Abstract: An electronic arrangement and method for providing a signal characterized by reduced phase noise having a signal source for providing a stimulus signal, a modulator coupled to the signal source for generating a modulated signal as function of the stimulus signal and a local oscillator signal, and a mixer combining the stimulus and modulated signals to generate a mixed signal that includes a component characterized by a mathematical difference of the stimulus signal and the modulated signal. The modulated signal is substantially identical to the stimulus signal and offset by a frequency of the local oscillator signal, so that the difference component of the mixed signal results in a local oscillator signal wherein the stimulus signal phase noise generated by the signal source has been mathematically cancelled.

Abstract: A data demodulation method, apparatus, and system are presented. The method includes obtaining notification information indicating that UE is in a high-speed moving state; performing time-frequency synchronization processing on first downlink data according to the notification information to obtain second downlink data; and performing demodulation processing on the second downlink data to obtain third downlink data, where in the demodulation processing, inter-TTIs filtering for a channel estimation is not performed, or a filtering coefficient as a weight of a current TTI for a channel estimation is greater than a filtering coefficient as a weight of a TTI that is at the time when the UE is in the non-high-speed moving state for a channel estimation. The demodulation method is applicable to a high-speed scenario for improving a downlink data throughput of the UE.

Abstract: The invention relates to a node for managing network connectivity of a device comprising an embedded Universal Integrated Circuit Card (eUICC). The node is configured to provision the eUICC for network connectivity of the device. The method comprises acquiring an identity of at least one Subscription Manager-Data Preparation (SM-DP) entity, acquiring an identity of at least one Subscription Manager-Secure Router (SM-SR) entity, creating an association between the identity of the at least one SM-DP entity, the identity of the at least one SM-SR entity and an identity of the eUICC, and storing the created association, wherein the stored association subsequently can be changed for the eUICC by changing at least one of the identity of the at least one SM-DP entity and the identity of the at least one SM-SR entity with which the eUICC is to be associated.

Abstract: An electronic arrangement and method for providing a signal characterized by reduced phase noise having a signal source for providing a stimulus signal, a modulator coupled to the signal source for generating a modulated signal as function of the stimulus signal and a local oscillator signal, and a mixer combining the stimulus and modulated signals to generate a mixed signal that includes a component characterized by a mathematical difference of the stimulus signal and the modulated signal. The modulated signal substantially identical to the stimulus signal and being offset by a frequency of the local oscillator signal, so that the difference component of the mixed signal results in a local oscillator signal wherein the stimulus signal phase noise generated by the signal source has been mathematically cancelled.

Abstract: Aspects of the disclosure provide a circuit having a jittered clock generator. The jittered clock generator is configured to add jitter of a controlled characteristic to a first clock signal of a clock frequency to generate a second clock signal to be used by a transceiver for operating at a radio frequency. The jitter of the controlled characteristic adjusts a clock harmonic at the radio frequency of the transceiver.

Abstract: One embodiment of the present invention provides a system for performing DC offset cancellation for a wireless receiver that includes one or more amplification stages between a demodulator and a baseband digital signal processor (DSP). During operation, the system calibrates values of static DC offset associated with a plurality of gain settings for at least one amplification stage, stores the calibrated DC offset values in a lookup table, receives a current gain setting for the amplification stage, maps a DC offset value from the lookup table based on the current gain setting, and cancels static DC offset for the amplification stage using the mapped DC offset value.

Abstract: A signal generator for a transmitter or a receiver for transmitting or receiving RF-signals according to a given communication protocol includes an oscillator and a mismatch compensator. The oscillator is configured to provide a signal generator output signal having a signal generator output frequency and comprises a fine tuning circuit for providing a fine adjustment of the signal generator output frequency based on a fine tuning signal and a coarse tuning circuit for providing a course adjustment of the signal generator output frequency based on a coarse tuning signal.

Abstract: An efficient baseband predistortion linearization method for reducing the spectral regrowth and compensating memory effects in wideband communication systems using effective multiplexing modulation technique such as wideband code division multiple access and orthogonal frequency division multiplexing is disclosed. The present invention is based on the method of piecewise pre-equalized lookup table based predistortion, which is a cascade of a lookup table predistortion and piecewise pre-equalizers.

