Plural Demodulation Patents (Class 329/316)
  • Patent number: 10523261
    Abstract: An electronic device includes an antenna configured to receive a wireless signal. The electronic device also includes a first correlator configured to correlate the wireless signal to a communication of a first wireless protocol type and a second correlator configured to correlate the wireless signal to a communication of a second wireless protocol type.
    Type: Grant
    Filed: March 31, 2016
    Date of Patent: December 31, 2019
    Assignee: APPLE INC.
    Inventors: Tushar Ramanlal Shah, Joseph Hakim
  • Patent number: 10466338
    Abstract: A method for detecting the presence of a signal in a frequency spectrum is provided. The method includes receiving the frequency spectrum. The power spectral density of the received frequency spectrum is estimated. A plurality of frequency bins are segmented for the frequency spectrum based on the estimated power spectral density. For segments with an estimated power spectral density above a first threshold, a radar spectral signature matching algorithm is applied to detect the presence of the signal and for segments with a power estimate below the first threshold and above a second threshold, additional techniques are applied to detect the presence of the signal.
    Type: Grant
    Filed: May 31, 2017
    Date of Patent: November 5, 2019
    Assignee: CommScope Technologies LLC
    Inventors: Khalid W. Al-Mufti, Ariful Hannan, Thomas B. Gravely, Navin Srinivasan
  • Patent number: 10404321
    Abstract: Aspects of the subject disclosure may include, for example, a system for receiving first electromagnetic waves via a transmission medium without utilizing an electrical return path, and inducing second electromagnetic waves at an interface of the transmission medium without the electrical return path. In an embodiment, the first and second electromagnetic waves have a non-optical frequency range. Other embodiments are disclosed.
    Type: Grant
    Filed: July 18, 2017
    Date of Patent: September 3, 2019
    Assignee: AT&T Intellectual Property I, L.P.
    Inventors: Robert Bennett, Paul Shala Henry, Farhad Barzegar, Irwin Gerszberg, Donald J. Barnickel, Thomas M. Willis, III
  • Patent number: 10340962
    Abstract: Under one aspect, a method for reducing interference in a received signal can include splitting a received signal into a first portion and a second portion, the received signal comprising a desired signal and an interference signal that spectrally overlaps the desired signal. The method also can include estimating an amplitude A(t) of the first portion as a function of time. The method also can include suppressing at least a portion of the interference signal in the estimated amplitude A(t) to generate an interference suppressed amplitude A?(t). The method also can include delaying the second portion by an amount of time corresponding to the estimation and suppression. The method also can include multiplying the interference suppressed amplitude A?(t) by the delayed second portion to obtain an output having reduced contribution from the interference signal.
    Type: Grant
    Filed: May 6, 2016
    Date of Patent: July 2, 2019
    Assignee: The Aerospace Corporation
    Inventors: Alexander C. Utter, Philip Dafesh, Phillip Brian Hess
  • Patent number: 10142981
    Abstract: A signal that is transmitted to a terminal apparatus itself is demodulated with high precision, and throughput is improved. A terminal apparatus that communicates with a base station apparatus includes a signal detection unit that demodulates a signal that is transmitted to the terminal apparatus itself, based on first modulation mapping in a case where a predetermined transmission mode is configured, and that demodulates a signal based on second modulation mapping in a case where a transmission mode other than the predetermined transmission mode is configured.
    Type: Grant
    Filed: February 24, 2016
    Date of Patent: November 27, 2018
    Assignee: SHARP KABUSHIKI KAISHA
    Inventors: Tomoki Yoshimura, Katsuya Kato, Osamu Nakamura, Ryota Yamada, Hiromichi Tomeba, Jungo Goto, Yasuhiro Hamaguchi
  • Patent number: 9722662
    Abstract: A semiconductor device and a serial data transmission line system have a reception circuit and an adaptive equalizer circuit. A supply source of a power supply supplied with the reception circuit is selected based on correction intensity of the correction value calculated by the adaptive equalizer circuit. When correction intensity of the correction value calculated by the adaptive equalizer circuit is not less than a threshold value, the supply source of the power supply supplied to the reception circuit and the adaptive equalizer circuit is switched, and a noise level of the power supply is reduced.
    Type: Grant
    Filed: December 17, 2014
    Date of Patent: August 1, 2017
    Assignee: Renesas Electronics Corporation
    Inventor: Toshifumi Yamaoka
  • Patent number: 9712356
    Abstract: A wireless transmission having a header and a payload is sent by transmitting a preamble of the header with a first modulation, wherein the preamble carries a coded modulation indicator. The payload and a remainder of the header are transmitted with a modulation associated with the coded modulation indicator. When the transmission is received, the preamble is demodulated in accordance with the first modulation. The coded modulation indicator is then decoded, and the payload and the remainder of the header are demodulated in accordance with the modulation indicated by the decoded modulation indicator.
