Abstract: A system comprises an analog front end (AFE), an analog-to-digital converter (ADC), and alias detection circuitry. The AFE may be operable to receive an analog signal via a communication medium, wherein a first frequency band of the analog signal is occupied by an OFDM symbol and a second frequency band of the analog signal is occupied by first aliases generated during digital-to-analog conversion of the OFDM symbol. The ADC is operable to digitize the particular band of the analog signal to generate a digital signal, wherein, during the digitization, aliasing of the first aliases results in second aliases which fall into the first frequency band. The alias detection circuitry is operable to detect the second aliases in the first frequency band of the digital signal, and process the digital signal based on the detected second aliases to generate an output signal.

Abstract: A User Equipment and an eNodeB system are configured for performing interference mitigation in the UE. Input circuitry in the wireless communication device receives an OFDM downlink channel signal associated with a serving cell and receives downlink control information for an interfering cell. The downlink control information is used by the UE to perform channel estimation for the interfering cell. An interference mitigation module is provided for calculating an interference-mitigated version of the received channel signal using estimated channel transfer functions for both the serving cell and the interfering cell, power control parameters and using set of modulation constellation points corresponding to the OFDM downlink channel. Other embodiments may be described and claimed.

Abstract: Methods and apparatuses are provided in which a processor of a transceiver selects one of a real component of a complex signal and an imaginary component of the complex signal. The complex signal has IQ imbalance. An adaptive filter of the transceiver performs a real multiplication operation using an adaptive filter coefficient and the one of the real component and the imaginary component of the complex signal to generate a complex compensation signal. An adder of the transceiver sums the complex signal and the complex compensation signal to generate a compensated signal in which the IQ imbalance is corrected. The compensated signal is output for digital processing.

Abstract: An example method for facilitating a high power efficient amplifier through digital pre-distortion (DPD) in cable network environments is provided and includes receiving a first signal and a second signal at a DPD coefficient finder in an amplifier module, the second signal including transformations of the first signal from distortions due to channel effects and amplifier nonlinearity, synchronizing the first signal and the second signal, thereby removing the channel effects, computing a first vector representing an inverse of the nonlinearity of the amplifier, computing a second vector representing an inverse of some of the channel effects and providing DPD coefficients to a DPD actuator in the amplifier module, the DPD coefficients including the first vector and the second vector, the DPD actuator predistorting an input signal to the amplifier module with the DPD coefficients, such that an output signal from the amplifier module retains linearity relative to the input signal.

Abstract: Methods and systems for optimizing amplifier operations are described. The described methods and systems particularly describe a feed-forward control circuit that may also be used as a feed-back control circuit in certain applications. The feed-forward control circuit provides a control signal that may be used to configure an amplifier in a variety of ways.

Abstract: Embodiments of the invention provide a DPD system where the transmit reference signal is transformed, including sub-sampling, frequency translation, and the like, to match the feedback signal, which goes thru a similar transformation process, to obtain an error signal. The same transformation is applied to a system model, which may be Jacobian, Hessian, Gradient, or the like, in an adaptation algorithm to minimize error.

Abstract: Systems and techniques for in-phase/quadrature estimation are described. As data frames are received at a wireless networking direct-conversion receiver, preambles of the data frames are examined to identify frequency-independent subcarriers. Preamble-based estimation is used to estimate in-phase/quadrature imbalance for frequency-independent subcarriers and blind estimation is used to estimate in-phase/quadrature imbalance for frequency-dependent subcarriers. The estimation may be performed continuously and refined as new frames are received. At appropriate intervals, compensation is performed using current imbalance estimates.

Abstract: Apparatus and methods for transceiver calibration are provided. In certain configurations, a transceiver includes a transmit channel and an observation channel. The transmit channel includes a transmit mixer that up-converts a transmit signal by a first or transmit local oscillator frequency. The observation channel includes an observation mixer that down-converts an observed signal from the transmit channel by a second or observation local oscillator frequency that is offset from the first local oscillator frequency. By observing the transmit channel using a local oscillator frequency that is offset relative to the transmit channel's local oscillator frequency, the observation channel can observe transmit channel impairments substantially independently from observation channel impairments.

Abstract: First and second inputs are received. The first input indicates a frequency offset of a frequency band allocated for signal transmission. The said allocated band is a subband of a total band available for transmission. The second input indicates a bandwidth of the allocated band. One or more filters of a transmitter of a communications system are controlled to operate cumulatively in a lowpass filtering mode, wherein the highest frequency in a pass band in the lowpass filtering mode is less than the highest frequency of the total band available for transmission. A signal is filtered using the filter(s).