Abstract: Various embodiments are directed towards suppressing inter-cell and intra-cell interference. In some embodiments, an intra-cell interference signal for a specified rake finger is received. An inter-cell interference signal is received. The intra-cell interference signals upstream of a chip-level equalizer are suppressed. The inter-cell interference signals upstream of the chip-level equalizer are suppressed.

Abstract: Adaptive path selection for interference cancellation is provided for wireless communication devices. Signal strength metrics are obtained for each of multiple signal paths. One or more of the signal paths are selected as cancellation candidates in response to determining that the signal paths are associated with a strong interfering path based at least in part on the signal strength metrics for the signal paths and threshold criteria. Cancellation is enabled for an estimated signal generated using the signal paths in response to the signal paths being selected as cancellation candidates.

Abstract: A method and apparatus removes bias from an initial signal-to-interference ratio (SIR). In an exemplary embodiment, an initial SIR calculator in an SIR processor calculates the initial SIR based on the signal received by the wireless receiver, while an average SIR calculator in the SIR processor generates an average SIR. Using the average SIR, a bias remover removes the bias from the initial SIR.

Abstract: In conventional radio frequency (RF) systems, transmitters will usually convert baseband signals to RF so as to be transmitted. As part of the conversion process, the transmitters will perform digital predistortion (DPD), which uses feedback from a power amplifier. However, there are usually mismatches between the in-phase (I) and quadrature (Q) paths within with feedback loop. Traditional IQ correction filters were ineffective at providing adequate compensation for these mismatches, but here a filter is provided that provides adequate out-of-band compensation by use of frequency selectivity.

Abstract: Receiver circuitry for processing a received Very Low Intermediate Frequency signal wherein the receiver circuitry comprises a main processing path. The main processing path comprises mixing circuitry arranged to mix a received VLIF signal with a frequency down conversion signal to produce a main path signal. The receiver circuitry further comprises a direct current cancellation path comprising mixing circuitry arranged to mix a DC element of the received VLIF signal with the frequency down conversion signal to produce a DC cancellation signal. The receiver circuitry still further comprises signal summing circuitry arranged to add the DC cancellation signal in anti-phase with the main path signal.

Abstract: A communications device includes a modulator and a filter downstream therefrom and operable to generate an output wideband complex signal with a frequency notch therein. The filter includes a finite impulse response (FIR) filter with L taps to generate N output values, with L>N. A Fast Fourier Transform (FFT) block is downstream from the FIR filter and has a length N so that filter transition regions occur between frequency bins of the FFT block. A notching block is downstream from the FFT block to generate the frequency notch. An Inverse Fast Fourier Transform (IFFT) block is downstream from the notching block and has the length N.

Abstract: In some embodiments, a method of reducing adjacent channel power ratio and compensating memory effects of multi-channel wideband communication systems using multiplexing modulation techniques is provided. The method includes generating an address from samples of a baseband input signal of a communication system. The method also includes retrieving from a memoryless lookup table an entry in accordance with the address. The method further includes pre-equalizing the baseband input signal, the pre-equalization depending on one or more magnitudes of the input signal. The method still further includes multiplying the pre-equalized baseband input signal and the lookup table entry.

Abstract: Preceding filters receive the inputs of a plurality of received signals associated respectively with a plurality of antennas. Subsequent filters band-limit the plurality of inputted received signals, respectively. A first combining unit derives a weight vector for the plurality of band-limited received signals and performs array synthesis on the plurality of band-limited received signals, using the derived weight vector. The second combining unit performs array synthesis on the plurality of inputted received signal signals, using the derived weight vector. A demodulator demodulates the array-synthesis result.

Abstract: In a wireless system including a wireless communication channel, a method for estimating a signal quality of a received signal includes the steps of receiving a signal from the wireless communication channel, the received signal including at least one field that is modulated and encoded in a substantially fixed manner, and generating at least one reference field based, at least in part, on the at least one field and on a channel estimation signal. The channel estimation signal is representative of at least one characteristic of the wireless communication channel. The method further includes the step of generating a signal quality estimate as a function of the at least one field in the received signal and the generated at least one reference field.

Abstract: Provided are an apparatus and method of receiving signals in a communication system based on multicarrier transmission. The receiving apparatus cancels Inter-Symbol Interference (ISI) in a time domain from a received signal having a delay time above a guard interval, and cancels Inter-Carrier Interference (ICI) in a frequency domain from the received signal.

