With Control (e.g., Automatic Gain Control, Automatic Frequency Control, Etc.) Patents (Class 455/136)
  • Patent number: 7522896
    Abstract: A conventional method of controlling the passband of a filter involves an increase in cost for a chip due to a large area of a detection circuit for determining the level of an interference wave. The present invention utilizes a result obtained by detecting the amplitude level of a signal with an automatic gain control circuit to appropriately control the passband of a filter. The amplitude level of all the signals including a desired wave and an interference wave is detected by utilizing the automatic gain control circuit to thereby control the passband of a filter on the basis of the result.
    Type: Grant
    Filed: October 18, 2005
    Date of Patent: April 21, 2009
    Assignee: Renesas Technology Corp.
    Inventors: Takashi Oshima, Masaru Kokubo
  • Patent number: 7515886
    Abstract: In a digital broadcast receiving tuner, a down-converter unit converts a high-frequency signal into a baseband signal directly or by once converting it into an intermediate frequency signal. A gain adjuster unit properly adjusts the actual level of the high-frequency signal and/or the intermediate frequency signal in correspondence with an AGC (automatic gain control) controlling voltage supplied from an external source. An amplifier properly adjusts the actual level of the baseband signal. A controlling unit properly controls the actual gain of the amplifier in response to a specific signal independent of the AGC controlling voltage. This configuration makes it possible to constantly secure optimal performance characteristics in whatever condition the received signal may be.
    Type: Grant
    Filed: February 11, 2004
    Date of Patent: April 7, 2009
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Hitoshi Ogino
  • Patent number: 7505748
    Abstract: A variable attenuator and method of attenuating a signal is presented. The variable attenuator contains an input that receives an input signal to be attenuated. A voltage divider between a resistor and parallel MOSFETs provides the attenuated input signal. The MOSFETs have different sizes and have gates that are connected to a control signal through different resistances such that the larger the MOSFET, the larger the resistance. The control signal is dependent on the output of the attenuator. The arrangement extends the linearity of the attenuation over a wide voltage range of the control signal and decreases the intermodulation distortion of the attenuator.
    Type: Grant
    Filed: September 28, 2005
    Date of Patent: March 17, 2009
    Assignee: Freescale Semicondductor, Inc.
    Inventors: Daniel P. McCarthy, Lawrence E. Connell, Neal W. Hollenbeck
  • Publication number: 20090068968
    Abstract: An RF transceiver includes a plurality of RF receivers for receiving a corresponding one of a plurality of received signals. Each of the plurality of the RF receivers includes an AGC module that generates an automatic gain control (AGC) signal based on the strength of the corresponding one of the plurality of received signals, and a low noise amplifier that amplifies the corresponding one of the plurality of received signals based on the AGC signal. A processing module generates a transmit power control signal based on the AGC signals from each of the plurality of RF receivers. A plurality of RF transmitters each generate a corresponding one of a plurality of transmit signals having a selected power level, wherein the selected power level is based on the transmit power control signal.
    Type: Application
    Filed: September 6, 2007
    Publication date: March 12, 2009
    Applicant: BROADCOM CORPORATION
    Inventor: Ahmadreza (Reza) Rofougaran
  • Publication number: 20090061800
    Abstract: An integrated circuit (IC) includes a plurality of RF receivers for receiving a corresponding one of a plurality of received signals. Each of the plurality of the RF receivers includes an AGC module that generates an automatic gain control (AGC) signal based on the strength of the corresponding one of the plurality of received signals, and a low noise amplifier that amplifies the corresponding one of the plurality of received signals based on the AGC signal. A processing module generates a power mode signal for adjusting a power consumption parameter of the IC, based on the AGC signals from each of the plurality of RF receivers.
    Type: Application
    Filed: September 5, 2007
    Publication date: March 5, 2009
    Applicant: BROADCOM CORPORATION
    Inventor: Ahmadreza (Reza) Rofougaran
  • Patent number: 7499687
    Abstract: In many circuits, including those operating in radio frequency (RF), there is commonly a need to perform DC offset cancellation. The DC offset is an error in an output signal in respect to the input that may cause a circuit to enter into undesirable or non-tolerable conditions of operation. While in most cases a static solution is provided the use of an analog loop may be inappropriate because of the adverse impact on speed. By adding a fast feedback loop finely impacting the adjustment of an amplifier, both the initial calibration is achieved as well as a recalibration of the system.
    Type: Grant
    Filed: November 9, 2005
    Date of Patent: March 3, 2009
    Assignee: Theta Microelectronics, Inc.
    Inventors: Konstantinos Papathanasiou, Spyridon Vlassis
  • Patent number: 7496162
    Abstract: In a communication receiver having a variable gain amplifier and an automatic gain controller, the automatic gain controller is operable to measure values of a system performance parameter indicative of the performance of the communication system, determine a statistical value of the system performance parameter, and adjust the variable gain of the amplifier in response to the statistical value to maintain the statistical value in a control range.