    Type: Grant
    Filed: January 27, 2016
    Date of Patent: July 18, 2017
    Assignee: Texas Instruments Incorporated
    Inventors: Kumaran Vijayasankar, Timothy M. Schmidl, Ramanuja Vedantham
  • Patent number: 9432172
    Abstract: Methods and systems are provided for simple cable phone and internet (SCPI) device that may be coupled with a cable modem (CM) and one or more SCPI head ends, e.g., via an SCPI access point. The CM may be capable of communicating a first modulated signal with a cable modem termination system (CMTS), via the SCPI device. The SCPI device may be capable of combining a second modulated signal to the first modulated signal thereby generating a combined signal. The SCPI device may be capable of sending the combined signal comprising the first modulated signal and the second modulated signal to the CMTS and an SCPI head end. The SCPI head end may be capable of processing the combined signal and extract information and/or data associated with a service. The SCPI head end may deliver the extracted information and/or data to an appropriate gateway.
    Type: Grant
    Filed: November 20, 2014
    Date of Patent: August 30, 2016
    Assignee: REMBRANDT WIRELESS TECHNOLOGIES, LP
    Inventors: Gordon Bremer, Paul Schneck
  • Patent number: 9082057
    Abstract: A Radio Frequency Identification (RFID) system according to one embodiment includes communication circuitry for enabling wireless communication with an RF reader; energy harvesting circuitry for generating an electric current from RF energy; a sensor loop coupled to the energy harvesting circuitry; and a status register coupled to the sensor loop for indicating a broken or unbroken status of the sensor loop. A method according to one embodiment includes generating an electric current in a Radio Frequency Identification (RFID) device, the current energizing a sensor loop; detecting a status of whether the sensor loop is broken or unbroken; storing the status in at least one of a status register and a nonvolatile memory; receiving a query from an RFID reader for the status; and sending the status to the RFID reader.
    Type: Grant
    Filed: August 19, 2010
    Date of Patent: July 14, 2015
    Assignee: Intelleflex Corporation
    Inventor: Michael McGregor
  • Patent number: 8149975
    Abstract: A system for identifying at least one phase transition in a phase-shift keying signal comprising a plurality of data samples corresponding to phase values. The system comprises a memory operable to store computing device executable instructions; and a computing device. The computing device is operable to generate a first falling edge region function for each data sample; generate a first rising edge function for each data sample; generate a first level function for each data sample; and generate a second falling edge function for each data sample. The second falling edge function equals the first falling edge function if the first falling edge function is greater than the first rising edge function and the first level function, and the second falling edge function equals zero.
    Type: Grant
    Filed: September 14, 2009
    Date of Patent: April 3, 2012
    Assignee: L3 Communications Integrated Systems L.P.
    Inventor: Stephen Ha
  • Patent number: 7912144
    Abstract: A modulating means for modulating and/or demodulating data for transmission from a first device to a second device, wherein the modulating means is capable of modulating and/or demodulating data according to at least a first and a second modulation technique.
    Type: Grant
    Filed: August 25, 2003
    Date of Patent: March 22, 2011
    Assignee: Samsung Electronics Co., Ltd
    Inventors: Terence Edwin Dodgson, Charles Tibenderana
  • Patent number: 7899134
    Abstract: In general, this disclosure describes techniques for demodulating wireless signals. In particular, the techniques of this disclosure dynamically select between two or more demodulators based on channel quality information measured over a plurality of measurement periods. For example, a wireless communication device (WCD) may switch from a first demodulator to a second demodulator when the channel quality information associated with the demodulators indicates a better channel quality for the second demodulator than the first demodulator for a consecutive number of measurement periods. As another example, the WCD may compute, for each measurement period, the difference between the channel quality information associated with each of the demodulators, sum the differences, and switch demodulators when the total accumulation of the differences exceeds a threshold.
    Type: Grant
    Filed: February 27, 2007
    Date of Patent: March 1, 2011
    Assignee: QUALCOMM, Incorporated
    Inventors: Nathaniel Lev Grossman, Gokhan Mergen, Nitin Kasturi
  • Publication number: 20100323648
    Abstract: A device mitigates reduction in reception performance caused by a harmonic component of a clock used for demodulation. The device includes a tuner performing frequency conversion by multiplying a received signal by a signal having a frequency corresponding to a frequency of a desired signal included in the received signal, and outputting the obtained frequency-converted signal; and a demodulation section generating a demodulated signal by demodulating the frequency-converted signal. The demodulation section operates in response to a master clock having a frequency corresponding to the frequency of the desired signal.
