With Control (e.g., Automatic Gain Control, Automatic Frequency Control, Etc.) Patents (Class 455/136)
  • Patent number: 7257383
    Abstract: The receiver is provided which comprises a mixer, a low pass filter coupled to the mixer and a plurality of gain controllers serially coupled to an output of the low pass filter (LPF). A plurality of analog-to-digital converters (ADCs) is coupled so that an input of a first of the ADCs is coupled to the output of the LPF. An input of each of a remaining portion of the ADCs is individually coupled to a corresponding output of each of the serially coupled gain blocks. An output path traced from the output of the LPF to an output of each of the analog-to-digital converters may be referred to as a processing path. Each processing path may comprise a gain controller and an ADC, except for the first processing path, which may have an ADC coupled directly to the output of the LPF.
    Type: Grant
    Filed: March 26, 2004
    Date of Patent: August 14, 2007
    Assignee: Broadcom Corporation
    Inventors: Christopher Young, Tushar Moorti
  • Patent number: 7251300
    Abstract: A method of frequency tracking based on recovered data, for use in an automatic frequency control subsystem at the receiver of a mobile station, is disclosed. The frequency tracking mechanism derives frequency error information from the recovered data to determine the adjustment needed at the mobile station's local voltage controlled oscillator in order to track the frequency of the base station.
    Type: Grant
    Filed: December 22, 2003
    Date of Patent: July 31, 2007
    Assignee: Spreadtrum Communications Corporation
    Inventors: Jiayi Zhuang, Jingdong Lin, Yueheng Sun
  • Patent number: 7236743
    Abstract: In a method for interference suppression using a quality-adjustable bandpass filter in a receiver circuit for carrier-modulated received signals (SIN), the bandpass filtered received signal (Bout) is demodulated, and a switching process is triggered with the demodulated received signal (Dout). In order to eliminate internal or self-induced interferences that would be caused by a switching process in the output portion of the receiver, a quality reduction of the bandpass filter is correlated with the switching process that causes the interference. The method is especially suitable in connection with circuits for infrared receivers, which can thereby be manufactured in a small size, without external components, and thus economically.
    Type: Grant
    Filed: August 3, 2001
    Date of Patent: June 26, 2007
    Assignees: Vishay Semiconductor GmbH, Atmel Germany GmbH, Melexis GmbH
    Inventors: Matthias Eichin, Alexander Kurz, Karl-Ulrich Stahl
  • Patent number: 7236740
    Abstract: A method and apparatus for retransmitting data in a mobile communication system wherein a receiver determines whether an initial data block received from a transmitter has an error. Upon detecting an error from the initial data block, the receiver estimates a current channel state and determines a retransmission frequency and a power level of the initial data block according to the estimated current channel state. Thereafter, the receiver transmits a retransmission request message of the initial data block together with the determined retransmission frequency and the determined power level to the transmitter. The transmitter retransmits the initial data block as many times as the retransmission frequency at the requested power level. The receiver then determines whether the retransmitted data blocks have errors, and provides the retransmitted data blocks to an upper layer upon failure to detect errors from the retransmitted data blocks.
    Type: Grant
    Filed: July 5, 2001
    Date of Patent: June 26, 2007
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Chang-Hoi Koo, Kyou-Woong Kim, Hwan-Joon Kwon
  • Patent number: 7212749
    Abstract: An Improved Signal Receiver Having Wide Band Amplification Capability is disclosed. Also disclosed is a receiver that is able to receive and reliably amplify infrared and/or other wireless signals having frequency bandwidths in excess of 40 MHz. The receiver of the present invention reduces the signal-to-noise ratio of the received signal to ?th of the prior systems. The preferred receiver eliminates both the shunting resistor and the feedback resistor on the input end by amplifing the signal in current form. Furthermore, the receiver includes transconductance amplification means for amplifying the current signal without the need for Cascode stages. Finally, the receiver includes staged amplification to amplify the current signal in stages prior to converting the signal into a voltage output.
    Type: Grant
    Filed: March 15, 2005
    Date of Patent: May 1, 2007
    Assignee: ZiLOG, Inc.
    Inventors: T. Allan Hamilton, Alan Grace
  • Patent number: 7194049
    Abstract: A digital automatic level control system employs delay elements, which enable information about a signal parameter from the past, present and future to be processed to provide an optimal gain that can be used to level rapidly varying signals, such as bursty signals. As digital time samples of a signal are passed through first and second buffers, first and second accumulators maintain running sums that are related to the sum of the samples presently in the first and second buffers, respectively. The sums in the first and second accumulators represent information about the signal parameter for the future and the past, respectively. By choosing the maximum of these two values, the system can anticipate the beginning of a signal burst, and still have enough delay to compensate the end of a signal burst. In one embodiment of the invention, multiple channel signals can be leveled, either individually or in groups.
