Differential (diphase) Patents (Class 375/330)
  • Patent number: 10341912
    Abstract: An interface between access points is enhanced by enabling an exchange of a cell characteristic information element (IE). The cell characteristic information can provide an access point with information about the characteristics/features/capabilities of its neighbor cells. Automatic neighbor relations are also enhanced to store and/or manage the cell characteristic information. Moreover, the cell characteristic information can be utilized by the access point to significantly improve handover (HO) decisions, increase load balancing performance, and/or decrease inter cell interference. The cell characteristic information can also improve network efficiency and avoid bottlenecks during cell reselection in Heterogeneous Networks (HetNets).
    Type: Grant
    Filed: April 20, 2017
    Date of Patent: July 2, 2019
    Assignees: AT&T INTELLECTUAL PROPERTY I, L.P., AT&T MOBILITY II LLC
    Inventors: Zhi Cui, Hongyan Lei
  • Patent number: 10256856
    Abstract: A method of detecting an obtruding signal in a radio receiver, a receiver and a computer program are disclosed. The receiver has a mixer arranged to mix a received signal to an analog baseband signal at or close to zero-frequency, a filter arranged to low-pass filter said analog baseband signal, and an analog-to-digital converter arranged to sample said filtered analog baseband signal at a sample frequency such that a digital baseband signal is formed. The method comprised receiving a radio frequency signal, mixing the radio frequency signal to the analog baseband signal at or close to zero-frequency, low-pass filtering said analog baseband signal, and analog-to-digital converting said filtered analog baseband signal at an over sample frequency such that a digital baseband signal is formed.
    Type: Grant
    Filed: October 31, 2014
    Date of Patent: April 9, 2019
    Assignee: TELEFONAKTIEBOLAGET LM ERICSSON (publ)
    Inventors: Sajal Kumar Das, Vijaykumar Kuppusamy
  • Patent number: 9621311
    Abstract: A wireless device transmits a frame by determining a plurality of Resource Units (RUs) of the frame, providing pilots in a first RU of the frame at a first set of positions, providing pilots in a second RU of the frame at a second set of positions, and transmitting the frame. The first set of positions is different from the second set of positions. A wireless device receives a frame including an RU including pilots and processes the pilots. When an RU for the data symbol includes an odd-numbered lowest subcarrier, the pilots are included at a first set of positions in the resource unit. When the RU includes an even-numbered lowest subcarrier, the pilots are included at a second set of positions in the resource unit. The second set of positions is different from the first set of positions.
    Type: Grant
    Filed: May 9, 2016
    Date of Patent: April 11, 2017
    Assignee: NEWRACOM, INC.
    Inventors: Dae Won Lee, Young Hoon Kwon, Sungho Moon, Yujin Noh
  • Patent number: 9449594
    Abstract: Embodiments of a system and method for adapting a phase difference-based noise reduction system are generally described herein. In some embodiments, spatial information associated with a first and second audio signal are determined, wherein the first and second audio signals including a target audio inside a beam and noise from outside the beam. A signal-to-noise ratio (SNR) associated with the audio signals is estimated. A mapping of phase differences to gain factors is adapted for determination of attenuation factors for attenuating frequency bins associated with noise outside the beam. Spectral subtraction is performed to remove estimated noise from the single-channel signal based on a weighting that affects frequencies associated with a target signal less. Frequency dependent attenuation factors are applied to attenuate frequency bins outside the beam to produce a target signal having noise reduced.
    Type: Grant
    Filed: September 17, 2013
    Date of Patent: September 20, 2016
    Assignee: Intel Corporation
    Inventors: Lukasz Kurylo, Georg Stemmer
  • Patent number: 9282467
    Abstract: A method for pilot sequence design in a communications system includes selecting an initial cell in the communications system, and grouping other cells in the communications system relative to the initial cell into one of a neighbor group and a non-neighbor group in accordance with a neighborness measure of each of the other cells to the initial cell. The method also includes designing pilot sequences that are substantially orthogonal to one another for the initial cell and the other cells in the neighbor group, and providing information about the pilot sequences to the initial cell and the other cells in the communications system.
    Type: Grant
    Filed: November 26, 2013
    Date of Patent: March 8, 2016
    Assignee: Futurewei Technologies, Inc.
    Inventors: Vahid Tarokh, Peiying Zhu, Gamini Senarath
  • Patent number: 9077403
    Abstract: A network multiple-input multiple-output (MIMO) wireless signal transmission and power control system includes a plurality of adjacently arranged cells. Each cell is a regular polygon and includes a plurality of adjoining sides, a base station located at a center of the cell, a plurality of directional antennas equipped at the base station, and a power adjustment unit electrically connected to the directional antennas. The directional antennas point towards connection points of the adjoining sides, and sectorize the cell into a plurality of kite-shaped sections by regarding the directional antennas as centers. The power adjustment unit controls power output of the directional antennas. By changing pointing directions of the directional antennas, the cell can be sectorized into the kite-shaped sections to significantly increase system capacity and communication quality.
