Angle Modulation Patents (Class 375/271)
  • Patent number: 7835468
    Abstract: A radio receiver includes a processing unit that may generate a respective phase value corresponding to each of a plurality of digital samples of a received complex frequency modulation (FM) signal. The receiver also includes an impulse unit that may detect whether a linear combination of a phase value of a current sample and a phase value of one or more previous samples will produce an impulse at an output of an FM demodulator. If the impulse unit detects that an impulse will be produced at the output, the impulse unit may replace the output of the FM discriminator with a predetermined value.
    Type: Grant
    Filed: March 13, 2006
    Date of Patent: November 16, 2010
    Assignee: Silicon Laboratories, Inc.
    Inventors: Javier Elenes, Dana J. Taipale
  • Patent number: 7826550
    Abstract: Aspects of a method and system for a high-precision frequency generator using a direct digital frequency synthesizer for transmitters and receivers may include generating a second signal from a first signal by frequency translating an inphase component of the first signal utilizing a high-precision oscillating signal that may be generated using at least a direct digital frequency synthesizer (DDFS) and at least a Phase-Locked Loop (PLL). A corresponding quadrature component of the first signal may be frequency translated utilizing a phase-shifted version of the high-precision oscillating signal. The inphase component of the first signal may be multiplied with the high-precision oscillating signal and the quadrature component of the first signal may be multiplied with the phase-shifted version of the high-precision oscillating signal. The second signal may be generated from the first signal by adding the frequency translated inphase component to the frequency translated quadrature component.
    Type: Grant
    Filed: February 28, 2007
    Date of Patent: November 2, 2010
    Assignee: Broadcom Corp.
    Inventor: Ahmadreza Rofougaran
  • Publication number: 20100272208
    Abstract: Most modern integrated circuit transceivers, especially wireless LAN, utilize a direct conversion radio architecture, which is highly advantageous from the perspectives of cost and flexibility, there exist several performance impairments, including gain and phase imbalances between the in-phase (I) and quadrature (Q) of a transmitter or receiver. Disclosed herein is a signal processing methodology and system for compensation of I/Q imbalance for a direct conversion packet-switched OFDM communications system. The imbalance, which accounts for transmitter I/Q imbalance, RX I/Q imbalance, phase/frequency error, and dispersive multipath fading. Both frequency dependent I/Q imbalance and frequency independent cases are considered, covering both wideband and narrowband modulation. The proposed estimation algorithms operate within the fully compliant framework of existing multi-user OFDM radio standards (WLAN, LTE, WimAX).
    Type: Application
    Filed: December 18, 2008
    Publication date: October 28, 2010
    Inventors: Jeffrey Ross Feigin, David Paul Brady
  • Patent number: 7787551
    Abstract: An improvement for a phasor fragmentation engine and method, whereby a phasor flipping algorithm is applied when determining fragment phasors for a non-constant envelope modulation signal (e.g. OFDM). The phasor flipping algorithm avoids sharp phase transitions for the fragment phasors, which cause an increase in bandwidth, by performing a comparison of the phasor angle separation between the prior and current time samples. This comparison corresponds to a determination of whether the modulation signal V has passed near or through zero.
    Type: Grant
    Filed: July 17, 2006
    Date of Patent: August 31, 2010
    Inventors: Kevin R. Parker, Stephen R. Hobbs, Jean-Paul R. DeCruyenaere
  • Patent number: 7782964
    Abstract: A method for selecting a frequency band, from among a plurality of frequency bands controllable by a radio network controller (RNC), to carry a data communication. The method may include obtaining frequency band usage measurements for a plurality of frequency bands, and using the frequency band usage measurements to select a particular frequency band of the plurality of frequency bands to carry the data communication. Frequency band usage measurements may be based on how many idle slots (and/or data channels) are carried through each of the plurality of frequency bands during a measurement time period. A comparison of the frequency band usage measurements can be used to determine which frequency band sent the greatest number of idle slots (or the fewest number of data channels). The method provides for selecting a frequency band best suited (e.g., has the most available capacity for carrying a data communication) for carrying the data communication.
    Type: Grant
    Filed: August 9, 2005
    Date of Patent: August 24, 2010
    Assignee: Sprint Spectrum L.P.
    Inventors: Ryan S Talley, Kristin Hayne, Tom Trueman, Jerry Wade, Robert Pippert
  • Patent number: 7769096
    Abstract: A quadrature-multiplexed continuous phase modulation (QM-CPM) signal is made up of the real parts of two underlying CPM signals whose information content can be recovered from just their real parts. The real parts of two such signals are I/Q multiplexed and transmitted onto a single channel to approximately double the bits/Hz of the underlying CPM signals, while maintaining the same or similar minimum distance. A class of QM-CPFSK (QM-continuous phase frequency shift keyed) signals are presented that use binary signaling but more phase states, and M2-ary QM-CPFSK signals are derived from constant envelope M-ary CPFSK signals. M2-ary multi-amplitude CPFSK signaling schemes are constructed that maintain the same distance as known multi-amplitude CPFSK schemes, but more than double the bandwidth efficiency in bits/Hz. In addition to these CPFSK based embodiments, embodiments are provided that more generally use CPM, non-continuous phase modulated signals, and even trellis-based PAM based signals.
