Abstract: A peak cancellation-crest factor reduction (PC-CFR) device includes a clipping unit configured to output a clipping error signal by clipping amplitude values of a first baseband complex signal based on a predetermined threshold value; a peak value determination unit configured to receive the clipping error signal, and determine a first amplitude value as a peak value when the first amplitude value is greater than a second amplitude value input before the first amplitude value and a third amplitude value input after the first amplitude value among amplitude values of the clipping error signal; a cancellation pulse generator (CPG) allocation unit configured to allocate the peak value to a CPG; and a subtractor configured to subtract a cancellation pulse generated from the CPG from the first baseband complex signal and output a second baseband complex signal with a reduced peak-to-average power ratio (PAPR).

Abstract: According to an aspect of the inventive concept, there is provided a crest factor reduction (CFR) core, including: a clipper clipping an input signal; a delay unit delaying the input signal; a first subtractor subtracting the clipped input signal from the delayed input signal; an error shaping filter filtering the subtracted signal for shaping an error which occurs by the clipping of the input signal; a digital filter filtering the input signal for cancelling noise of the input signal; and a second subtractor subtracting the filtered subtracted signal from the filtered input signal.

Abstract: A device and method that is configured to operate an active noise reduction system for a motor vehicle, where there is an active noise reduction system input signal that is related to the vehicle engine operation, and where the active noise reduction system comprises one or more adaptive filters that output noise reduction signals that are used to drive one or more transducers with their outputs directed to reduce engine noise. The engine harmonic noise level is estimated from the input signal that is related to the vehicle engine operation, and the output of the transducers is limited based on the estimate of the engine harmonic noise level.

Abstract: A system and method employ an arbiter-based automatic gain control (AGC) for managing a series of power adjustment circuits, such as amplifiers and/or attenuators. A central arbiter is employed for managing each stage of a series of power adjustment circuits, rather than each stage solely managing itself via a localized control loop. In one embodiment, a system comprises a series of gain stages each having at least one power adjustment circuit, such as at least one attenuator or amplifier. A power detector may be implemented to detect the power level of the output signal of each gain stage, and communicate information about the detected power levels for each stage to a central arbiter. Based at least in part on the received information, the arbiter controls each of the gain stages in a coordinated fashion.

Abstract: Techniques and devices are disclosed to provide multi-stage gain control in circuits or devices having two or more stages of signal amplification. A circuit with multi-stage gain control can include amplification stages coupled to receive an input signal and to produce an amplified output signal. Each amplification stage includes an amplifier that is adjustable in gain and a signal detector that is coupled to measure an output signal of the amplifier and to produce a detector signal indicative of a signal strength of the output signal of the amplifier. A gain control circuit is coupled to receive detector signals from the signal detectors in the amplification stages, respectively, and to control gains of the amplifiers of the amplification stages based on respective received detector signals, respectively.

Abstract: A system provides closed-loop gain control in a WCDMA mode and open loop control in an EDGE/GSM mode. Gain control is distributed across analog devices and a digital scaler in a wireless receiver. In the WCDMA mode, a loop filter generates an error signal that is forwarded to analog and digital control paths. The analog control path includes a first adder, a programmable hysteresis element, and a lookup table. The analog control signal is responsive to thresholds, which when used in conjunction with a previous gain value determine a new gain value. The digital control path includes a second adder, a programmable delay element, and a converter. A control word is responsive to a difference of the error signal, a calibration value, and the analog control signal. Blocker detection is provided in the WCDMA mode of operation. A controller sets system parameters using a state machine.

Abstract: Embodiments include a novel receiver architecture to optimize receiver performance in the presence of interference. In various embodiments, power estimation circuits are used to determine the exact nature of the interference and to optimize the performance correspondingly. Variable selectivity of at least one power estimation circuit is achieved using a filter with variable bandwidth, with power measurements taken using different bandwidth settings. Also, the actual method of optimizing the receiver performance is novel compared to the prior art in that the gain settings and the baseband filter order (stages to be used) will be optimized based on the nature of the interference as determined by the power detector measurements. For a device such as a cellular phone that operates in a dynamic and changing environment where interference is variable, embodiments advantageously provide the capability to modify the receiver's operational state depending on the interference.