    Type: Grant
    Filed: October 15, 2002
    Date of Patent: March 20, 2007
    Assignee: Northrop Grumman Corp.
    Inventors: Cyrus A. Dhalla, Michael S. Munoz
  • Patent number: 7184740
    Abstract: A direct conversion receiver (DCR) calibrated for phase and gain mismatch is provided. The DCR comprises a poly-phase filter that generates mismatched in-phase and quadrature-phase differential signals; the in-phase differential signal is mixed with first and second local oscillation signals; the quadrature-phase differential signal is mixed with third and fourth local oscillation signals; the first and second local oscillation signals have a first adjustable phase mismatch, and the third and fourth oscillation signals have a second adjustable phase mismatch; A mismatch estimation unit (MEU) estimates the entire phase/gain mismatch (signal distortion) of the DCR, The first and second adjustable phase mismatches are adjusted so that the signal distortion of the DCR, as estimated by the MEU is minimized. Thereafter, reduced-component DCRs (without an MEU), calibrated for the mismatches of a poly-phase filter, may be mass produced.
    Type: Grant
    Filed: November 18, 2003
    Date of Patent: February 27, 2007
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Young-jin Kim
  • Patent number: 7158772
    Abstract: A Gaussian family filter (e.g. an equiripple filter) comprises a first pole, a second pole, a third pole and a signal combiner. The first pole has a biquadratic low pass characteristic and is configured to provide a first low pass signal. The second pole is coupled to the first low pass signal, the second pole having a first-order low pass characteristic, and providing a second low pass signal and a high pass signal. The third pole is coupled to the second low pass signal and has a biquadratic low pass characteristic for generating a third low pass signal. The signal combiner is configured to combine the third low pass signal and the high pass signal to provide a combined signal.
    Type: Grant
    Filed: January 18, 2002
    Date of Patent: January 2, 2007
    Assignee: LSI Logic Corporation
    Inventor: Brian Merrigan
  • Patent number: 7130653
    Abstract: The present invention relates to a wireless transmission apparatus. The wireless transmission apparatus is used for transmitting a RF signal by a selected power allocation to meet the requirement of specific transmission standard. The wireless transmission apparatus comprises a memory, a processor and a power data converting module. The memory is used for storing a plurality of predetermined original power data profiles. Each original power data profile comprises a plurality of predetermined first original power ramp data and a corresponding power allocation for transmitting the RF signal. The processor is used for controlling the data flow. The power data converting module converts the data of original power data profile to a corresponding data of transmission power data profile.
    Type: Grant
    Filed: August 13, 2003
    Date of Patent: October 31, 2006
    Assignee: Mediatek Inc.
    Inventor: Ping-Chun Lin
  • Patent number: 7120404
    Abstract: A method and apparatus for operating a radio reception system, which comprises a plurality of receivers assigned to a common output device, in which one of the receivers is designated as audio receiver and is tuned to a frequency of a radio transmitter, and outputs a signal received from the transmitter to the output device. At least one second receiver is designated as search receiver, and continuously searches its own reception frequency band for a frequency of the same transmitter. The system changes to a frequency of this transmitter, which was found by the search receiver, if the quality of the signal received by the audio receiver falls below a certain limit.
    Type: Grant
    Filed: July 13, 2001
    Date of Patent: October 10, 2006
    Assignee: Harman Becker Automotive Systems GmbH
    Inventor: Stefan Gierl
  • Patent number: 7120440
    Abstract: Disclosed is a velocity estimator using a level crossing rate. The velocity estimator comprises a power calculator for calculating power values of a signal received from a mobile terminal; a mean power calculator for calculating mean power values for M power values according to a predetermined down-sampling factor M; an interpolator for interpolating the mean power values according to a predetermined interpolation ratio L; a root mean square calculator for calculating a root mean square value using an output of the interpolator; a level crossing counter for counting a level crossing frequency representing how many times the output of the interpolator crosses a level crossing threshold determined according to the root mean square value, for a predetermined time period; and a velocity calculator for calculating a velocity estimation value of the mobile terminal using the level crossing frequency.
