With Control (e.g., Automatic Gain Control, Automatic Frequency Control, Etc.) Patents (Class 455/136)
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Publication number: 20040214537Abstract: 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: ApplicationFiled: December 11, 2003Publication date: October 28, 2004Inventors: Keith P. Bargroff, Dale Hancock
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Publication number: 20040209582Abstract: 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: ApplicationFiled: October 9, 2003Publication date: October 21, 2004Inventors: Der-Zheng Liu, Shan-An Yang, Kuang-Yu Yen
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Publication number: 20040203404Abstract: 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: ApplicationFiled: December 31, 2002Publication date: October 14, 2004Inventor: Jan C. Olivier
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Publication number: 20040198277Abstract: 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: ApplicationFiled: March 31, 2004Publication date: October 7, 2004Applicant: MediaTek Inc.Inventor: Ti-Wen Yuan
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Publication number: 20040192236Abstract: In a time-division duplex (TDD) system, a reliable initialization scheme that is applicable to an automatic gain controller (AGC) at a base station is implemented in various forms depending on the availability of certain information such as signal-to-interference ratio (SIR), spreading factors and other parameters. A more accurate estimation of the initial control word of a gain-adjustable amplifier for one or more time slots is implemented. The scheme is applicable to AGC initialization for each time slot of the TDD system, but is also applicable to other systems of transmission, without limitation.Type: ApplicationFiled: October 14, 2003Publication date: September 30, 2004Applicant: InterDigital Technology CorporationInventors: Rui Yang, Donald M. Grieco, Leonid Kazakevich
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Publication number: 20040192239Abstract: A transmission weight vector computing unit computes transmission weight vectors. A transmission weight vector correcting unit obtains a corrected transmission weight vector W′(t). A predicted receiving power computing unit computes a predicted receiving power value Y(t). If a difference between the predicted receiving power value Y(t) and a predicted receiving power value in the past Y(t-T) is less than a threshold value, an update unit selects the corrected transmission weight vector W′(t). If, on the other hand, the difference is greater or equal to the threshold value, the update unit selects a corrected weight vector in the past W′(t-xT). If the modulation method is QPSK, a setting unit selects the transmission weight vector W(t). If the modulation method is 16 QAM, the setting unit selects the corrected transmission weight vector W′(t) or W′(t-xT) and outputs it as a final transmission weight vector signal.Type: ApplicationFiled: March 25, 2004Publication date: September 30, 2004Applicants: Sanyo Electric Co., Ltd., Sanyo Telecommunications Co., Ltd.Inventors: Seigo Nakao, Katsutoshi Kawai
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Publication number: 20040176054Abstract: A system and method for automatic gain control for a wireless transmit and receive unit in a time-slotted communications system includes initializing an automatic gain control loop, sampling a received signal, and estimating the power of the received signal. The estimated power of the received signal is compared with a reference power level and an error signal is generated based upon the difference between the estimated power and the reference power level. The error signals generated by a plurality of received signals are accumulated in an accumulator, and the value of the accumulator is looked up in a table to locate a control word for an attenuator. The control word is then passed to the attenuator to adjust the gain.Type: ApplicationFiled: July 3, 2003Publication date: September 9, 2004Applicant: InterDigital Technology CorporationInventors: Eldad Zeira, Mihaela Beluri, Robert Lind Olesen, Rui Yang
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Publication number: 20040171360Abstract: A reception circuit is designed to be free from the influence of noise from a Zener diode. This circuit may have a selection unit which selects a desired broadcast signal in accordance with control signal Vt, an amplifier unit which amplifies the broadcast signal, a booster circuit which increases power supply potential B+ to generate an increased potential, a control unit which is responsive to the increased potential, and generates a control signal used to designate a desired broadcast signal so as to supply the control signal to the selection unit, and Zener diode ZD which has Zener voltage Vz larger than maximum potential Vtmax of the control signal. This diode ZD suppresses or limits the increased potential to be equal to or lower than the Zener voltage. Since the Zener diode does not bring about any breakdown operation in a steady state, a noise-free reception can be assured.Type: ApplicationFiled: December 22, 2003Publication date: September 2, 2004Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Masami Oosawa, Takeshi Tokunaga