    Type: Grant
    Filed: May 21, 2013
    Date of Patent: July 7, 2015
    Assignee: NATIONAL YUNLIN UNIVERSITY OF SCIENCE AND TECHNOLOGY
    Inventors: Jeng-Shin Sheu, Sin-Hong Lyu
  • Patent number: 9042491
    Abstract: This disclosure provides systems, methods, and apparatus for receiving paging messages in fast fading scenarios. In one aspect, a method of demodulating a paging message during an assigned time slot by a wireless communications apparatus operating in an idle mode is provided. The method includes determining, in anticipation of the assigned time slot, an expected time position corresponding to a path of a pilot signal having a greater signal strength relative to other pilot signals. The method further includes assigning a first demodulation element to demodulate the pilot signal with reference to the expected time position and assigning a second demodulation element to demodulate the pilot signal with reference to a time offset from the expected time position. Other aspects, embodiments, and features are also claimed and described.
    Type: Grant
    Filed: January 17, 2013
    Date of Patent: May 26, 2015
    Assignee: QUALCOMM Incorporated
    Inventors: Bhaskara V. Batchu, Priyangshu Ghosh
  • Patent number: 9036739
    Abstract: A method and apparatus are provided for multiplexing Uplink Control Information (UCI) with data information in a Physical Uplink Shared CHannel (PUSCH) transmitted over multiple spatial layers where aspects of the UCI multiplexing include the determination of the number of coded UCI symbols in each spatial layer when the data information is conveyed using multiple Transport Blocks (TBs), the determination of the number of coded UCI symbols in each spatial layer when the PUSCH conveys a single TB retransmission for a Hybrid Automatic Repeat reQuest (HARQ) process while the initial TB transmission for the same HARQ process was in a PUSCH conveying multiple TBs, and the determination of the modulation scheme for the coded UCI symbols.
    Type: Grant
    Filed: November 7, 2013
    Date of Patent: May 19, 2015
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Aris Papasakellariou, Young-Bum Kim
  • Patent number: 9036661
    Abstract: Systems, devices, processors, and methods are described which may be used for the reception of a wireless broadband signal at a user terminal from a gateway via a satellite. A wireless signal may include a series of physical layer frames, each frame including a physical layer header and payload. The received signal is digitized and processed using various novel physical layer headers and related techniques to synchronize the physical layer frames and recover data from physical layer headers for purposes of demodulation and decoding.
    Type: Grant
    Filed: February 12, 2013
    Date of Patent: May 19, 2015
    Assignee: ViaSat, Inc.
    Inventors: Donald W. Becker, Matthew D. Nimon, William H. Thesling
  • Publication number: 20150098514
    Abstract: A technique for generating a bit log-likelihood ratio (LLR) in a communication system includes generating a demodulated signal based on a received symbol and a reference symbol. An input for a bit LLR generator is generated based on the demodulated signal and a normalization value that is based on the received symbol or the reference symbol. A bit LLR is generated for the received symbol, using the bit LLR generator, based on the input.
    Type: Application
    Filed: October 8, 2013
    Publication date: April 9, 2015
    Inventor: Raja V. Tamma
  • Patent number: 9001905
    Abstract: A method, comprising: periodically enabling reception of a signal at a receiver, every first time; transforming the received signal in order to determine data in the received signal; comparing the determined data with reference data; and using the difference between the determined data and the reference data to estimate a correction to a multiple of the first time in order to determine a distance between the receiver and an origin of the signal.
    Type: Grant
    Filed: May 11, 2010
    Date of Patent: April 7, 2015
    Assignee: Nokia Corporation
    Inventors: Ari Henrik Hamalainen, Ilari Aleksi Teikari
  • Patent number: 8989315
    Abstract: Methods, software, receivers and systems for communicating information over a cyclostationary channel. The method generally includes interleaving sections of a control sequence with bits of the information. The software and receivers are generally configured to implement one or more aspects of the methods disclosed herein, and the systems generally include those that embody the inventive receivers disclosed herein. The present invention is particularly useful in powerline channels, where certain parameters (such as noise) have time-dependent or periodic variations in value. By distributing the control sequence, the incidence of carrier recovery is reduced, the likelihood of successful packet or frame transmissions is increased, and data may be more reliably communicated.
    Type: Grant
    Filed: February 19, 2010
    Date of Patent: March 24, 2015
    Assignee: Marvell International Ltd.
    Inventors: Zhan Yu, Runsheng He
  • Patent number: 8989317
    Abstract: An efficient decoding of vector signaling codes is obtained using a circuit that ranks received signal levels, designates ranked values as representing particular code elements, and translates those particular code elements into a decoded result. An optimized ranking circuit combines analog crossbar switching of signal values with comparators that provide digital results. These elements may be repetitively tiled into processing arrays capable of larger ranking operations, or iteratively applied to selected portions of the data set under control of a sequencer or controller.
