Automatic Frequency Control Patents (Class 375/344)
  • Patent number: 9705474
    Abstract: According to one embodiment, in a complex band pass filter, a second input signal to be supplied to a second active filter circuit has a substantially 90 degree phase difference from a first input signal to be supplied to a first active filter circuit. The first feedback circuit includes a first element having a first impedance and feeds back an output signal of the first active filter circuit to input side of the second active filter circuit. The second feedback circuit includes a second element having a second impedance different from the first impedance and feeds back an output signal of the second active filter circuit to input side of the first active filter circuit. The output circuit outputs an output signal according to a signal from the first active filter circuit and to a signal from the second active filter circuit.
    Type: Grant
    Filed: March 25, 2016
    Date of Patent: July 11, 2017
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Naotaka Koide
  • Patent number: 9680667
    Abstract: A circuit includes a calculation circuit configured to calculate a noise power of a predetermined-training-sequence pattern repeatedly included in a first signal input into an adaptive equalizer, based on a second signal obtained by compensating the first signal by a compensation circuit, a channel-estimation value based on the second signal, and the predetermined-training-sequence pattern; and an average circuit configured to obtain an average value of estimation values of frequency offsets based on the predetermined-training-sequence pattern having the noise power equal to or smaller than a predetermined power, among estimation values of frequency offsets based on the predetermined-training-sequence pattern, wherein the compensation circuit is configured to compensate a frequency offset of the predetermined-training sequence pattern based on the average value and thereby obtain the second signal, and the adaptive equalizer is configured to perform adaptive-equalization processing of the first signal with a
    Type: Grant
    Filed: July 6, 2016
    Date of Patent: June 13, 2017
    Assignee: FUJITSU LIMITED
    Inventors: Daisuke Sasaki, Kazuhiko Hatae, Tomoki Katou, Nobukazu Koizumi, Masato Oota, Yasuo Ohtomo, Manabu Yamazaki, Masashi Sato
  • Patent number: 9660679
    Abstract: A wireless receiver automatic gain control system includes: a coarse amplification subsystem that receives and amplifies a carrier-modulated signal; a demodulator that generates a baseband signal from the amplified carrier-modulated signal; a fine amplification subsystem that amplifies the baseband signal; and a controller connected to the amplification subsystems. The controller: obtains a unified gain value for the amplification subsystems; based on the unified gain value, selects (i) one of a plurality of coarse gain values defining a set of coarse gain steps each spanning a plurality of unified gain steps, and (ii) one of a plurality of fine gain values defining a set of fine gain steps each spanning a single unified gain step; and sets (i) the gain of the coarse amplification subsystem to the selected coarse gain value, and (ii) the gain of the fine amplification subsystem to the selected fine gain value.
    Type: Grant
    Filed: July 26, 2016
    Date of Patent: May 23, 2017
    Assignee: PERASO TECHNOLOGIES INC.
    Inventors: Grigori Temkine, Craig Farnsworth, Arash Tabibiazar, Alexander Tomkins, Bradley Robert Lynch
  • Patent number: 9634699
    Abstract: Disclosed are an apparatus for controlling a wide-band signal transmission gain, which differently applies a transmission gain by the unit of an intermediate frequency (IF) at a transmitting side of a wide-band multi-IF wireless communication system which can convert multiple baseband digital signals into IF signals and thereafter, multiplex and simultaneously transmit the converted IF signals and a signal processing method of the same.
    Type: Grant
    Filed: February 11, 2016
    Date of Patent: April 25, 2017
    Assignee: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventor: Yong Su Lee
  • Patent number: 9621274
    Abstract: Consistent with the present disclosure a transmitter is provided that transmits data in either a “quasi-DP-BPSK” (“QDP”) mode or in a DP-QPSK mode. In the QDP mode, data bits are transmitted as changes in phase between first and second phase states along a first axis or as changes in phase between third and fourth phase states along a second axis in the IQ plane. Although the transmitter outputs an optical signal that changes in phase between each of the four states, a sequence bit identifies which axis carries the data bit. The sequence bit is one of a series of sequence bits that may be generated by a pseudo-random number generator. The series of sequence bits can be relatively long, e.g., 32 bits, to permit sufficiently random changes in the axis that carries the data.
    Type: Grant
    Filed: April 7, 2011
    Date of Patent: April 11, 2017
    Assignee: Infinera Corporation
    Inventors: John D. McNicol, Kuang-Tsan Wu
  • Patent number: 9525390
    Abstract: A switching circuit generates a switching pulse that is pulse modulated according to an input signal. An error amplifier includes a phase compensating filter that generates a feedback signal corresponding to the switching pulse. The error amplifier generates an error signal corresponding to a difference between the input signal and the feedback signal. A pulse modulator includes an oscillator that generates a carrier signal having a variable frequency. The pulse modulator pulse-modulates the carrier signal according to the error signal, so as to generate a pulse modulated signal. The phase compensating filter is configured such that its frequency characteristics can be adjusted according to the frequency of the carrier signal.
    Type: Grant
    Filed: August 19, 2015
    Date of Patent: December 20, 2016
    Assignee: ROHM CO., LTD.
