Abstract: A method for adjusting the signal to noise ratio of a receiver comprises measuring the peak power for an RF signal and determining, based on the measured peak power, whether the RF signal power is within a desired operating range. The method further includes adjusting an RF attenuation for the receiver, when it is determined that the RF signal power is not within the desired operating range. The method further comprises measuring a peak power for an IF signal, determining based on the measured peak power, whether the IF signal power is within a desired operating range, and adjusting an IF attenuation for the receiver, when it is determined that the IF signal peak power is not within the desired operating range.

Abstract: An electric wave receiving apparatus comprises: an antenna; an amplifier; filter circuits that extract signals in different frequency bands from an output of the amplifier; detector circuits that demodulate time codes from outputs of the filter circuits; automatic gain control circuits that generate gain control signals from the detector circuits; a selector that selects one gain control signal indicating a maximum signal level among the gain control signals; and an arithmetic processing section to be able to analyze the time codes of outputs of the plurality of detector circuits, wherein the one gain control signal is supplied to the amplifier to control an amplification factor of the amplifier so that signal levels output from detector circuits do not become excessive, and the arithmetic processing section selects an output to enable the analysis of the time code among the outputs of detector circuits to perform the analysis of the time code.

Abstract: In a transmission signal generating apparatus according to the present invention, a voice signal is amplified by a variable amplifier which varies its amplification factor in accordance with an amplitude control signal, and the amplitude of the voice signal output from the variable amplifier is limited by a variable limiter which varies its amplitude limiting range in accordance with the amplitude control signal. The thus amplified and amplitude-limited voice signal is supplied as a modulating signal to a voltage controlled oscillator constituting part of a PLL circuit which generates a transmission signal. A control signal generating section generates the amplitude control signal for the variable amplifier and the variable limiter by detecting the f/v sensitivity of the voltage controlled oscillator based on an output of a low pass filter constituting part of the PLL circuit.

Abstract: An intelligent automatic volume control technique (100) for a communication device is provided that takes a measurement of the background audio environment at the time a user manually selects the volume (102, 104). A user preference is established for the volume setting relative to the background audio level being experienced (106). The informational relationship is stored and used for automatic volume control (108). When the background noise changes (110), the automatic volume control makes an intelligent decision on changing the volume (116). The current background noise level, the initial user volume setting and the background noise level when that volume was set are all used in the volume change decision making process.

Abstract: Provided is a tuner, which comprises: an amplifier for amplifying received signals; a synchronization processor for mixing the received signals with oscillating frequency signals to output intermediate frequency signals of a selected channel; an intermediate frequency signal processor for filtering and amplifying the intermediate frequency signals; a demodulator for demodulating the amplified intermediate frequency signals and detecting intensity of the signals to output a gain control signal; and an attenuator for attenuating intensity of the received signals in response to the gain control signal.

Abstract: A direct conversion radio frequency (RF) tuner includes a mixer generating I and Q quadrature components. A phase detection circuit generates a phase error measurement between the I quadrature component and the Q quadrature component. A phase correction circuit corrects a phase of the Q component based on the phase error measurement, and outputs a phase-corrected Q quadrature component. An I quadrature component gain control circuit receives the I quadrature component and outputting an amplitude corrected I quadrature component. A Q quadrature component gain control circuit receives the phase corrected Q quadrature component and outputs an amplitude corrected Q quadrature component.

Abstract: An improved method and apparatus for using common mode feedback to maintain a predetermined DC level for an intermediate frequency output signal. A common mode feedback capacitor-select switch module is operable to use a bandwidth control signal from a radio interface of a wireless device to selectively connect a plurality of common mode feedback capacitors to an operational amplifier, thereby generating a common mode feedback signal as an input to an active mixer conversion gain module. The predetermined combination of common mode feedback capacitors is used in combination with a plurality of bandwidth capacitors to generate an overall capacitance that maintains the bandwidth of the system at a predetermined value.