    Type: Grant
    Filed: April 9, 2004
    Date of Patent: October 10, 2006
    Assignees: Samsung Electronics Co., Ltd., Yonsei University
    Inventors: Myeon-Gyun Cho, Daesik Hong
  • Patent number: 7116959
    Abstract: A diversity receiver system includes a plurality of radio receivers that each provide a uniquely associated receiver output signal and a uniquely associated receiver control signal indicative of the amount of gain applied by the associated radio receiver to create the uniquely associated receiver output signal. A selection mechanism receives the receiver control signals, and determines which of the radio receivers has applied the smallest gain correction to its associated receiver output signal, and provides a diversity receiver output signal indicative of the receiver output signal associated with the receiver that applied the smallest gain correction.
    Type: Grant
    Filed: September 30, 1997
    Date of Patent: October 3, 2006
    Assignee: Harman Becker Automotive Systems GmbH
    Inventors: Hermann Link, Stefan Schradi
  • Patent number: 7107085
    Abstract: A mobile communication terminal having adaptive array antennas is provided that is capable of transmitting signals to an intended base station without interfering other devices, even when a reception error occurs. The mobile communication terminal basically performs array transmission/reception using weight vectors produced in reception to weight and combine signals received via antennas, and thereby receives a desired signal. In transmission, the mobile communication terminal uses the weight vectors used in reception to weight and combine transmission signals and transmits them. However, when an error detection circuit detects a reception error in the desired signal, a transmission control unit turns off a switch for the antenna and transmits the transmission signals in a non-directional pattern via the antenna, so that the transmission signal reaches the intended base station.
    Type: Grant
    Filed: July 13, 2001
    Date of Patent: September 12, 2006
    Assignee: Sanyo Electric Co., Ltd
    Inventor: Yoshiharu Doi
  • Patent number: 7107027
    Abstract: Automatic gain control (AGC) functionality is distributed within a transmitter chain. A controller manages two or more variable gain amplifiers to achieve the desired result.
    Type: Grant
    Filed: November 29, 2001
    Date of Patent: September 12, 2006
    Assignee: Intel Corporation
    Inventor: Eliav Zipper
  • Patent number: 7092687
    Abstract: An apparatus for a direct down-conversion of modulated RF signals, the device including: a first power detector connected between an input port for the modulated RF signal and ground, which outputs a first DC signal, a second power detector connected between an input port for a local oscillator signal and ground, which outputs a second DC signal, the local oscillator signal having the same center frequency as the modulated RF signal, and a third power detector connected between the input port for the modulated RF signal and the input port for the local oscillator signal, which outputs a third DC signal.
    Type: Grant
    Filed: January 17, 2003
    Date of Patent: August 15, 2006
    Assignee: SONY International (Europe) GmbH
    Inventors: Dragan Krupezevic, Mohamed Ratni, Veselin Brankovic
  • Patent number: 7076224
    Abstract: A method and device are disclosed for receiving digital television signals by a frequency tuner. The power of the signal is measured after an analog/digital conversion in the frequency tuner, and the gain thereof is controlled on the basis of this power measurement according to a predetermined control law. The power of the analog signal, tapped between an input amplifier stage and a first frequency transposition stage, or immediately after the first frequency transposition stage, is also measured. The measured power is compared with a predetermined power threshold so as to obtain first binary information, and the gain control law is set on the basis of the value of the first binary information.
    Type: Grant
    Filed: December 4, 2002
    Date of Patent: July 11, 2006
    Assignee: STMicroelectronics S.A.
    Inventors: Florence Giry-Cassan, François van Zanten
  • Patent number: 7072627
    Abstract: A first signal component is received having a first signal strength and a second signal component is received having a second signal strength. A difference is identified between the first signal strength and the second signal strength. A determination is made as to whether the difference between the first signal strength and the second signal strength exceeds a threshold. If the difference between the first signal strength and the second signal strength exceeds a threshold, the first signal strength is adjusted to reduce the difference between the first signal strength and the second signal strength.
    Type: Grant
    Filed: June 27, 2002
    Date of Patent: July 4, 2006
    Assignee: Microsoft Corporation
    Inventor: Louis F. Coffin, III
  • Patent number: 7068990
    Abstract: The inventive receiver has a receiving branch for each of the two signals (EH, EV) and a demodulator (MHE, MVE) and means (SH, SV) for synchronising the phase of the received signal (EH, EV) with the transmitting phase are provided in said branches, respectively. Polaristion decouplers (XPIC-VH, XPIC-HV) which compensate cross-polar crosstalk between the two received signals (EH, EV) are provided for both of the receiving branches. The polarisation decoupling (XPIC-VH, XPIC-HV) of the two received signals (EH, EV) takes place after they have been demodulated (MHE, MVE) and before they have been phase-synchronised (SH, SV) so that the receiver can function as inexpensively as possible in terms of the components that it requires and so that it can also compensate cross polar channel crosstalk for circular QAM signal constellations.