    Inventor: Takayuki Ibusuki
  • Patent number: 9509377
    Abstract: A communication system provides for adaptive rank determination, for example, a rank 2 transmission in instances where a rank 1 transmission may be indicated under supported feedback modes in current standards where no explicit power adaptation can be assumed, for example, where a user equipment (UE) is limited to reporting a rank 1 channel due to a large dynamic range of a signal or due to a signal received by the UE from one base station (BS) antenna port drowning out a signal received by the UE from another BS antenna port. The communication system provides for the UE to implement rank 2 transmission in such instances by using per-antenna port power control at a BS serving the UE. In one embodiment, the BS controls the rank determination at the UE by signaling transmit power or power offset related parameters to use for rank and transmission parameters determination and feedback.
    Type: Grant
    Filed: November 7, 2011
    Date of Patent: November 29, 2016
    Assignee: Google Technology Holdings LLC
    Inventors: Krishna Kamal Sayana, Tyler A. Brown, Robert T. Love, Vijay Nangia
  • Patent number: 9503296
    Abstract: A quadrature detector performs a quadrature detection on an FM signal based on a local oscillation signal, and outputs a baseband signal. A first corrector and a second corrector perform a correction on the baseband signal based on a DC offset correction value. The DC offset detector performs a polar coordinate conversion on the baseband signal, and derives the DC offset value in such a way that respective amplitudes in a plurality of phase domains defined on an IQ plane approximate one another. An FM detector performs an FM detection on the corrected baseband signal, and generates a detection signal. A controller controls the frequency of the local oscillation signal in such a way that a phase component having undergone the polar coordinate conversion by the DC offset detector is rotated.
    Type: Grant
    Filed: January 10, 2016
    Date of Patent: November 22, 2016
    Assignee: JVC KENWOOD CORPORATION
    Inventor: Yasuhide Okuhata
  • Patent number: 9459295
    Abstract: An improved receiver system may include an input to receive an input signal, and a signal generating circuit to generate a desired oscillator signal that is a single sideband radio frequency signal of time varying frequency. The receiver may also include a downconversion stage to generate an intermediate frequency (IF) signal based on the input signal and the desired oscillator signal. A signal processing block in the receiver may be used to produce an output signal based on the IF signal by frequency shifting the IF signal by an amount that compensates for the time varying frequency of the desired oscillator signal. The desired oscillator signal may be generated using a vector signal generator that receives a control value from the signal processing block, converts the control value to a pair of analog input signals, and generates the desired oscillator signal by quadrature modulating the pair of analog input signals.
    Type: Grant
    Filed: July 10, 2013
    Date of Patent: October 4, 2016
    Assignee: National Instruments Corporation
    Inventor: Daniel S. Wertz
  • Patent number: 9451399
    Abstract: A method for receiving a reference signal for positioning in a wireless communication system by a user equipment (UE) is disclosed. The method includes receiving a plurality of reference signal sequences for positioning to which different frequency shift values are applied, calculating a correlation between the plurality of reference signal sequences for positioning and transmitted reference signal sequences for positioning corresponding to the plurality of reference signal sequences in a time domain, and determining a time domain index having a highest value from the correlation as a reference time point for positioning, wherein the frequency shift value is determined according to the sum of multiplication of an index of each reference signal sequence and a frequency shift interval, and frequency offset.
    Type: Grant
    Filed: July 24, 2015
    Date of Patent: September 20, 2016
    Assignee: LG ELECTRONICS INC.
    Inventors: Hanjun Park, Daesung Hwang, Kijun Kim, Hyunho Lee, Jonghyun Park, Hyangsun You
  • Patent number: 9444664
    Abstract: Embodiments of the present invention provide a method, includes: performing channel estimation on a signal of a current channel to obtain channel information of the current channel, performing calculation processing on the channel information obtained in current channel estimation and channel information obtained in previous channel estimation to obtain a phase difference of the current channel information, dividing the phase difference of the current channel information by a time interval between two times of channel estimation to obtain residual frequency offset information of the current channel, adding the residual frequency offset information of the current channel and frequency offset information which is of the channel and obtained in a previous calculation to obtain frequency offset information of the current channel, and outputting the frequency offset information of the current channel, so as to perform frequency offset correction on the signal of the channel according to the current frequency offse
    Type: Grant
    Filed: September 24, 2013
    Date of Patent: September 13, 2016
    Assignee: Huawei Technologies Co., Ltd.
    Inventors: Zihuan Chen, Dafeng Tian, Xiaodong Li, Qiao Liu
  • Patent number: 9430729
    Abstract: In one embodiment, an RFID apparatus is provided, which includes an input circuit that has an input impedance used for receiving RF signals. An RF-signal converter provides an apparatus-operating power signal in response to receiving the RF signals. An impedance circuit provides and selects impedance values in response to at least one select signal provided by a state-machine logic circuit. The state-machine logic circuit provides the select signal(s) in response to the apparatus-operating power signal for selecting the impedance values and therein permit the input impedance to be changed for tuning the RFID apparatus.