Abstract: Techniques for detecting and mitigating interference are described. A device (e.g., a cellular phone) senses interference levels and digitally reconstructs the expected interference in the received signal. The device may correlate the reconstructed interference with the received signal and determine interference in the received signal based on correlation results. The device may adjust the operation of one or more circuit blocks (e.g., a mixer, an LNA, etc.) in a receiver based on the detected interference in the received signal. Alternatively or additionally, the device may condition the digital interference to obtain conditioned reconstructed interference matching the interference in the received signal and may then subtract the conditioned interference from the received signal.

Abstract: A radio receiver which performs iterative decoding of a received signal is provided. The radio receiver comprises: a receiving unit receiving a signal on a symbol-by-symbol basis; a demodulation unit (303) demodulating the received signal; a last symbol timing generation unit (308) generating a last symbol timing signal on the basis of the signal demodulated by the demodulation unit (303); a modulation unit (304) modulating the signal demodulated by the demodulation unit (303); and a cancellation unit (306) cancelling an interference component of the received signal using a replica signal generated on the basis of the signal modulated by the modulation unit (304). The modulation unit (304) controls the timing of rearrangement of a data sequence on the basis of the timing of the last symbol. Thus, a radio receiver in which the receiving processing time is reduced can be provided.

Abstract: A receiver estimates I/Q imbalance in I and Q input signals using circuitry to separate different frequency components of the I and Q input signals, and estimation circuitry arranged to estimate I/Q imbalance at the different frequency bands. The separating of the bands may be carried out in the frequency domain, and may involve combining corresponding values representing corresponding negative and positive frequency bands, and converting the separated frequency domain representations to a time domain representation before the estimation. The estimated imbalance may be used to correct the I and Q signals at the different frequency bands.

Abstract: A receiver includes a band-pass filter that limits a passband of an IF (Intermediate Frequency) signal, an FSK detector that detects the IF signal passing through the band-pass filter to generate a detection signal, and a control block that controls a modulation sensitivity of the FSK detector and a pass bandwidth of the band-pass filter, in which the control block controls the modulation sensitivity of the FSK detector according to the pass bandwidth of the band-pass filter.

Abstract: Embodiments of the invention are concerned with correction of quadrature errors associated with digital communications systems, and in particular in a wireless transmit chain in which an up-converter and a down-converter both have a direct conversion architecture. One embodiment comprises a correction network for correcting a difference between a transmission characteristic of an in-phase signal path and a transmission characteristic of a quadrature signal path, said quadrature signal path being for the transmission of in-phase and quadrature parts of a signal and the signal comprising frequency components within a base band, wherein the correction network comprises an in-phase input port, a quadrature input port, an in-phase output port and a quadrature output port, wherein each input port is connected to each output port by a digital filter network, the digital filter network comprising a set of filter tap coefficients and configuration means for configuring values of said set of filter tap coefficients.

Abstract: Techniques for detecting and mitigating interference are described. A device (e.g., a cellular phone) senses interference levels and digitally reconstructs the expected interference in the received signal. The device may correlate the reconstructed interference with the received signal and determine interference in the received signal based on correlation results. The device may adjust the operation of one or more circuit blocks (e.g., a mixer, an LNA, etc.) in a receiver based on the detected interference in the received signal. Alternatively or additionally, the device may condition the digital interference to obtain conditioned reconstructed interference matching the interference in the received signal and may then subtract the conditioned interference from the received signal.

Abstract: A phase noise correction device having a function for accurately detecting a phase noise component and capable of reducing a load on a reception device is provided. A phase noise correction device for correcting a phase noise generated in a local oscillator includes: a division section that divides a signal generated in the local oscillator; a reference signal generation section that generates a signal of the same frequency as that of the divided signal; a phase difference detection section that detects a phase difference between the divided signal and the generated reference signal; and a phase noise correction section that gives a phase rotation to a baseband signal in the direction that cancels the phase noise according to the detected phase difference as a phase noise component.