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Publication number: 20040162043Abstract: A system for compensating radio frequency (RF) receiver gain (400) by implementing both automatic gain control (AGC) and digital normalization where the receiver includes at least one front-end configurable gain stage (401) for providing selectable gain to the receiver. An analog-to-digital converter (ADC) (407) for converting an analog input signal from the configurable gain stage (407) to a digital signal. An AGC controller (405) is then used to determine a level of gain of a received input signal and controlling the front-end configurable gain stage (401). A digital normalizer (411) then truncates the digital data from both the ADC (407) and subsequent digital stages for maximizing the dynamic range of the receiver. The invention offers advantages in controlling receiver gain when in crowded band conditions with many potentially interfering signals are present with a desired signal.Type: ApplicationFiled: February 14, 2003Publication date: August 19, 2004Applicant: Motorola, Inc.Inventors: David B. Taubenheim, Zhitao Jiang
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Publication number: 20040152432Abstract: Apparatus, and an associated method, for a direct conversion receiver by which to selectably increase the sensitivity of the receiver. The direct conversion receiver includes a baseband amplifier positioned in front of a baseband filter, and coupled to receive a direct-converted baseband signal. The gain at which the baseband amplifier amplifies the signal provided thereto is selected, in combination with gains applied to other amplification elements of the direct conversion receiver to distribute the gain across the receive chain. When a signal received at the receiver includes a large interfering signal component, the gain of the baseband amplifier is reduced to lessen the possibility that the amplified signal become saturated. A gain controller controls the gain of the amplification elements.Type: ApplicationFiled: January 31, 2003Publication date: August 5, 2004Inventor: Qizheng Gu
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Publication number: 20040142669Abstract: A method and a device for a receiver for electromagnetic waves having at least two antennas are described; using this method and this device it is possible to effectively suppress multipath interference, while a portion of the antenna signals may also be utilized for other purposes at least temporarily, e.g., to allow better utilization of the possibilities of RDS activities. To do so, a first antenna signal (1) is used as the basis for generating a playback signal (23) when the signal quality of the first antenna signal (1) is above a defined threshold for undisturbed reception—case 1. In this case 1, the signal quality of the first antenna signal (1) is determined. If the signal quality of the first antenna signal (1) falls below this threshold—case 2—then a new signal y generated from at least two antenna signals (1, 2) is used as the basis for generating the playback signal (23).Type: ApplicationFiled: March 22, 2004Publication date: July 22, 2004Inventors: Lothar Vogt, Detlev Nyenhuis
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Patent number: 6766158Abstract: A mixing system divides a local oscillator (“LO”) signal into two signals having a predetermined phase difference, mixes each of the two signal with an input signal to produce a mixed signal, and then combines the mixed signals to produce an output signal having substantially no third-order mixing products.Type: GrantFiled: March 30, 2001Date of Patent: July 20, 2004Assignee: Skyworks Solutions, Inc.Inventors: Alyosha C. Molnar, Rahul Magoon, Keith J. Rampmeier
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Patent number: 6754281Abstract: The invention relates to a digital demodulator whose architecture is adapted to multicarrier modulations (radio wave transmissions), but which remains suitable for use for monocarrier modulations (cable and satellite transmissions). With multicarrier modulations, the demodulator must carry out certain functions at a frequency of the order of sampling frequency and other functions at a frequency of the order of the symbol frequency. The invention comprises a separation of the architecture into three modules: a first module which carries out programs which are repeated with a first frequency, a second module capable of using programs which are repeated with a second frequency, and an interface module between the first and the second module. An advantage is that the memory size necessary for storing instructions for the first module is reduced. An application is for DVB standard transmission of digital TV programs.Type: GrantFiled: May 10, 2000Date of Patent: June 22, 2004Assignee: Koninklijke Philips Electronics N.V.Inventors: Eric Dujardin, Olivier Gay-Bellile
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Publication number: 20040116084Abstract: An active antenna power interface circuit couples a supply voltage from a radio receiver to an antenna feed. The circuit comprises a DC power input and a power switching element connected in series between the DC power input and the antenna feed. The power switching element has a control input for selecting a conducting state or a nonconducting state of the power switching element. A high side voltage sensor senses a first voltage proportional to a voltage at the DC power input. A low side voltage sensor senses a second voltage proportional to a voltage at the antenna feed. A controller is coupled to the control input and to the voltage sensors. The controller places the power switching element into the conducting state, samples the first and second voltages, calculates a voltage difference in response to the first and second voltages, compares the voltage difference to an upper limit and a lower limit.Type: ApplicationFiled: December 12, 2002Publication date: June 17, 2004Inventors: Dennis Paul Ward, Richard David Zerod