Abstract: A frequency conversion receiver comprises a passive mixer, a Low-Noise Amplifier (LNA) and a balun. The low-noise amplifier generates an amplified single-ended signal responsive to a single-ended receiver input signal. The passive mixer generates a mixer output signal responsive to a differential mixer input signal and a four-phase local oscillator signal. The balun transforms the amplified singled-ended signal into the differential mixer input signal, the balun having a first winding coupled to an output of the low-noise amplifier and a second winding coupled to an input of the passive mixer, the second winding having more turns than the first winding. The turn ratio of the second winding to the first winding provides gain compensation to the low-noise amplifier, and in conjunction with the low-noise amplifier and the passive mixer, provides a desired gain to the receiver and linearity over a dynamic range of the receiver input signal.

Abstract: A digital level control circuit, such as an Automatic Gain Control, includes a plurality of digitally selectable signal levels with transitions between levels gradually varied to avoid signal output level discontinuities. An up/down counter may be used to incrementally stepwise transition an output signal between the digitally selectable output levels. Stepwise application of a control signal to the appropriate switching elements (e.g., FETs) forming an attenuator circuit may be implemented to moderate a switching time of the switching elements to provide a more gradual transition between element operating states. A deglitch circuit may be employed to latch the switching elements to achieve the desired state at the end of a desired switching transition period.

Abstract: An improved adaptive mixer for use in the down conversion module of a wireless transceiver. The adaptive mixer comprises a conversion gain module that is operable to receive a radio frequency signal and to generate an intermediate frequency that is provided to a radio interface in a wireless transceiver. The radio interface is operable to generate a gain control signal and a bandwidth control signal. The gain control signal is provided to a gain control module that is operable to select a combination of load resistance values that will provide a predetermined gain level for the output of the conversion gain module. Bandwidth control logic in the adaptive mixer uses the bandwidth control signal to operably connect a plurality of bandwidth control capacitors to the conversion gain module to control the bandwidth of the output signal.

Abstract: An RF receiver comprising a radio-frequency (RF) down-converter for receiving and down-converting an input RF signal to a lower frequency analog signal (e.g., an IF signal or baseband signal) and analog processing circuitry for receiving the lower frequency analog signal from the RF down-converter and outputting a processed analog signal. The processed analog signal includes a DC-offset signal introduced by the RF down-converter and the analog processing circuitry. The RF receiver also comprises an ADC circuit for converting the processed analog signal to a sequence of digital samples and a DC-offset correction circuit for detecting the DC-offset signal in a digital output signal of the RF receiver. The DC-offset correction circuit adds a DC-offset correction signal to the lower frequency analog signal. Adding the DC-offset correction signal to the lower frequency analog signal reduces the DC-offset signal in the processed analog signal at the analog processing circuitry output.

Abstract: A system and method used for controlling an attenuator in a two-way communication device (100, 200) includes the steps of measuring (211) a relative signal strength indication (RSSI) at the input of the two-way communications device. The RSSI measurement is then compared (213, 217, 223) to both at least one predetermined interference threshold value (T1, T2, T3) and a selective squelch state (219, 225) for determining whether to switch an in-line attenuator to the input of the two-way communications device. The invention provides a method by which an attenuator may be used only when interference is present without it being continually switched in-line to cause signal degradation.

Abstract: Effective bandwidth of a communication link is determined in a heterogeneous, packet switched network between a source and a destination, where effective bandwidth is defined as the actual available bandwidth between the server and the client, minus the overhead of the various network protocols used to transmit the data. The method includes maintaining a database of bandwidth parameters indexed by destination address, and using the database when setting a communication channel.

Abstract: A tuning circuit having an amplitude-varying function is disclosed that comprises a coil, a capacitor, and a resistance-adjusting element connected in parallel to the coil and the capacitor for varying resistance at time of resonance of the tuning circuit, wherein the amplitude of an output signal of the tuning circuit is varied by varying the resistance with the resistance-adjusting element.