    Type: Application
    Filed: November 18, 2008
    Publication date: December 23, 2010
    Inventors: Haruka Takano, Shigeru Soga
  • Patent number: 7852912
    Abstract: A direct determination equalizer system (“DDES”) for compensating for the deterministic effects of a transmission channel and a data source is disclosed. The DDES may include an equalizer having equalizer-tap coefficients, a cross-correlator configured to receive the first sampled signal and an ideal signal and in response produce a cross-correlated signal, and a processor in signal communication with the equalizer and the cross-correlator. The equalizer is configured to receive a first sampled signal and in response produce an equalized output data signal sequence and the processor is configured to determine the equalizer-tap coefficients from the cross-correlated signal.
    Type: Grant
    Filed: March 25, 2005
    Date of Patent: December 14, 2010
    Assignee: Agilent Technologies, Inc.
    Inventors: Mark J. Woodward, Marlin E. Viss
  • Patent number: 7804376
    Abstract: Various example embodiments are disclosed herein. According to an example embodiment, a method may include receiving a plurality of data symbols, generating a continuous phase modulated waveform based on the data symbols, generating a plurality of coefficients which represent the continuous phase modulated waveform, and wirelessly transmitting the plurality of coefficients via a plurality of subcarriers.
    Type: Grant
    Filed: December 13, 2007
    Date of Patent: September 28, 2010
    Assignee: Nokia Siemens Networks Oy
    Inventors: Marilynn P. Green, Anthony Reid
  • Patent number: 7751303
    Abstract: Disclosed is a demodulation circuit for demodulating an IF signal which is input via an antennal and then over-sampled at a sampling rate four times a frequency of a baseband signal, the demodulation circuit including a mixer for converting the IF signal down to a baseband signal using a coefficient corresponding to either sine values or cosine values, a DEMUX for dividing the down-converted baseband signal into a plurality of signals, and a PPF having a plurality of sub-filters for filtering the divided signals input from the DEMUX and a plurality of adders for operating the output signals of the sub-filters. As a result, the demodulation circuit can be realized in a small hardware size and is capable of reducing power consumption.
    Type: Grant
    Filed: February 17, 2006
    Date of Patent: July 6, 2010
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Shi-chang Rho, Kwang-chul Kim, Jeong-taek Lee
  • Patent number: 7664171
    Abstract: A method for uplink burst equalization in broad wide access system, using the form of combining pre-training and burst equalization, that is, before transmitting user data, training the equalizer, then starting transmitting user data, in which, the equalizer uses decision user data as reference to track the changed wireless channel; if the change of channel exceeds the tracking region of equalizer, for example, the error rate exceeds threshold 1 but doesn't exceed threshold 2, the burst equalization will be performed; if the channel change exceeds the equalization region of equalizer, for example, the error rate exceeds threshold 2, the training will be performed again.
    Type: Grant
    Filed: December 26, 2003
    Date of Patent: February 16, 2010
    Assignee: ZTE Corporation
    Inventors: Changyin Sun, Yunfeng Wang
  • Patent number: 7653152
    Abstract: Apparatus and methods for data demodulation in FM-FSK communication systems may include comparing the power spectral density (PSD) of the received frequency spectrum with that of the previously received samples using digital signal processing on a multi-sample message. A narrow band FM-FSK receiver may include a filter configured to pass FM signal components of a predetermined signal band, a memory configured to store the filtered signal component, and a DSP operably connected to the filter and the memory. The DSP may be configured to output a digital signal based upon a comparison of successive DSP calculated frequencies associated with a peak power of a power spectrum density (PSD) of successive samples of the filtered multi-sample message.