Abstract: A device is provided for use of an antennal base formed of two antennas which pick up the emissions present and produce two radioelectric signals S1 and S2. These two signals are used to produce at least one intermediate-frequency signal Fl by demodulation of one of the two signals by the other (autotransposition). The demodulation is carried out by firstly transposing one of the signals, S1 for example, around a given frequency F1, the signal S2 being preserved around its initial central frequency F0. Thus, whatever the central frequency F0 of the emission picked up by the antennas, the demodulation produces a signal of central frequency F1, thereafter demodulated into a given intermediate frequency Fl by a local oscillator of constant frequency F2=F1+Fl. The device is applied to the production of a device for detecting emissions and for characterizing the emissions picked up.

Abstract: Aspects of a method and system for integrated blocker detection and automatic gain control are provided. In this regard, a communication device may generate one or more first signal strength indications based on a strength of a received signal at a first point in the analog front-end of the communication device. The communication device may generate one or more second signal strength indications based on a strength of the received signal at a second point in a digital processing module of the communication device. The first point in the analog front-end may be an input or an output of a down-conversion mixer. The second point in the digital processing module may be an output of an analog-to-digital converter or an output of a channel selection filter. The communication device may control, utilizing the first signal strength indication(s) and the second signal strength indication(s), a gain of one or more components of the communication device.

Abstract: Provided are a receiving apparatus and method for a wireless communication system using multiple antennas. A receiving method for a wireless communication system using multiple paths, the receiving method comprising: receiving signals through a predetermined number of multiple paths; sensing a carrier according to saturation state degrees of the signals, and providing saturation state information; calculating automatic gain components of the received signals by using the received signals and the saturation state information of the received signals; and performing a noise matching process to amplify noises on the predetermined multiple paths according to the automatic gain components during a predetermined period.

Abstract: An automatic gain control apparatus for a wireless receiver, including multiple variable gain amplifiers, one variable gain amplifier provided for each one of multiple receive chains and a gain controller to control a gain of the variable gain amplifiers provided for the plurality of receive chains. The gain controller includes multiple output level measurement units to measure an output level of a corresponding receive chain; a common gain determination unit to determine a common gain for each of the variable gain amplifiers based on a statistical value obtained from the output levels; multiple adjusted gain determination units, each adjusted gain determination unit determining an adjusted gain independently for each variable gain amplifier within a range narrower than the range of the common; and a gain setting unit to set a gain to each of the variable gain amplifiers based on the common gain and the adjusted gain.

Abstract: A system for controlling an RF gain of a receiver that reduces a time taken to maintain an input signal level at an optimum dynamic range is provided. The system includes a tuner that receives a radio frequency (RF) signal and down-converts the RF signal to an intermediate frequency (IF) signal, and a demodulator. The tuner includes a radio frequency programmable gain amplifier (RF_VGA), a filter and an IF programmable gain amplifier (IF_VGA). The demodulator includes an analog to digital converter (ADC), and an Automatic Gain Control (AGC) unit that (i) receives a digital signal and an IF gain of the IF_VGA. The ADC samples a filtered IF signal under oversampling conditions to obtain an oversampled signal that includes an in-band signal and an out-of-band signal. The AGC unit (ii) controls the RF_VGA, the IF_VGA and (iii) measures an RF energy of the RF signal.

Abstract: The present invention discloses apparatus and method for fast and robust automatic gain control (AGC). By using the power statistics and/or the amplitude statistics of multiple pairs of signed ADC outputs, the additional gain control can be determined and included in a statistics-aided AGC to successfully complete the AGC function for a received signal having a dynamic range up to 100 dB within a few micro-seconds.

