Predistortion (e.g., For Power Amplifier) Patents (Class 455/114.3)
  • Patent number: 8933752
    Abstract: A power amplifier apparatus that includes a processor that performs a first distortion compensation processing on an input signal using a distortion compensation coefficient to obtain a first signal and an amplifier that amplifies the first signal. The processor performs a second distortion compensation processing the amplified signal using the distortion compensation coefficient to obtain a second signal and updates the distortion compensation coefficient to enable convergence between the first signal and the second signal.
    Type: Grant
    Filed: October 20, 2011
    Date of Patent: January 13, 2015
    Assignee: Fujitsu Limited
    Inventors: Kazuo Nagatani, Yuichi Utsunomiya, Nobukazu Fudaba, Hiroyoshi Ishikawa, Hajime Hamada
  • Patent number: 8934860
    Abstract: A method for detecting an ingress of a short wave radio signal in a power line communication system which determines a strength of a common mode signal at a frequency of the power line communication system during a time period when no communication in the power line communication system at this frequency takes place and an ingress is detected if the strength of the common mode signal is above a determined threshold. A corresponding power line communication modem can implement such a method.
    Type: Grant
    Filed: May 8, 2009
    Date of Patent: January 13, 2015
    Assignee: Sony Corporation
    Inventor: Andreas Schwager
  • Patent number: 8929483
    Abstract: Digital baseband channel signals are received and up-sampled to a common sampling rate. The digital baseband channel signals are filtered using low pass filters. Complex frequency shifting is performed of the filtered digital baseband channel signals based on the associated different channel frequencies to obtain digital channel signals, which are combined to generate a digital wideband multi-channel signal that is a digital representation of an analog wideband multi-channel signal that is based on combining analog channel signals that correspond to the analog baseband channel signals. A non-linear pre-distortion of the digital wideband multi-channel signal is performed, the non-linear pre-distortion adding at least one of a gain and a phase shift to the digital wideband multi-channel signal such that the digital channel signals included within the digital wideband multi-channel signal are compensated for a non-linear distortion effected on the analog wideband multi-channel signal by a high-power amplifier.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: January 6, 2015
    Assignee: RKF Engineering Solutions, LLC
    Inventors: Michael Mandell, Ted Kaplan, Arnold Berman, Jeffrey Freedman, Brian Sipos, Scott Conrad Markley, Erik Halvorson, David Marshack
  • Patent number: 8929843
    Abstract: An antenna power coupler having a variable coupling factor is disclosed. In an exemplary embodiment, an apparatus includes a coupler configured to generate a power detection signal based on transmit signal power associated with a plurality of transmission technologies and a variable attenuator configured to apply a selected attenuation factor to the power detection signal to generate an adjusted power detection signal, the selected attenuation factor associated with a selected transmission technology.
    Type: Grant
    Filed: December 21, 2011
    Date of Patent: January 6, 2015
    Assignee: QUALCOMM Incorporated
    Inventors: Prashanth Akula, David Maldonado, Kevin Hsi Huai Wang
  • Patent number: 8923434
    Abstract: A method and an apparatus for modifying a complex-valued signal are described, the complex-valued signal representing a first symbol and a second symbol. A signal trajectory of the complex-valued signal between the first and second symbols is determined, and, if the signal trajectory passes nearby the constellation origin, the signal trajectory is altered to run closer to the constellation origin.
    Type: Grant
    Filed: February 11, 2013
    Date of Patent: December 30, 2014
    Assignee: Intel Mobile Communications GmbH
    Inventors: Andreas Menkhoff, Staffan Sahlin
  • Patent number: 8923787
    Abstract: A method and system for determining adaptation parameters for pre-distorters in a multi-band power amplifier system of a communication system are disclosed. A method includes receiving, at an adaptor, a reference signal comprising a first plurality of signals having substantially overlapping frequency spectra. Each of the first plurality of signals is input to a corresponding one of a plurality of pre-distorters. The adaptor also receives an observation signal comprising a second plurality of signals tuned to substantially a same frequency to have overlapping frequency spectra. Each of the second plurality of signals is derived from an output of the multi-band power amplifier system. The adaptor computes the adaptation parameters based on the reference signal and the observation signal.
    Type: Grant
    Filed: July 5, 2012
    Date of Patent: December 30, 2014
    Inventor: Pierre-André Laporte
  • Patent number: 8918069
    Abstract: A radio frequency transmitter comprising a modem which receives one or more input data signals and an adaptive predistortion signal and provides a baseband in-phase signal and a baseband quadrature signal. The transmitter may comprise a power amplifier module which receives the in-phase and quadrature phase signals and provides a radio frequency output signal. A predistortion module receives the radio frequency signal, downconverts the radio frequency signal to an intermediate frequency signal, and downconverts the intermediate frequency signal to a baseband feedback signal. The transmitter samples the feedback signal and provides an adaptive predistortion signal to the modem.