    Type: Grant
    Filed: June 8, 2000
    Date of Patent: June 27, 2006
    Assignee: Marconi Communications GmbH
    Inventor: Gerhard Herbig
  • Patent number: 7065335
    Abstract: An automatic gain control (AGC) circuit including: a forward transmission path (214) having applied at its input an input RF signal and to provide at its output an output signal; a variable gain AGC amplifier (210) in the forward transmission path for processing the input RF signal, which amplifier has a control input 240 and is responsive to a control signal applied at its control input to vary its gain; a feedback loop (220 to 240), coupled from the output of the forward transmission path and to the control input of the AGC amplifier; an integrator (230, 232), coupled to the control input of the amplifier; a voltage source (234), coupled to the integrator and to the control input of the amplifier; and a further variable gain device (215) for varying the gain or attenuation of a signal applied to the control input of the AGC amplifier.
    Type: Grant
    Filed: June 3, 2002
    Date of Patent: June 20, 2006
    Assignee: Motorola, Inc.
    Inventors: Moshe Ben-Ayun, Mark Rozental, Roman Pasternak, Izak Avayu
  • Patent number: 7062240
    Abstract: A multiple channel receiver (200) includes a communications receiver synthesizer (204) and at least one numerically controlled oscillator (NCO) (406) that produce local oscillator signals that are derived from a common reference oscillator (202). A DSP (212) and CPU (214) perform automatic frequency control (AFC) by adjustment of the reference oscillator (202) based upon a signal received by a receive channel using the local oscillator signal produced by the communications receiver synthesizer (204). The CPU (214) also provides a synchronous indication of adjustments to the reference oscillator (202) to control circuitry for the at least one NCO (406) so that the configuration of the NCO (406) can be altered so as to maintain a substantially constant frequency output during the adjustment of the reference oscillator (202).
    Type: Grant
    Filed: April 22, 2003
    Date of Patent: June 13, 2006
    Assignee: Motorola, Inc.
    Inventors: Wayne Wiggins Ballantyne, Thomas Michael King
  • Patent number: 7046749
    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: May 1, 2001
    Date of Patent: May 16, 2006
    Assignee: IPR Licensing, Inc.
    Inventors: Mark J. Takatz, Alton S. Keel, Jr., Stefan Haenggi
  • Patent number: 7035606
    Abstract: A clock control apparatus (3) receives wireless frequency information of a wireless communication apparatus (6) from an information communication apparatus (5). Also, the clock control apparatus (3) detects an operation clock frequency of a main CPU (4). Then, when the multiplied operation clock frequency coincides with the wireless frequency, the clock control apparatus (3) lowers a voltage of the operation clock of the main CPU (4) to a minimum voltage value at which the operation of the main CPU (4) is guaranteed. Alternatively, the clock control apparatus (3) may shift the clock frequency, or may frequency-modulate the clock frequency.
    Type: Grant
    Filed: January 25, 2001
    Date of Patent: April 25, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Iwao Matsuura, Tadahisa Kamiya, Koji Hakamata
  • Patent number: 7035605
    Abstract: A method for controlling frequency of a local oscillator in a DS-CDMA type receiver includes transforming a known spread spectrum signal into a sampled digital signal formed of symbols with a despreaded frequency spectrum, and determining a residual frequency error fe for each symbol including a first residual frequency error fe1. The method further includes correcting the frequency of the local oscillator with the residual frequency errors, and determining an average of absolute values of a predetermined number of successive residual frequency errors. The average is compared with a threshold, and if the average is greater than or equal to the threshold, the local oscillator frequency is corrected using an error equal to ?sgn(fe1) (1/T?|fe1|), where sgn is the sign function, | | is the absolute value function and T is duration of a symbol before determining the next residual frequency error associated with the next symbol.
    Type: Grant
    Filed: July 16, 2003
    Date of Patent: April 25, 2006
    Assignee: STMicroelectronics N.V.
    Inventors: Miguel Kirsch, Friedbert Berens
  • Patent number: 7002946
    Abstract: A cross product is determined for a received signal. A dot product is also determined for the received signal. If the cross product is greater than a predetermined threshold, the cross product is decremented by the product of the dot product multiplied by a constant value. If the cross product is less than or equal to the predetermined threshold, the cross product is incremented by the product of the dot product multiplied by the constant value. The incrementing or decrementing is continued until the frequency error approaches a minimum value.
    Type: Grant
    Filed: July 16, 2001
    Date of Patent: February 21, 2006
    Assignee: Qualcomm Inc.