    Type: Grant
    Filed: May 31, 2012
    Date of Patent: August 30, 2016
    Assignee: NXP B.V.
    Inventors: Rachid El Waffaoui, Christian Weidinger
  • Patent number: 9425842
    Abstract: A wireless receiver automatic gain control system includes: a coarse amplification subsystem that receives and amplifies a carrier-modulated signal; a demodulator that generates a baseband signal from the amplified carrier-modulated signal; a fine amplification subsystem that amplifies the baseband signal; and a controller connected to the amplification subsystems. The controller: obtains a unified gain value for the amplification subsystems; based on the unified gain value, selects (i) one of a plurality of coarse gain values defining a set of coarse gain steps each spanning a plurality of unified gain steps, and (ii) one of a plurality of fine gain values defining a set of fine gain steps each spanning a single unified gain step; and sets (i) the gain of the coarse amplification subsystem to the selected coarse gain value, and (ii) the gain of the fine amplification subsystem to the selected fine gain value.
    Type: Grant
    Filed: June 1, 2015
    Date of Patent: August 23, 2016
    Assignee: PERASO TECHNOLOGIES INC.
    Inventors: Grigori Temkine, Craig Farnsworth, Arash Tabibiazar, Alexander Tomkins, Bradley Robert Lynch
  • Patent number: 9363118
    Abstract: A non-contact power supply transmitter system 100 transmitting an electric power from a transmitting device (TX) 200 to a receiving device (RX) 300 with a non-contact power supply transmitter method, the TX 200 including: a transmitting coil 202; a driver 204 causing the transmitting coil 202 to generate a power signal of the electromagnetic field; and an FSK modulation unit 240 transmitting an FSK signal Sf through the transmitting coil 202, the RX 300 including: a receiving coil 302; an FSK demodulation unit 330 demodulating the FSK signal Sf received through the receiving coil 302; and a controller 312 inputting the FSK signal demodulated by the FSK demodulation unit 330, the FSK demodulation unit 330 is composed of an analog circuit. The non-contact power supply transmitter system, the receiving device, and the analog circuit can realize a low power, space-saving FSK communication.
    Type: Grant
    Filed: August 12, 2014
    Date of Patent: June 7, 2016
    Assignee: ROHM CO., LTD.
    Inventors: Takashi Noguchi, Tatsuya Iwasaki
  • Patent number: 9350529
    Abstract: A logical transmission system includes a driver configured to receive a source data and output a first voltage at a first node; a transmission line of a characteristic impedance configured to couple the first node to a second node; a three-point three-level slicer configured to receive a second voltage at the second node and output a first ternary signal, a second ternary signal, and a third ternary in accordance with a first reference voltage, a second reference voltage, a first clock, a second clock, and a third clock; and a CDR (clock-data recovery) unit configured to receive a reference clock, the first ternary signal, the second ternary signal, and the third ternary signal and output a recovered data, the first reference voltage, the second reference voltage, the first clock, the second clock, and the third clock.
    Type: Grant
    Filed: March 23, 2015
    Date of Patent: May 24, 2016
    Assignee: REALTEK SEMICONDUCTOR CORP.
    Inventors: Gerchih (Joseph) Chou, Chia-Liang (Leon) Lin
  • Patent number: 9350579
    Abstract: A method of determining a threshold for symbol detection, includes receiving a most previously input sample value and a result of detecting a most previous symbol, and determining the threshold for the symbol detection of a currently input sample value based on the most previously input sample value and the result of detecting the most previous symbol.
    Type: Grant
    Filed: May 19, 2014
    Date of Patent: May 24, 2016
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Joon Seong Kang, Chang Soon Park, Young Jun Hong
  • Patent number: 9350501
    Abstract: A base station which uses either one of a plurality of component carriers individually or uses an aggregate carrier which is an aggregate of the above-mentioned plurality of component carriers to carry out radio communications with a mobile terminal corresponding to the above-mentioned component carrier and also carry out radio communications with a mobile terminal corresponding to the above-mentioned aggregate carrier is provided. The base station notifies a bandwidth of an aggregate carrier which is an aggregate of all of the above-mentioned component carriers, as a bandwidth which the above-mentioned base station uses, to the mobile terminal corresponding to the above-mentioned aggregate carrier. As a result, while an improvement in the transmission rate is provided according to the aggregate carrier, the base station can also support an operation of a mobile terminal corresponding to a component carrier.
    Type: Grant
    Filed: April 21, 2010
    Date of Patent: May 24, 2016
    Assignee: Mitsubishi Electric Corporation
    Inventors: Miho Maeda, Mitsuru Mochizuki, Taiga Saegusa, Yasushi Iwane
  • Patent number: 9338032
    Abstract: A device includes an input configured to receive a signal, wherein the signal includes at least one data block and a plurality of signal parts known to the device, a first signal part at the beginning of the data block and a second signal part at the end of the data block. The device further includes an equalizer and a pre-equalizer coupled between the input and the equalizer, wherein the pre-equalizer is configured to estimate a phase shift between the plurality of signal parts.