    Type: Grant
    Filed: January 10, 2012
    Date of Patent: December 23, 2014
    Assignee: Aviat U.S., Inc.
    Inventors: Ying Shen, James Laudolff, Travis Mashburn, Todd Nichols, David C. Schafer, Thanh H. Nguyen
  • Patent number: 8913969
    Abstract: The present disclosure relates to amplitude based pre-distortion calibration of an RF communications terminal, such as a cell phone, by transmitting a first standard RF transmit burst from the RF communications terminal to an RF test instrument, which assimilates the first standard RF transmit burst. A calibration control system extracts information regarding the first standard RF transmit burst from the RF test instrument; determines amplitude based distortion of the RF communications terminal using the extracted information; determines amplitude based pre-distortion calibration information using the determined amplitude based distortion; and calibrates the RF communications terminal using the amplitude based pre-distortion calibration information. By using a single-shot transmit burst, calibration times may be minimized.
    Type: Grant
    Filed: May 21, 2010
    Date of Patent: December 16, 2014
    Assignee: RF Micro Devices, Inc.
    Inventors: Hirofumi Honjo, Suryanarayana Pappu, Mikko Sannala, Ricke W. Clark
  • Patent number: 8909179
    Abstract: A method and an apparatus for controlling a transmit signal of a radio frequency power amplifier are provided. The method includes: adjusting a power supply voltage of the power amplifier to an efficiency point power supply voltage under designated transmit power; querying correspondence between an input voltage and transmit power at each power level under the efficiency point power supply voltage; and adjusting, according to the correspondence, an input voltage to an input voltage corresponding to the designated transmit power. The embodiments of the present invention, the power amplifier is enabled to work at an optimum efficiency point while the transmit power of the power amplifier is under control, which improves efficiency of the power amplifier.
    Type: Grant
    Filed: December 10, 2012
    Date of Patent: December 9, 2014
    Assignee: Huawei Device Co., Ltd.
    Inventor: Gang Zhang
  • Patent number: 8908797
    Abstract: An apparatus and method for a Time Alignment (TA) operation used by an Envelope Tracking (ET) Radio Frequency (RF) Power Amplifier (PA) that amplifies RF signals are provided. The ET RF PA has an input signal including complex, reference, and feedback signals. The apparatus includes a fast convolution unit for receiving the reference signal and the feedback signal, fore extracting respective envelopes of the reference signal and the feedback signal, for generating a cross-covariance vector for the reference signal envelope and the feedback signal envelope, a delay estimation unit for receiving the cross-covariance vector from the fast convolution unit, for determining peak values of the cross-covariance vector, for performing a fine time delay estimation, and for generating time delay settings according to the fine time delay estimation, and delay filters respectively delaying a timing of the reference signal and the feedback signal according to the generated time delay settings.
    Type: Grant
    Filed: March 7, 2012
    Date of Patent: December 9, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Ernesto G. Jeckeln
  • Patent number: 8909175
    Abstract: A transmitter (70) generates a time-varying, detroughed, biasing signal (154) for an RF power amplifier (10) so that the RF power amplifier (10) is biased in accordance with an envelope tracking scheme. A trough-filling section (94) is responsive to an envelope tracking signal (86), which in turn is responsive to a magnitude signal (90) extracted from a complex baseband communication signal (76). The trough-filing section (94) includes a limiting stage (108) that forms a raw troughing signal (110) which expands the bandwidth of the envelope tracking signal (86). A filtering stage (116) reduces the bandwidth of the raw troughing signal (110) to form a trough-filling signal (122) that is combined back into the envelope tracking signal (86) using a linear process that maintains the bandwidth of the envelope tracking signal (86).
    Type: Grant
    Filed: June 27, 2013
    Date of Patent: December 9, 2014
    Assignee: CrestCom, Inc.
    Inventor: Ronald Duane McCallister
  • Patent number: 8909176
    Abstract: A radio transmission system comprising: a first Volterra Engine (VE) linearizer; a second VE linearizer coupled to the first VE linearizer; and a power amplifier (PA) coupled to at least one of the VE linearizers. Each VE linearizer compensates for a different distortion or nonlinearity aspect of an output signal from the PA.
    Type: Grant
    Filed: July 2, 2013
    Date of Patent: December 9, 2014
    Assignee: BlackBerry Limited
    Inventors: John-Peter van Zelm, Peter Rashev, John Holt
  • Publication number: 20140357204
    Abstract: Apparatus, methods and methods of manufacture are provided for the processing of a current mode signal. A first signal processing stage comprising at least one output terminal is configured to produce a current mode output signal. A mutual inductance stage is arranged to inductively couple the at least one output terminal of the first signal processing stage to at least one input terminal of a second signal processing stage, wherein an input signal is generated at the at least one input terminal of the second signal processing stage on the basis of the current mode output signal produced at the at least one output terminal of the first signal processing stage.