    Inventor: Andrew Sendonaris
  • Patent number: 6999740
    Abstract: An amplifier circuit unit including a signal amplifying transistor is provided with a first bypass circuit unit for bypassing a part of an input signal to a ground side according to the strength of the input signal, and a second bypass circuit unit for bypassing a part of the input signal to an output side according to the strength of the input signal, whereby gain attenuation control is effected. Also, the amplifier circuit unit is provided with a control circuit unit for decreasing the drain bias current of the signal amplifying transistor when the first bypass circuit unit bypasses the part of the input signal to the ground side, and interrupting the drain bias current of the signal amplifying transistor when the second bypass circuit unit bypasses the part of the input signal to the output side, whereby control of the drain bias current is effected.
    Type: Grant
    Filed: February 28, 2002
    Date of Patent: February 14, 2006
    Assignee: Sony Corporation
    Inventor: Takahiro Ogihara
  • Patent number: 6993303
    Abstract: The present invention avoids distortion in a radio frequency device due to a received RF signal which has a voltage strength that is too high. The invention comprises a radio frequency signal attenutation circuitry, a radio frequency signal processing circuitry, intermediate frequency processing circuitry, and a gain controlling unit. The gain controlling unit is configured to output a control signal to the radio frequency signal attenuation circuitry and intermediate frequency processing circuitry. The radio frequency signal attenuation circuitry is configured to attenuate a radio frequency signal prior to being processed by radio frequency processing circuitry and intermediate frequency processing circuitry. Accordingly, saturation in the radio frequency signal processing circuitry and intermediate frequency processing circuitry is avoided.
    Type: Grant
    Filed: July 24, 2002
    Date of Patent: January 31, 2006
    Assignee: LG Electronics Inc.
    Inventor: Soon-Ik Kwun
  • Patent number: 6985706
    Abstract: A method and apparatus for rapid alignment of adaptive feed forward power amplifiers are disclosed. Successful alignment settings are correlated with the operating conditions that affect the gain and phase of an amplifier. These operating conditions may include input power level, carrier frequency, temperature, DC supply voltage, or others. The successful alignment settings along with the corresponding operating conditions are stored in a list that is indexed using multi-dimensional attribute vectors. The elements of the list are generated automatically.
    Type: Grant
    Filed: January 21, 2004
    Date of Patent: January 10, 2006
    Assignee: Powerwave Technologies, Inc.
    Inventor: Richard Neil Braithwaite
  • Patent number: 6985705
    Abstract: The present invention provides for a system and method for improvement of radio transmitter and receiver frequency accuracy for a local radio communication unit that communicates digital data with a remote communication unit. In the local unit the received radio signal is down-converted, and converted to complex baseband digital samples by an analog-to-digital converter. A downlink digital phase rotator applies a fine frequency shift to the samples in accordance with a receiver frequency offset command. The resultant baseband signal is used by the data demodulator and by a receiver frequency error estimator to obtain receiver frequency errors. A data modulator generates baseband complex samples which are shifted in carrier frequency by an integrated uplink digital phase rotator in accordance with a transmitter frequency offset command. The modulated samples are then converted by a digital-to-analog converter and upconverted in frequency for radio transmission to the remote unit.
    Type: Grant
    Filed: October 19, 2004
    Date of Patent: January 10, 2006
    Assignee: Broadcom Corporation
    Inventor: Aki Shohara
  • Patent number: 6975674
    Abstract: There is disclosed a mixed mode equalization system for use in a transceiver capable of operating in a high frequency Ethernet local area network (LAN).
    Type: Grant
    Filed: May 12, 2000
    Date of Patent: December 13, 2005
    Assignee: National Semiconductor Corporation
    Inventors: Abhijit M. Phanse, Peter J. Sallaway, Thulasinath G. Manickam
  • Patent number: 6970523
    Abstract: A multiple channel diversity receiver includes joint automatic gain control (AGC) signal processing wherein the first and second channels of the multiple channel diversity receiver share at least one joint AGC loop. The maximum difference between the AGC feedback signal in the control loop for the first channel and the AGC feedback control signal in the control loop for the second channel is limited to a selectable maximum differential. The AGC control loop with the stronger first RF signal thus limits the maximum amount that the weaker signal is amplified in the AGC control loop with the weaker second RF signal. By limiting the AGC feedback signal in the control loop of the second channel to a maximum differential with respect to the AGC feedback signal in the control loop of the first channel, the weaker signal is not overly amplified thereby avoiding the undue amplification of noise in the second channel.
