Abstract: A converter in a radio-frequency (RF) apparatus includes a feedback circuitry. The feedback circuitry has a shielded input and a shielded output. The shielded input and the shielded output of the feedback circuitry tend to reduce interference in the converter.

Abstract: Control of a digital communication system having a plurality of communication lines on which signals are transmitted and received is implemented using a variety of methods and systems. According to one embodiment of the present invention, a method is implemented where the signals are affected by interference during transmission and each of the communication lines has at least one transmitter and at least one receiver. A model is created of the interference characteristics due to the signals carried on the communication lines. Interference characteristics for a line are determined based on the model and actual signals carried on other communication lines different from the line for which the characteristics are being determined. Actual interference is compensated for on the communication line using the determined interference characteristics.

Abstract: This disclosure relates to linearization in polar modulators of wireless communication devices, to attain linear amplification and high power efficiency during transmission.

Abstract: Disclosed are a nonlinear distortion compensating receiver and nonlinear distortion compensation method, wherein nonlinear distortion is reduced with a simple circuit configuration. A correction (opposite characteristics) filter (104) has characteristics opposite that of the frequency characteristics of a direct sampling mixer (102) and corrects signals sampled by the direct sampling mixer (102). In the main path, a LPF (106) extracts a frequency band component of a desired signal from the corrected signal. In the replica path, a BPF (107) extracts the frequency band component of a blocker signal from the corrected signal. A cubing circuit (108) uses the frequency band component of the blocker signal to generate a replica signal for the nonlinear distortion. An adaptive filter (110) performs filter processing on the replica signal while updating the filter coefficients.

Abstract: This disclosure relates to low noise amplifiers (LNAs) and more particularly to LNAs integrated on integrated circuit (IC) chips along with radio frequency (RF) amplifiers. In one implementation, an impedance translator is coupled to an amplifier, the impedance translator to cause the amplifier to selectively amplify the one or more components of a received signal.

Abstract: Receiver design techniques are provided that are capable of producing relatively efficient, linear radio frequency (RF) receivers. During a design process, components of an analog receiver chain and digital nonlinearity compensation techniques are considered together to achieve reduced power consumption in the receiver.

Abstract: A method, apparatus, and radio receiver system for canceling multi-user interference in a single-carrier radio communication system. A front-end receiver such as a RAKE receiver receives a radio signal formatted in a sequence of frames, and outputs a plurality of user signals. A processing selector selects on a frame-by-frame basis, either a first signal processing chain that serially decodes and removes the interference contributions of the user signals, or a second signal processing chain that simultaneously decodes and removes the interference contributions of the user signals in parallel. The processing selector may select the first signal processing chain when the number of user signals is greater than or equal to a threshold value, and may select the second signal processing chain when the number of user signals is less than the threshold value.

Abstract: A radio frequency receiver on an integrated circuit (RFIC) includes an oscillator circuit, which generates a radio frequency (RF) oscillatory signal having a predetermined frequency that is outside of an intermediate frequency passband of the RFIC. An amplitude modulator modulates the RF oscillatory signal to produce an amplitude modulated signal which is applied to a mixer that downconverts the amplitude modulated signal. A calibration circuit receives the downconverted signal, including second order modulation (IM2) products, and, responsive to the IM2 products, generates a bias signal that is applied to the mixer to reduce the IM2 products.

Abstract: A communication device including multiple microphones is provided. The communication device includes at least two microphones. The communication device further includes a sidetone feedback notifier for producing a notification signal. The sidetone feedback notifier is coupled to the microphones. The notification signal is based on the combination of, a first input audio signal provided for by a first microphone, and a second input audio signal provided for by a second microphone. The sidetone feedback notifier is coupled to a notification device for providing a feedback signal to a user based on the notification signal.

Abstract: This disclosure relates to linearization in polar modulators of wireless communication devices and associated methods, to attain linear amplification and high power efficiency during transmission.

Abstract: Methods and apparatuses for minimizing co-channel interference in communications systems are disclosed. A method in accordance with the present invention comprises shifting a characteristic of the first signal with respect to a like characteristic of the second signal to mitigate co-channel interference, and transmitting the first signal and the second signal over different channels of the communication system.