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Publication number: 20040106381Abstract: An interference canceling method and apparatus reduces the level of signal impinging on a wireless receiver due to the transmitted signal from the same transceiver. A signal sampler, such as directional coupler samples a portion of the transmitted signal. The gain and phase of the sampled signal are adjusted to create an equi-amplitude signal that is 180 degrees out of phase with the unwanted coupled transmit signal. The combination of the gain-phase adjusted signal with the received signal effectively cancels the unwanted transmit signal. Once configured, the interference canceller can continue to operate without further adjustment. Adjustments can be made periodically, however, when necessary to accommodate for changes such as environmental changes.Type: ApplicationFiled: September 5, 2003Publication date: June 3, 2004Applicant: Engim IncorporatedInventor: Sam Tiller
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Publication number: 20040097205Abstract: A method and an apparatus for automating gain control of a radio frequency communication system can adapt a radio frequency communication system to an environment where a radio channel characteristic is rapidly or slowly changed. This can be achieved by extracting a maximum absolute value of a reception signal received by a receiver of a radio frequency communication system, determining a gain control value of the reception signal on the basis of the maximum absolute value and a predetermined threshold, and controlling gain of the reception signal according to the determined gain control value.Type: ApplicationFiled: October 24, 2003Publication date: May 20, 2004Applicant: LG Electronics Inc.Inventor: Do Hoon Kim
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Publication number: 20040097255Abstract: The automatic control system of a mobile terminal for time division duplex (TDD) based communication system includes an RF processing module which controls quality of a transmission channel, and a baseband modem connected to the RF processing module through a transmission data line and a reception data line. The baseband modem generates automatic control signals based on control information received from a base station and transmitting the automatic control signal to the RF processing module through the transmission data line in a reception mode of the mobile terminal. The automatic control signals are transmitted to the RF processing module through the transmission data line, which is in the idle state, in the reception mode. Additional control lines are not required to transmit the respective automatic control signals. Therefore, utilization of the transmit data line between the baseband modem and the RF processing module can be improved.Type: ApplicationFiled: November 12, 2003Publication date: May 20, 2004Applicant: LG ELECTRONICS INC.Inventor: Jae-Wook Yu
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Publication number: 20040092238Abstract: This disclosure is directed to techniques that can be executed by a wireless device to perform various signal processing tasks associated with wireless communication. The techniques involve gain state switching based on an output of an analog-to-digital (A/D) converter, rather than gain state switching techniques in which an estimation of signal strength at the antenna is mapped to gain states. Use of the A/D converter output for gain state selection can provide more accurate and dynamic switchpoints.Type: ApplicationFiled: November 8, 2002Publication date: May 13, 2004Inventor: Daniel F. Filipovic
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Publication number: 20040087288Abstract: The invention provides systems, methods, and devices that compensate for temperature, frequency, and sampling effects in a broadband communication device's power measurements. One embodiment of a system includes a thermal device, and an automatic gain control circuit coupled to the thermal device. One method includes the acts of disabling a TOP operation, setting a RF input power, reading an AGC GAIN value, and setting the broadband communications device based on the read AGC value. Furthermore, a broadband communications device according to the invention may operate by disabling a TOP operation, setting a RF input power, reading an AGC GAIN value, and setting the broadband communications device based on the read AGC value.Type: ApplicationFiled: October 28, 2003Publication date: May 6, 2004Inventor: Adam Lapid