Abstract: Methods and apparatuses are provided for adjusting a transmission gain in a transmitter of an electronic device. A transmitted signal is received at a digital signal processor (DSP) of the transmitter. The transmitted signal is also transmitted through a transmission path of the transmitter resulting in a load impedance. A looped-back signal is received at the DSP via a loop-back path of the transmitter that returns from the transmission path. The DSP estimates the load impedance from the transmitted signal and the looped-back signal. The DSP sets the transmission gain of the transmission path based on the load impedance and saturation values for a load current and a load voltage.

Abstract: A transceiver front-end circuit for a cellular radio architecture for a vehicle, where the transceiver circuit employs components for reducing power consumption. The transceiver circuit includes a receiver module having a delta-sigma modulator that converts analog receive signals to a representative digital signal in an interleaving process, where the delta-sigma modulator includes a combiner, a low noise amplifier (LNA), an LC filter and a quantizer circuit. The LC filter is a multi-order filter and the quantizer circuit is an interleaving quantizer circuit that interleaves multiple groups of bits from the filter. The order of the LC filter is selectively reduced in situations where a full dynamic range of the cellular radio is not required and a bit resolution of the quantizer circuit is reduced so as to reduce the power requirements of the cellular radio.

Abstract: Embodiments of the present disclosure a digital predistortion system and method based on envelope tracking, and a radio frequency system, so as to reduce complexity of the digital predistortion system based on envelope tracking. The system includes: a digital predistorter, a digital-to-analog converter, a frequency mixer, a power amplifier, and a power supply apparatus; where a value range of a predistortion signal that is obtained when the digital predistorter uses a first processing manner is within a first interval, and in this case, a value of a supply voltage generated by the power supply apparatus is a constant; a value range of the predistortion signal that is obtained when the digital predistorter uses a second processing manner is within a second interval, and in this case, a change of the supply voltage generated by the power supply apparatus tracks a change of an envelope signal of the predistortion signal.

Abstract: A method and apparatus for modulating a baseband signal in beam space MIMO are provided. The baseband signal modulation apparatus may calculate a load value of a plurality of antenna elements using a baseband signal. The baseband signal modulation apparatus may change a phase or a magnitude of a baseband signal or a first band signal having a higher frequency than that of the baseband signal to correspond to the calculated load value.

Abstract: Data is received characterizing a first signal and a second signal. The first signal and a function of the second signal is compared at a plurality of time-shifts to estimate a time-difference between the first signal and the second signal. The function of the second signal includes the second signal, a complex conjugate of the second signal, and a constant. The comparison is provided. At least one of receiving, comparing, and providing is performed by at least one processor of at least one computing system.

Abstract: A method for reducing power consumption in a transceiver front-end circuit for a cellular radio. The transceiver circuit includes a receiver module having a delta-sigma modulator that converts analog receive signals to a representative digital signal in an interleaving process, where the delta-sigma modulator includes a combiner, a low noise amplifier (LNA), an LC filter and a quantizer circuit. The LC filter is a multi-order filter and the quantizer circuit is an interleaving quantizer circuit that interleaves multiple groups of bits from the filter. The method includes selectively reducing the order of the LC filter in situations where a full dynamic range of the cellular radio is not required and reducing a bit resolution of the quantizer circuit so as to reduce the power requirements of the cellular radio.

Abstract: A method is provided for generating precoder data, comprising: obtaining transmit power data indicative of a transmit power of a plurality of multiple-input/multiple-output signals; obtaining signal quality data, the signal quality data including at least one measure of a quality of the plurality of multiple-input/multiple-output signals; obtaining channel data with respect to a wireless channel, the channel data including a measure of respective channel parameters of each of a plurality of channel paths in the wireless channel; constraining one or more system performance parameters; and determining first and second precoder diagonal values (wA and wB) based on the signal quality data, the transmit power data, the channel data, and the one or more constrained system performance parameters.

Abstract: A method for generating signals to be transmitted within a BSS channel, where a set of component channels is collectively coextensive with the BSS channel, includes determining that a first duplicate, in frequency, of a low bandwidth mode data unit will be located at an edge of the BSS channel. Each duplicate includes OFDM tones and has a bandwidth less than the narrowest channel of the component channels. The OFDM tones in each duplicate include one or more data tones, one or more pilot tones, and one or more guard tones. The method also includes generating a transmission signal comprising the duplicates, at least in part by scaling down at least one data tone, and/or zeroing out at least one data tone, of the first duplicate in response to determining that the first duplicate will be located at an edge of the BSS channel.