    Type: Grant
    Filed: December 2, 2013
    Date of Patent: May 10, 2016
    Assignee: Intel IP Corporation
    Inventors: Michael Genossar, Yaniv Kaver, Vladimir Kravtsov, Uriel Lemberger
  • Patent number: 9306680
    Abstract: A method and a device for calibrating frequency synthesizer in communication terminal are provided. The method may include: controlling the communication terminal to transmit a continuous wave signal in a specified channel; controlling a measurement device to measure the continuous wave signal to obtain a measured frequency deviation value of the frequency synthesizer in the communication terminal; calculating a center oscillation frequency point of a reference crystal oscillator of the communication terminal and a frequency calibration step corresponding to the center oscillation frequency point based on the measured frequency deviation value; and storing the center oscillation frequency point and the corresponding frequency calibration step in the communication terminal. The method can reduce frequency calibration cost and time.
    Type: Grant
    Filed: July 28, 2014
    Date of Patent: April 5, 2016
    Assignee: SPREADTRUM COMMUNICATIONS (SHANGHAI) CO., LTD.
    Inventors: Dian Xu, Yi Zhao, Yufeng Jin
  • Patent number: 9288697
    Abstract: It is an objective of the present invention to provide a circuit with a wideband received signal strength indicator, used for multiple systems. By using the switches and the analog-to-digital converter and the demodulator, the circuit of the present invention has the advantages of auto gain control, circuit size reduction and power-saving.
    Type: Grant
    Filed: July 11, 2013
    Date of Patent: March 15, 2016
    Assignee: MICROCHIP TECHNOLOGY INCORPORATED
    Inventors: Peng-Sen Chen, Mei-Show Chen, Jeng-Hong Chen
  • Patent number: 9270139
    Abstract: A core module for a portable computing device includes wireless power receiver circuitry, battery power circuitry, power supply circuitry, a processor, and an RF link interface. The wireless power receiver module, when operable, receives a wireless power transmit signal and converts it into a supply voltage. The battery power circuitry, when operable, outputs a battery voltage. The power supply circuitry, when operable, converts the supply voltage or the battery voltage into one or more power supply voltages. The processor is operable to select one of the battery voltage, the supply voltage, and one of the one or more power supply voltages to produce a selected voltage. The RF link interface outputs the selected voltage on to an RF link of the portable computing device for providing power to one or more multi mode RF units within the portable computing device.
    Type: Grant
    Filed: July 24, 2015
    Date of Patent: February 23, 2016
    Assignee: BROADCOM CORPORATION
    Inventors: Ahmadreza (Reza) Rofougaran, Maryam Rofougaran, Brima B. Ibrahim, Hooman Darabi
  • Patent number: 9252998
    Abstract: A radio includes a radio frequency (RF) subsystem to process analog information. A digital subsystem receives input from the RF subsystem, and may include a frequency error estimator and a transmitter. The frequency error estimator may be configured to receive samples from the digital subsystem and to estimate a frequency misalignment, between transmitter and receiver, of each of a plurality of received signals in real time. The transmitter may be configured to transmit to each of a plurality of downstream endpoints on frequencies based in part on the respective estimated frequency misalignments. Such transmissions, at a frequencies expected by each of the downstream endpoints, allows the use of narrower receiver filters by those endpoints. In one example, the plurality of received signals may be received simultaneously and be associated with packets of a plurality of different channel plans, with different channel bandwidths and/or channel spacing, and different channel modulation schemes.
    Type: Grant
    Filed: February 25, 2013
    Date of Patent: February 2, 2016
    Assignee: Itron, Inc.
    Inventor: Danny Ray Seely
  • Patent number: 9248003
    Abstract: A receiver for determining the location of a marker that is excited with an exciting waveform. A sensing array having coils is used to sense magnetic flux from the resonating marker. The coils provide inputs to the receiver. The receiver includes a correlation processor for analyzing the inputs in a coherent manner. Further, the receiver is adapted to tune to the resonant frequency of a marker.
    Type: Grant
    Filed: December 31, 2003
    Date of Patent: February 2, 2016
    Assignee: Varian Medical Systems, Inc.
    Inventors: J. Nelson Wright, Laurence J. Newell, Edward J. Vertatschitsch
  • Patent number: 9246542
    Abstract: In general, the subject matter described in this specification can be embodied in methods, systems, and program products for identifying data that is designated for wireless transmission to a remote computing device. A digital signal that encodes the data for transmission across a band of radio frequency channels is generated. Multiple radio frequency channels in the band that are available are determined. The digital signal is filtered to substantially reduce a power level of the digital signal at frequencies that correspond to channels in the band that have not been determined to be available. The filtered digital signal is converted to an analog signal. The analog signal is provided to an analog transmitter that isolates the band of channels to generate an isolated analog signal and that wirelessly transmits the isolated analog signal over the multiple available channels using one or more antennas.
    Type: Grant
    Filed: October 7, 2013
    Date of Patent: January 26, 2016
    Assignee: Google Inc.
