 9, 2001
    Assignee: Hughes Electronics Corporation
    Inventors: Tom Jackson, Dave Roos
  • Patent number: 5715236
    Abstract: A system and method for communicating information signals using spread spectrum communication techniques. PN sequences are constructed that provide orthogonality between the users so that mutual interference will be reduced, allowing higher capacity and better link performance. With orthogonal PN codes, the cross-correlation is zero over a predetermined time interval, resulting in no interference between the orthogonal codes, provided only that the code time frames are time aligned with each other. In an exemplary embodiment, signals are communicated between a cell-site and mobile units using direct sequence spread spectrum communication signals. In the cell-to-mobile link, pilot, sync, paging and voice channels are defined. Information communicated on the cell-to-mobile link channels are, in general, encoded, interleaved, bi-phase shift key (BPSK) modulated with orthogonal covering of each BPSK symbol along with quadrature phase shift key (QPSK) spreading of the covered symbols.
    Type: Grant
    Filed: November 24, 1993
    Date of Patent: February 3, 1998
    Assignee: Qualcomm Incorporated
    Inventors: Klein S. Gilhousen, Irwin M. Jacobs, Roberto Padovani, Lindsay A. Weaver, Jr., Charles E. Wheatley, III, Andrew J. Viterbi
  • Patent number: 5659569
    Abstract: A method and system, for use in a communication system in which data is transmitted in data frames of a predetermined time duration, for the positioning of the data within the data frames for transmission. A computation circuit computes according to the deterministic code a pseudorandom position for the data within each data frame. A positioning circuit positions the data within each data frame in the computed position.
    Type: Grant
    Filed: February 14, 1994
    Date of Patent: August 19, 1997
    Assignee: QUALCOMM Incorporated
    Inventors: Roberto Padovani, Yu-Cheun Jou, Daniel Ray Kindred, John G. McDonough, Timothy Irvin Rueth
  • Patent number: 5623515
    Abstract: A data communication system comprises a main device with a first microcomputer and an operating device with a second microcomputer. The devices are connected to each other by a first wire and by a second wire. In addition to that, input interrupt terminals of both devices are connected to the second wire. One device starts the sending of data by pulling the second wire to a first level, the detection of this by the other device is signalled back via the first wire and both devices then start an internal timer. When a predetermined time, corresponding to a data item to be sent, has lapsed the sending device pulls the second line again to the first level. This is detected by the other device, which measures the lapsed time and which uses this time to determine the data item sent by consulting preset conversion rules, that give a relation between time and a data element.
    Type: Grant
    Filed: June 30, 1994
    Date of Patent: April 22, 1997
    Assignee: U.S. Philips Corporation
    Inventor: Kenichi Seto
  • Patent number: 5581547
    Abstract: Mobile stations randomly set delay amounts for each message to be sent, on the basis of the timing of a symbol received from a base station, and delay transmission signals for time intervals corresponding to the delay amounts. The base station 11 despreads signals received from the mobile stations to extract basic symbol timing for each mobile station and, at the thus extracted timing, takes each despread output into the corresponding demodulator for demodulation.
    Type: Grant
    Filed: October 25, 1994
    Date of Patent: December 3, 1996
    Assignee: NTT Mobile Communications Network Inc.
    Inventors: Narumi Umeda, Youichi Douzono, Tadashi Matsumoto
  • Patent number: 5535239
    Abstract: A method and system, for use in a communication system in which data is transmitted in data frames of a predetermined time duration, for the positioning of the data within the data frames for transmission. A computation circuit computes according to the deterministic code a pseudorandom position for the data within each data frame. A positioning circuit positions the data within each data frame in the computed position.
    Type: Grant
    Filed: August 16, 1994
    Date of Patent: July 9, 1996
    Assignee: Qualcomm Incorporated
    Inventors: Roberto Padovani, Yu-Cheun Jou, Daniel R. Kindred, John G. McDonough, Timothy I. Rueth