Abstract: The present invention provides a method, a device and a system for extending channels, and belongs to the field of communications technologies. The method includes: generating a non-cascade extended channel by using a first channel and a second channel; and generating a first-level cascade extended channel by using the non-cascade extended channel and a third channel, where the first channel and the second channel are both twisted-pair channels, and the third channel is a twisted-pair channel or another non-cascade extended channel. The device includes a first transformer and a second transformer. The system includes a first device and a second device.

Abstract: A method and apparatus for dynamic resource allocation of an RF sampling system based on a signal quality measurement determined by generating a plurality of time-interleaved samples from a received radio frequency (RF) signal and combining the plurality of time-interleaved samples to generate the signal quality.

Abstract: Disclosed are methods and apparatus for predicting a channel quality indicator in a communication system, and in particular a delayed receiver. A disclosed method for determining the predictive channel quality indicator for a delayed receiver includes determining at least one channel quality indicator from a non-delayed receiver. The method also includes determining another channel quality indicator from the delayed receiver, and then calculating the predictive channel quality indicator for the delayed receiver through a function of the channel quality indicators from the non-delayed receiver and the channel quality indicator from the delayed receiver. Corresponding apparatus are also disclosed.

Abstract: In a control of receiving service information, a controller in a radio communication terminal (AT) controls a communication section to receive broadcast data continuously for one cycle while a broadcast service is executed. When a packet among the broadcast data can not be received for some reason, retransmission of the packet is awaited. During the waiting period, transfer rates are respectively calculated based on all previously received data and the latest data received (e.g., during the preceding 30 seconds). Then, a time until the required packet is received for the next time is estimated. Until that time, intermittent reception is performed by the radio communication terminal (AT) at an interval assigned for the radio communication terminal.

Abstract: A system includes a transceiver configured to receive a composite signal. The composite signal is a composite of a transmit signal and a receive signal. A replica transmitter is configured to generate a replica transmit signal based on the transmit signal. A transmit canceller is configured to recover the receive signal at least in part by resistively summing the composite signal and the replica transmit signal.

Abstract: A method of determining signal quality in a cable network comprises the steps of: providing a network model (1) comprising an interconnection model (2) and component models (3), providing an input signal (IS), determining an output signal (OS) using the input signal and the network model, and determining the signal quality from the input signal (IS) and the output signal (OS). The input signal (IS) comprises multiple constituent signal components, each signal component representing a class of input signals. The step of determining the output signal involves determining intermodulations of the constituent signal components by effecting frequency domain convolutions of the spectra of the constituent signal components.

Abstract: The present invention is directed to systems and method for attenuating intermodulation interference. In particular, methods and systems to attenuate intermodulation interference contained within an aggregate signal having a transmitted signal that was transmitted over a communications channel having channel effects that produce the intermodulation interference are provided. The communications channel may be a cable television distribution network and the signal may be a cable television signal. A method is provided to predict when intermodulation interference will be large, so that actions within a receiver can be taken to reduce the impact of the interference and improve overall receiver performance.

Abstract: In a method for processing a signal received by a receiver, at a first wireless receiver (20, 62) a first signal (x(t), x1(t)) comprising first and second signal components is received. The first signal component is intended for the first wireless receiver (20, 62) and the second signal component is related to at least one of a sending signal (s(t)) generated by a transmitter (29, 69) or to a second signal (x2(t)) intended for a second wireless receiver (61). To the first wireless receiver (20, 62) a reference signal (r(t), r1(t), r2(t)) which is proportional to the sending signal (s(t)) or to the second signal (x2(t)). At the first wireless receiver (20, 62) and from the reference signal (r(t), r1(t), r2(t)) an estimation signal which estimates the second signal component is generated. A filtered signal (y(t), y1(t)) is generated by subtracting the estimation signal from the first signal (x(t), x1(t)).

Abstract: An approach is provided for minimizing co-channel interference in a communication system is disclosed. A header of a first frame is scrambled based on a first unique word. A header of a second frame is scrambled based on a second unique word. The first frame including the corresponding scrambled header and the second frame including the corresponding scrambled header are transmitted, respectively, over adjacent co-channels of the communication system. Each of the frames further includes a payload and a pilot block. The payload and the pilot block of the first frame are scrambled based on a first scrambling sequence. The payload and the pilot block of the second frame are scrambled based on a second scrambling sequence. The above arrangement is particularly suited to a digital satellite broadcast and interactive system.