Abstract: A circuit and method for adjusting the operating characteristics of a tuner in accordance with information derived from the signals being processed by the tuner. Depending upon signal type and/or signal strength, the power levels of certain components are adjusted and/or certain components are added to (or subtracted from) the tuner.

Abstract: An improved method and apparatus for using common mode feedback to maintain a predetermined DC level for an intermediate frequency output signal. A common mode feedback capacitor-select switch module is operable to use a bandwidth control signal from a radio interface of a wireless device to selectively connect a plurality of common mode feedback capacitors to an operational amplifier, thereby generating a common mode feedback signal as an input to an active mixer conversion gain module. The predetermined combination of common mode feedback capacitors is used in combination with a plurality of bandwidth capacitors to generate an overall capacitance that maintains the bandwidth of the system at a predetermined value.

Abstract: A transmission system or apparatus includes a transmitter or source of transmitted RF or microwave power which is selectively connectable via a transmitter connector to an antenna having an antenna feed via an antenna connector so that a variety of antennas with differing characteristics can be used with a given transmitter. Each antenna preferably has a marker or indicating element incorporated into the antenna feed. The marker or indicating element includes a physically measurable property or parameter corresponding to a physical characteristic of the attached antenna. In the preferred embodiment, the indicating element is a resistance connected in parallel with the antenna feed and having a selected resistance value (e.g., in ohms) which indicates the physical characteristic of gain for antenna. The transmission system also includes an indicating element sensor configured to sense or measure the marker or indicating element and generate a transmitter control signal in response to that measurement.

Abstract: An apparatus and a method of controlling a low noise amplifier of a receiver, in which the activation of the low noise amplifier is automatically controlled using an automatic gain control current for a received signal. The apparatus may include a low noise amplifier, an automatic gain control current detector, a switch, and a controller. The low noise amplifier amplifies a noise-free received signal. The automatic gain control current detector detects an automatic gain control current based on the level of a signal output from the low noise amplifier. The switch controls the activation of the low noise amplifier. The controller controls the operation of the switch according to the automatic gain control current detected by the automatic gain control current detector.

Abstract: An apparatus for controlling speaker volume of a mobile terminal is provided. The apparatus comprises a voice outputting unit for converting a radio signal to an audio signal and feeding the audio signal to a speaker; a pressure sensing unit for sensing a contact pressure applied by a user to produce a control signal; and an output control unit for controlling the speaker volume based on the control signal.

Abstract: A direct conversion radio frequency (RF) tuner includes a mixer generating I and Q quadrature components. A phase detection circuit generates a phase error measurement between the I quadrature component and the Q quadrature component. A phase correction circuit corrects a phase of the Q component based on the phase error measurement, and outputs a phase-corrected Q quadrature component. An I quadrature component gain control circuit receives the I quadrature component and outputting an amplitude corrected I quadrature component. A Q quadrature component gain control circuit receives the phase corrected Q quadrature component and outputs an amplitude corrected Q quadrature component.

Abstract: The invention relates to a cellular phone terminal system, and in particular to a method for changing timbre of a voice signal during conversation in a cellular phone terminal system having a filter for filtering a PCM input signal. The method comprises the steps of: waiting for a timbre selector key input for a desired timbre when a timbre converter key is inputted during conversation; and setting a filter coefficient of the filter correspondingly to the timbre selector key input and filtering the PCM signal to change timbre.

Abstract: Apparatus, article of manufacture, and method for automatic adjustment of sound reproduction settings on an audio or audio/visual system based on listener preference and/or experience is provided. In one embodiment, an audio system includes an apparatus for adjusting an output parameter of the audio system, the apparatus comprising: a memory for storing a stored output parameter setting associated with an audio program being played on the audio system; and a processor configured to: determine whether a stored output parameter setting is associated with an audio program being processed on the audio system; if the stored output parameter setting is associated with the audio program, compare the stored output parameter setting to a saved output parameter setting; and if the stored output parameter setting is greater than the saved output parameter setting, change the output parameter to the stored output parameter setting.