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Publication number: 20040087287Abstract: An Automatic Gain Control system (AGC) in which an adder adds a Radio Frequency (RF) signal power of only the low-frequency component of a RF signal and an intermediate-frequency (IF) signal of an output from a variable-gain intermediate-frequency amplifier, which is higher than the frequency of the low-frequency component, and outputs the result to an A/D converter. This construction makes it possible to input power data for the RF stage to a demodulation LSI. The demodulation LSI separates the low-frequency component from the input signal, and by detecting the power of the extracted signal, is able to obtain the output data for the RF signal, and it separates the IF component from the input signal, and by detecting the power of the extracted signal, is able to obtain the output data for the IF signal.Type: ApplicationFiled: October 22, 2003Publication date: May 6, 2004Applicant: Pioneer CorporationInventor: Yoshinori Abe
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Publication number: 20040087278Abstract: Circuitry to transmit an analog data signal over a wireless communication link includes a receiver that receives a data signal, an automatic gain control circuit that keeps a peak amplitude of the data signal substantially constant and within a predetermined linear amplification range, and a transmitter, having the predetermined linear amplification range, that receives the data signal from the automatic gain control circuit and that outputs the data signal.Type: ApplicationFiled: May 28, 2003Publication date: May 6, 2004Inventors: Ernie Lin, Adolf J. Giger
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Publication number: 20040053586Abstract: An automatic gain control (AGC) and DC estimation and correction technique for wireless communication devices is provided. An AGC signal, which controls a gain applied to a received signal by a gain stage to generate a scaled signal, is assigned one of a relatively small number of values in accordance with the amplitude of the scaled signal. An estimate of a DC offset in the scaled signal corresponding to each value of the AGC signal is stored in a memory. A DC estimation arrangement then reads the stored estimate associated with the particular value of the AGC signal from the memory and generates a current DC estimate based thereon. The current estimate is then used to correct the scaled signal for DC offset and to update the stored estimate.Type: ApplicationFiled: August 29, 2003Publication date: March 18, 2004Inventors: Sean Simmons, Muhammad Dajani, Zoltan Kemenczy
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Publication number: 20040048592Abstract: An A-rail circuit outputs a control signal AGCOUTA whereas a B-rail circuit outputs a control signal AGCOUTB in an AGC circuit. AGCOUTA controls an AGC amplifier (A) while AGCOUTB controls an AGC amplifier (B). A difference value between a power of an input signal and (an amount of variable adjustment SWEEP+a power reference value AGCR). If an output signal of a loop filter in the A-rail circuit attains AGCARAIL>AGCATOB, AGCARAIL=AGCATOB is fixed, and AGCBRAIL is adjusted based on the difference value. If an output signal of a loop filter in the B-rail circuit attains AGCBRAIL<AGCBTOA, AGCBRAIL=AGCBTOA is fixed, and AGCARAIL is adjusted based on the difference value. A control circuit in the AGC circuit acquires a bit error rate, identifies a value of SWEEP allowing a minimum bit error rate, and fixes the value of SWEEP at the identified value.Type: ApplicationFiled: March 5, 2003Publication date: March 11, 2004Applicant: MITSUBISHI DENKI KABUSHIKI KAISHAInventor: Kazuya Yamanaka
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Publication number: 20040038656Abstract: System and method for reducing distortion in a receiver by adjusting amplifier linearity. A preferred embodiment comprises measuring a received signal's power level and then making an adjustment the linearity of a receiver's amplifier, wherein the amplifier lies within the receiver chain. A second measurement of the received signal power level is made, followed by a calculation of the difference of the signal power levels. If the difference is less than expected, distortion is insignificant and linearity should be reduced to reduce power consumption. If the difference is greater than expected, then distortion is significant and the amplifier's linearity should be increased to reduce distortion. These measurements can be repeated to find an optimal operating point to minimize distortion and power consumption.Type: ApplicationFiled: May 19, 2003Publication date: February 26, 2004Inventors: John H. McCall, Richard K. Kornfeld, Ana L. Welland
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Publication number: 20040033790Abstract: An automatic gain control system wherein the logarithm of the gain on an amplifier (14, FIG. 1) is increased if the amplitude of the amplified signal S2 falls below the lower threshold L2 of a pair of thresholds, and wherein the logarithm of the is decreased if the amplitude exceeds the upper threshold L1 of the pair.Type: ApplicationFiled: May 28, 2003Publication date: February 19, 2004Inventors: Andrew Thurston, Jonathan Lucas
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Patent number: 6690921Abstract: A gain of a receiving amplifier can be measured by inputting pilot signals each having a different frequency into an input side and an output side of the receiving amplifier respectively, then detecting these pilot signals respectively by a main apparatus having an abnormality detecting function, and then comparing their relative values.Type: GrantFiled: August 11, 2000Date of Patent: February 10, 2004Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Toshihiro Nagayama, Kazuhiko Ikeda, Kazuhiko Takeyama, Koji Ishii, Takayoshi Morino