    Type: Grant
    Filed: July 25, 2006
    Date of Patent: January 26, 2010
    Inventor: Abdullah A. Al-Eidan
  • Publication number: 20100013553
    Abstract: A diversity receiver includes: a plurality of demodulating means for demodulating inputted OFDM signals, to output their demodulated signals; noise component calculating means provided for each demodulating means, for calculating noise components included in the demodulated signals outputted from corresponding demodulating means; channel profile calculating means provided for each demodulating means, for calculating channel profiles based upon the demodulated signals outputted from corresponding demodulating means; transmission channel decision means for determining transmission channel based upon the channel profiles; reliability information generating means for generating reliability information indicating reliability of the demodulated signals outputted from each demodulating means, based upon the noise components and the results of the determinations by the transmission channel decision means; a weighting factor calculating means for calculating, depending on the reliability information, weighting factors
    Type: Application
    Filed: September 8, 2009
    Publication date: January 21, 2010
    Inventors: Jun IDO, Mitsuru Takeuchi
  • Patent number: 7570716
    Abstract: In a data carrier (1) which includes receiving means (5) for receiving a modulated carrier signal (MTS) which contains a data signal (DS1) encoded in conformity with an encoding method (MA, PW, MI, RTZ, FSK, PSK), demodulation means (9) for demodulating the received modulated carrier signal (MTS) and for outputting the encoded data signal (DS1) contained therein, decoding means (10, 20) for decoding the encoded data signal (DS1) and for outputting data (D1, D2), and data processing means (11) for processing the data (D1, D2) output by the decoding means (10, 20), the decoding means (10, 20) are provided with at least a first decoding stage (12) and a second decoding stage (13), the first decoding stage (12) being arranged to decode a data signal (DS1) encoded in conformity with a first method (RTZ) whereas the second decoding stage (13) is arranged to decode a data signal (DS1) encoded in conformity with a second method (MI).
    Type: Grant
    Filed: January 19, 2000
    Date of Patent: August 4, 2009
    Assignee: NXP B.V.
    Inventors: Franz Amtmann, Dominik J. Berger, Wolfgang Eber, Stefan Posch, Robert Rechberger
  • Patent number: 7133467
    Abstract: The number of spreading codes multiplexed in a received signal is detected, and switches 4 and 5 are switched to the RAKE demodulation section 2 side if the detected number of spreading codes is less than a predetermined threshold value, and to the JD demodulation section 3 side if greater than or equal to the predetermined threshold value. As a result, joint detection demodulation is used only when the number of multiplexed spreading codes is large—that is, when the number of users is large—and consequently power can be saved during demodulation.
    Type: Grant
    Filed: September 27, 2001
    Date of Patent: November 7, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Akihiko Nishio, Hideo Fujii, Masaki Hayashi
  • Patent number: 7068990
    Abstract: The inventive receiver has a receiving branch for each of the two signals (EH, EV) and a demodulator (MHE, MVE) and means (SH, SV) for synchronising the phase of the received signal (EH, EV) with the transmitting phase are provided in said branches, respectively. Polaristion decouplers (XPIC-VH, XPIC-HV) which compensate cross-polar crosstalk between the two received signals (EH, EV) are provided for both of the receiving branches. The polarisation decoupling (XPIC-VH, XPIC-HV) of the two received signals (EH, EV) takes place after they have been demodulated (MHE, MVE) and before they have been phase-synchronised (SH, SV) so that the receiver can function as inexpensively as possible in terms of the components that it requires and so that it can also compensate cross polar channel crosstalk for circular QAM signal constellations.
    Type: Grant
    Filed: June 8, 2000
    Date of Patent: June 27, 2006
    Assignee: Marconi Communications GmbH
    Inventor: Gerhard Herbig
  • Patent number: 7016661
    Abstract: The present invention provides a multimode receiver design for mitigation of frequency offset by selective demodulation of an input modulated signal. The receiver (103) comprises a plurality of demodulators (207). Each of the plurality of demodulators (207) has the same functionality but different receiver sensitivity versus frequency-offset mitigation characteristics. Each of these demodulators incorporates a different demodulation technique. A suitable demodulator is selected to demodulate the received signal. The choice of a suitable demodulator is based on the value of the frequency offset (305, 307).
    Type: Grant
    Filed: October 10, 2003
    Date of Patent: March 21, 2006
    Assignee: Motorola, Inc.
    Inventors: Paul E. Gorday, Edgar Herbert Callaway, Jr., Frederick L. Martin, Qicai Shi
  • Patent number: 6927623
    Abstract: To improve the quality of the demodulated signal without altering the form in which an AM radio wave is transmitted, the received amplitude-modulated signal is converted to a single-sideband signal, and the information signal demodulated from the phase term of this converted single-sideband signal.
    Type: Grant
    Filed: October 18, 2002
    Date of Patent: August 9, 2005
    Assignees: Nippon Hoso Kyokai, NHK Engineering Services, Inc., RCOM Corporation, Japan Kyastem Co., Ltd.