Abstract: The present invention discloses an apparatus and method for power-saving switch on a pair of configurable analog-to-digital converters. The apparatus mainly comprises an antenna, an antenna switch, a zero-IF RF receiver, and a baseband demodulator. By using a first and a second control signal to control the ON/OFF states of a plurality of switches and a plurality of stage units in the configurable analog-to-digital converters, and the third control signal to control the ON/OFF states of a plurality of LNA stages and the gain of a plurality VGAs, the power saving of the analog-to-digital converter is easily achieved.

Abstract: A system provides closed-loop gain control in a WCDMA mode and open loop control in an EDGE/GSM mode. Gain control is distributed across analog devices and a digital scaler in a wireless receiver. In the WCDMA mode, a loop filter generates an error signal that is forwarded to analog and digital control paths. The analog control path includes a first adder, a programmable hysteresis element, and a lookup table. The analog control signal is responsive to thresholds, which when used in conjunction with a previous gain value determine a new gain value. The digital control path includes a second adder, a programmable delay element, and a converter. A control word is responsive to a difference of the error signal, a calibration value, and the analog control signal. Blocker detection is provided in the WCDMA mode of operation. A controller sets system parameters using a state machine.

Abstract: Disclosed is a radio frequency (RF) receiver for receiving a communication channel modulated on one or more carrier frequencies. The receiver may include a gain adjustable RF amplifier, a wideband signal power measurement circuit, and control logic. The control logic may be adapted to use outputs of one or more measurement circuits to classify interfering signals based on measured signal power and spectral proximity to the one or more channel carrier frequencies, and to adjust the gain of the radio frequency amplifier based on the classification.

Abstract: Disclosed is a radio frequency (RF) receiver for receiving a communication channel modulated on one or more carrier frequencies. The receiver may include a gain adjustable RF amplifier, a wideband signal power measurement circuit, and control logic. The control logic may be adapted to use outputs of one or more measurement circuits to classify interfering signals based on measured signal power and spectral proximity to the one or more channel carrier frequencies, and to adjust the gain of the radio frequency amplifier based on the classification.

Abstract: Embodiments include a novel receiver architecture to optimize receiver performance in the presence of interference. In various embodiments, power estimation circuits are used to determine the exact nature of the interference and to optimize the performance correspondingly. Variable selectivity of at least one power estimation circuit is achieved using a filter with variable bandwidth, with power measurements taken using different bandwidth settings. Also, the actual method of optimizing the receiver performance is novel compared to the prior art in that the gain settings and the baseband filter order (stages to be used) will be optimized based on the nature of the interference as determined by the power detector measurements. For a device such as a cellular phone that operates in a dynamic and changing environment where interference is variable, embodiments advantageously provide the capability to modify the receiver's operational state depending on the interference.

Abstract: An RF circuit is disclosed having a low-noise amplification (LNA) circuit and a bypass path that provides a bypass around the LNA circuit. In the amplification mode, the bypass path is open and the LNA circuit amplifies the receive signal in accordance within a power gain frequency response. During the amplification mode, the LNA circuit is tuned such that a power gain resonance frequency band of the power gain frequency response is within the receive frequency band. On the other hand, in the bypass mode, the bypass path is closed and the receive signal is not amplified but rather bypasses the LNA circuit. Also, during the bypass mode, the power gain frequency response of the LNA circuit is transposed to reduce or eliminate excessive insertion losses caused by the LNA circuit within the receive frequency band.

Abstract: A controller in a receiver monitors RSSI and AGC gain levels to determine signal conditions and adjust filter performance accordingly to optimize power consumption while providing acceptable signal quality. When RSSI level is high and AGC gain is low, a strong signal-of-interest is present. In this case, adaptive filter bias currents may be reduced raise the noise floor and degrade intermodulation to reduce power consumption because the strong signal-of-interest can tolerate the higher noise and distortion. When the RSSI level is low and AGC gain is high, a weak signal is present a low noise mode may be effected by increasing bias current to filters used to lower the noise floor, but intermodulation effects may still be tolerated so those filters may be cut back. Other cases are supported. RSSI and AGC gain level thresholds may be dynamically altered based on relative RSSI and AGC levels.