Abstract: A radio frequency receiver subject to a large in-band interferor employs active cancellation with coarse and at least one cancellation signals, each with a respective radio frequency combiner, in order to increase the effective dynamic range of the receiver for weak signals of interest. One or both can be digitally synthesized. This is particularly applicable for co-site interference, whereby the interfering transmit signal is directly accessible. A similar system and method may also be applied to external interferors such as those produced by deliberate or unintentional jamming signals, or by strong multipath signals. An adaptive algorithm may be used for dynamic delay and gain matching. In a preferred embodiment, a hybrid technology hybrid temperature system incorporates both superconducting and semiconducting components to achieve enhanced broadband performance.

Abstract: A second-order distortion correcting receiver and a second-order distortion correcting method, wherein second-order inter-modulation distortion can be cancelled with high precision and with a simple circuit configuration, without requiring a complicated adjustment step. A non-linear active element unit (110) performs non-linear processing on an input signal to output a differential output signal and common mode output signal. A common mode detection unit (120) extracts the common mode output signal. A weighting unit (130) weights the extracted common mode output signal and thereby generates a corrected signal. A corrected signal injection unit (140) injects the corrected signal into a differential output signal to output a corrected differential output signal. A DC detection unit (150) calculates the average DC component of the corrected differential output signal. A weight determining unit (160) uses the average DC component to determine the weighting coefficient used by the weighting unit (130).

Abstract: The present patent application comprises a linear transconductor having at least one input and at least one output, comprising a differential amplifier having a plurality of transistors and a plurality of inputs, wherein a difference of input signals is amplified, a cascode circuit having a plurality of transistors, wherein the transistors are operably connected to the differential amplifier, wherein reverse isolation between an input and an output of the linear transconductor is improved by decoupling the input and the output of the linear transconductor by mounting at least one transistor of the plurality of transistors of the cascode circuit as a common-gate stacked on the at least one transistor of the differential amplifier, an active load having a plurality of transistors operably connected between the cascode circuit and supply voltage, and an auxiliary device operably connected to the connection between the active load, the cascode device and ground.

Abstract: A method and system for detecting intermodulation emissions, such as passive intermodulation emissions, is provided. The method comprises retrieving signal quality measurement (SQM) data, and determining whether there is an intermodulation hit in the SQM data. If there is no intermodulation hit, the SQM data is stored in a first data set; if there is an intermodulation hit, the SQM data is stored in a second data set. The method then determines whether there are one or more faults in the first data set. If there are, a confirmation count for an intermodulation failure is cleared, and the method starts again. If there are not one or more faults in the first data set, a determination is made whether there are one or more faults in the second data set. If not, the confirmation count is cleared, and the method starts again. An intermodulation failure can be confirmed if there are one or more faults in the second data set.

Abstract: An apparatus and a method for reducing cross-talk between audio channels in a mobile terminal are provided. The apparatus includes an ear jack, a radio signal tuner, a baseband, and a switching unit. The ear jack includes a common port for a reference potential of an earphone and a radio signal. The radio signal tuner processes a radio signal input via the common port. The baseband determines an on/off state of a radio reception function to output a control signal. The switching unit connects the common port of the ear jack to one of a ground and the radio signal tuner according to the control signal.

Abstract: The present invention provides a method for interference cancellation in a wireless communication system. One embodiment of a method includes accessing information indicative of one or more first signals transmitted by one or more first mobile units from one or more first sectors. The method also includes accessing information indicative of one or more second signals transmitted by one or more second mobile units from one or more second sectors different than the first sectors. The method further includes canceling interference caused in the second signal(s) by the first signal(s) using the accessed information indicative of the first signal(s) and the second signal(s). The method also includes jointly scheduling and allocating resources to one or more mobile stations in one or more sectors of one or more base stations.