Abstract: Disclosed is an improved noise reducing apparatus using an anti-circuit, including a digital logic circuit and a digital anti-circuit corresponding to the digital logic circuit. The digital anti-circuit functions to cancel noise generated by the digital logic circuit. The anti-circuit includes logic to generate a similar number of switching edges as the logic circuit, where the anti-circuit edges are in the opposite direction as the logic circuit. The anti-circuit may have a circuit structure close to that of the noisy circuit, or can be formed of components different in structure but generating an output pattern similar to (and opposite from) the noisy circuit. In some embodiments, the differently structured components can include a state machine coupled to a memory or look-up-table.

Abstract: An access terminal for processing a communication signal includes a receiver. The receiver is configured to determine a bias point for the communication signal based on a quality measurement of the communication signal, the quality measurement having a carrier-to-interference (C/I) estimate associated therewith. The receiver is further configured to determine a C/I cap for the communication signal using the C/I estimate, the C/I cap being configured to cap a signal to interference-plus-noise ratio (SINR) of the communication signal. In addition, the receiver is configured to process the communication signal using the determined bias point and the determined C/I cap. A method is also provided for processing a communication signal.

Abstract: A threshold noise-canceling method comprising the steps of: receiving an angle-modulated signal; identifying in the angle-modulated signal potential threshold noise events that exceed a first threshold value; calculating average values of the phase of the angle-modulated signal before and after a potential threshold noise event; identifying every potential threshold noise event as a threshold noise event when the difference between the corresponding before and after average values of the phase is greater than a second threshold value; and canceling out each threshold noise event by adding to the phase of the angle-modulated signal a 2? phase shift of polarity opposite to that of the corresponding threshold noise event.

Abstract: Interference in a wireless communication is minimized, or at least reduced, by scaling the symbols received from an interfering transmitter. Input samples from the interfering transmitter are isolated and decovered to generate received symbols. The gains of the received symbols are scaled to reduce the interference and the scaled symbols are covered to produce output samples that are spread to generate interference cancelled samples with reduced interference from the interfering transmitter. The function applied to scale the symbols may be linear or nonlinear.

Abstract: There is provided an FM demodulator comprising a transistor (Q323), a filter unit for producing first and second amplitude-modulated signals from a received frequency-modulated signal, wherein the filter unit is coupled to the switching transistor (Q323), and first and second diodes (D300) connected in opposite relationship for rectifying the first and second amplitude-modulated signals of the filter unit. The filter unit has an LC network and is so dimensioned that there is a linear relationship between the output voltage and the input frequency. The demodulator further has an operating point adjusting unit for adjusting an operating point of the transistor. The operating point adjusting unit (100) is adapted to effect operating point adjustment with a noise negative feedback.

Abstract: One embodiment relates to a circuit for active loss compensation. The circuit includes a parallel inductor-capacitive (LC) tank circuit having a first single-ended output. A first adjustable capacitor, which includes a first terminal and a second terminal, is coupled to the first single-ended output. The circuit also includes a first pair of transistors having sources coupled to a first common node. One transistor of the first pair of transistors has a drain coupled to the first single-ended output and the other transistor of the first pair of transistors has a gate coupled to the second terminal of the first adjustable capacitor. Other embodiments are also disclosed.

Abstract: A system having a signal processor for detection of a signal type of a signal is disclosed. One embodiment includes a processor designed to determine a first variable which is characteristic of a first spectrum element of the signal spectrum, and to determine a second variable which is characteristic of a second spectrum element of the signal spectrum. A system is provided for determination of a ratio between the first variable and the second variable, and a detector which is designed to detect the signal type on the basis of the ratio.

Abstract: An OFDM telecommunications system includes a transmitter and a receiver. The receiver includes a canceller configured to reduce inter-carrier interference (ICI) in an OFDM symbol in the frequency domain.

Abstract: Disclosed is an improved noise reducing apparatus using an anti-circuit, including a digital logic circuit and a digital anti-circuit corresponding to the digital logic circuit. The digital anti-circuit functions to cancel noise generated by the digital logic circuit. The anti-circuit includes logic to generate a similar number of switching edges as the logic circuit, where the anti-circuit edges are in the opposite direction as the logic circuit. The anti-circuit may have a circuit structure close to that of the noisy circuit, or can be formed of components different in structure but generating an output pattern similar to (and opposite from) the noisy circuit. In some embodiments, the differently structured components can include a state machine coupled to a memory or look-up-table.