    Type: Grant
    Filed: November 30, 2004
    Date of Patent: February 24, 2009
    Assignee: STMicroelectronics, Inc.
    Inventor: Steven F. Srebranig
  • Patent number: 7483500
    Abstract: An Automatic Gain Control (AGC) circuit as used in a digital receiver that utilizes a main loop filter that is of a relatively wide bandwidth. A pre-filter, wideband variance is determined from the input digital signal, and a post-filter, narrowband variance is also determined. The wideband and narrowband variances are then compared to determine if the wideband signal power indicates a variance level that is too great to permit normal loop operation. By reapplying this difference in the power levels to the filter output as needed, such as by a scaling operation, the loss in dynamic range is effectively recovered. In a preferred embodiment, an adjustable gain input amplifier feeds an intermediate frequency (IF) signal to an analog-to-digital converter (ADC). The digitized IF signal is then down-converted to a baseband frequency and subjected to digital filtering. A narrowband sample variance (PN) of the digitally filtered (narrowband) data is then determined.
    Type: Grant
    Filed: April 6, 2006
    Date of Patent: January 27, 2009
    Assignee: IPR Licensing, Inc.
    Inventors: Mark J. Takatz, Alton S. Keel, Jr., Stefan Haenggi
  • Patent number: 7474883
    Abstract: A receiver in a radio communication system and method for optimizing a use of an available dynamic range. The receiver has an automatic gain controller in an automatic gain control loop, a first measuring device, connected to the automatic gain controller, operable to measure a total received energy, a second measuring device, connected to the automatic gain controller, operable to measure the inband signal energy, wherein the automatic gain controller is operable to adjust the gain based on both the total received energy and the inband signal energy.
    Type: Grant
    Filed: June 6, 2005
    Date of Patent: January 6, 2009
    Assignee: Infineon Technologies AG
    Inventor: Mikael Rudberg
  • Patent number: 7471937
    Abstract: A system and method for inverting automatic frequency control applied to a reference signal used to process an input signal is disclosed. When receiving an input communication signal, a receiver controls the frequency of the reference signal to compensate for frequency differences between a transmitter and a local oscillator in the receiver. The frequency control applied to the reference signal causes frequency variations in a resultant processed signal when the input signal is processed using the reference signal. The frequency of a second reference signal is controlled such that further processing of the resultant processed signal removed effects of the frequency control applied to the reference signal. The processing which applies frequency control to the reference signal is performed in real time while the inversion process is performed in a separate processing section.
    Type: Grant
    Filed: July 18, 2005
    Date of Patent: December 30, 2008
    Assignee: Research In Motion Limited
    Inventors: Sean B. Simmons, Zoltan Kemenczy
  • Patent number: 7469134
    Abstract: In order to avoid disappearance of output symbols in accompaniment with DC voltage fluctuations occurring at the timing of switching gain in receiving systems for mobile telephones or the like compatible with W-CDMA systems, the present invention provides a variable gain amplifier circuit, a gain control circuit and a mobile communication terminal apparatus, in which a PGA section is comprised of PGAs having different amplification widths continuously arranged in plural stages as in, two coarse adjustment PGAs, a fine adjustment PGA and a coarse adjustment PGA from the input side to the output side; and a gain control circuit has a memory storing a history of gain control with regard to the PGA section and a logic circuit individually controlling gain of each PGA.
    Type: Grant
    Filed: November 29, 2004
    Date of Patent: December 23, 2008
    Assignee: Sony Ericsson Mobile Communications Japan, Inc.
    Inventors: Atsushi Yoshizawa, Masahisa Tamura
  • Patent number: 7456747
    Abstract: A method and apparatus is disclosed for operating an RFID read/write unit with transmitting signal suppression. The RFID read/write unit comprises a radio frequency part including a transmitter and a receiver, and a baseband part based on digital signal processing. The method involves producing an amplitude and phase weighted copy of a transmitting signal, namely a compensation signal, with the baseband part. After linear modulation of the compensation signal, a resultant signal at an input of the receiver is subtracted in an addition stage from a spurious coupling signal. The transmitting signal has an auxiliary signal impressed upon a carrier signal from the RFID read/write unit with a frequency offset fd, for the purpose of processing without any DC voltage in the receiver downstream of an RX converter. The input of the receiver comprises a turn-on and turn-off attenuation element which protects the radio frequency part.
    Type: Grant
    Filed: April 5, 2007
    Date of Patent: November 25, 2008
    Assignee: Elektrobit Wireless Communications Ltd.