    Type: Grant
    Filed: March 7, 2003
    Date of Patent: November 29, 2005
    Assignee: ATI Technologies, Inc.
    Inventors: Christopher H Strolle, Anand M Shah, Thomas J Endres, Samir N Hulyalkar, Troy A Schaffer
  • Patent number: 6963733
    Abstract: The present invention reduces automatic gain control (AGC) transients using first and second AGC processing branches to receive a signal. A gain is selectively adjusted (if desired) in the one of the AGC processing branches during a first time period. However, a gain is not adjusted in the other AGC processing branch during that first time period. The signals generated by the first and second AGC processing branches are then diversity processed to generate a received signal. The diversity processing effectively reduces the effect of any AGC transient.
    Type: Grant
    Filed: October 31, 2001
    Date of Patent: November 8, 2005
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Patrik Eriksson, Mats Eriksson
  • Patent number: 6959176
    Abstract: A communications terminal, in particular a mobile radio station, having an AF amplifier stage, which includes a gain adjustment for adjusting the gain factor as a function of the speech volume.
    Type: Grant
    Filed: April 3, 2000
    Date of Patent: October 25, 2005
    Assignee: Siemens Aktiengesellschaft
    Inventor: Werner Krueger
  • Patent number: 6954624
    Abstract: A transmitter into which a modulated signal (TX) is fed, the transmitter comprising an adjustable amplifier (1) for adjusting transmission power level, the modulated signal (TX) being fed into to the input of the amplifier (1), an amplification branch (11) arranged after the adjustable amplifier (1) on the signal path, the amplification branch comprising a power amplifier (3) for further amplifying the transmission power level, and at least one filter (27, 28) arranged after the power amplifier (3) on the signal path for filtering the frequency band to be transmitted. The transmitter further comprises an antenna (9) after the amplification branch (11) on the signal path for transmitting signals. The transmitted is characterized by a bypass branch (10) which operatively couples the output of the adjustable amplifier (1) and the antenna (9) and is used for bypassing the amplification branch (11) and connecting signals to be transmitted at low transmission power levels directly to the antenna (9).
    Type: Grant
    Filed: September 10, 2001
    Date of Patent: October 11, 2005
    Assignee: Nokia Mobile Phones Ltd.
    Inventor: Miikka Hämäläinen
  • Patent number: 6934524
    Abstract: A data-pattern feedback mechanism is introduced into the peak detection process of an automatic frequency compensation system in a Gaussian Frequency Shift Keying (GFSK) modulated system, providing fast and accurate fine-stage automatic frequency compensation (AFC). Maximum positive and negative peak registers are updated with new values as necessary based on detection during a sequence of identical binary bit values (e.g., during a “00” for detection of maximum negative peak frequency, or during a “11” for detection of maximum positive peak frequency), in a particular data frame. As soon as an initial value is determined for both the maximum positive and negative peak frequencies (e.g., after the first occurrence of a “11” and a “00”, in any order), fine-stage automatic frequency compensation can be initiated. Subsequent adjustments to the VCO of the local oscillator will further refine the frequency offset towards the ideal of zero.
    Type: Grant
    Filed: April 25, 2002
    Date of Patent: August 23, 2005
    Assignee: Agere Systems Inc.
    Inventors: Eric John Hansen, Wenzhe Luo, Zhigang Ma, Richard L. McDowell
  • Patent number: 6892080
    Abstract: A booster amplifier that can be coupled to virtually any cellular telephone handset is provided for use with virtually any cellular communications network. The power output of the booster amplifier is dynamically controlled based upon signals received from the handset to improve the quality and range of communications between the handset and the base stations of the cellular network without interfering with normal communications between the cellular network and other handsets.
    Type: Grant
    Filed: November 27, 2001
    Date of Patent: May 10, 2005
    Assignee: Arrista Technologies, Inc.
    Inventors: Elwood Dalen Grant Friesen, Wybrandus Theodore Schellekens
  • Patent number: 6865168
    Abstract: A communication system includes a first communication station for transmitting first data and second data at a first transmission power level and a second transmission power level, respectively, and a second communication station for receiving the first data and the second data transmitted from the first communication station as a reception signal. The second communication station generates transmission power control information based on the received first and second data, and transmits the generated transmission power control information to the first communication station. The first communication station receives the transmission power control information from the second communication station, and controls the first transmission power level and the second transmission power level independently of each other based on the transmission power control information.
    Type: Grant
    Filed: February 26, 1999
    Date of Patent: March 8, 2005
    Assignee: Oki Electric Industry Co., Ltd.