Abstract: A gain control circuit of the wireless receiver comprises a plurality of stages-amplifier, an analog gain control circuit, and a digital gain control circuit, wherein the analog gain control circuit generates an analog controlling voltage for regulating the gain of the post-amplifier by an analog gain controlling process, and the digital gain control circuit is used for determining a plurality of gain curves for the pre-amplifier, and the gain curves are all operating between the first default voltage and second default voltage. While the analog controlling voltage is over the first default voltage or second default voltage, the gain curve will be switched, thereby, the analog gain controlling process can be with the digital gain controlling process therein for improving the linearity of the gain regulation and reducing the transient response during the gain switching process.

Abstract: A receiver including an amplifier module, a control unit, a mixer and an IF amplifier is provided. The amplifier module, including multiple amplifier units with different gains, amplifies an input signal. The control unit enables at least one of the amplifier units according to a gain control signal, wherein the enabled at least one amplifier unit generates an output RF signal in response to the input signal. The mixer coupled with each amplifier unit in series down-converts the output RF signal into an IF signal according to a local oscillation frequency. The IF amplifier having a variable gain is coupled to the mixer for amplifying the IF signal to an output signal according to the gain control signal. The control unit obtains the gain control signal according to the output signal and a reference signal.

Abstract: A receiver has an input stage (LNA) that comprises, in a signal direction from an input (SI) to an output (SO), an input transistor (Q1) and an attenuator (D1, D2, R7-R12, C2-C5). The attenuator provides an attenuation that depends on a control signal (VDC). The input stage comprises a transistor-biasing circuit (R2) that biases the input transistor in dependence on the control signal.

Abstract: An apparatus such as a television signal receiver provides an AGC function which reduces cross-modulation distortion. According to an exemplary embodiment, the apparatus includes first and second amplifiers coupled in series and a gain control circuit. The gain control circuit controls the gains of the first and second amplifiers in response to the magnitude of the input signal. The gain of the first amplifier remains substantially unchaged at a first level while the magnitude of the input signal is within a first range. The gain of the second amplifier is gradually reduced in the first range. The gain of the first amplifier remains substantially unchaged at a second level, which is lower than the first level, while the magnitude of the input signal is within a second range. The gain of the second amplifier gradually reduced in the second range. The gain of first amplifier is gradually reduced at least in part of a third range while the magnitude of the input signal is within the third range.

Abstract: A gain control apparatus in a receiver of multiband OFDM system includes: an amplifier amplifying a received signal based on a first auto gain control signal; an analog-to-digital converter for converting the amplified signal into a digital signal; band reception signal extractor for extracting a signal of a desired reception band from the converted digital signal for each reception band, and controlling gain of the extracted signal according to a second auto gain control signal; a reception power detector for detecting a reception power value of whole band from the converted digital signal; and a multiband integration baseband processor for generating the first auto gain control signal by using the detected reception power value of the whole band, and generating the second auto gain control signal to be provided to the band reception signal extraction units, resource allocation information for each band and a reception power for each reception band.

Abstract: A method includes receiving data elements representative of constellation points of a modulated signal. Each data element includes a gain. The method also includes identifying a common gain value among the received data elements, and adjusting the data elements to include the common gain value.

Abstract: An enhanced programmable automatic level control loop comprising an input for receiving an input RF signal; a level modulator, wherein the level modulator receives the input RF signal and a control signal and wherein the level modulator produces a first signal; a mixer that receives the first signal and mixes it with an LO signal to produce a second signal; a programmable attenuator that receives the second signal and produces an output signal; a level detector that monitors RF power of the output signal and produces a DC voltage proportional to the RF power; and wherein the DC voltage is received at a loop amplifier which produces the control signal.