    Inventor: Roland Kung
  • Patent number: 7450533
    Abstract: A wireless transmitting device includes a first and a second antennas, a first and a second transmitters connected to the first and the second antenna, respectively, signal provide unit provide a short preamble sequence, a first and a second signal fields to the first transmitter, and provide an AGC preamble sequence, a data and a long-preamble sequence to estimate a channel response to the first and the second transmitters, and a controller to power on the transmitters at different timings, respectively.
    Type: Grant
    Filed: May 19, 2005
    Date of Patent: November 11, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsuguhide Aoki, Ichiro Seto, Kazumi Sato
  • Patent number: 7450670
    Abstract: An improved AGC subsystem for preferred use in quadrature amplitude modulation receivers offers improved automatic gain control of received signals in fading channels by generating an error signal only from constellation signal points having large signal-to-noise ratios for increase the signal-to-noise ratio of the gain control error signal for lowering dispersion of symbol signals in the constellation signal space for improving data detection of symbol signals with the improved performance with as much as one dB in the signal-to-noise ratio.
    Type: Grant
    Filed: June 14, 2005
    Date of Patent: November 11, 2008
    Assignee: The Aerospace Corporation
    Inventors: Gee L. Lui, Kuang Tsai, Milton K. Sue
  • Patent number: 7447271
    Abstract: Radio receiving apparatus includes antennas, radio units adjusting gains of received signals, and outputting the adjusted received signals, respectively, converters converting the adjusted received signals into digital signals, selector device which selects several of the digital signals, combination of the selected digital signals exhibiting good receiving characteristic, controller which determines the gains and outputs single control signal included in information of the determined gains to certain radio units, the certain radio units being included in the radio units and connected to certain converters of the converters which output digital signals included in the selected combination, weight calculator which calculates weight for each of the selected digital signals to enhance the receiving characteristic if the controller outputs the single control signal, synthesizer which synthesizes, into synthetic digital signal, digital signals obtained by multiplying each of the selected digital signals by the wei
    Type: Grant
    Filed: October 31, 2007
    Date of Patent: November 4, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koji Akita, Kazumi Sato, Kuniaki Ito, Akihiro Tsujimura
  • Patent number: 7444126
    Abstract: In a video IF channel the gain of the circuit is achieved ahead of the IF filter and the output of the filter, including its noise, need only be amplified a relatively small amount, thus preserving an acceptable signal to noise ratio. In one embodiment, a variable gain amplifier is used as the first stage amplifier and a fixed gain amplifier is used for the output stage.
    Type: Grant
    Filed: December 22, 1995
    Date of Patent: October 28, 2008
    Assignee: Microtune (Texas), L.P.
    Inventor: Adam Stanislaw Wyszynski
  • Patent number: 7436903
    Abstract: A multicarrier transmitter may transmit cyclically delayed linear combinations of two or more data streams with three or more antennas. In some embodiments, the multicarrier transmitter may transmit cyclically delayed linear combinations of three data streams with four antennas.
    Type: Grant
    Filed: September 29, 2004
    Date of Patent: October 14, 2008
    Assignee: Intel Corporation
    Inventors: Sumeet Sandhu, Minnie Ho
  • Patent number: 7436793
    Abstract: A system and method for effectively performing a transmit power adjustment procedure in a wireless network includes a forward receiver that monitors a wireless forward link for forward data that is transmitted over the wireless forward link by a forward transmitter. The forward transmitter initially transmits the forward data at a minimum power level, and gradually increases the minimum power level to a power level threshold at which the forward receiver first detects the forward data on the forward link. Once the forward receiver and the forward transmitter are successfully coupled over the wireless forward link, the forward transmitter may then transmit forward data at a normal operating power level. The foregoing transmit power adjustment procedure ensures that the forward receiver receives forward data only from the forward transmitter, and prevents other proximate wireless devices from inadvertently intercepting forward data transmitted by the forward receiver.
    Type: Grant
    Filed: September 9, 2004
    Date of Patent: October 14, 2008
    Assignees: Sony Corporation, Sony Electronics Inc.
    Inventor: Christopher J. Read
  • Patent number: 7433663
    Abstract: A multiple receiving antennae system having a plurality of radio frequency (RF) modules being responsive to incoming signals for processing the same to generate baseband signals. The multiple receiving antennae system further processes baseband signals to generate digital baseband signals, in accordance with an embodiment of the present invention. The multiple receiving antennae system further still includes a plurality of automatic gain control (AGC) modules being responsive to digital baseband signals for processing the same to generate a plurality of gain values. The plurality of gain values are used in the plurality of RF modules for independent gain adjustment of the incoming signals. The plurality of gain values are used to generate adjusted signals with enhanced signal to noise ratio (SNR) to improve the performance of the multiple receiving antennae system, whereby the plurality of gain values are used to enhance reception of incoming signals by improving SNR.
    Type: Grant
    Filed: May 27, 2005
    Date of Patent: October 7, 2008
    Assignee: Ralink Technology, Inc.
