Abstract: Disclosed herein are systems and methods for recovering a sub-carrier signal from a multiplexed signal having an embedded pilot tone signal. The recovery system includes circuitry for recovering a pilot signal from the received multiplexed signal, for generating a frequency-doubled signal from the recovered pilot signal, and for phase-shifting the frequency-doubled signal by a pre-determined phase difference from the embedded pilot tone signal. Another recovery system includes circuitry for recovering a pilot signal from the received multiplexed signal, for phase-shifting the pilot signal by a pre-determined phase difference from the embedded pilot tone signal, and for generating a frequency-doubled signal from the phase-shifted signal.

Abstract: The present invention relates to a method, an Automatic Gain Control control unit and a receiver for Noise change output signalling. It also relates to an Adjustment Unit, a receiver and a base band detector for adjustment of an Automatic Gain Control output signal on the basis of the Noise change output signalling. In a first step a receiver receives a communication input signal. In a second step at least one Automatic Gain Control attenuator or amplifier in the receiver attenuates the communication input signal. In a third step the receiver produces at least one AGC output signal. In a fourth step at least one AGC control unit in the receiver initiates a changed gain setting on the receiver, when the level of an AGC control unit input signal received by the unit has been below a first threshold level or above a second threshold level during a detection interval.

Abstract: An interference signal reducing apparatus of a wireless communication system divides a signal that is input through a receiving antenna into a first signal and a second signal having a magnitude larger than that of the first signal and detects a frequency and a magnitude of an interference signal from the first signal, thereby generating an interference removal signal and then adds an interference removal signal to the signal that is input through the receiving antenna and thus reduces a magnitude of the interference signal.

Abstract: Disclosed herein are systems and methods for recovering a sub-carrier signal from a multiplexed signal having an embedded pilot tone signal. The recovery system includes circuitry for recovering a pilot signal from the received multiplexed signal, for generating a frequency-doubled signal from the recovered pilot signal, and for phase-shifting the frequency-doubled signal by a pre-determined phase difference from the embedded pilot tone signal. Another recovery system includes circuitry for recovering a pilot signal from the received multiplexed signal, for phase-shifting the pilot signal by a pre-determined phase difference from the embedded pilot tone signal, and for generating a frequency-doubled signal from the phase-shifted signal.

Abstract: Provided are apparatus and method for receiving signals in a wireless communication system.

Abstract: Methods and apparatus to perform radio frequency (RF) analog-to-digital conversion are described. According to one example, a receiver includes an amplifier to amplify received analog RF signals and a mixer-free circuit for converting the received analog RF signals to digital signals.

Abstract: A portable electronic unit has a transmission-side section that transmits a signal and a receiving-side section that receives a signal from the transmission-side section. The receiving-side section includes a gain control amplification device that amplifies and outputs a signal from the transmission-side section. The gain control amplification device has a first amplification circuit that amplifies and outputs a signal from the transmission-side section, a detection circuit that detects and outputs a signal from the first amplification circuit, a gain control amplification circuit that amplifies and outputs a signal from the detection circuit, and a gain control circuit that controls a gain in the gain control amplification circuit in response to a level of a signal from the detection circuit.

Abstract: Methods and apparatus to perform radio frequency (RF) analog-to-digital conversion are described. According to one example, a receiver includes an amplifier to amplify received analog RF signals and a mixer-free circuit for converting the received analog RF signals to digital signals.

Abstract: Described herein is a method of automatic gain control and simultaneous digital correction of three types of variations in I/Q receivers: gain imbalance, phase imbalance, and DC offset. Three adaptation loops can operate simultaneously and use the output of an analog to digital converter (ADC) as their input, with the output driving digitally controllable analog components. With appropriate knowledge of signal statistics, the algorithm automatically optimally fills the ADC's full input signal range, providing an automatic gain control function and thus maximizing the signal-to-quantization-noise ratio. In so doing, it corrects gain imbalances between I and Q paths, while additional circuitry corrects DC offsets and phase imbalances.