    Inventors: Yasuhiro Ito, Yasuaki Nishida, Takashi Ando, Kazuhiro Daikoku, Shinichi Hosoya
  • Patent number: 6912249
    Abstract: A system and method for training a radio receiver to mitigate the effects of ISI caused by multi-path includes receiving a header of a transmitted packet at the receiver, the header containing at least one flag to identify a corresponding reference training sequence to be selected by the receiver and to indicate whether a training sequence is inserted in a packet. The receiver decodes the header to determine whether a training sequence is indicated by the flag and to select the corresponding reference training sequence. The training sequence is transmitted positioned within a data packet at a midamble between the header and a first segment of the data packet. The received training sequence is compared with the selected reference training sequence and the equalization parameters of the receiver are adjusted based on the results of the comparison. The selected reference training sequence corresponds to the modulation scheme applied to the payload.
    Type: Grant
    Filed: March 15, 2001
    Date of Patent: June 28, 2005
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventor: Jacobus Haartsen
  • Patent number: 6901108
    Abstract: An adaptive controller generates a sequence of dither signals for each of a plurality of control parameters. Each dither signal sequence is uncorrelated with every other dither signal sequence. Each nominal control signal has the first of its respective dither signal values simultaneously summed with it to form the control parameter values used by the controller. Updated control signals are applied in parallel to the controller outputs and a performance measure is taken and stored. The second signals in the dither control sequences are then summed with their respective nominal controls and applied in parallel to the controller and a second performance measure is taken and stored. This process is repeated for the length of the dither control signal sequence to yield a sequence of performance measurements. The sequence of performance measurements is correlated with each of the dither sequences, forming sequences of correlator outputs, one for each control signal.
    Type: Grant
    Filed: May 4, 2001
    Date of Patent: May 31, 2005
    Assignee: Lucent Technologies Inc.
    Inventors: James Russell Blodgett, Gerald L. Frazer, Michael W Goodwin, Karen E. Leonard, James P Moffatt, Fan Zhang
  • Patent number: 6809584
    Abstract: A demodulator for demodulating a modulated input signal transmitted at a carrier frequency includes a current mirror for receiving the modulated input signal and generating a first and a second current-mirror output signals of same amplitude and frequency as the modulated input signal. The demodulator further includes a first and a second switch-controlled sampling circuits connected to the current mirror for receiving the first and second current mirror output signals respectively. The demodulator further includes a switching signal generator provided for generating a first and a second switch control signals having a frequency substantially equals to the carrier frequency with a flexibly adjustable phase difference between the first and the second switch control signals.
    Type: Grant
    Filed: October 31, 2002
    Date of Patent: October 26, 2004
    Inventor: Jeng-Jye Shau
  • Patent number: 6628706
    Abstract: Channel estimation is performed for a received signal, wherein different parts of the received signals are modulated using different modulation types. The channel is first estimated based on part of a received signal modulated with a first modulation type. This channel estimate is then transformed into a channel estimate corresponding to at least a second modulation type.
    Type: Grant
    Filed: December 6, 1999
    Date of Patent: September 30, 2003
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventor: Bengt Lindoff
  • Patent number: 6593805
    Abstract: A demodulation apparatus of the present invention comprises: an A/D converter for sampling and quantizing a baseband signal; a transversal filter having time-shifted tap coefficients; a decision unit for decoding the signal which has undergone the transversal filter; and a decision point estimation unit for instructing the transversal filter to select the tap coefficient to be selected based on information from the decision unit. Thus, the demodulation apparatus can operate at the same frequency as a sampling frequency of the A/D converter and can perform decision with accuracy equivalent to an arbitrary oversampling number.
    Type: Grant
    Filed: May 9, 2001
    Date of Patent: July 15, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yoshinori Kunieda, Kazuo Tomita, Hidekuni Yomo
  • Patent number: 6483381
    Abstract: This invention discloses a demodulation method. The method includes steps of: A) Receiving a modulated input signal having an input signal frequency. B) Generating a first switch control signal at a first switching frequency substantially equal to the input signal frequency. C) Generating a second switch control signal having the same frequency as the first switch control signal and having a phase that is approximately 90 degrees different from a phase of the first switch control signal. And D) Controlling at least two switching circuits with the first and second switch control signals for obtaining at least two sets of sampled amplitudes of the input signals for generating switching output signals for each of the switching circuits defined by subtracting the sampled amplitudes when the first switch control signal is high by the sampled amplitudes when the first switch control signal is low for each of the switching circuits to generate demodulated output signals for the modulated input signal.
    Type: Grant
    Filed: October 22, 1997
    Date of Patent: November 19, 2002
    Inventor: Jeng-Jye Shau
  • Patent number: 6459333
    Abstract: An FM demodulator in accordance with the present invention receives a composite signal from an antenna and corresponding processing circuitry. The composite signal includes a carrier signal having a voice/data signal modulated thereon. The composite signal is processed to separate the voice/data signal from the carrier signal. The voice/data signal is separated into an in-phase (I) signal and a quadrature (Q) signal. The Q signal is differentiated and then divided by the I signal to obtain the voice/data signal. Alternatively, I signal is differentiated and then divided by the Q signal to obtain the voice/data signal.