    Inventor: Po-Yuen Cheng
  • Patent number: 7430404
    Abstract: A tuner circuit according to the invention includes two AGC control units supplying AGC voltages V1 and V2 to an AGC amplifier, respectively. When the AGC voltage V1 is higher the AGC voltage V2, a voltage on a cathode of a diode becomes high, and the diode 11 is turned off. When the AGC voltage V2 is higher than the AGC voltage V1, a voltage on an anode of the diode becomes high, and the diode 11 is tuned on. Therefore, in the case of an ordinary signal level, the AGC voltages establish a relationship of, and the AGC voltage V2 performs the control. When an excessively large disturbing signal is input, the AGC control unit controls the AGC amplifier to suppress deterioration of performance.
    Type: Grant
    Filed: November 7, 2005
    Date of Patent: September 30, 2008
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Koji Oiwa
  • Patent number: 7430403
    Abstract: A hysteresis control method for a control system includes setting an arbitrary reference value for an existing position of a control width and calculating a difference between a present input value and the arbitrary reference value. A direction of increase/decrease from a control value and an input value variation width are calculated. A control value is calculated for the present input value time from the calculated input value variation width and the calculated direction of increase/decrease.
    Type: Grant
    Filed: March 1, 2005
    Date of Patent: September 30, 2008
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventor: Shoichi Kobayashi
  • Patent number: 7428262
    Abstract: A method and apparatus for channel estimation in a rake receiver of a CDMA communication system operates with a finite-impulse-response channel estimation filter with L taps and having a fixed delay. A pilot sequence of a received sequence of data from a channel of the communication system on the rake receiver is input. A quality of the channel of the communication system is determined using noise or Doppler measurements. These measurements are used in adjusting a bandwidth of the filter to accommodate the channel quality while keeping the fixed delay, which minimizes the delay buffer size. The filter is then used to operate on the received sequence of data to provide coherent modulation.
    Type: Grant
    Filed: August 13, 2003
    Date of Patent: September 23, 2008
    Assignee: Motorola, Inc.
    Inventors: Bryan W. Zancho, Christopher P. Larosa, Alexandre Mallette, John P. Oliver
  • Patent number: 7426376
    Abstract: An apparatus includes a semiconductor package, a radio receiver and a processor. The radio receiver is located in the semiconductor package and includes at least one gain stage. The processor is located in the semiconductor package to execute stored instructions to control the gain stage(s).
    Type: Grant
    Filed: June 30, 2005
    Date of Patent: September 16, 2008
    Assignee: Silicon Laboratories Inc.
    Inventors: Vishnu S. Srinivasan, G. Tyson Tuttle, Dan B. Kasha, Alessandro Piovaccari
  • Patent number: 7421260
    Abstract: In RF transceivers, a method and system for a second order input intercept point (IIP2) correction are provided. A DC offset sensor may detect DC offset voltages produced by blocker signals in “I” and “Q” signal component paths in an RF receiver. The DC offset sensor may generate control signals which may be utilized by a first and second injection circuits to generate DC offset currents that compensate for the DC offset voltages in the signal component paths. An injection circuit may utilize current drivers to generate binary weighted currents which may be added together to produce a DC offset current. The polarity of the DC offset current and the selection of which current drivers to use may be determined by the control signals. A calibration voltage may also be utilized to correct or adjust the gain in the injection circuit.
    Type: Grant
    Filed: October 29, 2004
    Date of Patent: September 2, 2008
    Assignee: Broadcom Corporation
    Inventor: Hooman Darabi
  • Patent number: 7421261
    Abstract: The present invention relates to a blind detection of a received signal having at least one property, which initially is unknown to the receiver, however, limited to a finite set of alternatives ({p1, p2, . . . , pm}). According to the invention, the unknown property is automatically identified as follows. A respective quality measure (q1, q2, . . . , qm) is derived from the incoming signal (r(n)), which each represents a particular property in the finite set of alternatives ({p1, p2, . . . , pm}). The quality measures (q1, q2, . . . , qm) are obtained according to a procedure that involves a computationally efficient rejection of any unwanted signal components in the incoming signal (r(n)). Then, the quality measures (q1, q2, . . . , qm) are compared with each other in order to find a quality measure, which best fulfills a blind selection criterion. The quality measure (qi) thus obtained corresponds to the initially unknown property (pi).
    Type: Grant
    Filed: April 24, 2002
    Date of Patent: September 2, 2008
    Assignee: Telefonaktiebolaget L M Ericsson (PUBL)
    Inventors: Henrik Sahlin, Johan Axnäs, Andreas Hedberg
  • Patent number: 7415259
    Abstract: An automatic gain control (AGC) for a Satellite Digital Audio Radio Service (SDARS) receiver, a method of automatically controlling gain and a SDARS receiver incorporating the AGC or the method. In one embodiment, the AGC includes: (1) an AGC function selector configured to compare first and second time division multiplexed (TDM) power signals and a nonzero threshold and select an AGC function based thereon and (2) an AGC function applier associated with the AGC function selector and configured to apply the AGC function to the first and second TDM power signals to develop therefrom an AGC control signal.