    Inventors: E. Daniel McCloskey, C. Philip Gossett
  • Patent number: 9220079
    Abstract: A signal analysis device includes a synchronization data generation unit, a synchronization correction value calculation unit, and a correction unit. The synchronization unit outputs an A/D-converted correction signal as first synchronization data. The first synchronization data is associated with time based on the timing of a trigger signal input from the outside. The synchronization correction value calculation unit calculates, as a first synchronization correction value, an amplitude ratio, a phase difference, and a time difference between the first synchronization data and second synchronization data input from the outside on the basis of the first synchronization data and the second synchronization data. The correction unit corrects the amplitude, phase, and timing of the RF signal output from the object to be measured, on the basis of the first synchronization correction value or a second synchronization correction value input from the outside.
    Type: Grant
    Filed: July 3, 2014
    Date of Patent: December 22, 2015
    Assignee: ANRITSU CORPORATION
    Inventors: Shinichi Ito, Go Inoue, Jun Ono, Keisuke Nishio, Yuki Kondo
  • Patent number: 9195862
    Abstract: A radio frequency identifying reader (RFID) and a method for locating a tag by the RFID includes transmitting, by the RFID reader, signals to the tag on at least two frequencies and receiving a corresponding reflection signal, combining, by the RFID reader, received reflection signals and acquiring the combined signal which is received, and mapping the combined signal that is received to a constellation point in a constellation map to locate the tag such that the tag can be more easily located.
    Type: Grant
    Filed: January 14, 2011
    Date of Patent: November 24, 2015
    Assignee: Siemens Aktiengesellschaft
    Inventors: Dieter Horst, Dan Yu, Yong Yuan
  • Patent number: 9197477
    Abstract: A circuit for processing Carrier Aggregation (CA) is provided. The circuit includes a plurality of Component Carrier (CC) processors, each CC processor configured to estimate a frequency offset for a related CC and to compensate the estimated frequency offset, a reference clock generator configured to generate a reference clock using a reference frequency offset as one of frequency offsets output from the plurality of CC processors, a plurality of reception Phase Lock Loop (PLL) units, each reception PLL unit configured to generate a reception carrier frequency for the related CC corresponding to the reference clock, and a plurality of transmission PLL units, each transmission PLL unit configured to generate a transmission carrier frequency for the related CC corresponding to the reference clock.
    Type: Grant
    Filed: January 10, 2014
    Date of Patent: November 24, 2015
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Joo-Hyun Do, In-Hyoung Kim
  • Patent number: 9197286
    Abstract: An apparatus includes: an offset adjustment unit supplying an offset correction signal corresponding to a frequency switching to an adder unit receiving output from a mixer; a timing adjustment unit adjusting the timing of a frequency switching signal supplied to a local oscillator and the timing of an offset correction amount switching signal supplied to the offset adjustment unit for changing an offset amount in correspondence with the frequency switching in the local oscillator; a noise amount measurement and calculation unit receiving a signal obtained by amplifying and filtering the signal from the adder unit, to measure a noise amount of the signal and generates a timing determination signal based on the noise amount; and a control unit controlling frequency switching signal timing and the offset correction amount switching signal supplied to the timing adjustment unit, based on the timing determination signal from the noise amount measurement and calculation unit.
    Type: Grant
    Filed: August 8, 2014
    Date of Patent: November 24, 2015
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventor: Takahiro Kawano
  • Patent number: 9191130
    Abstract: The invention relates to a multi-carrier method in a measurement device for improving reach of a measurement, said method comprising: transmitting a first signal in a sequence, measuring a response to said first signal, calculating a first transfer function for frequency of each modulated subcarrier in the first signal, transmitting a second signal of the sequence, wherein at least one subcarrier in the second signal has modulation different from that of the subcarriers in the first signal, measuring a response to said second signal, calculating a second transfer function for frequency of each modulated subcarrier in the second signal, said second transfer function comprising for each frequency a thereto associated second distortion component, calculating a mean value of all first and second transfer functions. The invention further relates to a measurement device for performing said method.
    Type: Grant
    Filed: January 5, 2012
    Date of Patent: November 17, 2015
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Miguel Berg, Antoni Fertner, Daniel Cederholm, Per Ola Börjesson
  • Patent number: 9191964
    Abstract: Disclosed is a method for improving the efficiency of sharing a frequency between a plurality of adjacent systems using an idle band. A method for allocating an operating channel priority between frequency sharing systems according to the present invention includes: a coarse channel priority allocating operation of collecting information about a target white space object (WSO) for priority allocation of an operating channel and information about the operating channel, and classifying the operating channel based on a predetermined criterion; and a fine channel priority allocating operation of removing the operating channel by checking an interference level of the classified operating channel.
    Type: Grant
    Filed: June 26, 2013
    Date of Patent: November 17, 2015
    Assignee: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Dong Hun Lee, Hyun Duk Kang, Byung Jang Jeong
  • Patent number: 9166682
    Abstract: The present document relates to a method and apparatus in optical transmission systems for the estimation of the carrier phase and the degree of non-linear distortions incurred in an optical transmission channel. A plurality of signal samples are provided at succeeding time instances such that the plurality of signal samples: is associated with a modulation scheme and a carrier phase; has been transmitted over the optical transmission channel; comprises a plurality of signal phases, respectively; comprises a plurality of data phases and a plurality of residual phases, respectively; and the plurality of residual phases is associated with the carrier phase. The method comprises further canceling the plurality of data phases from the plurality of signal phases by taking into account the modulation scheme; thereby yielding the plurality of residual phases; and determining a set of autocorrelation values of the plurality of residual phases for a set of lag values, respectively.