    Type: Grant
    Filed: February 5, 2001
    Date of Patent: October 1, 2002
    Assignee: Motorola, Inc.
    Inventor: Shahriar Emami
  • Patent number: 6373883
    Abstract: A radio receiver is adapted to receive radio signals in at least two frequency bands, in which the radio signals are modulated by information signals. The radio receiver includes a device for down-converting a received radio signal to an intermediate frequency signal by using a local oscillator, and a demodulating device for recovering the information signals from the intermediate frequency signal. The frequency of the local oscillator is selected so that the frequencies of at least one of the frequency bands are above the frequency of the local oscillator, and the frequencies of at least one of the frequency bands are below the frequency of the local oscillator.
    Type: Grant
    Filed: January 22, 1999
    Date of Patent: April 16, 2002
    Assignee: Robert Bosch GmbH
    Inventors: Henrik Soerensen, Michael Brammer
  • Patent number: 6297691
    Abstract: A receiver receives modulated message signals in non-coherent FSK and coherent 8PSK protocols. A selectively configurable processor demodulates the message signals, and includes a demodulator that derives in-phase and quadrature signals based on the message signals. A phase detector is responsive to the in-phase and quadrature signals and delayed in-phase and quadrature signals to derive a phase signal. A selector is responsive to the in-phase and quadrature signals to selectively connect a loop filter between the phase detector and the demodulator. When the selector connects the filter between the phase detector and demodulator, the demodulator is responsive to filtered phase signals to lock onto a frequency of the message signals so that the processor operates as a phase locked loop to demodulate coherent modulated signals.
    Type: Grant
    Filed: June 9, 2000
    Date of Patent: October 2, 2001
    Assignee: Rosemount Inc.
    Inventors: Stephen D. Anderson, Daniel V. Hulse, Kevin B. Moore, Paul D. Kammann, Gabriel A. Maalouf
  • Patent number: 6204735
    Abstract: A novel communications method for generating specific unique information containing waveforms, for geometrically modulating a signal with those waveforms, and an apparatus for generating the waveforms, geometrically modulating carrier waves with those waveforms, or broadcasting the novel waves by RF, microwave, electric cable, or fiberoptic conduits.
    Type: Grant
    Filed: May 14, 1999
    Date of Patent: March 20, 2001
    Assignee: Quantum Optics Corporation
    Inventor: John P. Cairns
  • Patent number: 6167081
    Abstract: A demodulation subsystem includes an equalizing demodulator and a non-equalization demodulator, each of which receive a baseband signal, and an output control selector that selects the output of one of the equalizing demodulator and the non-equalizing demodulator based on a bit error rate of the signal.
    Type: Grant
    Filed: September 3, 1999
    Date of Patent: December 26, 2000
    Inventors: James L. Porter, John W. Diehl, Wayne H. Bradley
  • Patent number: 6163209
    Abstract: A technique for demodulating a message signal from an angle modulated carrier signal. A noncoherent, independent, periodic reference is generated to have a predetermined phase characteristic and which is noncoherent with and independent of the angle modulated carrier signal. The phase of the reference is then compared with the phase of the carrier to determine the message signal on the angle modulated carrier. The phase of the noncoherent, independent, periodic reference is associated with a measured value for the reference. The phase of the angle modulated carrier signal is associated with a voltage value for the angle modulated carrier signal. These values are measured and then compared to determine the message signal on the modulated carrier signal. Time variations of the comparison of values are directly related to the message signal in the case of a PM carrier. Changes in the time variations of the voltage comparison are related to the message signal for a FM carrier.
    Type: Grant
    Filed: December 17, 1998
    Date of Patent: December 19, 2000
    Inventor: Glen A. Myers
  • Patent number: 6037835
    Abstract: A method for multi-mode autonomous selection demodulation is disclosed. The method includes the step of providing a receiver with demodulation circuitry (110-112) capable of demodulating a plurality of waveform modulation techniques. The method also includes the step of receiving a modulated information waveform and a preamble associated with the modulated information waveform. The method also includes the steps of matching the preamble against a predefined set of patterns corresponding to a plurality of modulation techniques at the receiver and identifying a corresponding demodulation technique. Additionally, the method configures the demodulation circuitry (110-112) to apply the corresponding demodulation technique to the modulated information waveform.
    Type: Grant
    Filed: May 12, 1998
    Date of Patent: March 14, 2000
    Assignee: TRW Inc.