    Type: Grant
    Filed: November 22, 2006
    Date of Patent: August 3, 2010
    Assignee: Trellis Phase Communications, LP
    Inventors: John P. Fonseka, Eric Morgan Dowling
  • Patent number: 7715484
    Abstract: The invention relates to an orthogonal frequency division multiplexing system with PN-sequence. In the synchronization of the invention, both timing offset and frequency offset are estimated and compensated by utilizing a time and frequency synchronization device. In addition, the PN-sequence with the cyclic prefix is added to the OFDM symbol before transmitting. The time and frequency synchronization device of the invention comprises two synchronization circuits from the cyclic prefix and PN-sequence when calculating the timing offset and frequency offset of receiving signal. As a result, the OFDM system of the invention not only has better performance in fading channel, but also has the better bandwidth utilization without extra bandwidth for transmitting the PN-sequence.
    Type: Grant
    Filed: December 9, 2005
    Date of Patent: May 11, 2010
    Assignee: Industrial Technology Research Institute
    Inventors: Yun-Yen Chen, Chih-Peng Li, Wei-Wen Hu
  • Patent number: 7715483
    Abstract: A method of allocating sub-channel signal interleaving patterns to BSs forming a wireless communication system that divides a frequency band into a plurality of sub-carriers and including a plurality of sub-channels, which are a set of predetermined adjacent sub-carriers. The method includes: creating a basic orthogonal sequence having a length identical to a number of the sub-carriers forming the sub-channel; creating a plurality of sequences having a same length as the basic orthogonal sequence by cyclic-shifting the basic orthogonal sequence a predetermined number of times or performing a modulo operation based on a number of the sub-carriers forming the sub-channel, after adding a predetermined offset to the cyclic-shifted basic orthogonal sequence; selecting a predetermined number of sequences corresponding to a number of the BSs from among the plurality of sequences; and allocating the selected sequences as the sub-channel signal interleaving patterns for the BSs.
    Type: Grant
    Filed: March 11, 2005
    Date of Patent: May 11, 2010
    Assignee: Samsung Electronics Co., Ltd
    Inventors: Jae-Hee Cho, Jae-Ho Jeon, Soon-Young Yoon, Sang-Hoon Sung, Ji-Ho Jang, In-Seok Hwang, Hoon Huh, Jeong-Heon Kim, Seung-Joo Maeng
  • Patent number: 7702299
    Abstract: The amplitude modulator comprises: an angle modulator for angle-modulating a phase signal to be inputted; a waveform shaping means in which, (1) when the magnitude of an amplitude signal to be inputted becomes smaller than a first prescribed value, a waveform of the amplitude signal is shaped so that the magnitude of the amplitude signal of the portion which becomes small becomes the first prescribed value; and/or (2) the waveform shaping means in which, when the magnitude of the amplitude signal to be inputted becomes larger than the second prescribed value which is larger than the first prescribed value, the waveform of the amplitude signal is shaped so that the magnitude of the amplitude signal of the portion which becomes larger becomes the second prescribed value; and an amplitude modulator for amplitude modulating the signal of the output of the angle modulator by the signal of the output of the waveform shaping means.
    Type: Grant
    Filed: July 2, 2007
    Date of Patent: April 20, 2010
    Assignee: Panasonic Corporation
    Inventors: Toru Matsuura, Hisashi Adachi, Masaharu Udagawa
  • Patent number: 7664168
    Abstract: The present invention has an object enabling stable data communication hard to perform a malfunction in a simple circuit configuration which can miniaturize a system and does not need any strict accuracy by executing data communication in a connection using two terminals or less. The present invention is featured by being related to a data carrier device including a signal terminal for performing signal input from a data carrier driving device. The data carrier device includes a data communication circuit receiving an input of a pulse having a part having a different duty ratio and a pulse frequency constant on the whole from the data carrier driving device through the signal terminal to generate a data signal.
    Type: Grant
    Filed: November 7, 2005
    Date of Patent: February 16, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventor: Yoshikazu Yamazaki
  • Patent number: 7664203
    Abstract: Methods and systems for processing a single sub-channel that includes two or more combined channels. Using intermediate frequency sub-sampling, two or more channels from a broad band signal are combined into a single sub-channel for further analog and digital processing. Each of the two or more channels is down converted to an intermediate frequency, filtered to remove certain undesired channels, and combined such that the two or more channels are adjacent to each other. A digital representation of the sub-channel is produced from the combined intermediate frequency channels. Each channel within the digital representation is down converted to baseband, and the in-phase and quadrature components are separated from each other. Compared to one direct down conversion technique, intermediate frequency sub-sampling as described in the application may reduce the number of analog to digital converters and control amplifiers used in analog processing by a factor of four.