Abstract: A mismatch compensating device includes: a signal generator, synchronously outputting first and second signal; a gain and phase compensator, processing the first and second signals according to a gain parameter and a phase parameter to generate compensated first and second signals; a DAC, performing a digital-to-analog conversion on the compensated first and second signals to generate first and second analog signals; an analog front-end circuit, processing the first and second analog signals to output a joint signal; a mismatch detecting circuit, detecting the power of the joint signal to generate a detection result; a frequency-dependent mismatch compensator, compensating at least one of the first and second signals; and a control circuit, setting the gain and phase parameters and a parameter of the frequency-dependent mismatch compensator according to the detection result to compensate frequency-independent gain and phase mismatch and a frequency-dependent mismatch response.

Abstract: The present invention provides a method of transmitting broadcast signals. The method includes, encoding, by an encoder, PLP (Physical Layer Pipe) data; time interleaving, by a time interleaver, the encoded PLP data; frame mapping, by a framer, the time interleaved PLP data onto at least one signal frames; frequency interleaving, by a frequency interleaver, data in the at least one signal frames; and waveform modulating, by a waveform module, the frequency interleaved data in the at least one signal frame and transmitting, by the waveform module, broadcast signals having the modulated data, wherein the frequency interleaving is conducted according to an interleaving mode, wherein the interleaving mode is determined based on a FFT (Fast Fourier Transform) size.

Abstract: A sum of products calculation of a predetermined tap number of tap data and a prescribed tap number of coefficients is carried out and a sum of the predetermined number of tap data is calculated. A replica signal is calculated on the basis of the sum of products calculation result, the sum of the tap data, and a correction coefficient. A residual signal is calculated as the difference between the replica and received signals. The predetermined tap number of coefficients is updated based on the predetermined tap number of tap data and the residual signal, and the correction coefficient calculated from the residual signal. Here, the tap data is either a data symbol before the superimposition of a DC component or an estimation thereof. This allows an adaptive FIR filter used in channel estimation of a received signal by a digitally modulated wave whereupon a DC component is superimposed.

Abstract: The overall performance of a dual-path ADC system may be improved by using a VCO-based ADC for small-amplitude signals and employing non-linear cancellation to remove nonlinearities in signals output by the VCO-based ADC. In particular, VCO-based dual-path ADC systems of this disclosure may be configured to receive a first digital signal from a first ADC and a second digital signal from a second ADC, wherein the second digital signal is more non-linear than the first digital signal. The dual-path systems may also be configured to determine one or more non-linear coefficients of the second digital signal based, at least in part, on processing of the first and second digital signals. The dual-path systems may be further configured to modify the second digital signal based, at least in part, on the determined one or more non-linear coefficients to generate a more linear second digital signal.

Abstract: According to one embodiment of the present disclosure, a current-mode driver with built-in CTLE provides signal correction for a transmitter. The current-mode driver includes a digital current source operable to use a data signal to produce a main current signal. The current-mode driver also includes a filtering circuit comprising a resistor and a capacitor. The filtering circuit is operable to receive a negative data signal and produce a filtered data signal. The filtering circuit may be tuned to produce a zero at a pole frequency in the filtered data signal that compensates for signal degradation caused by the optical transmitter. The current-mode driver also includes an analog current source coupled in parallel to the digital current source, wherein the analog current source is operable to generate a subtraction current signal proportional to the filtered data signal. The subtraction current signal combined with the main current signal are operable to drive the transmitter.

Abstract: There is disclosed an amplifier arrangement comprising a plurality of amplifiers each arranged to amplify one of a plurality of different input signals, the arrangement comprising an envelope tracking modulator for generating a common power supply voltage for the power amplifiers, and further comprising an envelope selector adapted to receive a plurality of signals representing the envelopes of the plurality of input signals, and adapted to generate an output envelope signal representing the one of the plurality of envelopes having the highest level at a particular time instant as the input signal for the envelope tracking modulator.