    Type: Application
    Filed: May 30, 2014
    Publication date: December 4, 2014
    Applicant: Broadcom Corporation
    Inventors: Jari Johannes HEIKKINEN, Juhani Kalervo AALTO
  • Patent number: 8903337
    Abstract: A high performance and cost effective method of RF-digital hybrid mode power amplifier systems with high linearity and high efficiency for multi-frequency band wideband communication system applications is disclosed. The present disclosure enables a power amplifier system to be field reconfigurable and support multiple operating frequency bands on the same PA system over a very wide bandwidth. In addition, the present invention supports multi-modulation schemes (modulation agnostic), multi-carriers and multi-channels.
    Type: Grant
    Filed: May 15, 2013
    Date of Patent: December 2, 2014
    Assignee: Dali Systems Co. Ltd.
    Inventors: Wan-Jong Kim, Kyoung-Joon Cho, Shawn Patrick Stapleton
  • Patent number: 8903336
    Abstract: A method for compensating signal distortions in multiple transmitting branches entering a composite amplifier.
    Type: Grant
    Filed: May 13, 2013
    Date of Patent: December 2, 2014
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Tony Fonden, Richard Hellberg, Mats Klingberg, Spendim Dalipi
  • Patent number: 8903338
    Abstract: A system for implementing linearization of a radio frequency (RF) power amplifier (PA) in a base station, as well as various component circuitry for implementing said system. By means of a smart partitioning of the signal processing for predistortion between the analog domain and the digital domain, a more linear relationship between the digital input data and the output RF signal is achieved. Linearization of the PA's output signal is obtained using a mixed-signal apparatus. The digital baseband signal enters the RF signal source. The RF signal source comprises an in-band predistortion circuit, a micro-controller and digital modulator. The output of the digital modulator is an RF signal that enters the PA module. The PA module is composed of the PA and the RF power amplifier linearizer (RFPAL). The RFPAL comprises an RF predistortion circuit, and RF signal analyzer and a microcontroller. In addition, a backward data interface connects the RF signal source with the RFPAL.
    Type: Grant
    Filed: August 28, 2013
    Date of Patent: December 2, 2014
    Assignee: Scintera Networks LLC
    Inventor: Qian Yu
  • Patent number: 8903002
    Abstract: A computational processor uses a binary signal, being a set of 1- or 0-valued elements of a same number as a number of elements in an input signal, to generate computational data whose elements are exclusive OR values between each element of the input signal and a corresponding element in the binary signal at a same position. The modulator 13 modulates the input signal and the computational data according to a primary modulation scheme, and generates primary-modulated signals. An IFFT calculator applies an inverse fast Fourier transformation to the primary-modulated signals to generate inverse transformation data. A transmitter generates a baseband signal based on generated inverse transformation data whose peak-to-average power ratio matches a standard, and generates and transmits a transmission signal from the baseband signal and data specifying computations conducted to generate the inverse transformation data that matches the standard.
    Type: Grant
    Filed: December 9, 2013
    Date of Patent: December 2, 2014
    Assignee: Icom Incorporated
    Inventor: Nobuyoshi Nishikawa
  • Publication number: 20140349716
    Abstract: Disclosed herein is a passive, voltage mode transmitter assembly and method of operation. The passive, voltage mode transmitter assembly comprises a baseband filter configured to filter a source baseband signal, a harmonics filter, connected to the baseband filter, configured to remove harmonics from the filtered, source baseband signal, a passive, voltage mode mixer, connected to the harmonics filter, configured to up-convert an output of the harmonics filter to a radio signal, and a power amplifier, connected to the passive, voltage mode mixer, configured to amplify the radio signal.
    Type: Application
    Filed: March 18, 2014
    Publication date: November 27, 2014
    Applicant: ST-Ericsson SA
    Inventor: Andreas AXHOLT
  • Patent number: 8897728
    Abstract: The method for memory effects quantification and comparison in RF transmitters and amplifiers is a method in which a processor performs a spectrum analysis of an RF transmitter or RF amplifier device under test (DUT). The processor then calculates a normalized frequency (fn) according to the relation: f n = f - f c BW . The processor then utilizes the normalized frequency calculation in a spectrum asymmetry index (SAI) computation characterized by the relation: SAI = 1 K ? ? f n = f n , start f n = f n , stop ? ? ? P ? ( f n ) - P ? ( - f n ) ? . Next, utilizing the absolute value of the normalized frequency according to the relation: ? f n ? = ? f - f c BW ? , the processor displays the calculated SAI and causes a display device to display a mirrored spectrum as a function of the absolute value of the normalized frequency around a zero frequency.
    Type: Grant
    Filed: April 29, 2013
    Date of Patent: November 25, 2014
    Assignee: King Fahd University of Petroleum and Minerals
    Inventor: Oalid Hammi
  • Publication number: 20140342680
    Abstract: A transmission signal amplifying apparatus has an OFDM subcarrier division unit, a transmission side analog unit, a digital distortion compensation unit, and a main signal combiner. The OFDM subcarrier division unit divides a signal whose frequency bands are continuous, and outputs a plurality of subcarrier aggregations obtained by the division in a state in which the frequency bands are adjacent to each other. The transmission side analog unit amplifies signals of a plurality of systems having the respective output subcarrier aggregations for the respective signals of the respective systems, while maintaining the above-described state. The digital distortion compensation unit compensates distortions of the amplified signals of the plurality of systems. The main signal combiner combines the signals of the plurality of systems whose distortions have been compensated, and outputs as an RF signal.