    Type: Grant
    Filed: June 24, 2004
    Date of Patent: August 19, 2008
    Assignee: Agere Systems Inc.
    Inventors: David A. Fishman, Robert C. Malkemes, Denis P. Orlando, Jie Song, Eric Zhong, Ying Zhu
  • Patent number: 7406300
    Abstract: A wireless communication system includes at least one repeater antenna assembly for providing adequate RF coverage within a building, such as a home. An example repeater antenna assembly has an automatically adjustable gain that is controlled responsive to a pathloss associated with a received signal to avoid base station transceiver desensitization and positive feedback. A disclosed assembly avoids base station desensitization and positive feedback. Another disclosed technique maintains a selected minimum link budget within the building.
    Type: Grant
    Filed: July 29, 2004
    Date of Patent: July 29, 2008
    Assignee: Lucent Technologies Inc.
    Inventor: Victor Pan
  • Patent number: 7398070
    Abstract: A variable gain amplifying circuit includes a gate-grounded amplifying FET and a collector-grounded amplifying transistor. A gate voltage of the FET and a base voltage of the transistor are adjusted by a supplied AGC voltage. When an input RF signal has small amplitude, the gate voltage is increased by a high AGC voltage so as to increase a main current of the FET, thereby increasing a signal gain of the FET. When the input RF signal has large or medium amplitude, the gate voltage is decreased by a low AGC voltage so as to decrease a main current of the FET, thereby decreasing the signal gain of the FET.
    Type: Grant
    Filed: November 8, 2005
    Date of Patent: July 8, 2008
    Assignee: Alps Electronic Co., Ltd
    Inventors: Masaki Yamamoto, Masaaki Endo
  • Patent number: 7398066
    Abstract: A method and apparatus for recovering a data symbol from a communication signal in which the communication signal is processed to produce a baseband waveform that is then sampled to obtain a channel sequence. The channel sequence is decoded to obtain an estimate of the data symbol together with a measure of the reliability of the data symbol. The processing of the communication signal is adjusted dependent upon the measure of the reliability of the data symbol. This abstract is not to be considered limiting, since other embodiments may deviate from the features described in this abstract.
    Type: Grant
    Filed: November 30, 2004
    Date of Patent: July 8, 2008
    Assignee: STMicroelectronics, Inc.
    Inventor: Gregory Proehl
  • Publication number: 20080146176
    Abstract: According to various exemplary embodiments, apparatus, systems, and methods are disclosed for use with antenna systems operable for receiving first and second signals having respective first and second frequencies. In one exemplary embodiment, a controller selectively controls whether an amplifier is electrically powered via a first receiver associated with the first frequency or a second receiver associated with the second frequency depending on whether the first receiver, second receiver, or both are present and activated.
    Type: Application
    Filed: December 15, 2006
    Publication date: June 19, 2008
    Inventors: Ayman Duzdar, Tan Dinh Quach, Keith J. Schrag
  • Patent number: 7386285
    Abstract: An AGC circuit controls LNA and VGA amplifiers such that a received signal is converted at a high speed with tracking errors prevented according to each modulation scheme. The AGC circuit generates LNA and VGA control signals controlling the LNA and VGA amplifiers, respectively. A digital signal, converted from the received signal, is calculated for a power value, on which scaling is performed by a scaling section to then be provided through an adder and a register to a control signal generator for generating the LNA and VGA control signals. The scaling section compares the power value with a target value to perform scaling with a scaling coefficient according to the sign of the comparison value so that an increase of the tracking error is avoided, thus preventing phenomena where the AGC control oscillates without convergence, thereby making it possible to attain the optimum automatic gain control.
    Type: Grant
    Filed: September 29, 2005
    Date of Patent: June 10, 2008
    Assignee: Oki Electric Industry Co., Ltd.
    Inventor: Shigeki Yamauchi
  • Patent number: 7373126
    Abstract: The gain control signal generating unit generates a gain control signal, using a signal yielding the greatest level among signals of the respective signal processing units. The gain standardizing unit stores, in the offset storage units, offsets corresponding to gain deviations occurring in the respective signal processing units when gains of the variable gain amplifiers are uniformly controlled using the gain control signal. The offsets are added to the gain control signal for each signal processing unit, and the variable gain amplifiers are controlled, using the respective offset-added gain control signals. Under the control of the calibration control unit, the calibration signal supply unit and offset determining unit supply a calibration signal and a gain control signal for calibration, respectively. The offset determining unit determines offsets to standardize the levels of signals of the signal processing units, and updates the offsets storage units with the determined offsets.