    Type: Grant
    Filed: February 14, 2005
    Date of Patent: February 16, 2010
    Assignee: Microsoft Corporation
    Inventors: Dan Q. Tu, Louis F. Coffin, III
  • Publication number: 20100027705
    Abstract: A method for calculating zero-crossing reference sequences ({ti}) for the data detection of a sequence of zero crossings ({{circumflex over (t)}i}) of a received signal is disclosed. The data detection is determined in a receiver, wherein the received signal is based on a data symbol sequence ({dk}) angle-modulated at a transmitter and transmitted to the receiver. The zero-crossing reference sequences ({ti}) are calculated in accordance with an equation specifying an output of a finite state machine that describes, at least approximately, the signal generation in the transmitter.
    Type: Application
    Filed: January 23, 2009
    Publication date: February 4, 2010
    Inventors: Andre NEUBAUER, Juergen NIEDERHOLZ
  • Publication number: 20100020892
    Abstract: The present invention relates a symbol generation apparatus for multiple antennas having low receiving complexity and having flexibility with respect to an increase in the number of antennas. The symbol generation apparatus includes a plurality of space-time channel encoders respectively corresponding to a plurality of channels, and an inverse fast Fourier transformer group. The respective space-time channel encoders receive a digital-modulated symbol group from the corresponding channel, perform a space-time encoding operation with respect to a plurality of space areas and at least one time area, shift phases by using a plurality of phase values, and generate a plurality of phase-shifted space-time codewords.
    Type: Application
    Filed: March 13, 2007
    Publication date: January 28, 2010
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Seung-Joon Lee, Dong-Seung Kwon
  • Patent number: 7646824
    Abstract: Aspects of a method and system for a fast-switching Phase-Locked Loop using a Direct Digital Frequency synthesizer may include generating a second signal from a first signal by: frequency translating an inphase component of the first signal utilizing a filtered fast-switching oscillating signal generated using at least a direct digital frequency synthesizer (DDFS), and frequency translating a corresponding quadrature component of the first signal utilizing a phase-shifted version of the generated and filtered fast-switching oscillating signal. The inphase and quadrature components of the first signal may be multiplied with the filtered fast-switching oscillating signal and a phase-shifted version of the filtered fast-switching oscillating signal, respectively.
    Type: Grant
    Filed: February 28, 2007
    Date of Patent: January 12, 2010
    Assignee: Broadcom Corporation
    Inventor: Ahmadreza Rofougaran
  • Patent number: 7636386
    Abstract: A multiple path angle modulator includes a closed secondary loop added to a main control loop to automatically adjust a scaling factor related to high frequency gain. The main control loop is configured as a primary path to process the low frequency portion of the angle modulation signal, and the secondary loop is configured as an auxiliary path to process the high frequency portions of the angle modulation signal. The secondary loop senses calibration information and uses it to continuously calibrate the gain within the modulation loop in real time while the system performs its primary operation, thereby eliminating the need for a system shut down or calibration specific timing, such as a lapse time, to balance the modulation paths. Calibration is continuously performed as a background process. The angle modulator is applicable to all modulation type systems.
    Type: Grant
    Filed: November 15, 2005
    Date of Patent: December 22, 2009
    Assignee: Panasonic Corporation
    Inventors: Earl W. McCune, Jr., Wendell B. Sander
  • Publication number: 20090310786
    Abstract: Systems for audio and data transmission in a broadcast band are disclosed. The system comprises a channel condition assessment module at the transmit side to identify an un-occupied or empty channel to transmit. The system also comprises a means to achieve automatic channel coordination between the transmit side and the receive side. Further, the transmit side includes a digital interface module and the receive side includes a digital output interface module configured to control an embedding electronic device. Means for enhancing audio privacy and digital data rate are also disclosed.
    Type: Application
    Filed: June 30, 2009
    Publication date: December 17, 2009
    Applicant: QUINTIC HOLDINGS
    Inventors: Yifeng Zhang, Victor Ren, Bo Xia
  • Patent number: 7623604
    Abstract: A communications receiver may include an adaptive filter unit for removing coherent interference components from a received signal. In the absence of a signal of interest, the filter may adapt dynamically to remove current interference components. When a signal of interest is detected, the filter may be controlled to stop (or at least reduce) its adaptation, to prevent removal of the signal of interest. The received signal may be down-converted to a complex baseband by conditioning circuitry. A detector may detect the signal of interest, and control the filter. Autocorrelation may be used to estimate a characteristic of the signal of interest in the complex baseband. The detector may include hysteresis to react quickly to the start of signal of interest, and more slowly to an end of the signal of interest. The signal of interest may be a frequency shift keyed (FSK) signal. A demodulator may demodulate FSK components based on the autocorrelation result.
    Type: Grant
    Filed: June 29, 2004
    Date of Patent: November 24, 2009
    Assignee: IMRA Europe S.A.