    Type: Grant
    Filed: November 7, 2012
    Date of Patent: March 24, 2015
    Assignee: Kandou Labs, S.A.
    Inventors: Brian Holden, Amin Shokrollahi
  • Publication number: 20150063495
    Abstract: In some implementations, a method of a receiver includes receiving an M-ary differential phase-shift keying (DPSK) signal containing a phase offset and optionally a phase rotation. The phase offset of the received signal may be estimated. A soft detection metric employing the estimated phase offset may be calculated to provide enhanced receiver performance. The method may include subtracting the phase offset estimate from the received signal prior to calculating the soft detection metric and/or de-rotating the phase of the received signal by the same amount of the phase rotation prior to estimating the phase offset of the received signal. Estimating the phase offset may be based on maximum likelihood principle. The soft detection metric may be a log-likelihood ratio (LLR) for soft detection of the received M-ary DPSK signal and the calculation of the LLR may be based upon a conditional joint probability density function of two consecutively received symbols.
    Type: Application
    Filed: August 27, 2013
    Publication date: March 5, 2015
    Inventors: Shouxing Qu, Huan Wu, Yan Xin, Arnold Sheynman
  • Patent number: 8964905
    Abstract: The present invention relates to a low power serial link employing differential return-to-zero signaling. A receiver circuit consistent with some embodiments includes an input circuit for receiving differential serial data signals that form a differential return-to-zero signaling and a clock recovery circuit. The clock recovery circuit is coupled to the input circuit and includes a logic gate configured to generate a clock signal by using said differential serial data signals.
    Type: Grant
    Filed: June 30, 2011
    Date of Patent: February 24, 2015
    Assignee: NetLogic Microsystems, Inc.
    Inventor: Marc Loinaz
  • Patent number: 8952838
    Abstract: A time domain switching analog-to-digital converter apparatus and methods of utilizing the same. In one implementation, the converter apparatus comprises a carrier signal source, and at least one reference source. The carrier signal is summed with the input signal and the summed modulated signal is fed to a comparator circuit. The comparator is configured detects crossings of the reference level by the modulated waveform thereby generating trigger events. The time period between consecutive trigger events is used to obtain modulated signal deviation due to the input signal thus enabling input signal measurement. Control of the carrier oscillation amplitude and frequency enables real time adjustment of the converter dynamic range and resolution. The use of additional reference signal levels increases sensor frequency response and accuracy. A dual channel converter apparatus enables estimation and removal of common mode noise, thereby improving signal conversion accuracy.
    Type: Grant
    Filed: August 17, 2012
    Date of Patent: February 10, 2015
    Assignee: Lumedyne Technologies, Inc.
    Inventors: Richard Waters, Brad Chisum, Mark Fralick, John D. Jacobs, Ricardo Dao, David Carbonari, Jacques Leveille
  • Patent number: 8937989
    Abstract: Systems and methods are provided for channel estimation using linear phase estimation. These systems and methods enable improved channel estimation by estimating a linear channel phase between received pilot subcarrier signals. The estimated linear phase can then be removed from the received pilot subcarrier signals. After the estimated linear phase is removed from the received pilot subcarrier signals, a channel response can be estimated. A final estimated channel response can be generated by multiplying the results of the linear channel estimation by the estimated linear phase.
    Type: Grant
    Filed: January 8, 2014
    Date of Patent: January 20, 2015
    Assignee: Marvell International Ltd.
    Inventors: Jungwon Lee, Raj M. Misra, Adina Matache, Konstantinos Sarrigeorgidis
  • Patent number: 8938031
    Abstract: Disclosed herein are methods and techniques for reducing phase slips in optical communications systems and in particular methods and techniques that operate in receivers for a coherent communication system transmitting modulated data symbols exhibiting N-ary symmetrical constellation and predetermined reference symbols.
    Type: Grant
    Filed: September 10, 2012
    Date of Patent: January 20, 2015
    Assignee: Acacia Communications Inc.
    Inventor: Pierre Humblet
  • Patent number: 8934557
    Abstract: A network node jointly precodes multi-user (MU) multiple-input multiple-output (MIMO) transmissions simultaneously sent from geographically distributed base stations to a plurality of mobile terminals over associated downlink MU-MIMO channels. The node receives feedback that describes statistics of the downlink MU-MIMO channels, including channel mean and covariance. The node then computes, based on the channel means and covariances, uplink input covariances for the mobile terminals that would collectively maximize a first or second-order approximation of the ergodic capacity of dual uplink MU-MIMO channels, subject to a global transmit power constraint that comprises the sum of individual transmit power constraints for the base stations.