    Type: Application
    Filed: April 9, 2014
    Publication date: November 20, 2014
    Applicant: FUJITSU LIMITED
    Inventor: Shin WATANABE
  • Patent number: 8891668
    Abstract: In accordance with some embodiments of the present disclosure, a method for estimating and correcting phase shift in a wireless communication device, may include converting a digital signal output by digital circuitry of the wireless communication device into a compensated digital signal based on a calculated phase error. The method may also include converting the compensated digital signal into a wireless communication signal. The method may additionally include calculating an estimated instantaneous reference phase of the digital signal output by the digital circuitry. The method may further include calculating an estimated transmit phase of the wireless communication signal. Moreover, the method may include calculating a phase error based on a difference between the estimated instantaneous reference phase and the estimated transmit phase of the wireless communication signal.
    Type: Grant
    Filed: June 30, 2011
    Date of Patent: November 18, 2014
    Assignee: Intel IP Corporation
    Inventors: Pravin Premakanthan, Mahib Rahman, Mark Kirschenmann
  • Patent number: 8891347
    Abstract: Systems and methods for wireless communication in a system including a transmitter, a receiver, and a plurality of propagation paths formed between the transmitter and the receiver which are capable of carrying a signal transmitted by the transmitter to the receiver. The method includes transmitting a first signal from the transmitter to the receiver via a propagation path of the plurality of propagation paths, receiving the first signal at the receiver, performing a channel estimation of the first signal to obtain path parameter information of the propagation path, sending the channel estimation from the receiver to the transmitter via the propagation path, predistorting a second signal at the transmitter according to the channel estimation, transmitting the predistorted signal from the transmitter to the receiver via the propagation path, and receiving the predistorted signal at the receiver.
    Type: Grant
    Filed: July 28, 2011
    Date of Patent: November 18, 2014
    Assignee: Empire Technology Development LLC
    Inventor: Xuefeng Yin
  • Patent number: 8880010
    Abstract: A transmitter circuit is described. The transmitter circuit includes a first local oscillator that generates a first frequency equal to a duplex frequency. The transmitter circuit also includes a second local oscillator that generates a second frequency equal to a receive frequency. The transmitter circuit further includes a first mixer that combines the first frequency with a first input signal. The transmitter circuit also includes a first feedback loop. The first feedback loop includes a second mixer that combines the second frequency with a transmit signal and a first filter and a first adder that combines an output of the first mixer with an output of the first filter. The transmitter circuit also includes a third local oscillator that generates a third frequency equal to the receive frequency. The transmitter circuit further includes a third mixer that combines the third frequency with an output of the first adder.
    Type: Grant
    Filed: December 30, 2009
    Date of Patent: November 4, 2014
    Assignee: QUALCOMM Incorporated
    Inventor: Gary J. Ballantyne
  • Patent number: 8879663
    Abstract: Adaptive filtering is used to substantially cancel distortion in radio frequency (RF) signals. Such adaptive filtering can be used in an RF transmitting module to pre-compensate an RF signal with compensation (inverse) distortion to cancel inherent transmission path distortion from the RF signal. Adaptive filtering can also be used in a multi-carrier RF receiving module to cancel from a given carrier signal distortion due to cross talk from adjacent carrier signals. Adaptive filtering in an RF transceiver can be used to cancel from a received RF signal distortion arising from leakage of a transmit signal into the receive path.
    Type: Grant
    Filed: June 26, 2012
    Date of Patent: November 4, 2014
    Assignee: L-3 Communications Corp.
    Inventors: Osama S. Haddadin, Roy E. Prymek, William K. McIntire
  • Patent number: 8874052
    Abstract: A wireless communication system (400) for power amplification of an input signal includes a power amplifier (404) operable to amplify a data signal (405). An envelope generator 408 or detector is operable to determine an envelope signal (410) from the data signal. A tracking power supply or other power supply control circuit (409) is operable to control a supply voltage of the power amplifier with the envelope signal. An allocation manager (441) is operable to determine a resource block allocation within a channel for the data signal. A delay circuit (443) is operable to insert a delay (550) between the envelope signal and the data signal as a function of the resource block allocation within the channel, thereby intentionally causing unbalanced leakage about the resource block allocation. Increased leakage on one side of the allocation results in improved leakage on the other side.