    Inventors: Ronald P. Smith, Mark Kintis, Harvey L. Berger
  • Patent number: 6005896
    Abstract: A radio data communication device that can perform a packet communication with the packet configuration suitable for transmission of a large volume of data in packet communications utilizing a low rate transmission mode and a high rate transmission mode. The transmitter side transmits packets only in a low rate mode or in a high rate mode after transmission in a low rate mode or only in a high rate mode. The receiver side simultaneously demodulates packets in the low rate mode and the high rate mode to detect the synchronous signal for each mode and judges whether or not in which mode the data has been transmitted, thus selecting the successive receive mode.
    Type: Grant
    Filed: November 26, 1997
    Date of Patent: December 21, 1999
    Assignee: NEC Corporation
    Inventor: Hidenori Maruyama
  • Patent number: 5987068
    Abstract: In a radio communication system (100), enhanced communication capability is provided while maintaining standard channel modulation compatibility. At a transmitter (110, 200, 600), a first information signal is generated from data according to a predefined standard modulation scheme (212, 613). A second information signal is generated from data that provides supplemental information to the standard modulated data (213, 616). For transmission, the first and second information signals are combined into a composite signal (214, 619) that represents the first information signal when interpreted according to the predefined standard modulation scheme.
    Type: Grant
    Filed: November 8, 1996
    Date of Patent: November 16, 1999
    Assignee: Motorola, Inc.
    Inventors: Simon Hugh Cassia, Andrew John Aftelak, Boon Tiong Tan, Kwan Yee Lee
  • Patent number: 5920238
    Abstract: A novel communications method for generating specific unique information containing waveforms, for geometrically modulating a signal with those waveforms, and an apparatus for generating the waveforms, geometrically modulating carrier waves with those waveforms, or broadcasting the novel waves by RF, microwave, electric cable, or fiberoptic conduits.
    Type: Grant
    Filed: October 8, 1996
    Date of Patent: July 6, 1999
    Assignee: Quantum Optics Corporation
    Inventor: John P. Cairns
  • Patent number: 5767738
    Abstract: A receiver (156) includes both a coherent and noncoherent demodulator. When the confidence that estimates of the channel is high, the coherent demodulator is implemented. When the confidence that estimates of the channel is low, the noncoherent demodulator is implemented. A controlling microprocessor (162) controls the selection process and also provides a signal (158) to enable the noncoherent demodulator in instances when noncoherent demodulation would most likely be better than coherent demodulation. As an example, such an instance would be immediately after handoff of a mobile station (505) from a source base-station (503) to a target base-station (502).
    Type: Grant
    Filed: October 21, 1996
    Date of Patent: June 16, 1998
    Assignee: Motorola, Inc.
    Inventors: Tyler A. Brown, Dennis J. Thompson, Fuyun Ling
  • Patent number: 5745005
    Abstract: A communication device which is capable of automatically discriminating whether a received signal is a carrier-wave-modulated signal or a single-pulse-modulated signal and obtaining a corresponding demodulated signal, thereby reducing a burden to a user in using the device. The device comprises a demodulating circuit for demodulating a carrier-wave-modulated signal, a demodulating circuit for demodulating single-pulse-modulated signal, a switch circuit for selecting either of two demodulating circuits and a carrier detecting circuit for detecting the presence or absence of a carrier-frequency component of the carrier-wave-modulated signal, characterized that the switch circuit selects an output of the demodulating circuit for the carrier-wave-modulated signal when the carrier of the carrier-wave-modulated signal is detected by the carrier detecting circuit.
    Type: Grant
    Filed: June 14, 1996
    Date of Patent: April 28, 1998
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Masayuki Natsumi
  • Patent number: 5697086
    Abstract: A combination of two phase-lock loops, and a cancellation circuit are used to remove a dominant FM signal from within a signal environment. The two phase-lock loops together produce a replica of the highest power (i.e. dominant) FM signal. The cancellation circuit uses this replica in a demodulation, notch-filtering, and remodulation process to excise the dominant FM signal, leaving the other signal(s) undisturbed. Potential applications include co-channel FM signal/interference cancellation and optimizing utilization of RF spectrum.
    Type: Grant
    Filed: April 15, 1994
    Date of Patent: December 9, 1997
    Assignee: GTE Government Systems Corporation
    Inventor: Esteban O. Svoboda
  • Patent number: 5648985
    Abstract: An integrated circuit chip set is provided for use in a radio communication system in which a modulated digital input signal is processed for transmission and a modulated signal received from an antenna is processed to provide an output signal, wherein the modulation of the signals is either QPSK or FSK and the signal transmission and reception is by either TDD or FDD.