    Inventors: Philippe Loiseau, Michel Gaeta, Luc Haumonte
  • Patent number: 7599627
    Abstract: An optical homodyne communication system and method in which a side carrier is transmitted along with data bands in an optical data signal, and upon reception, the side carrier is boosted, shifted to the center of the data bands, and its polarization state is matched to the polarization state of the respective data bands to compensate for polarization mode dispersion during transmission. By shifting a boosted side carrier to the center of the data bands, and by simultaneously compensating for the effects of polarization mode dispersion, the provided system and method simulate the advantages of homodyne reception using a local oscillator. The deleterious effects of chromatic dispersion on the data signals within the data bands are also compensated for by applying a corrective function to the data signals which precisely counteracts the effects of chromatic dispersion.
    Type: Grant
    Filed: May 31, 2001
    Date of Patent: October 6, 2009
    Assignee: Teradvance Communications, LLC
    Inventors: Marcel F. C. Schemmann, Zoran Maricevic, Antonije R. Djordjevic, Darby Racey
  • Publication number: 20090220024
    Abstract: The invention relates to a FM simulcast broadcast signal, in which an analogue and digital signal are combined for a transmission in a transmission channel with limited bandwidth as a total signal (s), which has a first phase speed (vs), an auxiliary signal (hs) is prepared in the complex region from the modulated digital signal (ds) for transmission and the FM modulated analogue signal (as) for transmission, which has a second phase speed (vas). Said auxlliary signal (hs) is placed in an used or at least largely unused frequency range of the digital signal (ds). The total signal (s) for transmission comprises the auxiliary signal (hs) and the FM modulated digital signal (ds) and the first phase speed (vs) of the total signal (s) corresponds at least approximately to the second phase speed (vas) of the analogue signal (as).
    Type: Application
    Filed: March 5, 2007
    Publication date: September 3, 2009
    Applicant: MICRONAS GMBH
    Inventors: Carsten Noeske, Christian Bock
  • Patent number: 7532678
    Abstract: During data transmission by multi-carrier modulation of data blocks modulated by Inverse Discrete Fourier Transformation (IDFT), carriers that are not occupied by data are occupied in such a way as to generate temporal functions that, after filtration, are Dirac-like temporal functions that reach maxima in an oversampled temporal resolution of different, preferably adjacent positions. A pair of the oversampled Dirac-like temporal functions and corresponding filter input functions that are not oversampled is iteratively selected. The pair is displaced to a position of a peak value resulting from the data occupation of the remaining carriers, subtracted from the oversampled Dirac-like temporal functions after being weighted and, as iterative modifications, applied in parallel to the Dirac-like temporal functions and a corresponding temporal signal without oversampling and without filtration.
    Type: Grant
    Filed: September 11, 2002
    Date of Patent: May 12, 2009
    Assignee: Infineon Technologies AG
    Inventors: Werner Henkel, Valentin Zrno
  • Patent number: 7532673
    Abstract: A broadband communications system uses modulation symbol transport over communications links to replace baseband or bandpass signal transport, thereby providing longer communication distances, lower communication link bandwidth, and greater signal quality. Subsequent to transporting the modulation symbols, the symbols are modulated and further transmitted over the RF transmission network.
    Type: Grant
    Filed: January 30, 2004
    Date of Patent: May 12, 2009
    Assignee: Scientific-Atlanta, Inc.
    Inventors: James E. Cannella, Jr., Larry S. McKinney, William D. Woodward, Jr.
  • Patent number: 7529313
    Abstract: An apparatus includes: an affine transformer that subjects input complex IF signals I(t) and Q(t) to affine transformation according to affine transformation coefficients, and outputs compensated signals a(t) and b(t); a quadrature modulator that applies quadrature modulation on a local oscillation signal according to the compensated signals, and outputs a modulated signal (RF transmission signal); a quadrature wave detector that removes a carrier component from the modulated signal and outputs complex feedback signals I?(t) and Q?(t); and a control portion that extracts linear distortions remaining in the complex feedback signals I?(t) and Q?(t) as plural distortion coefficients (DC offsets of the I-phase and the Q-phase, an IQ gain ratio, and a deviation in orthogonality), and updates the current affine transformation coefficients in accordance with updating equations including the distortion coefficients to set updated affine transformation coefficients again in the affine transformation portion.
    Type: Grant
    Filed: September 9, 2005
    Date of Patent: May 5, 2009
    Assignee: Hitachi Kokusai Electric Inc.
    Inventors: Masashi Naito, Yasuhiro Takeuchi, Takashi Okada
  • Patent number: 7522672
    Abstract: The present invention provides a digital (computational) branch calibrator which uses a feedback signal sensed from an RF transmit signal path following the combining stage of LINC circuitry of a transmitter to compensate for gain and phase imbalances occurring between branch fragment signals leading to the combiner. The calibrator feeds a quiet (zero) base band signal through the transmit path during the calibration sequence (i.e. a period when data is not transmitted) and adjusts the phase and gain of the phasor fragment signals input thereto by driving the sensed output power to zero. The calibration is performed by alternating phase and gain adjustments with predetermined (programmable) and multiple update parameters stages (speeds). A baseband modulation is preferably used to distinguish false leakage (e.g. due to local oscillator, LO, feed through and DC offset in the base band Tx) from imbalance leakage.