    Type: Grant
    Filed: November 15, 2012
    Date of Patent: October 28, 2014
    Assignee: Motorola Mobility LLC
    Inventors: Ryan J. Goedken, Thomas D. Nagode, Dale G. Schwent
  • Patent number: 8874161
    Abstract: An apparatus and a method for reducing power consumption in a wireless communication system are provided. The apparatus includes an antenna, a Radio Frequency (RF) module, a first amplifier, an external power amplifier, and a controller. The RF module converts a baseband transmission signal to an RF signal. The first amplifier amplifies power of the RF signal inside the RF module. The external power amplifier amplifies power of an output signal of the first amplifier. When a transmission power level of a transmission signal is equal to or less than a maximum output level of the first amplifier, the controller controls to transmit the transmission signal amplified by the first amplifier via the antenna. When the transmission power level of the transmission signal is equal to or greater than the maximum output level of the first amplifier, the controller controls to transmit a transmission signal amplified by the external power amplifier via the antenna.
    Type: Grant
    Filed: August 27, 2012
    Date of Patent: October 28, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Sang-Yun Hwang, Jin-Woo Roh
  • Patent number: 8874050
    Abstract: A circuit and method for a saturation correction of a power amplifier (PA) is provided in order to maintain a desirable switching spectrum. The circuit includes a closed loop system that is responsive to a dynamic PA control signal known as VRAMP. The method samples a detector voltage that represents the output of the PA at the maximum voltage level of VRAMP. The sampled detector voltage is then reduced by a predetermined amount and applied as a fixed voltage PA control signal in the place of VRAMP. As a result, the closed loop system responds to the fixed voltage PA control signal to bring the PA out of saturation before VRAMP can begin a voltage decrease. Once the VRAMP voltage decreases, VRAMP is reapplied as a dynamic PA control signal in place of the fixed voltage control signal.
    Type: Grant
    Filed: May 5, 2010
    Date of Patent: October 28, 2014
    Assignee: RF Micro Devices, Inc.
    Inventors: Alexander Wayne Hietala, Jeffery Peter Ortiz, Timothy Keith Coffman
  • Patent number: 8874054
    Abstract: A device for receiving a broadband multi-channel radiofrequency signal includes a radiofrequency analog input stage connected to an intermediate-frequency conversion stage. The conversion stage includes at least one conversion chain having a frequency mixer that transposes the signal to an intermediate frequency connected to the input of an analog-digital converter with a high frequency sampling rate. The intermediate and sampling frequencies in each conversion chain are selected such that, considering the noise generated by the sampling overtones of the corresponding analog-digital converter, each of the radiofrequency signal channels has a signal/noise ratio that is greater at output than a predetermined value of at least one conversion chain.
    Type: Grant
    Filed: August 13, 2013
    Date of Patent: October 28, 2014
    Assignee: EADS Secure Networks
    Inventors: Benoit Clement, Gilles Latouche, Olivier Muller
  • Patent number: 8873674
    Abstract: A digital predistortion linearization method is provided for increasing the instantaneous or operational bandwidth for RF power amplifiers employed in wideband communication systems. Embodiments of the present invention provide a method of increasing DPD linearization bandwidth using a feedback filter integrated into existing digital platforms for multi-channel wideband wireless transmitters. An embodiment of the present invention utilizes a DPD feedback signal in conjunction with a low power band-pass filter in the DPD feedback path.
    Type: Grant
    Filed: September 24, 2012
    Date of Patent: October 28, 2014
    Assignee: Dali Systems Co. Ltd.
    Inventors: Wan-Jong Kim, Shawn Patrick Stapleton
  • Patent number: 8868012
    Abstract: A frequency-multiplied harmonic suppression RF circuit design method includes the steps of defining respective operating frequencies of predetermined major electronic components of the RF circuit to be designed, using these operating frequencies to calculate the values of respective frequency-multiplied harmonics and intermodulation distorsions, designing respective filters subject to the values of the frequency-multiplied harmonics and intermodulation distorsions obtained, calculating the locations of the frequency-multiplied harmonics in the RF circuit under design, installing the designed filters in the calculated locations, and testing and adjusting the installed filters.
    Type: Grant
    Filed: August 5, 2013
    Date of Patent: October 21, 2014
    Assignee: Shun-Fu Technology Corp.
    Inventor: Yung-Sheng Huang
  • Patent number: 8868011
    Abstract: Embodiments of apparatuses, methods, and systems for a radio frequency amplification circuit providing for fast loadline modulation are generally described herein. Other embodiments may be described and claimed.
    Type: Grant
    Filed: April 30, 2012
    Date of Patent: October 21, 2014
    Assignee: TriQuint Semiconductor, Inc.
    Inventor: Peter V. Wright
  • Publication number: 20140308908
    Abstract: Apparatus and a method for predistortion of a radio-frequency signal are described. At least one predistortion unit is described that is arranged to receive an analog baseband signal before amplification and to generate an analog predistortion signal based on said analog baseband signal. At least one mixer unit is also described and may be electrically coupled to the at least one predistortion unit. In this case, the at least one mixer unit is arranged to receive the analog baseband signal before amplification and the analog predistortion signal and to generate a weighted combination of said signals.