Abstract: Disclosed herein are systems and methods for recovering a sub-carrier signal from a multiplexed signal having an embedded pilot tone signal. The recovery system includes circuitry for recovering a pilot signal from the received multiplexed signal, for generating a frequency-doubled signal from the recovered pilot signal, and for phase-shifting the frequency-doubled signal by a pre-determined phase difference from the embedded pilot tone signal. Another recovery system includes circuitry for recovering a pilot signal from the received multiplexed signal, for phase-shifting the pilot signal by a pre-determined phase difference from the embedded pilot tone signal, and for generating a frequency-doubled signal from the phase-shifted signal.

Abstract: A signal gain control circuit. A gain stage receives and amplifies an analog signal by a first gain factor adjusted by a gain adjusting signal in a periodic manner with a first period, and outputs an amplified signal. An analog to digital converter converts the amplified signal to a first digital signal comprising a stream of samples. An amplifying device adjusts a second gain factor in a periodic manner with a second period in accordance with a characteristic metric of the distribution of the first digital signal and multiplying the first digital signal by the second gain factor to generate a second digital signal. A first gain adjusting device detects a strength of the second digital signal and generates the gain adjusting signal according to the signal strength of the second digital signal in a periodic manner with the first period.

Abstract: A radio receiver comprises an LNA which amplifies An RF signal, a quadrature demodulator which directly demodulates the amplified RF signal into a B/B signal, using a LO signal, a VGA which amplifies the B/B signal, a DC offset canceller which executes feedback control on the amplified B/B signal, and a gain controller which controls at least the gain of the LNA, the gain controller including a signal intensity detector which detects the intensity of the amplified B/B signal, a gain selector which selects a desired one of preset gains on the basis of the detected intensity, a timing controller which controls timing of switching to the selected desired gain, and a gain control signal generator which changes, in accordance with the controlled timing, the interval at which an LNA gain control signal is generated.

Abstract: A radio receiver comprises an LNA which amplifies An RF signal, a quadrature demodulator which directly demodulates the amplified RF signal into a B/B signal, using a LO signal, a VGA which amplifies the B/B signal, a DC offset canceller which executes feedback control on the amplified B/B signal, and a gain controller which controls at least the gain of the LNA, the gain controller including a signal intensity detector which detects the intensity of the amplified B/B signal, a gain selector which selects a desired one of preset gains on the basis of the detected intensity, a timing controller which controls timing of switching to the selected desired gain, and a gain control signal generator which changes, in accordance with the controlled timing, the interval at which an LNA gain control signal is generated.

Abstract: An audio signal processing apparatus and method in which power supplied to a power amplifier is controlled in a wide range from a small output power level to a large output power level in accordance with input audio signals. The apparatus includes an interface unit configured to convert input audio signals to digital audio signals, a digital signal processor configured to process the digital audio signals converted by the interface unit, a volume unit configured to adjust a volume of the digital audio signal processed by the digital signal processor and generate at least one volume modulated signal, and an amplifier configured to amplify the at least one volume modulated signal, wherein power supplied to the amplifier is based on a level of the digital audio signal converted by the interface unit and the at least one volume modulated signal from the volume unit.

Abstract: Systems and techniques are disclosed relating to communications. The systems and techniques involve supporting communications between a base station and a plurality of users by establishing an overhead channel between one of the users and the base station, and transmitting data from said one of the users to the base station on the overhead channel in response to a message having a threshold value related to a loading on the base station by the users. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or the meaning of the claims.

Abstract: A method of and device for automatic gain control (AGC) incorporates digitally controlled variable gain amplifiers (VGAs). An AGC circuit comprises multiple AGC stages, where each of the stages comprises: respective I and Q VGAs; a detector for detecting respective I and Q output signals received from the respective I and Q VGAs; an analogue to digital converter for converting the detected I and Q output signals; and a digital engine for adjusting the respective I and Q VGAs for differences between the detected I and Q output signals and a reference signal. Using staggered AGCs incorporating respective I and Q VGAs splits the total dynamic range between n stages, allowing for reduced gain requirements in the VGAs. Using digital control for setting the VGA gains reduces analogue variations and I/Q gain imbalances. Using multiple update rates or magnitudes in the VGA control improves dynamic settling time.