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Publication number: 20030232608Abstract: A receiver includes an amplifier which is responsive to a control signal to amplify an input signal and which outputs a corresponding amplified signal, a demodulator which demodulates the amplified signal to generate first and second components, a converter which generates first samples corresponding to the respective first and second components and which digitalizes the first sample, and an auto gain controller (AGC) which generates second samples corresponding to the digitalized first samples and which generates the control signal corresponding to the second samples.Type: ApplicationFiled: June 17, 2003Publication date: December 18, 2003Inventor: Shigeki Yamauchi
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Publication number: 20030228853Abstract: An analog/digital gain control device avoid some of the requirements associated with the nature of a closed-loop AGC circuits and which meets the remaining requirements without much difficulty uses an analog to digital conversion method that increases the number of effective ADC bits by compressing the baseband input analog signal using a logarithmic circuit. After the compressed analog signal is converted into a digital signal, a digital anti-log process or look-up table (LUT) is used to expand the digital signal back to the original linear scale. The word size of the output of the anti-log process is larger than the input word size due to the nature of the anti-log function. To reduce the word size of the digital signal an open loop normalization technique can be applied.Type: ApplicationFiled: December 27, 2002Publication date: December 11, 2003Applicant: InterDigital Technology CorporationInventors: Leonid Kazakevich, Rui Yang
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Publication number: 20030199258Abstract: A gain control part controls a gain varying part such that the gain of a received signal corresponds to the input level of the received signal in a first control mode and controls the gain varying part so as to fix the gain of the received signal in a second control mode. A setting part sets the gain control part in the first control mode in a communication state and sets the gain control part in the second control mode in a standby mode.Type: ApplicationFiled: March 7, 2003Publication date: October 23, 2003Applicant: Kabushiki Kaisha ToshibaInventors: Shigeru Matsuki, Hideki Aisaka
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Publication number: 20030181175Abstract: A receiver portion of a radio includes an analog circuit for determining a peak amplitude in a way that eliminates or reduces the effects of frequency errors that are introduced by crystals within filters and other devices. A voltage follower and a current mirror in which a MOSFET coupled to an output node produces a voltage across its gate to source terminals whose value is a function of a sum of the gate to source voltages of two MOSFET devices that receive a logarithm of an I modulated channel and a logarithm of a Q modulated channel, respectively.Type: ApplicationFiled: May 3, 2002Publication date: September 25, 2003Inventor: Hooman Darabi
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Publication number: 20030153291Abstract: An AGC circuit maintains a fixed level for starting AGC operation for an interference wave even if the local oscillation frequency is switched in a receiver that has a plurality of local oscillation frequencies. A frequency correction circuit for correcting the conversion gain characteristic from the antenna input up to the mixer output is provided for the input of a detector within the AGC control loop. The frequency correction circuit is provided with a trap circuit that has a fixed trap frequency by using an LC resonance circuit, for example.Type: ApplicationFiled: September 24, 2002Publication date: August 14, 2003Applicant: Pioneer CorporationInventor: Masahiro Tsushima
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Publication number: 20030153289Abstract: An automatic gain control (AGC) system (100) for a controlled gain receiver (1101) includes a magnitude generator (160) and a gain corrector (170). The magnitude generator (160) generates a binary voltage squared signal (165) having a binary value that is directly proportional to a recovered signal power of an intercepted signal (113). The gain corrector (170) determines an adjustment of a gain control value (195) as a multiple of increments that are approximately 3 decibel (dB), by shifting (475, 445) a reference threshold by one or more bits and comparing (485, 455) the shifted reference threshold to the binary voltage squared signal. An initial setting of a state of a step attenuator (114) during a track mode (172) is determined during a warm up mode (171) by comparing the binary voltage squared signal (165) to two different thresholds (245, 255). A filter (162) accommodates a variety of bandwidths and symbol rates by settings of an accumulator (505) and scaler (510) that are included in the filter (162).Type: ApplicationFiled: January 17, 2003Publication date: August 14, 2003Inventors: James David Hughes, John Richard Oakley, Clinton C. Powell