Abstract: A radio frequency identification (RFID) interrogator for determining a bandwidth of a backscattering signal to be backscattered by an RFID tag and a method of operating the same are provided. The RFID interrogator senses a predetermined frequency band to determine whether the predetermined frequency band has been occupied and determines a sensing result. The RFID interrogator further controls the bandwidth of the backscattering signal in response to the sensing result.

Abstract: A wireless communication unit includes a transmitter, a receiver, a selectivity element and a baseband processing module. The receiver has at least one summation module arranged to add a cancellation signal to the quadrature baseband receive signal. a baseband processing module arranged to: receive the quadrature baseband transmit signal and quadrature baseband receive signal; apply independent gain and phase adjustments to quadrature portions of the quadrature baseband transmit signal, based on at least one signal component of the quadrature baseband receive signal, to form independent cancellation signals; and apply the independent cancellation signals to the at least one summation module.

Abstract: Demodulator includes reception quality evaluation circuit for evaluating the quality of a received signal by comparison with a first reference value, and outputting an evaluation signal; and driving circuit receiving the evaluation signal. If reception quality evaluation circuit evaluates that the quality of the received signal is acceptable, power supply from driving circuit to DC offset control loop is stopped. This offers a high-frequency receiver that reduces power consumption.

Abstract: An apparatus, a method and a system for correcting a phase imbalance are described. Embodiments may measure the phase imbalance inherent in a tuner and use the imbalance measure to correct the output of the tuner. Embodiments may include a tone generator to produce a single frequency tone and a tuner to receive the single frequency tone and output an intermediate frequency. The intermediate frequency may be corrected by a correction loop. Other embodiments are described and claimed.

Abstract: A waveform reconstruction circuit receives an rf signal from an antenna, digitizes it, and then generates an undistorted reconstructed waveform. The reconstructed waveform can then be conventionally mixed and demodulated to extract useful signal information with enhanced receiver fidelity and sensitivity.

Abstract: An RF system for reducing intermodulation (IM) products is disclosed. The RF system includes a first nonlinear element and a second nonlinear element, wherein the second nonlinear element generates inherent IM products and the first nonlinear element is adapted to generate compensating IM products. Alternatively, the first nonlinear element generates inherent IM products and the second nonlinear element is adapted to generate compensating IM products. The amplitudes of the compensating IM products are substantially equal to amplitudes of the inherent IM products. The RF system further includes a phase shifter that is adapted to provide a phase shift that results in around 180° of phase shift between the inherent IM products and the compensating IM products. The phase shifter is coupled between the first nonlinear element and the second nonlinear element.

Abstract: Systems and techniques for adaptive interference filtering in a communications device are disclosed. The communications device may include a transmitter, a receiver, a duplexer coupled to the transmitter and the receiver, and an adaptive filter disposed between the duplexer and the receiver. A processor may be configured to monitor cross modulation in the receiver between transmitter leakage through the duplexer and a jammer, and adapt the filter to vary its transmit signal rejection as a function of the cross modulation.

Abstract: A radio receiver may determine whether a received frequency modulated radio signal includes interference from an adjacent channel. The receiver may compare a frequency deviation above the center frequency of the received signal to a frequency deviation below the center frequency of the received signal. The receiver determines that the radio signal is affected by adjacent channel noise when the frequency deviation below the center frequency is substantially different from the frequency deviation above the center frequency. Alternatively, the presence of noise from an adjacent channel may be detected by comparing a positive amplitude and a negative amplitude of a demodulated version of the frequency modulated radio signal. In this alternative, the receiver determines that the radio signal is affected by adjacent channel noise when the extent of the positive amplitude is substantially different from the extent of the negative amplitude.

Abstract: A wireless communications apparatus includes a setup-value storage storing therein setup information that includes a compensation coefficient that is used in frequency-characteristic compensation of a subcarrier signal that results from separating frequency components from a multicarrier modulated signal, an operation category indicating the type of handling of the compensation coefficient, and a category condition; a subcarrier-signal input unit that receives input of the subcarrier signal; an address generator that in conjunction with the input timing of the subcarrier signal, generates an address that corresponds to the subcarrier signal; an operation category selector that determines a category condition that the generated address satisfies, and selects the operation category that corresponds to the category condition; frequency-characteristic compensating unit uses the compensation coefficient that corresponds to the selected operation category and performs the frequency-characteristic compensation on th