    Type: Grant
    Filed: February 1, 2011
    Date of Patent: January 13, 2015
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Charles Casimiro Cavalcante, Alisson Guimarães, Tarcísío Ferreira Maciel, Lĩgia Sousa
  • Patent number: 8908810
    Abstract: A system and method are provided for implementing a soft Reed-Solomon (RS) decoding scheme, technique or algorithm to improve physical layer performance in cable modems and cable gateways. The algorithm is implemented in a forward error correction (FEC) module connected to a QAM demodulator. The RS decoding scheme is implemented without significantly complicating hardware or processing overhead. The soft Reed-Solomon (RS) decoding scheme extracts candidate RS symbols and their Log Likelihood Ratios (LLRs) from QAM symbols. The set of highest probable candidate blocks are then chosen and these are decoded using a variant of the Chase algorithm until a valid codeword is detected at the decoder output.
    Type: Grant
    Filed: December 27, 2012
    Date of Patent: December 9, 2014
    Assignee: Intel Corporation
    Inventors: Bernard Arambepola, Murat Badem, Parveen K. Shukla, Sahan Gamage, Thushara Hewavithana, Naor Goldman
  • Patent number: 8891688
    Abstract: A no signal period detecting unit (10) detects a no signal period in which no receiver signal is received. A capture unit (7) captures a synchronous timing of the receiver signal on the basis of a correlation value which is worked out by a delayed correlation computing unit (6). Further, the capture unit (7) cancels the capture of the synchronous timing in the case where this no signal period is detected by the no signal period detecting unit (10).
    Type: Grant
    Filed: July 21, 2010
    Date of Patent: November 18, 2014
    Assignee: Panasonic Corporation
    Inventors: Naoki Umeda, Mituru Maeda
  • Patent number: 8855485
    Abstract: When a circuit that calculates a frequency offset using a shape of a frequency spectrum is implemented by hardware, the circuit size can be reduced.
    Type: Grant
    Filed: April 14, 2011
    Date of Patent: October 7, 2014
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Tadao Nakagawa, Yasushi Takatori, Riichi Kudo, Munehiro Matsui, Koichi Ishihara, Takayuki Kobayashi, Etsushi Yamazaki, Akihide Sano, Eiji Yoshida, Masato Mizoguchi, Yutaka Miyamoto
  • Publication number: 20140270005
    Abstract: A termination network for a receiver device is provided to support both D-PHY signaling and N-factorial signaling. The first end of each of a plurality dynamically configurable switches is coupled to a common node. A first end of each of a plurality of resistances is coupled to a second end of a corresponding switch. A plurality of terminals receive differential signals and each terminal is coupled to a corresponding second end of a resistance. Each of a plurality differential receivers is coupled between two terminals of the termination network, wherein a first differential receiver and a second differential receiver are coupled to the same two terminals, the first differential receiver is used when the differential signals use a first type of differential signal encoding, the second differential receiver is used when the differential signals use a second type of differential signal encoding.
    Type: Application
    Filed: March 13, 2014
    Publication date: September 18, 2014
    Applicant: QUALCOMM Incorporated
    Inventors: Shoichiro Sengoku, George Alan Wiley, Chulkyu Lee, Joseph Cheung
  • Patent number: 8811541
    Abstract: A signal demodulation module is disclosed. The signal demodulation module includes an injection-locked oscillator, an envelope detector and a data slicer. The injection-locked oscillator has a central oscillating frequency equal to a frequency of a digital modulation signal received, and outputs a phase-locked oscillating signal which is in phase to the digital modulation signal. When input phase of the digital modulation signal changes, output phase of the injection-locked oscillator changes synchronously. The envelope detector is used for detecting an envelope line of the phase-locked oscillating signal and outputting an envelope signal accordingly. The data slicer is used for receiving the envelop signal and outputting a first digital signal according to a reference voltage and the envelop signal.
    Type: Grant
    Filed: March 11, 2013
    Date of Patent: August 19, 2014
    Assignee: National Taiwan University
    Inventors: Yi-Lin Tsai, Jian-You Chen, Bang-Cyuan Wang, Tsung-Hsien Lin
  • Patent number: 8804804
    Abstract: A system for estimating clock frequency offset and sampling clock offset in a communication system is provided. A receiver is configured to receive a communication signal having been transmitted from a transmitter via a communication channel. The receiver has a signal processor, wherein the signal processor is configured to generate an estimate of a carrier frequency offset and an estimate of a sampling clock offset from the received communication signal by: extracting a vector of pilot symbols from the received signal; performing equalization on the pilot symbols; performing clock frequency offset and sampling clock offset compensation on the pilot symbols; generating the estimate of a carrier frequency offset by estimating a common phase rotation using a first Taylor series approximation; and generating the estimate of the sampling clock offset by estimating phase differences between pairs of pilot symbols using a second Taylor series approximation.
    Type: Grant
    Filed: March 28, 2013
    Date of Patent: August 12, 2014
    Assignee: Antcor S.A.