Abstract: In a radio including analog and digital portions, with at least one A/D converter between the analog and digital portions, and the selectivity of the radio at least partly implemented in the digital domain, an AGC controller sets a first variable gain amplifier (VGA) (302) to low gain upon a determination that a wide-band power estimation exceeds a wide-band threshold. The wide-band threshold is selected to reduce the occurrence of A/D converter saturation. If the wide-band power estimation is less than the wide-band threshold, then for each VGA (302) in the analog portion, a determination is made whether a narrow-band power estimate exceeds a narrow-band threshold, corresponding to that VGA (302), plus a hysteresis value, in which case that VGA (302) is set to low gain; or whether the narrow-band energy estimate is less than the narrow-band threshold minus a hysteresis value, in which case that VGA (302) is set to high gain.

Abstract: The invention provides a signal amplifying stage, used in a signal receiver. The signal amplifying stage has: a fixed-gain low noise amplifier (LNA), amplifying an input signal; a variable-gain LNA (VG-LNA) array, amplifying the input signal, including a plurality of parallel VG-LNAs, the VG-LNA array being parallel with the fixed-gain LNA; a variable-gain amplifier (VGA), being in series with the fixed-gain LNA and the VG-LNA array, for amplifying output signals from the fixed-gain LNA and the VG-LNA array to generate an output signal; an attenuator, being in parallel with a combination of the fixed-gain LNA, the VG-LNA array and the VGA, for attenuating the input signal to generate the output signal; and a control loop, coupled to the VGA and the attenuator, for detecting power levels of the output signal to enable and control the fixed-gain LNA, the VG-LNA array, the VGA and the attenuator.

Abstract: A receiving apparatus may achieve optimal RF and IF gain control while suppressing saturated amplification due to interference. The receiving apparatus includes an RF variable gain Amp that amplifies a received RF signal, a mixer that converts an output signal of the RF variable gain Amp into an IF signal, an IF variable gain Amp that amplifies the IF signal, a demodulator that demodulates an output signal of the IF variable gain Amp, and an AGC circuit. The AGC circuit sets a period of gain control for the RF variable gain Amp to be shorter than a period of gain control for the IF variable gain Amp when gains of the RF variable gain Amp and the IF variable gain Amp are controlled based on the output signal of the IF variable gain Amp.

Abstract: A radio-frequency receiver includes an RF amplification circuit which amplifies a received RF signal and generates an amplified RF signal, a mixing circuit which converts the amplified RF signal into an intermediate-frequency signal, an IF amplification circuit which generates an amplified IF signal, a first level detection circuit which detects a level of the amplified RF signal, a second level detection circuit which detects a level of the IF signal, a third level detection circuit which detects a level of the amplified IF signal, a RF reference level generation circuit which generates an RF reference level based on one of respective detection signal levels of the first and second level detection circuits, and an RF gain control circuits which controls an amplification gain of the RF amplification circuit so that a detection signal level of the third level detection circuit becomes equal to the RF reference level.

Abstract: A heterodyne receiver comprising a gain controllable RF mixer (14) which has a first input connected to a first local oscillator (16) and a second input connected to an RF input. The receiver comprises a peak detector (38) which detects a peak value of an input signal at the second input of the HF mixer and generates a digital control signal if it is determined that the peak value of the input signal is above a predetermined level. A digital automatic gain control circuit (34) decreases upon reception of the digital control signal the gain of the RF mixer.

Abstract: A transceiver suitable for larger scale of integration employs direct conversion reception for reducing the number of filters. Also, the number of VCOs is reduced by utilizing dividers to supply a receiver and a transmitter with locally oscillated signals at an RF band. Dividers each having a fixed division ratio are used for generating locally oscillated signals for the receiver, while a divider having a switchable division ratio are used for generating the locally oscillated signal for the transmitter. In addition, a variable gain amplifier for baseband signal is provided with a DC offset voltage detector and a DC offset canceling circuit for supporting high speed data communications to accomplish fast cancellation of a DC offset by eliminating intervention of a filter within a feedback loop for offset cancellation.

Abstract: Reception levels are measured in respective branches to compare the results of the measurements with one another to select the result of the measurement of a maximum reception level which is the highest reception level. The gains of variable gain amplifiers (6, 7) of all the branches including variable gain amplifiers (6, 7) included in a branch corresponding to the maximum reception level are adjusted to the same value such that output levels of the variable gain amplifiers (6, 7) are set to a preset target level.