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Publication number: 20030148745Abstract: The invention relates to gain control for an amplifier for received radio signals by means of an automatic gain control signal (c). A down converter (103) produces signal components (I; Q) from received radio frequency signals (RF). The signal components (I; Q) are amplified in a respective amplifier (104; 105), low pass filtered (106; 107) and further amplified (108; 109). Then, the resulting signal components (IP-LP; Q−LP) are digitised in A/D-converters (110; 111 ) for further processing in a digital signal processor (112). The resulting signal components (IP-LP; QP-LP) are also fed to a respective signal level detector (113; 114) whose output signals ([I]; [Q]) are combined (115) into a combined signal (V&Sgr;). This signal (V&Sgr;) is forwarded to a gain control unti (116), which produces the automatic gain control signal (c).Type: ApplicationFiled: February 15, 2002Publication date: August 7, 2003Inventors: Christian Nystrom, Per Konradsson, Ari Grasbeck
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AGC circuit of an FM receiver that reduces interference while maintaining high reception sensitivity
Publication number: 20030139157Abstract: A first AGC voltage and a second AGC voltage are taken from the final stage of a radio-frequency circuit and the output side of a bandpass filter, respectively, and the gain of the radio-frequency circuit is controlled on the basis of the two AGC voltages. The pass-band width of the bandpass filter is approximately two times greater than the frequency interval of FM broadcast signals. The second AGC voltage is set higher than the first AGC voltage in the pass-band of the bandpass filter.Type: ApplicationFiled: January 16, 2003Publication date: July 24, 2003Applicant: Alps Electric Co., Ltd.Inventor: Atsushi Tominaga -
Publication number: 20030125091Abstract: A signal processing method and apparatus for obtaining a diversity gain in the communication system equipping the antenna array when a background noise is a space white noise or a non white noise is disclosed. The signal processing method and apparatus includes steps and functions of calculating a covariance matrix, estimating at least two time invariance vectors by performing an eigen-disintegration operation, estimating a channel vector and outputting a beam-forming vector. The present invention can improve the performance of the antenna array by using at least two time invariance vectors and it also increase a communication quality and quantity of the communication system, if the present invention is implemented to the wireless communication system.Type: ApplicationFiled: December 6, 2002Publication date: July 3, 2003Applicant: SAS TECHNOLOGIES CO., LTD.Inventors: Jin-Ho Choi, Sung-Soo Ahn
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Publication number: 20030124997Abstract: Disclosed is a linearization method in a mobile communication terminal wherein automatic gain control signals are divided into a plurality of entry regions, and which includes an initial value for a first entry region among the plurality of entry regions, a resolution constant and a slope character value for each entry region for generating a linear automatic gain control signal which guarantee a linearity of amplification gain of an amplifier.Type: ApplicationFiled: December 6, 2002Publication date: July 3, 2003Applicant: SAMSUNG ELECTRONICS CO., LTD.Inventor: Hung-Su Park
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Publication number: 20030114110Abstract: In a mobile communication device, an automatic frequency control method and apparatus are described that are capable of minimizing the number of timing changes that have to be made due to frequency errors without increasing the overall frequency sensitivity of the receiver unit. A frequency control unit of the present invention is capable of detecting a magnitude and direction of a timing drift that may arise from a frequency error. The automatic frequency control unit thereafter adjusts the frequency of the receiver unit in such a way so as to reverse the direction of the timing drift before it becomes too large. In this way, the number of timing changes that have to be made is reduced.Type: ApplicationFiled: December 19, 2001Publication date: June 19, 2003Inventors: Erik Dahlback, Jonas Ohlsson
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Patent number: 6577353Abstract: In a system for optimizing television reception by a television receiver receiving a diversity of input signals from a plurality of antennas, one of a plurality of combiners and television tuners selects the strongest combination of input signals for viewing and another scans the various combinations of input signals searching for a combination significantly stronger than the combination being viewed. A plurality of multiplexers selects the output signal of one combiner and transmits the selected signal to one of the tuners. A signal evaluation module evaluates the strength of the combinations of input signals and compares the strength of each combination of input signals to the strength of the viewing signal, looking for a superior signal. A control processor controls the combination of input signals selected by the combiners and the combiner output signal selected by the multiplexers.Type: GrantFiled: October 21, 1999Date of Patent: June 10, 2003Assignee: General Electric CompanyInventors: Kenneth Brakeley Welles, II, Mark Lewis Grabb, John Erik Hershey