Abstract: A transceiver according to some embodiments of the present invention receives data from a plurality of frequency separated transmission channels from a complementary transmitter of another transceiver and adjusts the power output of certain channels in a transmitter of the receiver. Upon start-up, the power output levels of signals in individual channels in the transmitter can be preset. A power balance can determine new power output levels of the transmitter from parameters in the receiver while receiving data transmitted by a similarly situated complementary transmitter in a second transceiver coupled to the transceiver. In some embodiments, a complementary receiver of the other transceiver determines the power outputs of the transmitter and the power levels are transmitted to the transmitter by the other transceiver.

Abstract: The present invention improves an inconvenience of the conventional system in that cordless hand sets must be registered in advance, and reduces the power consumption in the waiting state. The digital codeless telephone according to the invention uses a public telephone network. In the system of the invention, a transmitting party calls a receiving party by means of a message having a group identification code for direct communication between personal stations and information for a waiting mode change request. The system makes the receiving party prepare for receiving, by an event that the receiving party changes the waiting mode according to the message.

Abstract: Apparatus and methods for eliminating DC offset in a wireless communication device operable on a continuous basis or on a sampled basis. In a receive channel, the output of a forward variable gain amplifier is fed back to an RC circuit to charge the capacitor (C) to a voltage dependent on the DC offset in the variable gain amplifier output. The voltage on the capacitor is amplified and summed with the input to the variable gain amplifier. The RC circuit is configured to provide a high gain feedback at DC and very low frequencies, but very low gain at signal frequencies. Preferably the output of the forward variable gain amplifier is fed back to the RC circuit with a gain that is inversely proportional to the forward gain. Disconnection of the capacitor and feedback of the capacitor voltage provides sampled operation. Various embellishments and sample applications are disclosed.

Abstract: In receiver systems for cellular phones using the W-CDMA method, the change in DC voltage occurring when the gain of a programmable gain amplifier (PGA circuit) is switched to adjust the gain for a received signal, can be suppressed. A sample-and-hold circuit is installed containing a “sample” mode for directly outputting a signal from the PGA section and also containing a “hold” mode for outputting the electric charge of a specified voltage stored in a capacitor. This sample-and-hold circuit normally operates in “sample” mode so the output signal from the PGA section is directly output, but is operated in “hold” mode at the gain switching timing of the PGA circuit, so that the electric charge of the specified voltage stored in the capacitor is output for a specified length of time (equal to the time required for the DC voltage change to converge to a stable level).

Abstract: An automatic gain control circuit optimizes a follow-up performance of an automatic gain control loop to thus assure a good receiving operation. A generation timing or a generation period of a control signal GC is decided in response to a lapsed time in operation of the receiver device. For a predetermined rise period from a non-operated state to the steady operation state when a power supply is shifted from its OFF state to its ON state (power supply is turned ON) or at the time of intermittent receiving operation, the generation period of the control signal GC is set shorter than the generation period in a steady operation state so as to accelerate the response characteristic of the automatic gain control gain rather than the steady operation condition, and then switched to the generation period in the steady operation state after a predetermined time.

Abstract: A hearing compensation system for the hearing impaired comprises a plurality of bandpass filters having an input connected to an input transducer and each bandpass filter having an output connected to the input of one of a plurality of multiplicative AGC circuits whose outputs are summed together and connected to the input of an output transducer. The multiplicative AGC circuits attenuate acoustic signals having a constant background level without the loss of speech intelligibility. The identification of the background noise portion of the acoustic signal is made by the constancy of the envelope of the input signal in each of the several frequency bands. The background noise that will be suppressed includes multi-talker speech babble, fan noise, feedback whistle, florescent light hum, and white noise.