    Type: Grant
    Filed: August 30, 2007
    Date of Patent: April 21, 2009
    Inventor: Aryan Saed
  • Publication number: 20090080563
    Abstract: A signal generating apparatus is disclosed. The signal generating apparatus includes a test data generator for generating a test data; a fractional-N phase-locked loop device coupled to the test data generator for generating a synthesized signal according to the test data when the test data is received; and a calibrating device coupled to the fractional-N phase-locked loop device for measuring power of the synthesized signal to generate a calibration signal utilized for adjusting the fractional-N phase-locked loop device.
    Type: Application
    Filed: September 20, 2007
    Publication date: March 26, 2009
    Inventors: Hsin-Hung Chen, Ling-Wei Ke, Tai-Yuan Yu, Tser-Yu Lin
  • Patent number: 7499490
    Abstract: Methods and apparatus to encode message input symbols in accordance with an accumulate-repeat-accumulate code with repetition three or four are disclosed. Block circulant matrices are used. A first method and apparatus make use of the block-circulant structure of the parity check matrix. A second method and apparatus use block-circulant generator matrices.
    Type: Grant
    Filed: June 24, 2005
    Date of Patent: March 3, 2009
    Assignees: California Institute of Technology, The Regents of the University of California
    Inventors: Dariush Divsalar, Aliazam Abbasfar, Christopher R. Jones, Samuel J. Dolinar, Jeremy C. Thorpe, Kenneth S. Andrews, Kung Yao
  • Publication number: 20090003484
    Abstract: A method and system for modulating a signal includes providing a carrier including periodic waves, peaks of the periodic waves defining a carrier shape of the carrier; changing a plurality of the periodic waves so that peaks of the changed waves form a shaped signal having a signal shape which is different from the carrier shape; and detecting the shaped signal.
    Type: Application
    Filed: June 29, 2007
    Publication date: January 1, 2009
    Inventors: Wei Li, John Benko
  • Patent number: 7469020
    Abstract: Systems, methods, and apparatus for reducing dynamic range requirements of a power amplifier in a wireless device are provided. An exemplary method may include modulating a symbol stream to generate a modulated waveform. The exemplary method may further include generating at least one pulse having a peak aligned with an anticipated position of a peak or a null corresponding to the modulated waveform, where the anticipated position of the a peak or the null corresponding to modulated waveform may be determined by detecting a transition in a phase or an amplitude of the modulated waveform.
    Type: Grant
    Filed: April 26, 2005
    Date of Patent: December 23, 2008
    Assignee: Freescale Semiconductor, Inc.
    Inventors: James Wesley McCoy, Kevin B. Traylor
  • Patent number: 7457370
    Abstract: A frequency modulation method is proposed that enables an imprinting of a digital message formed by a sequence of symbols on a set of frequency bands. Each symbol of the digital message is hereby assigned just one symbol value out of a defined set of symbol values. According to the method at least two symbol transmission channels are defined with each symbol transmission channel being formed by a sub-set of frequency bands selected from the set of frequency bands and with each frequency band of a symbol transmission channel being allocated to a symbol value of the set of symbol values in a one-to-one relation such, that the symbol transmission channels defined differ from each other in at least one frequency band selected and/or in an allocation of a frequency band to a symbol value. Further, each of the defined symbol transmission channels is successively modulated with a single symbol value of the digital message according to the channel allocation scheme of the respective symbol transmission channel.
    Type: Grant
    Filed: April 6, 2005
    Date of Patent: November 25, 2008
    Assignee: Sony Deutschland GmbH
    Inventors: Jens-Uwe Jürgensen, Richard Stirling-Gallacher
  • Patent number: 7450669
    Abstract: An OFDM modulation apparatus receives a signal composed of OFDM symbols each of which is composed of an effective symbol and a guard interval, generates K delayed signals by delaying the received signal by K effective symbol periods, generates a signal by adding up all the K delayed signals, generates a first correlation signal that shows a correlation between the received signal and the addition-result signal, generates K×L second correlation signals from the first correlation signal, based on K×L combinations of K effective symbol periods and L fractions used to indicate the guard interval period, detects one among the K×L second correlation signals that indicates a largest correlation level, and detect periods of the effective symbol and the guard interval of the received signal in accordance with the detected second correlation signal.
    Type: Grant
    Filed: December 7, 2004
    Date of Patent: November 11, 2008
    Assignee: Panasonic Corporation
    Inventor: Ryosuke Mori
  • Patent number: 7440515
    Abstract: A system and method for controlling modulation. The system includes a plurality of modulators and a transmitting unit. The plurality of modulators decodes data from a data signal and also encodes the data into a clock signal. The transmitting unit transmits the encoded clock signal. According to the system and method disclosed herein, the present invention provides optimized coding efficiency while minimizing overall power consumption.