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Publication number: 20030086398Abstract: The invention relates to a method and an Automatic Gain Control (AGC) unit for automatically minimizing the impact of inter-cell interference and/or interference between co-existing systems. The AGC unit is located within a transceiver unit, the transceiver unit is located in a radio base station in a Code Division Multiple Access (CDMA) telecommunication system and the AGC unit is connected to a High Power Amplifier SPA) unit adapted to transmit radio signals to a mobile terminal and to a Low Noise Amplifier (LNA) unit adapted to receive radio signals from a mobile terminal, the High Power Amplifier (HPA) unit comprises means for automatically adoption of a maximum output power level adapted to the current inter-cell interference and/or interference between co-existing systems wherein the AGC unit comprises means for controlling the output power levels of the output signals of the HPA unit by an AGC unit by using estimated interference related parameters.Type: ApplicationFiled: May 29, 2002Publication date: May 8, 2003Inventor: Kimmo Hiltunen
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Publication number: 20030078017Abstract: The invention concerns a mixer, in particular for an dual conversion receiver. The mixer includes a first variable transconductance stage (A) controlled by a high frequency carrier signal, this first stage including first (37) and second (38) terminals delivering a first signal; and a second stage (B) connected to said first terminal of the first stage including, in parallel, first (T32) and second (T33) switching means respectively controlled by first (in2) and second (in2b) phase opposition control signals at a first intermediate frequency (IF1), these first and second switching means being powered by a substantially equal current supplied by polarisation means (34). The mixer according to the invention is characterised in that it further includes means (T36) for modulating said first signal delivered by said first stage by means of a third control signal (in3) at a second intermediate frequency (IF2).Type: ApplicationFiled: September 30, 2002Publication date: April 24, 2003Applicant: ASULAB S.A.Inventor: Arnaud Casagrande
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Publication number: 20030064738Abstract: A control system for a linear feed-forward amplifier, using the ratio of measured spurious energy. Measuring receivers are coupled to two monitoring points to measure the spurious energy content in the error signal and at the main output of a feed-forward amplifier. The control system measures the ratio of these detected spurious, and uses this to optimize the settings of the second loop distortion cancellation. With the addition of an extra monitoring point, the same technique may also be used to control an adaptive predistorter prior to the main amplifier.Type: ApplicationFiled: October 29, 2001Publication date: April 3, 2003Inventors: Richard D. Posner, Ross James Wilkinson
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Patent number: 6542202Abstract: A video signal processing apparatus capable of improving signal level while reducing noise component no matter a video signal of what illuminance is input is provided, which apparatus includes a video signal amplifying circuit amplifying an input video signal and outputting a video signal of a predetermined image size in accordance with a gain control coefficient, a frame addition circuit connected to the video signal amplifying circuit for adding outputs of the video signal amplifying circuit by a predetermined number of frames, a first signal level detecting circuit connected to the video signal amplifying circuit and calculating the gain control coefficient and a multiplication coefficient in accordance with an output of the video signal amplifying circuit, and a first multiplier connected to the frame addition circuit and the first signal level detecting circuit and receiving as inputs an output of the frame addition circuit and the multiplication coefficient.Type: GrantFiled: August 17, 1999Date of Patent: April 1, 2003Assignee: Sharp Kabushiki KaishaInventors: Mitsuhiko Takeda, Mamoru Oda
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Publication number: 20030022642Abstract: 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: ApplicationFiled: July 24, 2002Publication date: January 30, 2003Applicant: LG Electronics Inc.Inventor: Soon-Ik Kwun
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Publication number: 20030017806Abstract: A system and method for providing a multi-layer, high density wireless communication architecture is disclosed. An example of a transceiver module is provided to better demonstrate this system and method. The transceiver module comprises a transmitting layer having a top portion and a bottom portion. A filter layer having a top portion and a bottom portion is also provided, wherein the top portion of the filter layer is adjacent to the bottom portion of the transmitting layer. A logic layer having a top portion and a bottom portion is provided, wherein the top portion is adjacent to the bottom portion of the filter layer and wherein logic is located on the bottom portion of the logic layer. A series of via structures of connected at specific locations of the transceiver module to allow for electrical connections between the transmitting layer and the filter layer, and the filter layer and the logic layer. Shield layers are also provided to prevent harmful electronic coupling between layers.Type: ApplicationFiled: June 29, 2001Publication date: January 23, 2003Inventors: Albert Sutono, Joy Laskar, Kyutae Lim