    Type: Grant
    Filed: November 19, 2010
    Date of Patent: October 20, 2015
    Assignee: Alcatel Lucent
    Inventors: Jeremie Renaudier, Adrian Voicila, Sébastien Bigo
  • Patent number: 9164129
    Abstract: A voltage detection circuit includes: an amplifier which amplifies a voltage difference between first and second input signals input into non-inverting and inverting input terminals of the amplifier via first and second input portions; a first signal line which connects the first input portion to the amplifier; a second signal line which connects the second input portion to the amplifier; a first capacitor connected in parallel to the first signal line; a second capacitor connected in parallel to the second signal line; a first filter element which has an inductor component and a resistor component and is connected in series to the first signal line between the first capacitor and the amplifier; and a second filter element which has an inductor component and a resistor component and is connected in series to the second signal line between the second capacitor and the amplifier.
    Type: Grant
    Filed: April 16, 2013
    Date of Patent: October 20, 2015
    Assignee: KAYABA INDUSTRY CO., LTD.
    Inventors: Kouki Nagae, Noboru Yoshida, Shinichiro Hakamada
  • Patent number: 9160390
    Abstract: Methods and systems for impairment shifting may comprise receiving radio frequency (RF) signals in a receiver, downconverting the signals to baseband frequencies, and synchronizing the receiver to received signals. The frequency of a local oscillator (LO) may be adjusted to shift residual impairments to fall between desired baseband signals where they are least visible. The received RF signals may comprise analog, satellite, or cable, television signals. The LO frequency may be adjusted to configure the DC offset impairments to fall between luminance and chrominance harmonics. The LO frequency may be adjusted to configure I/Q imbalanced impairments from residual in-phase and quadrature mismatch of a picture carrier signal to fall about 300 kHz from a sound carrier signal in the analog television signals. The LO frequency may be adjusted to configure the I/Q imbalanced impairments from residual I/Q mismatch of a sound carrier signal to fall between luminance and chrominance harmonics.
    Type: Grant
    Filed: February 13, 2012
    Date of Patent: October 13, 2015
    Assignee: Maxlinear, Inc.
    Inventors: Chengzhi Zhou, Shuang Yu
  • Patent number: 9143087
    Abstract: Methods, systems, and devices are described for an adaptive demodulator that supports multiple modes. An FM signal may be received at a demodulator and parameters corresponding to the FM signal may be identified. Connections between multiple modules within the demodulator may be configured, based at least in part on the parameters, to select one of multiple demodulation modes supported by the demodulator to demodulate the FM signal. The modes may include a phase differencing mode, a phase-locked loop (PLL) mode, a frequency-compressive feedback (FCF) mode, and/or a quadrature detector mode. The parameters may include one or both of a signal strength of the FM signal and a maximum frequency deviation of the FM signal. Based on the parameters, one or more signals may be generated to configure the connections within the demodulator. A switch from one mode to another may occur when one of the parameters breaches a threshold value.
    Type: Grant
    Filed: November 19, 2013
    Date of Patent: September 22, 2015
    Assignee: QUALCOMM Incorporated
    Inventors: Eunmo Kang, Le Nguyen Luong, Yossef Tsfaty
  • Patent number: 9137006
    Abstract: Apparatus and method for performing entirely digital timing recovery for high bandwidth radio frequency communications. The received digital data source can be sampled from any (minimum 2×) non-integer oversampled transmitted data. This method re-samples the data through interpolation and phase adjustment. The output phase error adjusts the receiver's Analog-to-digital Convertor sampling clock to improve synchronization with the transmitter's Digital-to-analog Convertor clock phase, thus improving transmitted symbol recovery.
    Type: Grant
    Filed: October 22, 2014
    Date of Patent: September 15, 2015
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventor: Gerard Wohlrab
  • Patent number: 9130792
    Abstract: A serial communication circuit (FIG. 3) is disclosed. The circuit includes an equalizer circuit (306) arranged to receive a data signal (CH 1) and produce an equalized data signal. A log detector circuit (300) receives the data signal and produces a power signal indicating a power level of the data signal. A decision circuit (332) receives the power signal and produces a select signal. A first selection circuit (336) receives a plurality of first correction signals and applies one of the first correction signals to the equalizer circuit in response to the select signal.
    Type: Grant
    Filed: June 9, 2014
    Date of Patent: September 8, 2015
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Roland Sperlich, Huanzhang Huang, Charles M. Branch
  • Patent number: 9131198
    Abstract: A signal processing apparatus includes an initial detecting module, a mixer, a symbol rate detecting module, a judging module and a correcting module. The initial detecting module determines an initial carrier frequency offset of an input signal according to a spectrum of the input signal. The mixer adjusts the input signal according to the initial carrier frequency offset to generate a frequency-compensated signal. The symbol rate detecting module determines a symbol rate of the input signal. The judging module judges whether the initial carrier frequency offset is correct according to the frequency-compensated signal. When a judgment result of the judging module is negative, the correcting module determines a corrected carrier frequency offset according to the symbol rate and the spectrum.