Abstract: Systems and techniques relating to wireless communication devices and digital power amplifiers include, according to an aspect, an apparatus including: processor electronics; transceiver electronics coupled with the processor electronics, the transceiver electronics including modulation circuitry and a digital power amplifier coupled with the modulation circuitry; a clock source coupled with the transceiver electronics to provide a clock signal from the clock source to the digital power amplifier at a sampling clock frequency; a local oscillator coupled with the transceiver electronics to provide a local oscillator signal from the local oscillator to the modulation circuitry at a local oscillator frequency; and one or more antennas coupled with the digital power amplifier in the transceiver electronics; wherein the local oscillator frequency is an integer multiple of the sampling clock frequency; and wherein a parasitic frequency response of circuitry in the transceiver electronics acts as an implicit out-of-

Abstract: The present application relates to the technical field of radio communications, and relates specifically to a method, system, and device for transmitting coding instruction information and for determining a pre-coding matrix, for use in solving the problem that direct application of current codebooks to a three-dimensional beamforming/pre-coding technology causes performance degradation.

Abstract: Disclosed are a method and apparatus for processing a transmission signal using a window function that changes a spectrum characteristic of a symbol. A transmission apparatus includes a symbol generator that generate a plurality of consecutive symbols, and a symbol windowing processor that is coupled with the symbol generator. The symbol windowing processor applies a first window function and a third window function that uses a difference between the first window and a second window, and changes a spectrum characteristic of each of the plurality of consecutive symbols, and processes neighboring symbols from among the plurality of consecutive symbols of which spectrum characteristics are changed, such that the symbols partially overlap one another.

Abstract: A signal processing method and related equipment are provided, which are used for reducing the number of antennas needed by a proximal user equipment to detect a low power signal. The method comprises: adjusting a pre-coding vector of a high power data stream to allow a product of the pre-coding vector and an effective receiving channel for a low power data stream equal to a constant; performing superposition coding on the low power data stream and the adjusted high power data stream; and sending the superposition-coded data stream to user equipments, wherein the user equipments comprise a user equipment at a center of a cell and a user equipment at an edge of the cell, the high power data stream is an interference while the low power data stream is desirable for the user equipment at the center of the cell.

Abstract: Embodiments of the present invention disclose a method, an apparatus and a system for sending a physical layer signal, where the method for sending a physical layer signal includes: constructing a signal frame of a physical layer signal, where the signal frame includes one single-frequency sequence, the single-frequency sequence is used to enable a receiving apparatus to capture the signal frame in a frequency domain according to the single-frequency sequence, and the single-frequency sequence includes a plurality of single-frequency preset symbols; and sending the physical layer signal based on the signal frame. Applying the present invention can facilitate capturing the signal frame in a frequency domain by a receive end, and therefore, not only impact caused by frequency offset is overcome, but also multipath energy may be used effectively to improve performance of capturing.

Abstract: Some embodiments include a distributed estimation system. Other embodiments of related systems and methods are also disclosed.

Abstract: Systems and methods that enable use of enhanced receiver techniques together with measurement gaps for measuring or reading a signal or channel from a target cell are disclosed. In one embodiment, a wireless device has an enhanced receiver and operates to measure interference from a first cell during one or more gaps created for a second cell to thereby obtain one or more interference measurements and then mitigate the interference during reception of a signal from a cell other than the first cell based on the one or more interference measurements using an enhanced receiver technique. The one or more gaps for the second cell are one or more gaps in downlink reception from the second cell, uplink transmission to the second cell, or a combination thereof. In this manner, the need for simultaneous reception for both the first cell and the other cell for interference mitigation is avoided.

Abstract: The present disclosure describes apparatuses and techniques for shaping near-field transmission signals. In some aspects, a baseband data signal is shaped based on a coupling condition of an antenna. A radio frequency (RF) carrier signal is modulated with the shaped baseband data signal to provide a shaped transmission signal, which is then applied to the antenna to generate an RF field. The shaped transmission signal can be effective to reduce distortions of the RF field associated with the coupling condition.

Abstract: A noise canceler for use in a transceiver is disclosed. In an exemplary embodiment, an apparatus includes a split amplifier to output an amplified transmit signal, the split amplifier providing a first noise attenuation factor in a receive band. The apparatus also includes a transmit antenna to transmit the amplified transmit signal, the transmit antenna being isolated from a receive antenna by an antenna isolation factor that provides a second noise attenuation factor in the receive band. The apparatus also includes a noise canceler configured to subtract a detection signal from a received signal to obtain an adjusted received signal, wherein subtraction of the detection signal provides a third noise attenuation factor in the receive band, and wherein the first, second, and third noise attenuation factors combine to provide a selected amount of noise attenuation in the receive band.