Abstract: A method, apparatus and system for use in determining a pilot-to-data power ratio by receiving a data symbol (122) having a data amplitude, receiving a pilot signal (124) having a pilot amplitude, reverse training (350) an automatic gain (154) based on the data amplitude and the pilot amplitude, and determining a pilot-to-data power ratio (250) according to the reverse training of the automatic gain. In some embodiments the method further compensates for channel fading in the data symbol by providing for channel correction (340) on the data symbol, providing for channel correction (344) on the pilot signal and dividing the channel corrected data symbol by the channel corrected pilot signal providing a fading compensated data symbol, where the fading compensated data symbol (150) is provided prior to reverse training such that the reverse training is based at least in part on the fading compensated data symbol.

Abstract: A reception apparatus and a reception processing method are proposed to improve a reception characteristic by compensating deterioration of transmission quality independently of the traveling speed of a terminal. When a transmission signal sent via a radio transmission path is received and data is demodulated by carrying out various kinds of reception processing on the received signal, the present invention can perform reception processing best suited to a radio transmission path whose state changes according to the traveling speed of the terminal itself by receiving traveling speed information from speed detection means for detecting the traveling speed of the terminal itself and controlling reception processing on the reception signal according to the traveling speed information.

Abstract: A system and method are provided for controlling the gain of signals transported over transmission media in a distributed antenna network. The system includes a plurality of remote antenna units where each remote antenna unit includes a signal level comparator for comparing the level of the signals received by the respective antenna unit with a predetermined reference level, and a gain controller for reducing the gain of the remote antenna unit when the signal level comparator determines that the level of the received signal exceeds said predetermined reference level. The system may accommodate TDMA systems when a gain controller is used that is fast enough to respond within the time slots of the received signals. As a result, the signal levels output from the remote antenna units are prevented from exceeding a maximum signal level.

Abstract: In a method and an apparatus of transmitting a burst signal when the burst signal is transmitted from a transmitting station to a receiving station at a transmission power value and/or a transmission rate determined in accordance with a state of a radio channel between the transmitting and receiving station in a mobile communication system, based on a comparison result between a criterion predetermined according to a state of the radio channel and/or a transmission waiting state of the signal, whether or not the burst signal is to be transmitted is determined, and, when it is determined that the burst signal is to be transmitted, the burst signal is transmitted from the transmitting station to the receiving station.

Abstract: A method for operating a user equipment employing a CDMA technique comprises combining a plurality of spread spectrum data signals into a combined signal having a fluctuating power level corresponding to the data signals; modulating the combined signal to produce an RF signal; measuring average power of the combined signal over a selected time period; adaptively limiting the combined signal power to a calculated level based at least in part on the measured power; and transmitting the RF signal.

Abstract: A system and method for providing automatic gain control (AGC) with high dynamic range. An AGC system comprises an open loop control system and a closed loop control system. The open control loop system senses the power level of an input signal and preprocesses the input signal based on its sensed power level. For instance, a strong input signal is attenuated by a fixed level via an analog attenuator, a weak input signal is amplified by a fixed factor via a low noise amplifier, and an intermediate level input signal is directly passed to the closed loop control system of the AGC without any attenuation or amplification. By preprocessing the input signal, the closed loop control system can operate in a range that is optimal for its performance. For instance, a gain variable amplifier of the closed loop control circuit can be prevented from operating in a high attenuation status where its noise figure is very high. A wide band receiver using the AGC system may have a dynamic range over 100 dB.

Abstract: An optical signal receiving apparatus capable of substantially instantaneously and stably discriminating the logic from the header of a burst-like optical signal comprising a pre-amplifier circuit for amplifying an output from a photodiode receiving cell signals, a dummy side variable gain amplifying unit for performing the gain control by feedback control with respect to the output from the pre-amplifier circuit and outputting the gain at that time as gain information, a memory unit for holding the gain information, and a signal side variable gain amplifying unit for performing the gain control by feedfoward control by using the gain set by the gain information and outputting the amplified signal.