Abstract: A radio frequency receiver subject to a large in-band interferor employs active cancellation with coarse and fine cancellation signals, each with a respective radio frequency combiner, in order to increase the effective dynamic range of the receiver for weak signals of interest. One or both can be digitally synthesized. This is particularly applicable for co-site interference, whereby the interfering transmit signal is directly accessible. A similar system and method may also be applied to external interferors such as those produced by deliberate or unintentional jamming signals, or by strong multipath signals. An adaptive algorithm may be used for dynamic delay and gain matching. In a preferred embodiment, a hybrid technology hybrid temperature system incorporates both superconducting and semiconducting components to achieve enhanced broadband performance.

Abstract: A wireless communications device may include a portable housing and a temperature-compensated clock circuit carried by the portable housing. The device may further include a wireless receiver carried by the portable housing for receiving timing signals, when available, from a wireless network, and a satellite positioning clock circuit carried by the portable housing. A clock correction circuit may be carried by the portable housing for correcting the temperature-compensated clock circuit based upon timing signals from the wireless network when available, and storing historical correction values for corresponding temperatures. The clock correction circuit may also correct the temperature-compensated clock circuit based upon the stored historical correction values when timing signals are unavailable from the wireless network, and correct the satellite positioning clock based upon the temperature-compensated clock circuit.

Abstract: The present invention relates to an apparatus and a method for measuring an in phase and quadrature (IQ) imbalance. One embodiment according to the present general inventive concept can provide a method for measuring a Tx IQ imbalance generated in an IQ up-conversion mixer and an Rx IQ imbalance generated in an IQ down-conversion mixer, that includes measuring a first IQ imbalance corresponding to a first combination of the Rx IQ imbalance with the Tx IQ imbalance, measuring a second IQ imbalance corresponding to a second combination of the Rx IQ imbalance with the Tx IQ imbalance and obtaining the Tx IQ imbalance and the Rx IQ imbalance from the first IQ imbalance and the second IQ imbalance.

Abstract: A device may include a measurement receiver, a communication receiver, and a transmitter. The measurement receiver may include a receiver (RX) down-conversion component to receive an amplified signal from a low-noise amplifier of the communication receiver, selectively receive a signal from a first local oscillator associated with the communication receiver or a second local oscillator associated with the transmitter, and down-convert the amplified signal to baseband using the received signal from the first local oscillator or the second local oscillator. The measurement receiver may further include a delta-sigma analog-to-digital converter (ADC) to provide low quantization noise only for a particular frequency range to be measured, and a control component to configure the delta-sigma ADC to provide the low quantization noise at the particular frequency range.

Abstract: Adaptation convergence in an adaptive dispersion compensation engine (ADCE) of a high-speed serial interface is detected by monitoring the output of the error amplifier of one or more adjustment loops of the ADCE. Adaptation convergence is considered to have been detected upon detection of a predetermined number of transitions in the error amplifier output, each of which occurs within a preselected interval following the previous transition. The detector may be implemented with a timer that times the preselected interval and a counter that counts transitions in the error amplifier output. The timer restarts each time a transition occurs, and the counter outputs a convergence signal when it reaches the predetermined number, but is reset each time the timer reaches the preselected interval. The serial interface may be part of a programmable integrated circuit device and in any case the preselected interval and the predetermined number may be programmable.

Abstract: A system for detecting and minimizing interference in a radio receiver includes a plurality of bandpass filters having different response characteristics, a power detector configured to compare a power output of a first bandpass filter and a second bandpass filter, and logic to cascade a third bandpass filter when the difference in power output between the power output of the first bandpass filter and the power output of the second bandpass filter exceeds a threshold amount.

Abstract: A lock-in amplifier with an additional phase-sensitive detector is provided. A measurement signal is mixed in a multiplicative fashion with a reference signal, which is phase-shifted by 90 degrees, for a modulation frequency. In order to reliably filter out interference signal portions in a widest possible dynamic range and, at the same time, minimize unavoidable influence on the useful signal portion, a control device is connected downstream of the additional phase-sensitive detector. The control device determines a control variable corresponding to the strength of the interference signal from the measurement signal mixed with the reference signal phase shifted by 90 degrees and uses the control variable to change the integration duration of the integrator proportionally to the control variable, a corresponding cut-off frequency of an equivalent low pass being coordinated automatically.