Abstract: An improved multi-channel receiver for satellite broadcast applications or the like. In an exemplary embodiment, an AGC loop, under the control of an AGC processor, controls the gain of an analog sub-receiver adapted to simultaneously receive multiple signals to achieve a desired AGC setpoint signal intensity from the sub-receiver. Multiple digital demodulators, coupled to the sub-receiver by an analog-to-digital converter (ADC), demodulate the multiple received signals. The AGC controller, based upon which of the received signals are being demodulated, selects the desired AGC setpoint from a table of setpoints. The AGC controller may also provide selective power control to circuitry in the receiver and select the resolution of the ADC. The controller updates the AGC loop with step values selected from a group of values by an AGC control algorithm. Different groups of step values may be used by the controller depending on whether the signals are fading or not.

Abstract: An integrated circuit (IC) includes a plurality of RF receivers for receiving a corresponding one of a plurality of received signals. Each of the plurality of the RF receivers includes an AGC module that generates an automatic gain control (AGC) signal based on the strength of the corresponding one of the plurality of received signals, and a low noise amplifier that amplifies the corresponding one of the plurality of received signals based on the AGC signal. A processing module generates a power mode signal for adjusting a power consumption parameter of the IC, based on the AGC signals from each of the plurality of RF receivers.

Abstract: An improved multi-channel receiver for satellite broadcast applications or the like. In an exemplary embodiment, an AGC loop, under the control of an AGC processor, controls the gain of an analog sub-receiver adapted to simultaneously receive multiple signals to achieve a desired AGC setpoint signal intensity from the sub-receiver. Multiple digital demodulators, coupled to the sub-receiver by an analog-to-digital converter (ADC), demodulate the multiple received signals. The AGC controller, based upon which of the received signals are being demodulated, selects the desired AGC setpoint from a table of setpoints. The AGC controller may also provide selective power control to circuitry in the receiver and select the resolution of the ADC. The controller updates the AGC loop with step values selected from a group of values by an AGC control algorithm. Different groups of step values may be used by the controller depending on whether the signals are fading or not.

Abstract: An improved radio frequency receiver and method enabling the dynamic range of a radio frequency receiver to be extended are disclosed. In the receiver system, the effective received channel power is a combination of the wanted signal level, the noise floor and any in band spurious signals generated from blocking signals present at the input to the receiver system. When this total effective channel power is known, the front end gain is optimized by adaptively minimizing the total effective channel power. Since the wanted input signal power does not vary with the receiver gain setting, this optimizes the noise figure and input intercept point for the presented input signal conditions.

Abstract: A system (500) and method (400) are presented for calibrating an analog signal path (200) associated with an Ultra Wideband (UWB) receiver (103). The analog signal path includes a plurality of analog gain stages (210, 212-214, 216), a local oscillator mixer stage (211), a compensation stage (218), and a converter stage (219). An information signal includes whitened symbols (306). When a predetermined number of whitened symbols are accumulated for one of a plurality of gain configurations, an arithmetic mean is calculated and used an offset value. The offset value is retrieved whenever the gain configuration is activated and applied at the compensation stage to reduce the offset.

Abstract: A method and apparatus for improving signal reception in a receiver (100) by performing all-channel and/or on-channel estimations on a received signal so as to predict future RF environments. The prediction is achieved through the use of one or more detector systems (122, 124) positioned to sample and detect predetermined signal metrics of the received signal (103) prior to analog-to-digital conversion (112) and subsequent post-processing (114). Future estimations of the channel condition are thus generated prior to the arrival of the actual samples (115) at a controller section (116). The detectors (122, 124) provide triggers (123, 125) to the controller (116) so that active stages (130) within the receiver (100) can be adjusted and scaled as needed via a serial port interface (SPI) (126) based on signal conditions.