Abstract: A system, method and apparatus for digital communication that is insensitive to a sampling clock error. In one embodiment, a digital communication system that is insensitive to a sampling clock error is provided. The digital communication system includes a transmitting communication unit and a receiving communication unit. The transmitting communication unit is configured to generate a digital data communication signal and includes a modulator configured to modulate digital data such that the modulated digital data communication signal is invariant to a stretched frequency scale resulting from a lack of synchronization with a receiving communication unit. The receiving communication unit is configured to receive the digital data communication signal and includes a demodulator configured to demodulate the digital data.

Abstract: A method for beamforming digitized signals from a sensor array to enhance signals originating from a preselected angle of interest and a preselected range bin while suppressing interference signals from other angles of arrival. Snapshots of sensor data are acquired and used to estimate an autocorrelation function. An autoregressive model of power is determined over angles of arrival as polynomial coefficients and roots are calculated as associated with the interference signals. Roots are selected for suppression by providing nulls. Exponentials are constructed from the roots. The exponentials are used with variances from the autoregressive model to provide a synthetic covariance matrix having weights that suppress the interference signals.

Abstract: Techniques for compensating for signal impairments introduced by a mixer are discussed. One example system employing such techniques can include mixer predistortion circuitry configured to receive signal in-phase (I) and signal quadrature (Q) components of a signal and to generate a mixer predistortion signal based at least in part on the signal I and Q components, wherein the mixer predistortion signal compensates for nonlinearities caused by a mixer that upconverts the signal. Optionally, imbalance correction circuitry to compensate for gain and phase imbalance and/or skew correction circuitry to compensate for gain and phase skew can also be included.

Abstract: The present disclosure provides advantageously flexible and effective methods, circuits and systems for digital predistortion. In one embodiment, a predistortion component circuit includes multiple configurable delay line pairs and corresponding configurable look-up tables. Each configurable delay line pair includes a first delay line for delaying an input data signal to provide a delayed input and a second delay line for delaying an input magnitude signal to provide a delayed input magnitude. Each configurable look-up table receives the delayed input magnitude from, and outputs a look-up value for, an associated delay line pair of the plurality of configurable delay line pairs. Other embodiments, aspects and features are also disclosed herein.

Abstract: A device may use enhanced power amplifier (PA) linearization techniques such as adaptive feed-forward (FF) linearization using adaptive filters. In one example, an adaptive feed-forward linearizer may isolate a distortion signal based at least in part on the signals input to and output from a PA in a transmission path. The distortion signal may be used to cancel distortion at the output of the PA to produce an improved output signal. A first adaptive circuit may be used to produce the distortion signal and a second adaptive circuit may be used to produce an error cancellation signal based at least in part on the distortion signal. The error cancellation signal may be amplified and re-introduced to the transmission path to produce the improved output signal. Semi-adaptive circuits may be used in place of the adaptive circuits, or a hybrid approach may be used.

Abstract: A nonlinear distorter is configured to mitigate nonlinearity from a nonlinear component of a nonlinear system. The nonlinear distorter operates to model the nonlinearity as a function of a piecewise polynomial approximation applied to segments of a nonlinear function of the nonlinearity. The nonlinear distorter generates a model output that decreases the nonlinearity of the nonlinear component.

Abstract: A device coupled to a noisy channel having periodic impulse noise in a network may estimate an effective signal to noise ratio (SNR) by receiving a packet of symbols. The device may determined a number of bad symbols N(bad) ratio in the packet due to interference and a remaining plurality of good symbols in the packet. An SNR value may be computed based on only the plurality of good symbols in the packet of symbols to form an SNR(good) value. An SNR correction value (SNR(offset)) may be determined as a function of the N(bad) ratio and the SNR(good) value. An effective SNR value may then be calculated by adjusting the SNR(good) value according to SNR(offset).

Abstract: A digital predistortion apparatus comprising: a nonlinear device; a memory effect compensator; a constant value characteristic acquirer; a cost function generator; and a coefficient updater is described.

Abstract: Digital signal processors (DSPs) process the digital baseband signals associated with CPRI links between BBUs and RRHs. The DSPs may be implemented at the RRH nodes (e.g., at the link leading to the BBU node), at the BBU node (e.g., at the links leading to the RRH nodes), or at both. The DSPs may be used to increase performance of the RAN. For example, the DSPs may implement digital filters designed to enhance the performance of the RAN.