    Type: Application
    Filed: April 10, 2014
    Publication date: October 16, 2014
    Applicant: Broadcom Corporation
    Inventors: Juhani Kalervo AALTO, Jari Johannes HEIKKINEN
  • Patent number: 8855585
    Abstract: Apparatus and methods are disclosed related to low-voltage radio transmitters with high spectral purity. One such apparatus includes a baseband path with a predistortion stage, a programmable filter, and an upconverter core. In an embodiment, the programmable filter is placed between the predistortion stage and the upconverter core. In an embodiment, the programmable filter is configured by a controller to reject out-of-band noise introduced at the predistortion stage or earlier.
    Type: Grant
    Filed: August 2, 2010
    Date of Patent: October 7, 2014
    Assignee: Analog Devices, Inc.
    Inventor: Antonio Montalvo
  • Patent number: 8855232
    Abstract: A transmission apparatus includes a signal processing unit to perform a distortion compensation process on a transmitting signal based on a distortion compensation coefficient, and an updating unit to update a transmission power of the transmitting signal subjected to the distortion compensation process in certain processes, to transmit the transmitting signal at the updated transmission power. The signal processing unit may set a referring range of the distortion compensation coefficient stored in a storage unit, based on the transmitting signal before performing the distortion compensation process and the transmitting signal having the transmission power thereof updated by the updating unit.
    Type: Grant
    Filed: December 15, 2012
    Date of Patent: October 7, 2014
    Assignee: Fujitsu Limited
    Inventors: Satoshi Matsubara, Hideharu Shako
  • Patent number: 8855182
    Abstract: In an emphasis optimization device, a calculating unit calculates an inverse characteristic of an amplitude characteristic based on the amplitude characteristic of a transmission path, and an inverse Fourier transform unit performs an inverse Fourier transform on the inverse characteristic to obtain an impulse response. An extracting unit extracts, from the obtained impulse response, an impulse response corresponding to the number of taps necessary for emphasis to be added to a digital signal to be transmitted on the transmission path. An emphasis amount calculating unit converts the extracted impulse response into a value of the emphasis to calculate an emphasis amount.
    Type: Grant
    Filed: March 14, 2013
    Date of Patent: October 7, 2014
    Assignee: Anritsu Corporation
    Inventors: Takashi Murakami, Kosuke Sasaki, Ken Mochizuki
  • Patent number: 8855233
    Abstract: An apparatus for implementing digital baseband predistortion includes a transmission channel including a digital-to-analog converter, a modulator, an amplifier and a power amplifier, and further includes a feedback channel analog part including a diode detector, a filter and an analog-to-digital converter, and a feedback channel digital part including a predistorter, a mode obtaining unit, a predistortion coefficient generator and a feedback correcting unit. The diode detector is configured to obtain an envelope of an output signal of the power amplifier. Embodiments of the present invention further provide a method for implementing digital baseband predistortion by applying the foregoing single-chip. Due to a simple structure of the diode detector, not only the number of radio frequency devices on the feedback channel is reduced, implementation complexity of hardware is lowered, power consumption is reduced, but also a feedback channel analog part may be integrated onto the single-chip.
    Type: Grant
    Filed: December 31, 2012
    Date of Patent: October 7, 2014
    Assignee: Huawei Technologies Co., Ltd.
    Inventors: Hua Cai, Yanzhao Pang, Wei Wang, Wei Xue
  • Patent number: 8848819
    Abstract: Transmission quality is improved in an environment in which direct waves dominate in a transmission method for transmitting a plurality of modulated signals from a plurality of antennas at the same time. All data symbols used in data transmission of a modulated signal are precoded by hopping between precoding matrices so that the precoding matrix used to precode each data symbol and the precoding matrices used to precode data symbols that are adjacent to the data symbol in the frequency domain and the time domain all differ. A modulated signal with such data symbols arranged therein is transmitted.
    Type: Grant
    Filed: September 8, 2011
    Date of Patent: September 30, 2014
    Assignee: Panasonic Intellectual Property Corporation of America
    Inventors: Yutaka Murakami, Tomohiro Kimura, Mikihiro Ouchi
  • Patent number: 8843089
    Abstract: Coefficients of a pre-distorter are determined for distortion correction of a signal amplified by a radio frequency amplifier by sampling the signal at the pre-distorter input to generate a plurality of input samples and sampling the signal at the amplifier output to generate a plurality of output samples, each of the output samples corresponding to one of the input samples, calculating a figure of merit for one or more of the input samples on the basis of the one or more input samples, selectively updating a previously selected set of input samples with the one or more input samples on the basis of the calculated figure of merit, whereby to generate an updated selected set and determining the coefficients of the pre-distorter on the basis of the input samples in the updated selected set and the corresponding output samples.