    Type: Grant
    Filed: October 25, 2004
    Date of Patent: October 21, 2008
    Assignee: Atmel Corporation
    Inventors: Mikhail Itskovich, Daniel S. Cohen
  • Publication number: 20080205543
    Abstract: Aspects of a method and system for a high-precision frequency generator using a direct digital frequency synthesizer for transmitters and receivers may include generating a second signal from a first signal by frequency translating an inphase component of the first signal utilizing a high-precision oscillating signal that may be generated using at least a direct digital frequency synthesizer (DDFS) and at least a Phase-Locked Loop (PLL). A corresponding quadrature component of the first signal may be frequency translated utilizing a phase-shifted version of the high-precision oscillating signal. The inphase component of the first signal may be multiplied with the high-precision oscillating signal and the quadrature component of the first signal may be multiplied with the phase-shifted version of the high-precision oscillating signal. The second signal may be generated from the first signal by adding the frequency translated inphase component to the frequency translated quadrature component.
    Type: Application
    Filed: February 28, 2007
    Publication date: August 28, 2008
    Inventor: Ahmadreza Rofougaran
  • Publication number: 20080205542
    Abstract: Aspects of a method and system for efficient transmission and reception of RF energy in MIMO systems using polar modulation and direct digital frequency synthesis are provided. A plurality of carrier signals in a MIMO system may be polar modulated utilizing polar modulation. One or more direct digital frequency synthesizer may be utilized to phase modulate the plurality of carrier signals. The direct digital frequency synthesizer may be modulated utilizing a single reference clock. The clock may be a single fixed-frequency reference clock. The plurality of carrier signals may be amplitude modulated by controlling a gain of a power amplifier.
    Type: Application
    Filed: February 28, 2007
    Publication date: August 28, 2008
    Inventor: Ahmadreza Rofougaran
  • Patent number: 7359457
    Abstract: A transmission apparatus includes a frame configuration determiner that determines a modulation system from among a plurality of modulation systems on a communication situation. A first symbol generator modulates a digital transmission signal according to the modulation system determined by the frame configuration determiner and generates a first symbol, the first symbol comprising a first quadrature baseband signal. A second symbol generator modulates the digital transmission signal according to a predetermined modulation system and generates a second symbol, the second symbol comprising a second quadrature baseband signal.
    Type: Grant
    Filed: April 20, 2004
    Date of Patent: April 15, 2008
    Assignee: Matsushita Electric Indutrial Co., Ltd.
    Inventors: Yutaka Murakami, Shinichiro Takabayashi, Masayuki Orihashi, Akihiko Matsuoka
  • Publication number: 20080076355
    Abstract: A method for protecting Security Accounts Manager (SAM) files within a Windows® operating system is disclosed. A SAM file encryption key is generated by encrypting a SAM file via a syskey utility provided within the Windows® operating system. The SAM file encryption key is then stored in a virtual floppy disk by selecting an option to store SAM file encryption key to a floppy disk under the syskey utility. A blob is generated by performing a Trusted Platform Module (TPM) Seal command against the SAM file encryption key along with a value stored in a Performance Control Register and a TPM Storage Root Key. The blob is stored in a non-volatile storage area of a computer.
    Type: Application
    Filed: September 27, 2006
    Publication date: March 27, 2008
    Inventors: Rod D. Waltermann, David C. Challener, Philip L. Childs, Norman A. Dion, James Hunt, Nathan J. Peterson, David Rivera, Randall S. Springfield, Arnold S. Weksler
  • Publication number: 20080031376
    Abstract: There is provided with a transmission apparatus including: a first modulator configured to perform modulation processing on data to be transmitted to a first reception apparatus and thereby generate amplitude-phase data made up of data of amplitude and phase; a second modulator configured to perform modulation processing so as to decompose data to be transmitted to a second reception apparatus into a plurality of frequency components and thereby generate frequency data which is data on a frequency domain; and a transmitter configured to allocate the amplitude-phase data to first subcarriers out of a plurality of subcarriers and allocate the frequency data to second subcarriers which are different from the first subcarriers out of the plurality of subcarriers, thereby generate subcarrier data and transmit generated subcarrier data to the first reception apparatus and the second reception apparatus.
    Type: Application
    Filed: July 23, 2007
    Publication date: February 7, 2008
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Koichiro BAN
  • Patent number: 7305046
    Abstract: An I/Q modulator used for processing an I/Q signal to obtain a predistorted output signal. The I/Q signal has an I component and a Q component, and comprises a predistorter for predistorting, with a predistortion signal, a carrier signal, which comprises a first subcomponent and a second subcomponent that is substantially orthogonal to the first subcomponent, to obtain first and second predistorted subcomponents of the carrier signal. The predistortion signal depends on the I and Q components. A first multiplier multiples the I component by the first predistorted subcomponent to obtain a multiplied I component. A second multiplier multiples the Q component by the second predistorted subcomponent to obtain a multiplied Q component. An adder adds the multiplied I component and the negative multiplied Q component to obtain the predistorted output signal. Thus, a simplification of the I/Q modulator and a reduction in the number of necessary multipliers is achieved.
    Type: Grant
    Filed: March 2, 2001
    Date of Patent: December 4, 2007
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.