    Type: Grant
    Filed: April 21, 2004
    Date of Patent: May 13, 2008
    Assignee: Sanyo Electric Co., Ltd.
    Inventor: Masahiro Narita
  • Patent number: 7359686
    Abstract: A device for measuring voltage levels includes a root mean square (RMS) detector. The RMS detector includes a linear multiplier, a log converter, a low-pass filter and a temperature compensator. The linear multiplier multiplies a voltage of an input signal by the voltage of the input signal. The low-pass filter couples to an output of the linear multiplier. The log converter generates a logarithmic signal having a voltage that is logarithmically related to a voltage of an output of the low-pass filter. The temperature compensator adjusts the logarithmic signal based on a temperature of the RMS detector. The RMS detector is capable of determine an RMS voltage level of the input signal.
    Type: Grant
    Filed: February 16, 2005
    Date of Patent: April 15, 2008
    Assignee: Microtune (Texas), L.P.
    Inventors: Kim E. Beumer, Peter Kipfelsberger, Philip T. Hisayasu
  • Patent number: 7356110
    Abstract: The method is applicable to a receiver (1) of signals corresponding to packets of digital data transmitted in bursts, which comprises an analogue pickup subassembly (3) connected to a digital processing subassembly (8) by means for converting analogue signals into digital signals (7). Gain adjustment means (5) act on the amplification means (5) in order to alter the power of signals supplied to the conversion means. The method provides a preadjustment of the gain, in the absence of a burst, for detecting the arrival of signals even if they are weak, and an adjustment of the gain as a function of a power value of the signal determined from burst start symbols, as obtained after conversion. This adjustment is dependent on the recognition of symbols scheduled at the start of a burst, it is carried out during a time scheduled for a symbol otherwise left unexploited by the method.
    Type: Grant
    Filed: October 11, 2002
    Date of Patent: April 8, 2008
    Assignee: Thomson Licensing
    Inventors: Patrick Lopez, Thomas Schwanenberger, Samuel Guillouard
  • Publication number: 20080081573
    Abstract: Provided is a receiver capable of automatically controlling a gain of the receiver and receiving three or more band signals. A gain controlled receiver includes a low noise amplifier, a first variable gain control amplifier, a frequency mixer, a filter, a second variable gain control amplifier, and a gain control block. The gain controlled receiver automatically controls gains of the low noise amplifier, the first variable gain control amplifier, the frequency mixer, the filter, the second variable gain control amplifier by detecting strength of the signals processed in the receiver. Therefore, without an additional manual tuning operation, the gain of the receiver can be automatically maintained in an optimal state. A multi-band processing receiver includes a first receiving unit, a second receiving unit, and a switch. The multi-band processing receiver can process three or more RF signals in multi-band by using a single receiver.
    Type: Application
    Filed: October 1, 2007
    Publication date: April 3, 2008
    Applicant: FCI INC.
    Inventor: Myung Woon HWANG
  • Patent number: 7349709
    Abstract: A WLAN (Wireless Local Area Network) transmission technique is provided where data is transmitted in two or more different transmission modes at different transmission rates. A transmission gain is determined to be applied when transmitting data. The transmission gain is determined to be transmission mode dependent such that the transmission gain in a first transmission mode is greater than the transmission gain in a second transmission mode if the transmission rate in the first transmission mode is lower than the transmission rate in the second transmission mode.
    Type: Grant
    Filed: October 14, 2004
    Date of Patent: March 25, 2008
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Thomas Hanusch, Sascha Beyer, Michael Schmidt
  • Publication number: 20080070521
    Abstract: An electronic system comprises two or more receivers, each receiver having a defined range for input signals; and an automatic gain control circuit configured to adjust the gain of two or more signals and pass the two or more adjusted signals to the two or more receivers, wherein the automatic gain control circuit adjusts the gain of each of the two or more signals based on an analysis of all of the two or more signals.
    Type: Application
    Filed: September 12, 2006
    Publication date: March 20, 2008
    Applicant: Honeywell International Inc.
    Inventors: Brian West, Juan C. Fernandez
  • Patent number: 7333788
    Abstract: Disclosed herein is an iterative process for calibrating an AGC in a wireless system, wherein the iterative process includes transmitting a calibration signal, receiving the calibration signal, decoding the calibration signal to produce a measurement, storing the measurement and changing an AGC gain setting.