    Inventor: Kiyoki Sekine
  • Publication number: 20040266377
    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: Application
    Filed: June 23, 2004
    Publication date: December 30, 2004
    Applicant: LG Electronics Inc.
    Inventor: Jae Cheol Lee
  • Publication number: 20040259510
    Abstract: A receiver 30 has an adjustable gain control circuit 32 that provides gain control base on the magnitude of the signal at the input of an analog-to-digital converter 22. The magnitude of a gain increase or decrease can be based on the most significant bits of the analog-to-digital output, indicating whether the analog-to-digital converter is close to saturation, approaching saturation, or well below saturation.
    Type: Application
    Filed: June 23, 2003
    Publication date: December 23, 2004
    Inventors: Pascal Audinot, Vincent Roussel
  • Publication number: 20040259511
    Abstract: The invention provides an automatic gain control and antenna selection method used in a receiver of a radio communication system. The received signal power is estimated by digital signal processing after analog-to-digital conversion in the system, in order to adjust the gain of the front end analog signal until the magnitude of the analog signal is adjusted to an optimum range of the digital signal processing. In addition, the ADC is utilized to estimate the signal power as the basis of the antenna selection.
    Type: Application
    Filed: June 9, 2004
    Publication date: December 23, 2004
    Inventors: Der-Zheng Liu, Song-Nien Tang, Tai-Cheng Liu, Kuang-Yu Yen
  • Publication number: 20040242174
    Abstract: A method for adjusting automatic gain control of a radio receiver begins by determining power level of a radio frequency (RF) signal received by the radio receiver to produce a determined power level. The method then continues by comparing the determined power level with a plurality of power thresholds to determine whether an automatic gain adjustment is needed. The method then continues, when the automatic gain adjustment is needed, by determining, from the comparing the determined power level with the plurality of power thresholds, a sign of the automatic gain adjustment. The method continues by determining, from the comparing the determined power level with the plurality of power thresholds, a magnitude of the automatic gain adjustment. The method continues by addressing a gain adjustment look up table for at least a portion of the radio receiver based on the magnitude to produce a gain setting.
    Type: Application
    Filed: June 28, 2004
    Publication date: December 2, 2004
    Inventors: Hea Joung Kim, Paul Anthony Lettieri, Brima B. Ibrahim
  • Publication number: 20040235439
    Abstract: A method and apparatus to selectively disregard co-channel transmissions on a medium uses an automatic gain control/clear channel assessment (AGC/CCA) circuit to gather signal power information, which is used to establish receiver sensitivity thresholds. Raw and cyclical power measurements of a received signal are processed by the AGC/CCA circuit to determine whether a current received signal process should be halted, and a new signal acquisition sequence begun.
    Type: Application
    Filed: February 18, 2004
    Publication date: November 25, 2004
    Inventors: Paul J. Husted, William J. McFarland
  • Publication number: 20040229580
    Abstract: A direct conversion receiver with DC offset compensation. The receiver includes an antenna receiving a RF signal, a mixture module converting the RF signal to a baseband signal, a gain amplifier amplifying the baseband signal, an adder subtracting a DC offset current from the baseband signal, a DC offset cancellation circuit obtaining and converting a DC offset value to the DC offset current, a track-and-hold circuit receiving the baseband signal, holding and transferring a DC offset voltage to the DC offset current, and a switching circuit alternatively coupling and decoupling the DC offset cancellation and track-and-hold circuit to receive the baseband signal.
    Type: Application
    Filed: May 15, 2003
    Publication date: November 18, 2004
    Inventor: Peir-Weir Chen
  • Publication number: 20040229583
    Abstract: Conventional digital broadcast receiving tuners normally perform identical operations regardless of whether the actual level of a signal received within a receivable frequency band remains flat or irregular, and this makes it impossible to obtain optimal performance characteristics according to the level of the received signal.
    Type: Application
    Filed: February 11, 2004
    Publication date: November 18, 2004
    Inventor: Hitoshi Ogino
  • Publication number: 20040229581
    Abstract: In a diversity receiver comprising an AGC section for controlling the gain of a tuner, an equalizer equalizes an outputted signal from a fast Fourier transformer. A reliability calculator calculates the reliability value of each of carriers by an equalized pilot signal obtained from the equalizer. A reliability value corrector corrects the reliability value by outputted information from the AGC section. A carrier selecting/combining section performs one of selecting and weighting combining for the carrier in a branch in accordance with the corrected reliability value. When a Viterbi decoder is provided, the Viterbi decoder weights an output from the carrier selecting/combining section with a new reliability value to perform maximum likelihood decoding. It is possible to prevent a reliability value which does not reflect an actually received power from being calculated as a result of increasing a power by an AGC in spatial diversity for every OFDM or FDM demodulated carrier.