    Type: Grant
    Filed: June 3, 2013
    Date of Patent: September 23, 2014
    Assignee: BlackBerry Limited
    Inventor: Dorian Davies
  • Patent number: 8837635
    Abstract: Embodiments provide systems and methods to dynamically control a radio frequency (RF) transmitter based on monitored error vector magnitude (EVM) performance. Embodiments are enabled by a feedback path that allows estimating the EVM at the output of the transmitter and controlling the transmitter, including the power amplifier (PA), accordingly. As such, the transmitter (and the PA) can be operated as close as possible to the ideal operating point that meets, based on actual conditions, a specified EVM performance and desired output power. By doing so, the overall power consumption of the transmitter is reduced.
    Type: Grant
    Filed: June 7, 2012
    Date of Patent: September 16, 2014
    Assignee: Broadcom Corporation
    Inventors: Robert Lorenz, Djordje Tujkovic
  • Patent number: 8837620
    Abstract: Pre-distortion techniques, devices and systems for a multi-channel transmitter are described. An adaptation time is provided for each of the transmit chains in the multi-channel transmitter. During each adaptation time an output of a transmit chain is coupled to a shared feedback receiver. The shared feedback receiver generates a feedback signal that is used to vary pre-distortion for that transmit chain. A commutation controller varies at least one of: (a) an amount of the adaptation time for a transmit chain and (b) an order in which each of the transmit chains receives its adaptation time.
    Type: Grant
    Filed: May 3, 2011
    Date of Patent: September 16, 2014
    Assignee: Optis Cellular Technology, LLC
    Inventors: Tan Ho, Kris Bailey, Peter Zahariev Rashev
  • Patent number: 8831543
    Abstract: Disclosed are various embodiments for transmitting radio frequency signals. A radio frequency transmitter may be configured to generate an analog signal comprising an in-phase component and a quadrature-phase component. The in-phase component and the quadrature-phase component of the analog signal may be provided to multiple radio frequency processing chains. One of the radio frequency processing chains may generate an output radio frequency signal based on the in-phase component and the quadrature-phase component.
    Type: Grant
    Filed: February 4, 2013
    Date of Patent: September 9, 2014
    Assignee: Broadcom Corporation
    Inventors: Meng-An Pan, Ali Afsahi, Vikram Magoon, Arya Behzad
  • Patent number: 8831138
    Abstract: The circuit is provided for the transmission of data amplitude modulated radio frequency signals. The circuit includes a local oscillator for generating an oscillating signal at a determined carrier frequency, a unit for shaping data pulses to supply a data amplitude modulation control signal (Vmod), and a power amplifier receiving the oscillating signal and the data amplitude modulation control signal (Vmod) for the transmission of data amplitude modulated radio frequency signals by an antenna or an antenna arrangement. The data pulse shaping unit (13) includes a pulse shaper (21) for digitally adapting the data transition edges on the basis of an incoming digital data signal (d), and a digital-analog conversion stage (26, 27) for converting a digital data signal shaped in the unit, in order to supply the data amplitude modulation control signal (Vmod) to the power amplifier.
    Type: Grant
    Filed: December 19, 2012
    Date of Patent: September 9, 2014
    Assignee: EM Microelectronic-Marin SA
    Inventor: Michel Moser
  • Patent number: 8824980
    Abstract: A system and method provide for a radio transmitter with digital predistortion. The radio transmitter includes a high output power narrowband upconverter and a low output power wideband upconverter. In a stage of the radio transmitter, digital predistortion is applied to transmit data by setting digital coefficients by a digital predistortion algorithm, resulting in a predistortion signal. A predistortion signal is separated into a narrowband component and a wideband component, where the narrowband component corresponds to a desired traffic signal and the wideband component corresponds to a digital predistortion signal reflecting separated digital predistortion correction products. The narrowband upconverter provides a transmission path for a desired traffic signal or transmit data (the narrowband component of the digital predistortion signal), while the wideband upconverter provides a transmission path for the wideband component representing digital predistortion correction products.
    Type: Grant
    Filed: September 5, 2012
    Date of Patent: September 2, 2014
    Assignee: Analog Devices, Inc.
    Inventor: David J. McLaurin
  • Patent number: 8825065
    Abstract: Methods and apparatus for reducing out of band emissions through selective resource allocation, transmit power control, or a combination thereof. A resource controller, such as a base station, can allocate uplink resources to a requesting subscriber station based in part on an expected transmit power. The base station can allocate uplink bandwidth to the subscriber station based on an expected subscriber station uplink transmit power and a frequency of a restricted emissions band. Those subscriber stations having higher expected transmit powers are allocated bandwidth further from the restricted emissions band. The subscriber station can perform complementary transmit power control based on allocated uplink resources. The subscriber station can limit a transmit power based in part on a bandwidth allocation, modulation type allocation, or some combination thereof.
    Type: Grant
    Filed: January 19, 2007
    Date of Patent: September 2, 2014
    Assignee: Wi-Lan, Inc.