Abstract: This disclosure relates to low noise amplifiers (LNAs) and more particularly to LNAs integrated on integrated circuit (IC) chips along with radio frequency (RF) amplifiers.

Abstract: A wireless communications device comprising duplexing means for directing signals from a transmit path towards an antenna and for providing signals from the antenna to a receive path, wherein the transmit path is arranged to send a first signal to the duplexing means, the receive path is arranged to recover a second signal and the device further comprises detecting means for detecting the presence in the receive path of a third signal that will interact with the first signal to produce intermodulation distortion tending to hamper recovery of the second signal and control means responsive to the detecting means for enhancing linearity in the receive path to reduce said intermodulation distortion.

Abstract: A waveform reconstruction circuit receives an rf signal from an antenna, digitizes it, and then generates an undistorted reconstructed waveform. The reconstructed waveform can then be conventionally mixed and demodulated to extract useful signal information with enhanced receiver fidelity and sensitivity.

Abstract: In a compensator for compensating mismatches, and in methods for such compensation, the compensator compensates for mismatches in output signals of a system with mismatches during normal operation of the system with mismatches. The compensator comprises: a mismatch estimator that monitors at least two mismatched signals output by the system with mismatches during normal operation and that generates matching parameters indicating an amount of mismatch between the at least two mismatched signals, the mismatch estimator updating the matching parameters during normal operation of the system with mismatches, and a mismatch equalizer that compensates mismatches in the mismatched signals output by the system with mismatches during normal operation of the system with mismatches in response to the matching parameters.

Abstract: A circuit is provided for suppression of second-order intermodulation in a double-balanced mixer circuit. The circuit includes a duplicate transconductor element for duplicating AC current in a transconductor pair of the double-balanced mixer circuit. A fundamental cancellation element cancels a fundamental component of an AC current of the duplicate transconductor element, while preserving a second-order intermodulation component. A phase inversion element feeds an output current of the fundamental cancellation element to the transconductor pair of the double-balanced mixer circuit, to substantially remove the second-order intermodulation component from a differential output of the double-balanced mixer circuit.

Abstract: A method (1100, 1200) of generating a composite mitigation signal (216, 902, 1002) is presented. The composite mitigation signal includes an odd integer (N) of transitions (310, 312) between a first amplitude and a second amplitude of the composite mitigation signal. Successive sets of the transition bursts are separated by a desired phase delay or time delay (330), or such separations are defined by a base signal (416) having a frequency equal to a fundamental frequency of the composite mitigation signal. The composite signal generators (222, 900, 1000) that generate the composite mitigation signal are also presented.

Abstract: A polynomial nonlinear term generator is configured to receive an RF signal. An analog cubic term generator generates an analog cubic term signal and an analog square term generator generates an analog square term signal, both derived from the RF signal. A cubic term mixer assembly mixes a local oscillator (LO) signal with the cubic term signal to generate a synthetic IM3 signal. A square term ADC provides a digital square term signal and a cubic term ADC provides a digital cubic term signal. At least one digital multiplier has a first multiplier input terminal configured to receive a selected one of the digital square term signal and the digital cubic term signal, and a second multiplier input terminal configured to receive the digital square term signal. The multiplier provides as output a digital IMn product where n is greater than 3. A corresponding method is also described.

Abstract: A receiver arrangement includes a single ended multiband feedback amplifier, at least one single ended input, differential output mixer arrangement including a main mixer and a trim mixer, and a mixer feedback loop circuit configured to receive differential output signals generated by the mixer arrangement. The mixer feedback loop circuit generates a feedback signal based on the received differential output signals and provides the feedback signal to the mixer arrangement to minimize DC-offset and second order intermodulation products. The single ended multiband feedback amplifier may include an input stage and a programmable resonance tank circuit connected to the input stage for suppressing downconverted noise from harmonics of the LO-frequency, and a configurable feedback net that shapes the frequency response of a feedback loop including the feedback net based on a band operation of the single ended multiband feedback amplifier.