    Type: Grant
    Filed: March 18, 2013
    Date of Patent: September 8, 2015
    Assignee: MStar Semiconductor, Inc.
    Inventors: Chu-Hsin Chang, Kai-Wen Cheng, Yi-Ying Liao, Tung-Sheng Lin, Tai-Lai Tung
  • Patent number: 9124396
    Abstract: Receivers with capability for iterative-diversity reception of COFDM digital television transmissions of repeated similarly coded data are described. Also described are receivers with capabilities for receiving COFDM digital television transmissions in which earlier transmissions of coded data are later followed by subsequent transmissions of the same data differently coded. The receivers use maximal-ratio code combining techniques for repeated components in the COFDM digital television transmissions. The receivers use turbo decoding techniques for concatenated coding of data in the COFDM digital television transmissions.
    Type: Grant
    Filed: September 14, 2012
    Date of Patent: September 1, 2015
    Inventor: Allen LeRoy Limberg
  • Patent number: 9112697
    Abstract: Various embodiments provide for systems and methods for wireless communications that implement transmitter protection schemes using spatial combining. The protection scheme implemented by some embodiments provides for a number of benefits, including without limitation: hitless protection; constant power monitoring for each wireless channel being utilized; extra gain to wireless signals transmitted; beam steering, beam hopping, and beam alignment capabilities; and varying levels of transmission path protection (e.g., 1+1 protection, or 1+N protection). Additionally, the features of some embodiments may be applied to a variety of wireless communications systems including, for example, microwave wireless systems, cellular phone systems and WiFi systems.
    Type: Grant
    Filed: January 27, 2015
    Date of Patent: August 18, 2015
    Assignee: Aviat U.S., Inc.
    Inventors: Ying Shen, David Schafer
  • Patent number: 9112735
    Abstract: A pre-channelized spectrum analyzer utilizes a channelizer as a preprocessor for parallel-configured low-resolution spectrum analyzers so as to perform as a high resolution spectrum analyzer. The pre-channelized spectrum analyzer has a polyphase filter that channelizes a signal input and an IFFT that generates filter bank outputs derived from the channelized signal. Spectrum analyzers are in communications with the filter bank outputs so as to generate a spectral decomposition of a subset of those outputs. The spectrum analyzers each perform a window and an FFT function on a corresponding one of the filter bank subset.
    Type: Grant
    Filed: November 12, 2013
    Date of Patent: August 18, 2015
    Inventor: Fredric J. Harris
  • Patent number: 9106499
    Abstract: Methods and systems are disclosed for frequency-domain frame synchronization for multi-carrier communication systems. Received signals are sampled and converted into frequency domain components associated with subcarriers within the multi-carrier communication signals. A sliding-window correlation (e.g., two-dimensional sliding window) is applied to the received symbols represented in the frequency domain to detect frame boundaries for multi-carrier signals. The sliding-window frame synchronization can be applied by itself or can be applied in combination with one or more additional frame synchronization stages. The disclosed embodiments are particularly useful for frame synchronization of multi-carrier signals in PLC (power line communication) systems.
    Type: Grant
    Filed: June 24, 2013
    Date of Patent: August 11, 2015
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Jianqiang Zeng, Steven M. Bosze, Raja V. Tamma, Kevin B. Traylor
  • Patent number: 9054938
    Abstract: Generally speaking, methods and apparatuses which correct errors related to phase and gain imbalances in quadrature tuners are disclosed. The quadrature tuner may be online and operating, receiving data. An embodiment may generate a squared signal from the IF frequency signal of the tuner. In generating the squared signal, the embodiment may enable the extraction of phase error and gain error information of the IF signal. The embodiment may determine a phase error component, a gain error component, or both, by frequency translation. The frequency translation may involve down-converting the signal associated with the error component to direct current (DC) signals and enable the determination of the associated phase error and/or gain error. The embodiments may generate an adjusted signal via the IF signal by applying a phase correction signal or gain correction signal to components used to correct the IF signal.
    Type: Grant
    Filed: May 28, 2010
    Date of Patent: June 9, 2015
    Assignee: Intel Corporation
    Inventors: Isaac Ali, Nicholas Cowley
  • Patent number: 9054718
    Abstract: In one embodiment, a transceiver may set a first receive frequency of a first channel of the transceiver and a second receive frequency of a second channel of the transceiver. The transceiver may receive, during a first time interval, a first radio frequency (RF) signal on the first channel. The transceiver may determine that a first measured value indicative of a first detectable received RF signal on the first channel exceeds a first predetermined threshold, and in response, receive a first data frame on the first channel. The transceiver may receive, during a second time interval, a second RF signal on the second channel. The transceiver determine that a second measured value indicative of a second detectable received RF signal on the second channel exceeds the first predetermined threshold, and in response, receive a second data frame on the second channel.