    Type: Application
    Filed: October 8, 2003
    Publication date: November 18, 2004
    Inventors: Yoshitaka Mizoguchi, Akira Kisoda, Tomohiko Taniguchi, Tetsuya Yagi
  • Publication number: 20040229582
    Abstract: In order to provide a variable gain amplifier of enhanced linearity and wide variable gain range, an AM-modulated signal reception circuit in which the noise of an input portion is reduced so as to improve the follow-up characteristic of an AGC circuit, and an AM-modulated signal detection circuit which produces an output precisely corresponding to a peak value envelope, the variable gain amplifier comprises a differential input amplifier which includes transistors T1 and T2 (in FIG. 8) constituting a differential pair, and a constant current circuit Is operating as an absorption current circuit of the transistors T1 and T2, and a variable impedance which is connected between the sources of the respective transistors T1 and T2, wherein the gain of the differential input amplifier is made variable by variably controlling the value of the variable impedance.
    Type: Application
    Filed: December 16, 2003
    Publication date: November 18, 2004
    Applicant: Oki Electric Industry Co., Ltd.
    Inventors: Tokio Miyasita, Junichi Yanagihara, Takashi Taya
  • Publication number: 20040224653
    Abstract: Provided is an automatic gain controller for obtaining a high a signal-to-noise ratio (SNR), and for reducing power loss by controlling a gain until the gain reaches a maximum value, and a transmitting apparatus and method for use with a mobile communication terminal having the automatic gain controller. The automatic gain controller causes a variation of a gain at a radio frequency (RF) amplifier with respect to the variation of a control voltage to have a larger gradient than a variation of gain at an intermediate frequency (IF) amplifier with respect to the variation of the control voltage, and causes a total gain to have a decreasing gradient in accordance with the control voltage until the total gain reaches its maximum.
    Type: Application
    Filed: May 7, 2004
    Publication date: November 11, 2004
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventor: Hyun-seok Kim
  • Publication number: 20040214537
    Abstract: A cascadable AGC amplifier in a signal distribution system includes a low noise cascadable amplifier having a through path and a cascadable output. The cascadable amplifier is also configured to provide AGC over a predetermined input power range. The cascadable AGC amplifier can be configured to provide gain or attenuation. When the cascadable AGC amplifier is implemented in a signal distribution system, typically as part of a signal distribution device, an input signal can be gain controlled and supplied to multiple signal paths without distortion due to degradation of signal to noise ratio or distortion due to higher order amplifier products. The distributed signal is not significantly degraded by distortion regardless of the number of cascadable AGC amplifiers connected in series or the position of the cascadable AGC amplifier in the signal distribution system.
    Type: Application
    Filed: December 11, 2003
    Publication date: October 28, 2004
    Inventors: Keith P. Bargroff, Dale Hancock
  • Publication number: 20040209582
    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 sub-group.
    Type: Application
    Filed: October 9, 2003
    Publication date: October 21, 2004
    Inventors: Der-Zheng Liu, Shan-An Yang, Kuang-Yu Yen
  • Publication number: 20040203404
    Abstract: Apparatus, and an associated method, for estimating frequency offset introduced upon symbols of a sequence communicated by a sending station to a data destination during operation of a communication system. A received sequence is rotated by multiplying the symbols thereof by offset values selected from a set of offset values. Then, for each rotated sequence, an estimation of a data sequence is made. Noise indicia associated with each estimated data sequence is calculated. And, comparisons are made of the noise indicia associated with each of the estimated data sequences. Responsive to the comparisons, selection is made of the frequency offset that has been introduced upon the data sequence.
    Type: Application
    Filed: December 31, 2002
    Publication date: October 14, 2004
    Inventor: Jan C. Olivier
  • Publication number: 20040198277
    Abstract: Au automatic frequency control (AFC) system applies in a mobile station for automatically controlling a local frequency signal to be substantially synchronized with an input signal which is a first received signal SH from a base station, and for being capable of shifting the frequency of the local frequency signal to be close to that of a second received signal Snew from another base station when the input signal is changed from the first received signal SH to the second received signal Snew. The AFC system comprises a control module, a memory unit, and an automatic frequency controller. The memory unit stores a plurality of AFC parameter sets; each AFC parameter set corresponds to a base station within the wireless cellular system.
    Type: Application
    Filed: March 31, 2004
    Publication date: October 7, 2004
    Applicant: MediaTek Inc.
    Inventor: Ti-Wen Yuan