    Inventors: Eberhard Gamm, Reiner Retkowski, Gerald Ulbricht, Heinz Gerhaeuser
  • Publication number: 20070274412
    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: Application
    Filed: March 2, 2007
    Publication date: November 29, 2007
    Applicant: Infineon Technologies AG
    Inventor: Martin Feldtkeller
  • Patent number: 7260361
    Abstract: A method, apparatus and system relate to detecting an interfering device in a wireless network such as a wireless local area network (WLAN). In wireless networks using orthogonal frequency division multiplexing (OFDM) and adaptive bit loading (ABL), adaptive modulation information should be somewhat symmetric in uplink and downlink directions. By comparing modulation adaptations in the uplink and downlink directions of a communication channel between at least two terminals, identified differences can indicate the presence of a potential interferer in the wireless network. A location of the potential interferer can be estimated if a location of one or more network terminals experiencing interference is known or can be determined. An exemplary implementation for a device of the invention may be as an Access Point (AP) in the WLAN.
    Type: Grant
    Filed: December 29, 2003
    Date of Patent: August 21, 2007
    Assignee: Intel Corporation
    Inventor: Eric A. Jacobsen
  • Patent number: 7239846
    Abstract: The present invention relates to a signal modulation loop for the multi-mode mobile communication. The adaptive up-conversion modulation loop is applied in the multi-mode mobile communication, and is used for signal integration for the communication system comprising the second generation communication system, the global system for mobile communication (GSM), and the third generation communication system, the wideband code division multiple access (WCDMA), so as to achieve the object of multi-mode communication by using a single modulation loop.
    Type: Grant
    Filed: January 5, 2004
    Date of Patent: July 3, 2007
    Assignee: Industrial Technology Research Institute
    Inventors: Huan-Ke Chiu, June-Ming Hsu, Tzu-Yi Yang
  • Patent number: 7230993
    Abstract: A digital communication system (20) in which a signal constellation (30) of a dimensionality of at least four is used, with distance properties chosen to reduce the bit error rate compared to that of digital communication systems using signal constellations of half the dimensionality. A symbol generator (21) uses the higher dimensional signal constellation (30), or any orthogonal transformation of the higher dimensional signal constellation (30), to translate a bit stream into a stream of higher dimensional symbols, which it then provides to a modulator (22). The modulator (22) transmits each higher dimensional symbol in at least two parts, using a modulation scheme according to the prior art, such as QAM or QPSK.
    Type: Grant
    Filed: March 6, 2002
    Date of Patent: June 12, 2007
    Assignee: Nokia Corporation
    Inventors: Keijo Ruotsalainen, Markku Heikkilä
  • Patent number: 7228100
    Abstract: Program data is provided in association with a main audio program to a receiver of a duplicative radio broadcasting system wherein a duplicative broadcast (such as a hybrid IBOC broadcast) includes a primary channel and a backup channel in a predetermined frequency allocation. Both the primary channel and the backup channel transmit the main audio program, and the primary channel transmits program data not included in the backup channel. The receiver includes an audio output for reproducing the main audio program and a display for displaying the program data. The method includes recurrently compiling a program event list of the program data corresponding to a current program event and a plurality of upcoming program events. The program event list is recurrently transmitted within the primary channel. The receiver recurrently recovers the program event list and stores the program data in a memory. The program data of the current program event is displayed.
    Type: Grant
    Filed: March 25, 2003
    Date of Patent: June 5, 2007
    Assignee: Visteon Global Technologies, Inc.
    Inventors: Todd A. Toporski, J. William Whikehart
  • Patent number: 7221718
    Abstract: An I/Q demodulator optimized with a minimum amount of hardware. First and second multiplexers generate I and Q signals with respect to an input data signal; and first and second 2-decimation units decimate the I and Q signals generated by the first and second multiplexers, to output effective I and Q signals. A filtering unit filters the effective I and Q signals. As a result, a size of the hardware is reduced, and an operation frequency of the filter is reduced.
    Type: Grant
    Filed: January 30, 2003
    Date of Patent: May 22, 2007
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Chan-sub Park
  • Patent number: 7167528
    Abstract: A method and system for modulating data onto a carrier signal in a plurality of channels, each of the channels having a channel bandwidth, can be created for use in any two-way satellite communication system or other wireless communication application where frequency hopping with or without Doppler compensation is desired. The system preferably includes a digital modulator that outputs a modulated baseband signal, an intermediate frequency modulator that receives the modulated baseband signal and outputs an intermediate frequency signal derived from the modulated baseband signal, a frequency synthesizing system that outputs a synthesized intermediate frequency signal to the intermediate frequency modulator, and a circuit (numerically controlled oscillator) connected to the digital modulator which provides a signal to the digital modulator.
    Type: Grant
    Filed: June 11, 2002
    Date of Patent: January 23, 2007
    Assignee: General Instrument Corporation
    Inventors: Keming Joseph Chen, Mark Steven Schmidt
  • Patent number: 7162000
    Abstract: A delay locked loop circuit (200) in which multiple outputs are produced. A single delay line (24) is shared among multiple tap selection circuits (256A, 265B, 265C). Fixed phase shifts (412) can be introduced between multiple outputs. A modulating signal can be used in the tap selection processing to produce digital amplitude, frequency and/or phase modulation.