    Type: Grant
    Filed: November 30, 2011
    Date of Patent: June 9, 2015
    Assignee: Atmel Corporation
    Inventors: Tilo Ferchland, Sascha Beyer, Dietmar Eggert, Udo Walter
  • Patent number: 9042489
    Abstract: A carrier frequency offset compensation method for a communication system is provided. The method includes: mixing, filtering and interpolating an input signal according to a mixing parameter, a first filtering parameter and a first interpolation parameter, respectively, to generate a processed result; calculating a carrier frequency offset estimation value of the input signal according to the processed result; adjusting the mixing parameter according to the carrier frequency offset estimation value; and mixing, filtering and interpolating the input signal according to the adjusted mixing parameter, a second filtering parameter and a second interpolation parameter, respectively. The first interpolation parameter is associated with a cut-off frequency corresponding to the first filtering parameter.
    Type: Grant
    Filed: December 4, 2013
    Date of Patent: May 26, 2015
    Assignee: MSTAR SEMICONDUCTOR, INC.
    Inventor: Ko-Yin Lai
  • Patent number: 9042435
    Abstract: A transmitter and/or receiver for performing frequency domain equalization is provided. A transmitter includes a pilot position determination unit for determining positions for inserting pilots in a frequency domain based on frequency spectrums of data, and a pilot insertion unit for inserting the pilots between the frequency spectrums of the data according to the determined positions for inserting the pilots.
    Type: Grant
    Filed: March 25, 2013
    Date of Patent: May 26, 2015
    Assignees: Samsung Electronics Co., Ltd., Postech Academy-Industry Foundation
    Inventors: Dong Sik Kim, Ui Kun Kwon, Gi Hong Im, Chang Yong Shin
  • Patent number: 9037092
    Abstract: A method of determining at a receiver whether a received signal comprises a pure tone signal component. The method comprises: measuring a received signal over a measurement period; calculating, using maximum likelihood hypothesis testing, a likelihood ratio value for the measured signal and, determining, based on said likelihood ratio value, whether the measured signal comprises a pure tone signal component. The likelihood ratio value is a value indicative of the ratio of a likelihood LFSC that the measured signal comprises a pure tone signal component, and a likelihood LnoFSC that the measured signal does not comprise the pure tone signal component.
    Type: Grant
    Filed: September 30, 2013
    Date of Patent: May 19, 2015
    Assignee: BROADCOM CORPORATION
    Inventors: Morten R. Hansen, Lars P. B. Christensen
  • Patent number: 9032449
    Abstract: The present invention concerns a method and associated apparatus for reducing the time required to scan an incoming satellite transmission power spectrum for available signals and to determine the characteristics of those signals. The frequency range of interest is scanned in narrow slices to determine approximate input power within each slice. Center frequencies and symbol rates of individual transponders are then estimated based upon these input power approximations.
    Type: Grant
    Filed: November 13, 2009
    Date of Patent: May 12, 2015
    Assignee: Thomson Licensing
    Inventor: Brian David Bajgrowicz
  • Patent number: 9025650
    Abstract: A signal receiver is configured to receive multiple time-domain input signals. A plurality of the input signals among the multiple time-domain input signals is selected and transformed into frequency-domain signals. The frequency-domain signals are shifted in phase by a negative value of a respective reference phase, and the phase-shifted signals are combined into one signal. The combined signal is then multiplied with a stored signal to generate a signal product and transformed into a time-domain signal. Peak detection is performed on the time-domain signal.
    Type: Grant
    Filed: September 30, 2013
    Date of Patent: May 5, 2015
    Assignee: Neocific, Inc.
    Inventors: Titus Lo, Xiaodong Li
  • Patent number: 9014311
    Abstract: Systems, methods, apparatuses, and computer program products for an interleaved multi-beam acquisition waveform providing concurrent beam selection, automatic gain control (AGC) and automatic frequency correction (AFC) are provided. The access point (AP) may send an acquisition waveform on multiple beams, then return and retransmit an AFC on the multiple beams thus interleaving beam switching with the acquisition and frequency correction waveforms. AGC correction can be deferred until the end, relying on the fact that the transmitter may be detected at close range using a one of the multi-beams that is attenuated.
    Type: Grant
    Filed: October 15, 2013
    Date of Patent: April 21, 2015
    Assignee: Nokia Solutions and Networks Oy
    Inventors: Mark Cudak, Timothy Thomas, Thomas Kovarik
  • Publication number: 20150103937
    Abstract: Systems, methods, apparatuses, and computer program products for an interleaved multi-beam acquisition waveform providing concurrent beam selection, automatic gain control (AGC) and automatic frequency correction (AFC) are provided. The access point (AP) may send an acquisition waveform on multiple beams, then return and retransmit an AFC on the multiple beams thus interleaving beam switching with the acquisition and frequency correction waveforms. AGC correction can be deferred until the end, relying on the fact that the transmitter may be detected at close range using a one of the multi-beams that is attenuated.
    Type: Application
    Filed: October 15, 2013
    Publication date: April 16, 2015
    Inventors: Mark CUDAK, Timothy THOMAS, Thomas KOVARIK