Abstract: In order to compensate for a frequency offset or a change in the phase of the transmission channel over time during mobile radio transmission of data symbols, the data symbols are transmitted by way of carrier-frequency, modulated data bursts. Sample values of the received signal, which are known in advance and correspond to first and second symbols, are evaluated in order to estimate the frequency offset or the change in the phase of the transmission channel over time. These first and second symbols are transmitted with a defined phase angle by way of the data burst, and are arranged separated from one another in the data burst. Edge symbols in a data burst are advantageously used as first and second symbols, or as a symbol pair, for estimation.

Abstract: Interference mitigation strategies are presented for use within a transmitter in a wireless system. In at least one embodiment, one or more transmit signals may be generated that are capable of suppressing common channel interference effects within an associated receiver. In other embodiments, one or more transmit signals may be generated that are capable of suppressing dedicated channel interference effects within an associated receiver.

Abstract: A tuner and a demodulating unit thereof are provided. A trap filter for a specific frequency is installed in the IF demodulating unit so as to eliminate a frequency signal acting as a beat component.

Abstract: This method reduces the variance of the estimation of the signal-to-noise rate in a multiuser digital communications system. These communications require a sending of a phase reference symbol prior to sending a information, where the estimation is made of the signal-to-noise rate in order to use a modulation with a maximum number of bits per symbol, maintaining a bit error probability in reception within certain given margins. The method minimizes and equalizes the variance of the samples obtained for the different values, even and odd of bits per carrier, which the system uses. The estimation is necessary for selecting the number of bits per carrier in order to be adapted to the channel and as back-up information in the event of using a receiver with diversity.

Abstract: The present invention has a N pieces of receiving antennas, a propagation path characterization estimator, a weight generator for interference canceller, an array processing interference canceller, a weight generator for signal estimator, a signal estimator, a transmission signal classification apparatus, and a decoding order decision apparatus. The antenna inference elimination circuit eliminates only signal component relating to transmission signal component which does not belong to groups. The signal estimator performs separation and decoding of the transmission signal belonging to the group. The transmission signal classification apparatus classifies the transmission signals from sets of the transmission antennas in which a cross-correlation value of the vector is larger than a threshold value, into one group, and classifies the transmission signal in which the cross-correlation value is smaller than the threshold value, into another group.

Abstract: Provided are a method and system for removing an offset direct current (DC) component from an input waveform. The method includes multiplying the input waveform with a demodulation waveform to produce a first differential current signal. An absolute value representation of the demodulation waveform is multiplied with a reference DC offset value to produce a second differential current signal. The first and second differential current signals are then differenced.

Abstract: A wireless receiver includes a local oscillator, a mixer, a band pass filter, a DC offset determination module, a DC offset correction module, a subtraction module, and a down converter. The local oscillator produces a local oscillation that a mixer uses to down convert the RF information signal to produce a Very Low Intermediate Frequency (VLIF) information signal at a VLIF and having a DC offset. The band pass filter band pass filters the VLIF information signal. The DC offset determination module produces a DC offset indication for the VLIF information signal. The DC offset correction module generates a DC offset correction based upon the DC offset indication. The subtraction module subtracts the DC offset correction from the VLIF information signal to substantially remove a DC offset of the post-filtered VLIF information signal. The down converter down converts the VLIF information signal to a baseband information signal.

Abstract: A noise blanker (40, 106) monitors and removes noise from a sampled signal by adaptive filtering (98, 150) the sampled signal to generate trained adaptive filter prediction coefficients. The sampled signal is provided as an output signal when the noise blanker is in a training mode. A noise monitor (34, 154) detects whether noise contained within the sampled signal exceeds a predetermined threshold and provides a control signal in response to the detecting. The noise blanker is placed in a prediction mode for a predetermined amount of time in response to asserting the control signal. A prediction output signal is generated using a plurality of prediction coefficients as an all-pole filter. The prediction output signal has minimal noise content.

Abstract: A receiver (202) has a down-conversion receiver (304) for transforming a signal (201) from a first operating frequency to a second operating frequency that is lower than the first operating frequency, and a receiver filter (308) with chopper stabilization for filtering unwanted portions of the signal (306) at the second operating frequency and for generating a final filtered signal (203) at the second operating frequency.