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Publication number: 20020187762Abstract: A system (10) and method (100) for digitizing a complete band of RF channels to allow simultaneous processing of more than one channel. Multiple tunable bandpass filters (14) are used for the particular channels to be processed. The filter outputs are combined (16) to form one signal for digitization (18). In another embodiment, an undesired signal is rejected (112) to provide more available power for a reception of a desired signal.Type: ApplicationFiled: June 6, 2001Publication date: December 12, 2002Inventors: J. William Whikehart, Yao H. Kuo
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Publication number: 20020137510Abstract: An apparatus for providing automatic gain control for use in a satellite terminal of a satellite communication system capable of transmitting a plurality of different modes of data. The apparatus includes a demodulator circuit having an analog to digital converter; a first variable attenuator having an attenuation value set on the basis of a measured power level of a predetermined data signal; and a second variable attenuator having an attenuation value set on the basis of the mode of data being received by the satellite terminal, where each of the data modes have a corresponding predetermined attenuation value associated therewith which is utilized as the attenuation value of the second variable attenuator when the satellite terminal receives the data mode.Type: ApplicationFiled: January 10, 2002Publication date: September 26, 2002Applicant: HUGHES ELECTRONICSInventors: Richard Sims, Richard Clewer, Neal Becker, Yezdi Antia, J. Mark Steber
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Publication number: 20020137483Abstract: Broadcast data receiver apparatus is provided. The apparatus includes a broadcast data receiver (BDR) connected to at least one LNB. The BDR provides a power supply to allow operation of the LNB. At least two analogue to digital converter sampling points are provided to allow the input and output voltages to be measured at the LNB, thereby allowing the voltage drop across a linear regulator (8) of the LNB to be assessed. Control means are provided to control the power supply from the BDR to the LNB in response to the voltage measurements obtained.Type: ApplicationFiled: March 21, 2002Publication date: September 26, 2002Applicant: PACE MICRO TECHNOLOGY PLC.Inventors: Mark Smith, Philip Yates, Colin Faulkner
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Publication number: 20020122512Abstract: In response to the base station receiving a received signal, the received signal having a first spread-spectrum signal and an interfering signal. An automatic gain control (AGC) circuit generates an AGC-output signal which is despread by a despreader and then processed as a received-power level. A power command signal is generated using a threshold test and the received-power level.Type: ApplicationFiled: February 7, 2002Publication date: September 5, 2002Applicant: InterDigital Technology CorporationInventor: Gary R. Lomp
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Publication number: 20020123311Abstract: A frequency offset correction value estimation section (21) receives a signal including a predetermined fixed pattern from a transmission side, thereafter, selects a combination of fixed patterns used in a process of estimating a frequency offset is selected depending on the state of a channel, and an estimation result of the frequency offset calculated by the combination of the fixed patterns is output as a correction value of a determined frequency offset. A frequency offset correction section (22) receives the received signal obtained after the correction is performed for correcting a frequency offset of the received signal on the basis of the correction value, and an equalizer (23) demodulates the received signal by using a predetermined algorithm.Type: ApplicationFiled: March 14, 2002Publication date: September 5, 2002Inventor: Takayuki Nagayasu
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Publication number: 20020115419Abstract: The invention aims to minimize the analogue/digital converter over-dimensioning within the framework of reception of signals originating from a satellite and exhibiting power levels which can vary over time. The invention proposes a technique of automatic gain control which handles the setting of the noise level associated with the amplified signal. The automatic gain control is achieved by neutralizing the signal received by the antenna, and by adjusting the gain during the neutralization of the signal received until a predetermined noise level is obtained at the end of the reception facility. The invention also pertains to a device comprising the means for implementing the method.Type: ApplicationFiled: February 13, 2002Publication date: August 22, 2002Inventors: Jean-Yves Le Naour, Patrice Hirtzlin, Olivier Mocquart