    Inventor: Todd Sutton
  • Patent number: 8824981
    Abstract: An envelope tracking system and a method for adjusting a nonlinear transfer function of an envelope tracking power supply for a power amplifier are provided. An output signal of the power amplifier is provided to a feedback receiver for determining an actual performance of the envelope tracking power amplifier. An assumed performance of the envelope tracking power amplifier is determined by evaluating the non-linear transfer function at a value defined by an input signal for a transmitter including the power amplifier. A difference between the assumed performance and the actual performance provides a correctional value for the nonlinear transfer function.
    Type: Grant
    Filed: January 31, 2013
    Date of Patent: September 2, 2014
    Assignee: Intel Mobile Communications GmbH
    Inventors: Andreas Langer, Gunther Kraut, Berndt Pilgram
  • Patent number: 8824593
    Abstract: A wireless transmitter is disclosed that is capable of pre-compensating for oscillator phase noise. In the transmitter, an undesired phase noise being generated by a voltage-controlled oscillator can be detected by comparing the output of the voltage-controlled oscillator to a reference oscillator output. The phase can then be detected by calculating a desired number of zero crossings over a given time period, and comparing this value to an actual number of zero crossings detected in the signal generated by the voltage-controlled oscillator over the same period. From this, the phase component can be determined and digitally pre-compensated in a data signal.
    Type: Grant
    Filed: March 29, 2012
    Date of Patent: September 2, 2014
    Assignee: Broadcom Corporation
    Inventor: Alireza Tarighat Mehrabani
  • Patent number: 8817900
    Abstract: A system and method are provided for frequency domain peak power reduction on a plurality of orthogonal frequency divisional multiplexing (OFDM) signals in a communications system, wherein frequency domain processing of at least one OFDM signal carrier is iteratively performed to reduce peak power transmissions. OFDM signal carriers can include both in-band sub-carrier signals, and guard-band sub-carrier signals. Each iteration of peak power reduction takes as an input the frequency domain representation of the signal from the previous iteration that has been altered with respect to an error signal also represented in the frequency domain, determines an error signal (in the frequency domain), and subtracts this from the input to produce a further peak power reduced frequency domain signal. If there are no peaks above the configured peak power reduction threshold, then the signal passes through the FPPR iterations with no change.
    Type: Grant
    Filed: April 10, 2012
    Date of Patent: August 26, 2014
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventors: Neil McGowan, Marthinus Willem Da Silveira
  • Patent number: 8811532
    Abstract: Systems and methods are disclosed for compensating for non-linearity of a power amplifier using space mapping based predistortion. In one embodiment, a transmitter includes a power amplifier that amplifies a power amplifier input signal, a predistorter that effects predistortion of the power amplifier input signal to compensate for a non-linear characteristic of the power amplifier using a space mapping based model of an inverse of the non-linear characteristic of the power amplifier, and an adaptation sub-system that adaptively configures the space mapping based model of the non-linear characteristic of the power amplifier. In one embodiment, the adaptation sub-system adaptively configures a space mapping based model of the non-linear characteristic of the power amplifier and adaptively configures the space mapping based model of the inverse of the non-linear characteristic of the power amplifier based on the space mapping based model of the non-linear characteristic of the power amplifier.
    Type: Grant
    Filed: April 11, 2012
    Date of Patent: August 19, 2014
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventor: Chunlong Bai
  • Patent number: 8811917
    Abstract: A RF-digital hybrid mode power amplifier system for achieving high efficiency and high linearity in wideband communication systems is disclosed. The present invention is based on the method of adaptive digital predistortion to linearize a power amplifier in the RF domain. The power amplifier characteristics such as variation of linearity and asymmetric distortion of the amplifier output signal are monitored by the narrowband feedback path and controlled by the adaptation algorithm in a digital module. Therefore, the present invention could compensate the nonlinearities as well as memory effects of the power amplifier systems and also improve performances, in terms of power added efficiency, adjacent channel leakage ratio and peak-to-average power ratio. The present disclosure enables a power amplifier system to be field reconfigurable and support multi-modulation schemes (modulation agnostic), multi-carriers and multi-channels.
    Type: Grant
    Filed: April 23, 2008
    Date of Patent: August 19, 2014
    Assignee: Dali Systems Co. Ltd.
    Inventors: Wan Jong Kim, Kyoung Joon Cho, Shawn Patrick Stapleton, Jong Heon Kim, Dali Yang
  • Patent number: 8811914
    Abstract: A method and apparatus for processing a terahertz frequency electromagnetic beam are disclosed. For example, the method receives the terahertz frequency electromagnetic beam via a metamaterial having a plurality of addressable magnetic elements, where a resonant frequency of each of the plurality of addressable magnetic elements is capable of being programmably changed via an adjustment, and activates selectively a subset of the plurality of addressable magnetic elements to manipulate the terahertz frequency electromagnetic beam.
    Type: Grant
    Filed: August 18, 2010
    Date of Patent: August 19, 2014
    Assignee: AT&T Intellectual Property I, L.P.
    Inventors: David Michael Britz, Robert Raymond Miller, II