    Inventor: Ioannis Sarris
  • Patent number: 8744014
    Abstract: A FFR (fractional frequency reuse)-based network MIMO (multiple-input multiple-output) transmission architecture in a cellular system that employs cell sectoring using directional antennas. Each cell is sectorized into three outer sectors using three directional antennas which transmit in three different directions using three different frequency subbands. The cell sectors are arranged based on a frequency partition scheme so that three sectors in three neighboring cells form a coordinated group for network MIMO transmission. A regular and a rearranged frequency partition are described. Further, a practical implementation of SON (self organizing network)-based three-cell FFR-based network MIMO for a wireless OFDM system is described.
    Type: Grant
    Filed: April 23, 2010
    Date of Patent: June 3, 2014
    Assignee: Mediatek Inc.
    Inventors: Chu-Jung Yeh, Li-Chun Wang, I-Kang Fu
  • Patent number: 8724744
    Abstract: The present invention discloses a method and apparatus for wide dynamic range phase conversion. In one embodiment, inphase and quadrature signal components of a complex input signal are collapsed into a single quadrant to produce a first signal representation. A scaling operation is subsequently performed on the first signal representation to produce a second signal representation. Lastly, the second signal representation is converted into the phase domain.
    Type: Grant
    Filed: August 19, 2005
    Date of Patent: May 13, 2014
    Assignee: General Instrument Corporation
    Inventors: David P. Gurney, Anthony R. Schooler
  • Publication number: 20140064412
    Abstract: A system includes a DPSK transmitter and a DPSK receiver. The DPSK transmitter is configured to encode a signal and transmit the encoded signal as a sequence of symbols. The DPSK receiver is configured to decode the sequence of symbols into bit values. The DPSK receiver further includes a first decoder which is configured to receive the sequence of the symbols, and to estimate extrinsic information for each symbol and forward the extrinsic information to a second decoder. Moreover, if magnitude of a LLR received form a second decoder is greater than a threshold, the first decoder is configured to determine a bit value of a received symbol, without considering neighboring symbols in the sequence of symbols. Still moreover, if the magnitude of the LLR received from the second decoder is not greater than the threshold, the first decoder is configured to continue to decode the received symbol and consider neighboring symbols in the sequence of symbols.
    Type: Application
    Filed: August 30, 2013
    Publication date: March 6, 2014
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Jing Lin, Il Han Kim, Tarkesh Pande, Anuj Batra
  • Patent number: 8660215
    Abstract: A method and apparatus for decoding binary frequency shift key signals in which an exclusive-OR of the sign of a real waveform with a sign of the imaginary waveform at a time shortly after the real (or, alternatively, the imaginary) waveform crosses zero is used to determine a bit represented by the signal. In some embodiments, particularly those in which the bit period is about one-half of the carrier signal frequency, both the real and imaginary waveforms are monitored to detect the zero crossing in order to account for the situation in which data transitions prevent zero-crossings on one of the waveforms.
    Type: Grant
    Filed: March 16, 2010
    Date of Patent: February 25, 2014
    Assignee: Siemens Rail Automation Corporation
    Inventor: Brian Joseph Hogan
  • Publication number: 20140037023
    Abstract: A transmitting system, a receiving system, a transmitting method and a receiving method capable of implementing communications with multiple rates are described.
    Type: Application
    Filed: March 8, 2013
    Publication date: February 6, 2014
    Applicant: Wuhan Research Institute of Posts and Telecommunications
    Inventor: Wuhan Research Institute of Posts and Telecommunications
  • Patent number: 8630371
    Abstract: Systems and methods are provided for channel estimation using linear phase estimation. These systems and methods enable improved channel estimation by estimating a linear channel phase between received pilot subcarrier signals. The estimated linear phase can then be removed from the received pilot subcarrier signals. After the estimated linear phase is removed from the received pilot subcarrier signals, a channel response can be estimated. A final estimated channel response can be generated by multiplying the results of the linear channel estimation by the estimated linear phase.
    Type: Grant
    Filed: May 18, 2012
    Date of Patent: January 14, 2014
    Assignee: Marvell International Ltd.
    Inventors: Jungwon Lee, Raj M. Misra, Adina Matache, Konstantinos Sarrigeorgidis
  • Patent number: 8615056
    Abstract: A differential phase shift keying demodulator having an input structured to receive current data representing a current phasor and past data representing at least two past phasors, and a phase differentiator structured to process the current data and reference data representing a reference phasor to provide resulting data representing a phase difference between said current and reference phasors. The differential phase shift keying demodulator also includes a reference phasor computational module configured to generate said reference data basing on said past data representing the at least two past phasors.
    Type: Grant
    Filed: December 29, 2010
    Date of Patent: December 24, 2013
    Assignee: STMicroelectronics S.r.l.