    Type: Grant
    Filed: November 30, 1994
    Date of Patent: July 15, 1997
    Assignee: Rockwell Semiconductor Systems, Inc.
    Inventors: Bjorn E. Bjerede, Joseph T. Lipowski, Benny Madsen, Sheldon L. Gilbert, James E. Petranovich
  • Patent number: 5648986
    Abstract: A digital radio communication device which prevent deterioration of an error rate of a demodulated signal caused by equalization processing of an output of a digital demodulation circuit, and that can always provide optimal reception regardless of presence or absence of delayed waves. A bit error estimation circuit 6 estimates a bit error of demodulated serial data S3 output by the digital demodulation circuit 6 and outputs results of estimation to a control circuit 7 as an estimated bit error signal S5. The control circuit 7 switches a selector 9 through a selector control signal S6 generated on the basis of the estimated bit error signal S5 and the received field strength indicator signal S2 from a reception circuit 2 so as to select the demodulated serial data S3 or S4 output by either the digital demodulation circuit 6 or the equalizer 5 for output as demodulated data S7.
    Type: Grant
    Filed: December 19, 1995
    Date of Patent: July 15, 1997
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kaoru Tatsumi, Kazuo Yamamoto
  • Patent number: 5615411
    Abstract: A composite signal recognizer, separator, and FM demodulator apparatus for processing received radio signals. The receiver utilizes N demodulators to process a received signal, where N is equal to or greater than the number of co-channel signals or perceived interference. Detailed in both cross-coupled and cascaded fashion, the receiver first tracks to a predominant (stronger) signal, and regeneratively improves track on other (weaker) signals by subtracting the predominant signal or the predominant noise portion from the input of further demodulation stages.
    Type: Grant
    Filed: April 22, 1994
    Date of Patent: March 25, 1997
    Assignee: Rockwell International
    Inventor: Duane L. Abbey
  • Patent number: 5602484
    Abstract: A multipath component detector detects the correlation between a received signal and a reference signal in a training period of the received signal and estimates and outputs the multipath received component levels at a plurality of timing points. A component ratio calculator calculates the ratio of each received component to the overall received power. By this, the level ratio of a specified received component can be detected. Power dissipation can be minimized by switching the detector to a differential detector or an adaptive equalizer in accordance with the result of the delay spread measurement.
    Type: Grant
    Filed: January 18, 1995
    Date of Patent: February 11, 1997
    Assignee: NTT Mobile Communications Network Inc.
    Inventors: Hiroshi Suzuki, Kazuhiko Fukawa
  • Patent number: 5594755
    Abstract: Apparatus for use in equipment providing digital radio link between a fixed radio unit and a mobile radio unit. The apparatus includes demodulators arranged to receive inphase and quadrature phase input signals. A channel estimator is provided for deriving a decision directed channel estimate from one or more signals which is used by the demodulator for demodulating one or more of the signals transmitted over the same radio channel. The apparatus is for use in the demodulation of dual binary phase shift keying signals and various embodiments are possible. In addition, the apparatus may be used in conjunction with precombining Rake architecture.
    Type: Grant
    Filed: August 18, 1994
    Date of Patent: January 14, 1997
    Assignee: Roke Manor Research Limited
    Inventor: Anthony P. Hulbert
  • Patent number: 5563556
    Abstract: A novel communications method for generating specific unique information containing waveforms, for geometrically modulating a signal with those waveforms, and an apparatus for generating the waveforms, geometrically modulating carrier waves with those waveforms, or broadcasting the novel waves by RF, microwave, electric cable, or fiberoptic conduits.
    Type: Grant
    Filed: September 27, 1995
    Date of Patent: October 8, 1996
    Assignee: Quantum Optics Corporation
    Inventor: John P. Cairns
  • Patent number: 5548243
    Abstract: A demodulator receives a radio signal and causes a carrier signal reproducing circuit to reproduce the carrier signal of the received signal. One amplifier amplifies the amplitude of the reproduced carrier signal by K, and another amplifies the amplitude of the reproduced carrier signal by (K+2). An adder adds the reproduced carrier signal, amplified by K, and the received signal. A subtracter subtracts the received signal from the reproduced carrier signal amplified by (K+2). The output signal of the adder is demodulated by a first FM demodulator and the output signal of the subtracter is demodulated by a second FM demodulator. Another subtracter outputs the difference between the demodulated signals from the first and second FM demodulators as a demodulated signal of the received signal.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: August 20, 1996
    Assignee: Icom Incorporated
    Inventors: Weimin Sun, Shigeki Kajimoto