Abstract: Information is recovered from a composite signal including first and second component signals modulated according to respective first and second modulations, for example, 8-PSK and GMSK. The composite signal is processed based on predetermined characteristics of the first and second modulations, for example, signal rotations, to generate a channel model for the first component signal and a whitening filter for the second component signal. The composite signal is filtered according to the whitening filter to generate a filtered signal. A symbol hypothesis for a symbol of the first component signal is evaluated using a metric with respect to the filtered signal that is a function of the whitening filter and the channel model, for example, in a multidimensional Viterbi symbol estimation algorithm. The invention may be embodied as methods, apparatus and computer program products.

Abstract: A method for providing maximum likelihood detection with decision feedback interference cancellation is provided. The method includes estimating a current symbol with previous symbol interference (PSI) removed based on estimated previous symbols. A next symbol is estimated with PSI removed based on the estimated current symbol and/or the estimated previous symbols. The current symbol is re-estimated with PSI removed based on the estimated previous symbols and next symbol interference (NSI) removed based on the estimated next symbol. This method of providing maximum likelihood detection with decision feedback interference cancellation may be used in direct sequence spread spectrum systems with relatively short block spreading, such as IEEE802.11b Wireless LAN standard, or in any other suitable systems.

Abstract: The invention concerns a method for receiving a signal using a multiple carrier and code division multiple access modulation, comprising a demodulating step by application of a mathematical transform of the temporal domain to the frequency domain, a step which consists in equalizing the transformed signal and a step which consists in despreading the equalized signal. The invention is characterised in that said equalizing step takes into account, for each of the components of said transformed signal, perturbations affecting the carrier bearing said component and at least one other of said carriers and at least some of said spread codes.

Abstract: An adaptive interference cancellation receiving system uses synthesizer phase accumulation. A coupler coupled to a transmitter samples an undesired transmit signal. An adaptive interference canceller (AIC) module varies phase and amplitude of the sampled undesired transmit signal to provide a cancellation output signal. The AIC module has a frequency synthesizer with phase accumulation for varying the phase of the sampled undesired transmit signal. An antenna receives receive signals and the undesired transmit signal. A summing circuit connected to the receive antenna and the adaptive interference module sums the receive signals, the received undesired transmit signal, and the cancellation signal to cancel the received undesired transmit signal. An AIC controller module is coupled to the summing circuit output to detect a null in the undesired transmit signal, to generate a cancellation feedback signal, and to provide the cancellation feedback signal to the AIC module.

Abstract: A demodulator has a resistor and a capacitor that may be subject to tolerances. For tolerance correction, the FM demodulator is preferably supplied with a reference frequency, which corresponds to the nominal mid-frequency of the demodulator, which is a function of the resistor and the capacitor. Any discrepancy between the actual mid-frequency of the demodulator and its nominal mid-frequency leads to the production of a voltage that differs from a nominal voltage at the output. A detector detects this error and adjusts the values of the resistor or capacitor until the error between the nominal voltage and the voltage is zero or is a minimum. The described principle can be used, for example, in integrated mobile radio receivers.

Abstract: A direct conversion receiver (DCR) with a pair of quadrature conversion paths. Each of the quadrature conversion paths receives an RF input signal and converts the RF input signal to a digital baseband signal. The quadrature conversion paths each include a mixer mixes the RF input signal with a carrier phase signal. Quadrature baseband signals from the mixer pass through an analog filter which provides a filtered baseband signal. An analog to digital converter (ADC) converts the quadrature baseband component to a digital baseband signal. A 5th order elliptical filter filters the quadrature baseband component. The 5th order elliptical filter may be before or after the ADC. A digital baseband component from the ADC and filtered by the 5th order elliptical filter passes to a phase equalizer which compensates for phase distortion from the analog filter. The quadrature digital baseband outputs from the quadrature conversion paths are passed to a baseband processor.

Abstract: An FM demodulator has a differential output demodulator for receiving an FM signal and for outputting a positive differential signal and a negative differential signal of a demodulated signal of the FM signal, a DC offset detector electrically connected to the differential output demodulator for generating a DC offset signal according to peak signals of the positive differential signal and the negative differential signal, and a correction circuit electrically connected to the differential output demodulator and the DC offset detector to compensate for the demodulated signal according to the DC offset signal.