    Inventors: Domenico Di Grazia, Michele Renna
  • Patent number: 8571143
    Abstract: A quadrature signal phase controller includes a first phase shifter and a second phase shifter. The first phase shifter generates phase shifted first in-phase differential output signals and phase shifted first quadrature-phase differential output signals. The second phase shifter generates phase shifted second in-phase differential output signals and phase shifted second quadrature-phase differential output signals. Each of the first and second phase shifters increases or decreases the phase difference between the first in-phase differential output signals and the second quadrature-phase differential output signals, and the phase difference between the second in-phase differential output signals and the first quadrature-phase differential output signals, in response to a change in a level of the first control signal and a change in a level of the second control signal.
    Type: Grant
    Filed: June 4, 2012
    Date of Patent: October 29, 2013
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Sang Soo Ko
  • Publication number: 20130279548
    Abstract: A variation on conventional DPSK binary modulation schemes is provided. One modulation scheme uses 3?/8 differential binary phase shift keying (3?/8-DBPSK) where one symbol is transmitted by phase change of 3?/8 radians and the other symbol is transmitted by phase change of ?5?/8 radians. Alternatively, this can be thought of as adding a constant 3?/8 radians to the symbol angle for every bit modulated by conventional DBPSK. In another example, assume a first and second symbols, k?1 and k, respectively, are sent. Where k is the same symbol as k?1, a phase rotation of 3?/8 radians from the kth symbol is used to represent the symbol at k?1; and where the k?1 symbol is the opposite of the kth symbol, its rotation 11?/8 radians from the kth symbol. Other modulation schemes using other phase rotations can be provided.
    Type: Application
    Filed: April 20, 2012
    Publication date: October 24, 2013
    Inventors: ABU S. AMANULLAH, Dumitru Mihai Ionescu, Lichung Chu
  • Patent number: 8532226
    Abstract: The invention relates to a EHF wireless communication receiver comprising a phased array radio arranged for receiving a beam of signals in a predetermined frequency band. The phased array radio comprises a plurality of antenna paths, each arranged for handling one of the incoming signals and forming a differential I/Q output signal, each antenna path comprises a downconversion part and a phase shifting part for applying a controllable phase shift; a signal combination circuitry is connected to the antenna paths and is arranged for combining the differential I/Q output signals; and a control circuitry is connected to the phase shifting parts of the antenna paths and is arranged for controlling the controllable phase shift. In each antenna path, the phase shifting part is a baseband part downstream from the downconversion part and the phase shifting part comprises a set of variable gain amplifiers arranged for applying controllable gains to the respective downconverted incoming signals in the I/Q branches.
    Type: Grant
    Filed: June 23, 2010
    Date of Patent: September 10, 2013
    Assignee: IMEC
    Inventor: Piet Wambacq
  • Patent number: 8526540
    Abstract: A method and device is provided for detecting data symbols in a received radio signal. Each data symbol is allocated transmit-side a symbol value-specific PN sequence of successive PN chips in the chip clock, and the allocated PN sequences are offset QPSK modulated. The method for incoherent detection includes converting the received radio signal into a complex baseband signal sampled in the chip clock, generating a demodulated signal by differential demodulation of the complex baseband signal, calculating correlation results by correlating the demodulated signal with the derived sequences, and deriving the values of the data symbols by evaluating the correlation results. Each derived sequence is assigned to a PN sequence allocable transmit-side and includes derived chips, whose values correspond to a logic linking of particular PN chips of the PN sequence allocable transmit-side that is assigned the derived sequence. The invention relates furthermore to a corresponding receiving unit.
    Type: Grant
    Filed: June 13, 2012
    Date of Patent: September 3, 2013
    Assignee: Atmel Corporation
    Inventors: Frank Poegel, Eric Sachse, Michael Schmidt
  • Patent number: 8520780
    Abstract: A method (500) of demodulation, the method comprising the steps of receiving (510) a radio frequency signal, converting (520) the received radio frequency signal to a baseband signal, performing (530) symbol timing recovery on the baseband signal, and demodulating (540) the baseband signal. The baseband signal comprises alternating symbols spaced therebetween at an alternating first interval length and a second interval length, where the first interval length and second interval length are dissimilar. Communication units and a method of modulation are also described.
    Type: Grant
    Filed: June 19, 2008
    Date of Patent: August 27, 2013
    Assignee: Motorola Solutions, Inc.
    Inventor: Alexander Radus
  • Patent number: 8509355
    Abstract: A method and apparatus are provided for low power simultaneous frequency, automatic gain control and timing acquisition in a low power radio receiver. A baseband signal received is split into a limited signal having limited data and a non-limited signal. The limited signal is fed through a limited phase-shift keying (PSK) correlation path in which a PSK correlator operating on the limited signal simultaneously determines coarse frequency estimations, timing estimations, and packet synchronization detection. The non-limited signal is fed through an automatic gain control path where automatic gain control is performed on the non-limited signal simultaneously with the coarse frequency and timing estimations and packet synchronization detection performed by the PSK correlator.