    Type: Grant
    Filed: December 12, 2003
    Date of Patent: February 19, 2008
    Assignee: Texas Instruments Incorporated
    Inventors: Henry S. Eilts, Srinath Hosur
  • Patent number: 7308037
    Abstract: Radio receiving apparatus includes antennas, radio units adjusting gains of received signals, and outputting the adjusted received signals, respectively, converters converting the adjusted received signals into digital signals, selector device which selects several of the digital signals, combination of the selected digital signals exhibiting good receiving characteristic, controller which determines the gains and outputs single control signal included in information of the determined gains to certain radio units, the certain radio units being included in the radio units and connected to certain converters of the converters which output digital signals included in the selected combination, weight calculator which calculates weight for each of the selected digital signals to enhance the receiving characteristic if the controller outputs the single control signal, synthesizer which synthesizes, into synthetic digital signal, digital signals obtained by multiplying each of the selected digital signals by the wei
    Type: Grant
    Filed: September 28, 2004
    Date of Patent: December 11, 2007
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koji Akita, Kazumi Sato, Kuniaki Ito, Akihiro Tsujimura
  • Patent number: 7308238
    Abstract: An apparatus and method for performing automatic frequency control of a mobile communication terminal detects a current peak position value from a downlink pilot signal and then calculates a difference value (dev) between the current peak position and a previous peak position value. A zero-run value is then calculated by counting the number of successive 0s in the difference value (dev), and an AFC voltage from controlling an oscillator is obtained based on the difference value. This difference value is then used to control a frequency of a transmitter in the terminal. Accordingly, an accurate oscillation frequency can be generated without being affected by noise existing in the communication environment and thus communication performance can be enhanced.
    Type: Grant
    Filed: June 23, 2004
    Date of Patent: December 11, 2007
    Assignee: LG Electronics Inc.
    Inventor: Jae Cheol Lee
  • Patent number: 7302241
    Abstract: A wireless communication unit (300) incorporates a receiver comprising radio frequency circuitry (210, 220, 230, 240) for receiving a radio frequency signal and converting the radio frequency signal to a low frequency signal. A signal level adjustment circuit receives the low frequency signal and an analogue to digital converter (370), operably coupled to the signal level adjustment circuit receives an adjusted low frequency signal and providing a digital received signal. A signal processor (108) operably coupled to the analogue to digital converter (370) processes the digital received signal. The signal level adjustment circuit includes a low frequency amplifier (360) whose gain is arranged to be dependent upon a clip point of the analogue to digital converter (370).
    Type: Grant
    Filed: December 16, 2002
    Date of Patent: November 27, 2007
    Assignee: Motorola, Inc.
    Inventor: Matthias Koenig
  • Patent number: 7295820
    Abstract: An automatic gain control (AGC) circuit has an automatic gain controlled amplifier connected in series with a DC blocking capacitor. A reference DC voltage is selectively applied to an input of the automatic gain controlled amplifier and to an output of the DC blocking capacitor output so as to cause the DC blocking capacitor to store a charge proportional to a DC voltage offset introduced by the controllable gain amplifier. The selectively application of the reference DC voltage is momentarily applied for a duration of less than about 1 microsecond and preferably about 0.4 microseconds. The AGC circuit, including both the amplifier and capacitor, are fabricated as an integrated circuit device.
    Type: Grant
    Filed: April 27, 2004
    Date of Patent: November 13, 2007
    Assignee: Synad Technologies Limited
    Inventor: Hassan Shafeeu
  • Patent number: 7292830
    Abstract: Noise floor searching is performed for a cellular base station to increase accuracy of receiver gain estimates. This allows adjustment of gain in a radio module to account for gain in front-end devices, and achieve a desired overall receiver target gain. The gain of the RF front-end devices is estimated based on the difference between measured Rx noise power at a receive port of the radio module and the noise floor of the radio module. In one embodiment, frequency sweeping across a receive band using a narrowband filter is done to search for minimum noise power. Interference detection may also be employed to increase awareness of any interfering signals that are presented at a configured channel. It is determined whether the interference is wideband or narrowband.
    Type: Grant
    Filed: March 31, 2004
    Date of Patent: November 6, 2007
    Assignee: Nortel Networks Limited
    Inventors: Bing Leung Cheung, Roman Nemish
  • Patent number: 7286795
    Abstract: The present invention relates to a system and method for terrestrial transmission of RF signals comprising: an antenna, where said antenna includes an active device and a passive device and a decoder. The passive device receives RF signals and passes the signals to the active device. The active device includes at least one amplifier, where active device down converts the RF signals to IF signals and applies a gain to at least one of the RF signals and the IF signals. The decoder connects to the antenna, where decoder receives and analyzes the IF signals from said antenna and upon receipt of the IF signals sends commands to the active device in order to maintain an acceptable IF signal, where said commands instruct the active device to selectively adjust the gain.
    Type: Grant
    Filed: July 23, 2003
    Date of Patent: October 23, 2007
    Assignee: MDS America, Inc.