Abstract: In a communication terminal that is capable of carrying out communications based on a plurality of communication standards, for example, a cellular phone, information representing a reception carrier frequency of a wireless channel being received by a cellular-phone functional block is output from a CPU to a contactless-IC-card-reader/writer functional block. In the contactless-IC-card-reader/writer functional block, a controller controls a switching circuit to switch a transmission carrier frequency being used so that harmonic components of an electromagnetic wave radiated from a coil antenna will not work as an electromagnetic-interference wave that affects reception sensitivity of the cellular-phone functional block.

Abstract: The invention relates to a hearing aid, preferably a programmable hearing aid, having at least one microphone (1), at least one signal processor with at least one channel, an output amplifier (9) and an output transducer (10), at least one of the channels containing a signal processing circuit (4) with at least one percentile estimator (6) for the continuous determination or calculation of at least one percentile value of the input signal from a continuous analysis and evaluation of the frequency and/or amplitude distribution of the input signal, whereby the percentile value(s) serve either directly or indirectly as control signals for controlling the gain and/or the frequency response of the electronic processing circuit, the percentile estimator (6) consisting essentially of a comparator stage (12) with two inputs and two outputs, the first input being directly or indirectly connected to the input of the hearing aid, its two outputs controlling a first control stage (13) the output signals of which control

Abstract: A wireless LAN base station is provided with a noise signal scanning antenna separately from a wireless signal reception antenna. An attenuation circuit section attenuates the received signal from the noise scanning antenna according to an attenuation factor from an attenuation factor storage section. A distance setting storage section stores a distance between the wireless signal reception antenna and the noise scanning antenna. An attenuation factor storage section holds pieces of data each of which indicates the relationship between the distance between the antennas and an attenuation factor in the form of a table. An attenuation circuit section employs the attenuation factor so as to attenuate the received signal from the noise signal scanning antenna. A subtraction circuit section subtracts an output signal of the attenuation circuit section from the signal from the wireless signal reception antenna, and reduces or eliminates a noise from the received signal from the wireless signal reception antenna.

Abstract: In a portable telephone which transmits and receives data having at least one of a voice signal and an image datum which are radio signals, the controlling device controls an amplifier so that a user can hear, at a first state that an ear is not near to a speaker, the voice from the speaker when the data from a base station includes a discrimination datum which represents the image datum. The controlling device controls the amplifier so that the user can hear, at a second state that the ear is near to the speaker, the voice from the speaker when the data from the base station does not include the discrimination datum which represents the image datum.

Abstract: A radio receiver (100) has an IF (intermediate frequency) filter (200) for dynamically adjusting its intermediate frequency. The filter (200) includes a filter bank (301), power/amplitude estimator circuits (308, 310, 312), and weighting circuits (314, 316, 318). The filter bank (301) generates sub-bands, each sub-band having a predetermined frequency range. The power/amplitude estimators (308, 310, 312) provide an estimated power/amplitude in each sub-band. A filter control (320) uses the power/amplitude estimates to determine a percentage of each sub-band signal that is permitted to be coupled a summation circuit (319). The summation circuit (319) sums the weighted sub-band signals to provide a filtered output signal to a demodulator (212).

Abstract: 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.

Abstract: A digital automatic gain control linearizer for controlling a variable gain control element for automatically controlling gain, using an analog signal obtained by converting input digital data includes a memory an average calculation unit. The memory outputs upper and lower limit data corresponding respectively to the upper and lower limits of a binary data range which can be expressed by a plurality of upper bits forming the digital data. The average calculation unit calculates the average of one and other data of the upper and lower limit data, and repeats average calculation a predetermined number of times using the calculated average at least one of the upper limit data and the lower limit data. Average calculation is repeated a number of times corresponding to the lower-bit value of the digital data except for the plurality of upper bits, and the variable gain control element is controlled in accordance with the average calculated by the average calculation unit.