    Type: Grant
    Filed: June 30, 2008
    Date of Patent: August 13, 2013
    Assignee: Medtronic, Inc.
    Inventors: Peter Bradley, Richard F. Woicik, Andrew M. Bottomley, Eric D. Corndorf
  • Patent number: 8503568
    Abstract: A differential encoding and decoding system and method for multiplexed data is disclosed. The multiplexed data is formed from a plurality of input data sources. The differential encoding and decoding uses a delay proportional to the number of input data streams in the plurality. In this fashion, errors that propagate from an error in one of the input data sources does not interfere with other input data sources upon de-multiplexing.
    Type: Grant
    Filed: September 7, 2006
    Date of Patent: August 6, 2013
    Assignee: The Boeing Company
    Inventors: Brian K. Pheiffer, Chak M. Chie
  • Patent number: 8472564
    Abstract: An automatic zero-crossing signal demodulation and classification device for rapidly identifying unknown modulation in a signal identifies unknown modulation in a signal, demodulates differential phase shift keying signals and automatically recognizes certain phase shift keying signals. This is accomplished by eliminating unknown term fc in differential phase estimation, introducing a symbol rate tracking mechanism, applying hysteresis nonlinearity to eliminate phase shaping effect and using weighted average to estimate phase difference. Better estimates are accomplished by using hysteretic nonlinear function to detect zero-crossing points in eliminating false detecting of zero-crossing points caused by additive noise, and calculating differential phase without directly using center frequency to simplify estimation process.
    Type: Grant
    Filed: April 2, 2012
    Date of Patent: June 25, 2013
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventor: Wei Su
  • Patent number: 8462899
    Abstract: A method and device for multi-user detecting of an OFDM transmission signal are provided. The method includes: combining received signals, at corresponding time-frequency symbol positions in all of multiple repeated Block Units in relation to the same data symbol, into a received data sequence; determining a combined repeated channel response sequence array corresponding to the received data sequence; and detecting the received data sequence using the combined repeated channel response sequence array to obtain data symbols of multiple users. The technical solution can effectively restrain the multi-address interference and the interference between symbols during OFDM transmitting signal and improve the system performance greatly.
    Type: Grant
    Filed: September 25, 2008
    Date of Patent: June 11, 2013
    Assignee: China Academy of Telecommunications Technology
    Inventors: Yingmin Wang, Shaohui Sun, Hai Bi, Shiqiang Suo, Yeming Tang
  • Patent number: 8451922
    Abstract: Disclosed is a signal processing method and apparatus in MIMO system. In a mobile communication system having a plurality of transmitting antennas, the present invention includes the steps of receiving a feedback signal including status information of at least one channel, segmenting one of the first data blocks to segment into at least one or more of the second data blocks, attaching a CRC to each of the at least one or more of the second data blocks, allocating the at least one or more second data blocks to a plurality of the transmitting antennas, respectively, and transmitting the at least one or more of the second data blocks. In a mobile communication system having a plurality of receiving antennas, the present invention includes the steps of receiving at least one data block including a CRC or dummy bits, acquiring channel status information using the CRC or dummy bits, and transmitting the channel status information.
    Type: Grant
    Filed: March 18, 2008
    Date of Patent: May 28, 2013
    Assignee: LG Electronics Inc.
    Inventors: Sim Dong-Hi, Seo Dong-Youn, Kim Bong-Hoe
  • Patent number: 8401038
    Abstract: Systems, devices, processors, and methods are described which may be used for the reception of a wireless broadband signal at a user terminal from a gateway via a satellite. A wireless signal may include a series of physical layer frames, each frame including a physical layer header and payload. The received signal is digitized and processed using various novel physical layer headers and related techniques to synchronize the physical layer frames and recover data from physical layer headers for purposes of demodulation and decoding.
    Type: Grant
    Filed: June 17, 2009
    Date of Patent: March 19, 2013
    Assignee: ViaSat, Inc.
    Inventors: Donald W. Becker, Matthew D. Nimon, William H. Thesling
  • Publication number: 20120314815
    Abstract: A method and device is provided for detecting data symbols in a received radio signal. Each data symbol is allocated transmit-side a symbol value-specific PN sequence of successive PN chips in the chip clock, and the allocated PN sequences are offset QPSK modulated. The method for incoherent detection includes converting the received radio signal into a complex baseband signal sampled in the chip clock, generating a demodulated signal by differential demodulation of the complex baseband signal, calculating correlation results by correlating the demodulated signal with the derived sequences, and deriving the values of the data symbols by evaluating the correlation results. Each derived sequence is assigned to a PN sequence allocable transmit-side and includes derived chips, whose values correspond to a logic linking of particular PN chips of the PN sequence allocable transmit-side that is assigned the derived sequence. The invention relates furthermore to a corresponding receiving unit.