    Inventor: Jean-Claude Ducasse
  • Patent number: 7280811
    Abstract: A multimode wireless terminal suitable for received level monitoring for a base station serving as an intersystem handover destination includes a first wireless transmitter-receiver unit for GSM, a second wireless transmitter-receiver unit for WCDMA, and a communication processor unit and an antenna switch unit connected to these wireless transmitter-receiver units. While conducting communication with a WCDMA network system via the second wireless transmitter-receiver unit, a level of a signal received from a GSM base station is monitored via the first wireless transmitter-receiver unit. A communication processor unit determines whether the level monitoring is interfered with by a WCDMA transmission signal, on the basis of a relation between a WCDMA transmission frequency and a reception frequency supplied from the GSM base station.
    Type: Grant
    Filed: June 22, 2004
    Date of Patent: October 9, 2007
    Assignee: Renesas Technology Corp.
    Inventors: Yoshikazu Sugiyama, Masaki Noda, Makoto Katagishi, Yutaka Igarashi
  • Patent number: 7277685
    Abstract: A method includes amplifying the plurality of received signals, generating a plurality of time domain samples of the amplified signals with at least an analog-to-digital converter (ADC), determining at least a candidate power according to root-mean-square (RMS) powers of a first group of symbols received at the receiver antennas, and setting the gain of the amplifier according to a selected candidate power with the processor. The received RMS power for one antenna is determined as the square root of the averaged product of each received symbol and its complex conjugate for all symbols of the first group. The candidate power can be determined considering a subgroup of antennas using an RMS value, an arithmetical mean value, or a geometric mean value of this subgroup.
    Type: Grant
    Filed: October 9, 2003
    Date of Patent: October 2, 2007
    Assignee: Realtek Semiconductor Corp.
    Inventors: Der-Zheng Liu, Shan-An Yang, Kuang-Yu Yen
  • Patent number: 7277684
    Abstract: An object of the invention is to receive a weak signal with high sensitivity and reduce distortion and signal suppression when a strong interference signal exists. When a high-frequency signal received by an antenna is to be amplified by an antenna amplifier and when an interference wave of high field strength exists, a switch circuit is switched by an output switchover circuit from the output of an amplifier to a through-circuit. The through-circuit guides the high-frequency signal, directly to the output side without passing through the amplifier. When the switching operation of the switch circuit is performed based on low-frequency components which are highly correlated with distortion components due to intermodulation, the switching operation can be performed more adequately. Noises can be reduced by performing a smoothing process on the switching operation, and the use of an inverting amplifier can prevent occurrence of oscillation.
    Type: Grant
    Filed: April 25, 2003
    Date of Patent: October 2, 2007
    Assignee: Fujitsu Ten Limited
    Inventors: Naoki Kushima, Kazuo Takayama, Tetsuharu Imoto, Kazushige Ogino, Hirokazu Matsunaga, Nobuyoshi Tateishi
  • Patent number: 7277679
    Abstract: Methods and apparatuses, including computer program products, for spatial processing in a remote terminal unit. One embodiment is a wireless remote terminal receiver in a wireless terminal unit for operation in a wireless communication system. The wireless remote terminal receiver includes an antenna array, and a receive processing unit to process signals received by the antenna array by applying a selected spatial processing mode of a plurality of spatial processing modes. The modes include one or more modes of one or more spatial processing methods. The receiver also includes a selector to select the spatial processing mode from the plurality of spatial processing modes. The selecting includes selecting the spatial processing method in the case that the set of spatial processing modes are of more than one spatial processing method.
    Type: Grant
    Filed: October 7, 2002
    Date of Patent: October 2, 2007
    Assignee: Arraycomm, LLC
    Inventors: Craig H. Barratt, Athanasios A. Kasapi
  • Patent number: 7269398
    Abstract: An automatic gain control circuit for a receive apparatus for a mobile object which automatically controls the gain of a variable gain amplifier amplifying a received signal from an antenna installed in the mobile object and outputting the amplified signal to the receive apparatus. The circuit comprises an intensity detector that detects an intensity of the received signal; a comparator that compares the detected intensity with first and second threshold voltages; and a controller that outputs a control signal for adjusting the gain to the variable gain amplifier based on the comparing results of the comparator so that the gain of the variable gain amplifier has a hysteresis with respect to the intensity of the received signal.
    Type: Grant
    Filed: July 29, 2004
    Date of Patent: September 11, 2007
    Assignee: Sanyo Electric Co., Ltd.
    Inventor: Takao Saeki
  • Patent number: 7266353
    Abstract: The invention improves the control behavior of a control circuit for digital signals which is used in AGCs (automatic gain control), using a simple supplementary circuit. In a first example of an embodiment, the output signal of an integrator member is looped back to the input of said integrator member in the loop-back branch of the control circuit. In a second example, a counter is provided. Said counter monitors the overflow of the integrator member and weights the input signal accordingly.
    Type: Grant
    Filed: September 27, 2000
    Date of Patent: September 4, 2007
    Assignee: Micronas GmbH
    Inventor: Andreas Menkhoff