Abstract: A radio receiver (100) has an IF (intermediate frequency) filter (200) for dynamically adjusting its intermediate frequency. The filter (200) includes a filter bank (301), power/amplitude estimator circuits (308, 310, 312), and weighting circuits (314, 316, 318). The filter bank (301) generates sub-bands, each sub-band having a predetermined frequency range. The power/amplitude estimators (308, 310, 312) provide an estimated power/amplitude in each sub-band. A filter control (320) uses the power/amplitude estimates to determine a percentage of each sub-band signal that is permitted to be coupled a summation circuit (319). The summation circuit (319) sums the weighted sub-band signals to provide a filtered output signal to a demodulator (212).

Abstract: A receiver in a communication system is coupled to a transmission channel for receiving communication signals transmitted over a transmission channel. The receiver includes signal receiving electronics for receiving communication signals directed to the receiver. The receiver also includes a controller, responsive to the receipt of a communication signal by the signal receiving electronics, to provide an enunciator enable signal, and a clock signal generator for generating a clock signal. The receiver further includes an enunciator coupled to the clock signal generator, for producing an electronic sound signal. The enunciator includes a volume control module for receiving a first periodic signal and providing a volume control signal. The enunciator also includes a divider for receiving the clock signal and providing a corresponding output signal having a frequency corresponding to the frequency of the clock signal frequency divided by a divider value.

Abstract: Method and system for controlling operation of radiotelephone speaker volume and/or microphone gain. Using signals from one or more proximity sensors associated with the radiotelephone device, the device determines if a radiotelephone user is within a selected proximity zone for the device. If the user is within the proximity zone, the system adjusts the speaker volume control and/or the microphone gain control according to an estimated user-device distance. If the user is beyond the proximity zone, the system may adjust the speaker volume and/or microphone gain to its maximum value, may provide a notification that the user not within the proximity zone, or may disable the speaker and/or microphone. Several varieties of proximity sensors are used, individually and in combination.

Abstract: A variable gain amplifier device controlled by a first gain control signal comprises a gain controlled amplifier having a gain and including a differential pair of first and second MOS type transistors configured to operate in a weak inversion region; and a control signal converter configured to convert the first gain control signal into a second gain control signal, and supply the second gain control signal to the gain controlled amplifier to exponentially vary the gain with respect to the first gain control signal.

Abstract: An amplifier (125) having automatic gain control (AGC) includes a gain stage (220), having a variable amplifier (215), for amplifying a signal received by the amplifier (125). The amplifier (125) also includes an AGC circuit (228) that adjusts amplification of the gain stage (220) and that includes a manual switch (246) having first and second switch settings. Sequential operation from the first switch setting to the second switch setting causes the AGC circuit (228) to automatically and correctly set the gain of the amplifier (125) without further human intervention.

Abstract: A comparing unit 18, when a radio unit 1 receives a radio signal, compares an ambient noise level detected by a noise sensor 17 with a preset threshold value. If the ambient noise level is smaller than the threshold value, the comparing unit 18 outputs a set value signal SH, and sets a receiving voice level set value of a receiving voice level setting unit 19 to “SMALL”, a transmitting voice level set value of a transmitting voice level setting unit 20 to “LARGE” and a calling sound level set value of a calling sound level setting unit 22 to “SMALL”, respectively.

Abstract: A radio receiver with a potentiometer as the volume control is described, wherein an unintentional displacement of the potentiometer during the switched-off phase becomes effective only with a delay when the radio receiver is switched on by means of a switch which is separate from the potentiometer.

Abstract: A cable modem is configured to include a tuner having a front end which includes a duplex filter stage and a decoupler stage and a rear end which includes a single conversion tuner. The duplex filter stage couples the tuner to a network, a computer system and the front end decoupler stage. Signals received from the network are directed by the front end duplex filter stage to the front end decoupler stage while signals received from the computer system are directed by the front end duplex filter stage to the network. The front end decoupler stage passes RF signals received at an input thereof to an input of the single conversion tuner coupled to an output of the front end decoupler circuit. The single conversion tuner selects, from the plurality of RF signals received thereby, an RF signal to be converted into an IF signal for output therefrom while rejecting the remainder of the plurality of RF signals.