    Type: Application
    Filed: June 13, 2012
    Publication date: December 13, 2012
    Inventors: Frank Poegel, Eric Sachse, Michael Schmidt
  • Patent number: 8324963
    Abstract: In one embodiment, a circuit provides two quadrature components, I and Q, from a received modulated signal, from three mutually phase-shifted components of the received signal. The circuit can demodulate three mutually phase-shifted components of a baseband signal, in order to provide two quadrature demodulation components. The circuit includes three circuit inputs, each designed to received said three components, respectively. The circuit further includes a first and second adder circuit. The circuit also includes a bank of weighting circuits linked, at input, to the three circuit inputs and linked, at output, to the inputs of the first and second adder circuits so as to transmit to each adder input, with a determined weighting, a particular one of said three components, the weightings being chosen so that the first and second adder circuits provide said two quadrature demodulation components.
    Type: Grant
    Filed: July 29, 2009
    Date of Patent: December 4, 2012
    Assignee: Groupe des Ecoles des Telecommunications—Ecole Nationale Superieure des Telecommunications
    Inventors: Bernard Huyart, Kaïs Mabrouk
  • Patent number: 8315338
    Abstract: To detect phase mismatches between in-phase and quadrature signals of a quadrature demodulator. The phase mismatches can be detected using the signals obtained by removing high frequency components of output of a multiplier by a low pass filter, the output being the product of the in-phase signals of which low frequency components are removed by a first high pass filter by the quadrature signals of which low frequency components are removed by a second high pass filter.
    Type: Grant
    Filed: March 8, 2011
    Date of Patent: November 20, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Shigenori Hayase, Kazuyuki Hori
  • Patent number: 8306157
    Abstract: A receiver can be configured to include an RF front end that is configured to downconvert a received signal to a baseband signal or a low Intermediate Frequency (IF) signal. The receiver can downconvert the desired signal from an RF frequency in the presence of numerous interference sources to a baseband or low IF signal for filtering and channel selection. The filtered baseband or low IF signal can be converted to a digital representation. The digital representation of the signal can be upconverted in the digital domain to a programmable IF frequency. The digital IF signal can be converted to an analog IF signal that can be processed by legacy hardware.
    Type: Grant
    Filed: July 6, 2010
    Date of Patent: November 6, 2012
    Assignee: Maxlinear, Inc.
    Inventors: Kishore Seendripu, Raymond Montemayor, Sheng Ye, Glenn Chang, Curtis Ling
  • Publication number: 20120250800
    Abstract: A receiver system for early detection of a segment type of an input signal based on BPSK and DBPSK modulated carriers is provided. The receiver system includes a tuner that converts the input signal into an intermediate frequency (IF) signal, a signal conditioning module that converts the IF signal into a baseband signal, a Frequency Domain Synchronisation (FDS) block that detects the segment type of the input signal based on a carrier powers, a Transmission and Multiplexing Configuration Control (TMCC) decode block that performs a decoding operation on the received signal, a channel estimation block that estimates a channel and obtains a channel information. The TMCC decode block uses the channel information obtained from channel estimation block to correct a fast-frequency selective fading on the received signal before the decoding operation.
    Type: Application
    Filed: March 30, 2012
    Publication date: October 4, 2012
    Applicant: SAANKHYA LABS PRIVATE LIMITED
    Inventors: Subrahmanya Kondageri Shankaraiah, Abhijeet B Magadum
  • Publication number: 20120243641
    Abstract: A quadrature signal phase controller includes a first phase shifter and a second phase shifter. The first phase shifter generates phase shifted first in-phase differential output signals and phase shifted first quadrature-phase differential output signals. The second phase shifter generates phase shifted second in-phase differential output signals and phase shifted second quadrature-phase differential output signals. Each of the first and second phase shifters increases or decreases the phase difference between the first in-phase differential output signals and the second quadrature-phase differential output signals, and the phase difference between the second in-phase differential output signals and the first quadrature-phase differential output signals, in response to a change in a level of the first control signal and a change in a level of the second control signal.
    Type: Application
    Filed: June 4, 2012
    Publication date: September 27, 2012
    Inventor: Sang Soo Ko
  • Patent number: 8265199
    Abstract: A receiving circuit includes a positive-side level judgment circuit, a negative-side level judgment circuit, and a gate circuit, and is configured to receive input of an AMI-coded signal, convert the signal to a binary output signal, and output the same. The positive-side level judgment circuit judges whether the voltage of an input signal is greater or less than a threshold on the positive side. The threshold on the positive side is provided with a hysteresis characteristic by a positive feedback. The negative-side level judgment circuit judges whether the voltage of an input signal is greater or less than a threshold on the negative side. The threshold on the negative side is provided with a hysteresis characteristic by a positive feedback loop. The gate circuit logically combines the outputs of the positive-side and negative-side level judgment circuits so as to generate the output signal.
    Type: Grant
    Filed: May 28, 2007
    Date of Patent: September 11, 2012
    Assignee: Daikin Industries, Ltd.
    Inventor: Takashi Okano