Abstract: A tuner down-converts a Radio Frequency (RF) wireless signal and outputs the converted signal. The tuner compensates for a TOP depending on a temperature and: detects a received signal strength depending on a RF output of the tuner and transmitting the detected strength to a gain control unit; measures an operating temperature of the tuner and transmits the measured temperature value; receives the measured temperature value to compare the received temperature value with a reference TOP value, compensating compensates for the TOP value depending on variation in temperature and outputting outputs the compensated value; and receives the compensated value to control the RF output based on the TOP value and the received signal strength.

Abstract: An apparatus, a carrier medium storing instructions to implement a method, and a method for controlling the gain of a radio receiver for receiving packets of information in a wireless network. The receiver is connected to an antenna subsystem and has receive signal path including a plurality of sections including a first section coupled to the antenna subsystem and a next section. Each section has an adjustable gain and is able to provide a measure of the signal strength at its output. The method includes waiting for a start of packet indication, providing a measure of the signal strength at the output of the first section and the next section, and adjusting the gains of the first and the next sections using the provided measured signal strengths. In one embodiment, the receive signal path includes a filter, the provided measure for the first section is before the filter, and the provided measure for the second section is after the filter.

Abstract: A receiver for processing a signal comprises a first amplifier circuit and a second amplifier circuit. The first amplifier circuit is operated in association with a first gain profile. The second amplifier circuit is operated in association with a second gain profile. The receiver further comprises a gain control circuit that determines a quality indicator associated with a modulated signal. The gain control circuit adjusts the first gain profile and the second gain profile based at least in part upon the determined quality indicator.

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.

Abstract: A received signal level is detected in each of a wide band, middle band, and narrow band and each detected signal is converted to a digital signal. A DSP 18 determines the enabled/disabled state of an LNA 3 and an attenuator 4 as well as a gain adjustment amount based on the signal level of each band. For example, the gain adjustment is not performed when the signal level of the narrow band including a desired frequency is not larger than a prescribed value even the signal level of the wide band or middle band is larger than a prescribed value. When the signal level of the narrow band is larger than the prescribed value exceeding a gain adjustable limit level in the attenuator 4, the gain of the LNA 3 is adjusted, while maintaining the gain adjustable amount in the attenuator 4 around the limit level, to reduce the gain as a whole.

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.

Abstract: In a radio including analog and digital portions, with at least one A/D Convener between the analog and digital portions, and the selectivity of the radio at least partly implemented in the digital domain, an AGC controller sets a first variable gain amplifier (VGA) (302) to low gain upon a determination that a wide-band power estimation exceeds a wide-band threshold. The wide-b and threshold is selected to reduce the occurrence of A/D converter saturation. If the wide-band power estimation is less than the wide-band threshold, then for each VGA (302) in the analog portion, a determination is made whether a narrow band power estimate exceeds a narrow-band threshold, corresponding to that VGA (302), plus a hysteresis value, in which case that VGA (302) is set to low gain; or whether the narrow-band energy estimate is less than the narrow-band threshold minus a hysteresis value, in which case that VGA (302) is set to high gain.

Abstract: Multi-segment gain control system. Apparatus is provided for a multi-segment gain control. The apparatus includes logic to convert a gain control signal to an exponential signal, and logic to map the exponential signal to multiple control signals that are used to control multiple gain stages to produce linear multi-segment gain control.

Abstract: A digital broadcast receiving apparatus, which has a receiving circuit for receiving a transmitted high frequency signal of a plurality of time division multiplexed programs, includes a circuit for selecting a better receiving characteristic condition while a desired program is not received.

Abstract: The invention relates to a method for increasing the sensitivity of a chain of amplifiers that comprises the steps of amplifying a signal by means of a first amplifier with a gain factor A1=A1,m*?A1, where A1,m denotes a constant gain factor and A1 denotes a gain factor variation with 1?A1,min?A1?A1,max, further amplifying the signal by means of a second amplifier with a controllable gain factor A2?A2,max, where variations A1 of the gain of the first amplifier are compensated by reducing the gain A2 of the second amplifier, so that the difference between the chain gain factor AC=A1*A2 and a target chain gain factor AT?AT,max becomes zero.