    Type: Grant
    Filed: January 16, 2002
    Date of Patent: January 9, 2007
    Assignee: Motorola, Inc.
    Inventors: Robert E. Stengel, Joseph P. Heck, David E. Bockelman
  • Patent number: 7127002
    Abstract: A system and a method for multiplying data throughput in a SCSI bus includes identifying multiple frequencies within a bandwidth of a SCSI bus. A binary value is assigned to each one of the multiple frequencies. One of the multiple frequencies is selected. The assigned binary value of the selected frequency corresponds to a set of bits to be transmitted during a first sampling cycle. The selected frequency is transmitted on the SCSI bus during the first sampling cycle.
    Type: Grant
    Filed: August 23, 2002
    Date of Patent: October 24, 2006
    Assignee: Adaptec, Inc.
    Inventor: Fadi A. Mahmoud
  • Patent number: 7120202
    Abstract: In a wireless communication apparatus which has the functions of both ASK modulation and QPSK modulation, which can be manufactured at a low cost, and which is small in size, an output terminal of a QPSK modulator is connected to a carrier wave input terminal of an ASK modulator via a switch. Also, an antenna is connected to an output terminal of the ASK modulator via a switch. Furthermore, a mixer is provided between the switches and. The switch connects the QPSK modulator and the ASK modulator at the time of a transmission, whereas it connects the QPSK modulator and the mixer at the time of a reception. The switch connects the ASK modulator and the antenna at the time of a transmission, whereas it connects the antenna and the mixer at the time of a reception. Thus, at the time of a transmission, an ASK-modulated wave or a QPSK-modulated wave is output using the ASK modulator and the QPSK modulator.
    Type: Grant
    Filed: March 14, 2002
    Date of Patent: October 10, 2006
    Assignee: Murata Manufacturing Co., Ltd.
    Inventor: Akihiro Sasabata
  • Patent number: 7088267
    Abstract: A duplex-system digital-data transmitting apparatus includes a digital-data signal source which outputs serial data at a signal output end. The level of the data is converted by a first level converter circuit. The data is supplied to an FSK modulator circuit to be FSK-modulated. Carriers are, for example, at 11 MHz and 13 MHz and correspond to digital signals “1” and “0”, respectively. The modulated signal is amplified by a driver and is coupled to the human body by a capacitor of about 100 pF. When the human body comes into contact with an electrode, the modulated signal transmitted through the human body is amplified by a pre-amplifier, demodulated by a demodulator circuit, and shaped by a comparator. The level of the shaped signal is converted by a second level converter circuit, and the signal is supplied to a serial input end of a receiving unit. Transmission and reception are performed using a half-duplex system.
    Type: Grant
    Filed: December 1, 2000
    Date of Patent: August 8, 2006
    Assignee: Sony Corporation
    Inventor: Shigeru Tajima
  • Patent number: 7085327
    Abstract: An improvement for a phasor fragmentation engine and method, whereby a phasor flipping algorithm is applied when determining fragment phasors for a non-constant envelope modulation signal (e.g. OFDM). The phasor flipping algorithm avoids sharp phase transitions for the fragment phasors, which cause an increase in bandwidth, by performing a comparison of the phasor angle separation between the prior and current time samples. This comparison corresponds to a determination of whether the modulation signal V has passed near or through zero.
    Type: Grant
    Filed: October 18, 2002
    Date of Patent: August 1, 2006
    Inventors: Kevin R. Parker, Stephen R. Hobbs, Jean-Paul R. DeCruyenaere
  • Patent number: RE40134
    Abstract: At the transmitter side, carrier waves are modulated according to an input signal for producing relevant signal points in a signal space diagram. The input signal is divided into, two, first and second, data streams. The signal points are divided into signal point groups to which data of the first data stream are assigned. Also, data of the second data stream are assigned to the signal points of each signal point group. A difference in the transmission error rate between first and second data streams is developed by shifting the signal points to other positions in the space diagram expressed at least in the polar coordinate system. At the receiver side, the first and/or second data streams can be reconstructed from a received signal. In TV broadcast service, a TV signal is divided by a transmitter into low and high frequency band components which are designated as first and second data streams respectively.
    Type: Grant
    Filed: October 5, 2000
    Date of Patent: March 4, 2008
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Mitsuaki Oshima, Seiji Sakashita
  • Patent number: RE40206
    Abstract: At the transmitter side, carrier waves are modulated according to an input signal for producing relevant signal points in a signal space diagram. The input signal is divided into, two, first and second, data streams. The signal points are divided into signal point groups to which data of the first data stream are assigned. Also, data of the second data stream are assigned to the signal points of each signal point group. A difference in the transmission error rate between first and second data streams is developed by shifting the signal points to other positions in the space diagram expressed at least in the polar coordinate system. At the receiver side, the first and/or second data streams can be reconstructed from a received signal. In TV broadcast service, a TV signal is divided by a transmitter into low and high frequency band components which are designated as first and second data streams respectively.
    Type: Grant
    Filed: August 7, 2003
    Date of Patent: April 1, 2008
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Mitsuaki Oshima, Seiji Sakashita