Abstract: A method of compensating phase imbalance comprises, detecting power outputs of a first output signal related to a first phase compensation value and of a second output signal related to a second phase compensation value; calculating a first absolute difference between an in-phase value and a quadrature value of the power output of the first output signal; calculating a second absolute difference between an in-phase value and a quadrature value of the power output of the second output signal; determining a minimum difference by comparing the first absolute difference with the second absolute difference; determining an optimal phase compensation value and a suboptimal phase compensation value from the first and the second phase compensation values according to the minimum difference; and obtaining an updated optimal phase compensation value with a binary search algorithm.

Abstract: Exemplary embodiments are related to digital pre-distortion in envelope tracking systems. A device may include an amplitude modulation-to-phase modulation (AM-PM) distortion unit configured to generate an AM-PM distortion component in response to receipt of phase data of an input transmit signal. The device may also include a local oscillator (LO) path coupled to the distortion unit and configured to convey a local oscillator (LO) signal that varies based on the AM-PM distortion component.

Abstract: Techniques are described for optimizing the processing facilities of a receiver in a wireless communication environment, taking into account processing performance set against the computing resources and/or power consumption required to obtain that processing performance. A radio receiver for a wireless communications system can include channel equalization means arranged to receive samples of an incoming signal and to generate an equalized output, said channel equalization means including means for processing said digital samples in accordance with an equalizer algorithm. The receiver includes means for estimating parameters of a channel over which the incoming signal has been transmitted. The receiver can also include means for selecting from a plurality of equalizer algorithms an equalizer algorithm for execution by the processing means based on at least one said estimated channel parameter. Related methods and algorithms are described. Related computer program products are also described.

Abstract: A serializer and de-serializer circuit which is particularly well-suited for use in communicating digital data from one integrated circuit (chip) to another for implementing chip-to-chip communications is presented. The circuits are scalable and utilize a multi-frequency quadrature amplitude modulation (QAM) mechanism for converting digital data bits from a parallel form into a serial analog stream for communication over a chip I/O connection. The serializer has multiple digital-to-analog converters (DACs) whose outputs are directed to QAM mixer inputs, within QAMs at multiple frequencies, whose outputs are summed into a single analog signal for communication over an I/O connection. The de-serializer amplifies the analog signal which is received by QAM mixers at different frequencies, whose outputs are low pass filtered and converted back to parallel digital data bits.

Abstract: A spurious frequency attenuation servo comprises a first signal generated at a first frequency including at least one spur at at least one respective spurious frequency (spur). The signal is filtered by a first fixed filter. A single sideband (SSB) mixer is configured to output a SSB output signal that comprises a difference of frequencies of an output of the first fixed filter mixed with another signal. The SSB output signal includes a direct current component and the spur, and is received by a second fixed filter, which filters out the SSB output signal and outputs the spur. At least one spur attenuation controller is configured to accumulate error after reading an error term in the spur and to keep integrating until the error term is driven to zero. At least one spur killer is configured to remove the spur when the error term is driven to zero.

Abstract: To suppress noise generation in a wide band and to suppress a clock speed from being increased in a sigma-delta modulation apparatus and a sigma-delta modulation power amplifier. A sigma-delta modulator creates a sigma-delta modulated signal for a digital output from a digital modulator, according to a clock given in advance. A threshold comparator indexes a portion in which the level of a digital output from the digital modulator is higher than a predetermined threshold and sends the resulting output. A replacing unit replaces the indexed portion with an output from a corresponding thinning unit. A filter unit performs band elimination filter processing on an output from the replacing unit and a digital-to-analog converter (D/A) performs digital-to-analog conversion on an output from the filter unit.

Abstract: A radio receiver circuit (10) configurable to operate in a carrier-aggregation, CA, mode and in a non-CA mode is disclosed. It comprises a first receive path (30) arranged to be operatively connected to an antenna (15) and a second receive path (40) arranged to be operatively connected to the same antenna (15). It further comprises a control unit (50) operatively connected to the first receive path (30) and the second receive path (40). In the CA mode, the control unit (50) controls the first receive path (30) to receive a first CC (6) and the second receive path to receive a second CC (8). In the non-CA mode, the control unit (50) selectively controls the first receive path (30) and the second receive path (40) to both receive the same single CC (6).

Abstract: A signal transmitting device includes: a signal processing circuit arranged to process an input signal to generate a processed input signal according to a compensating signal; a signal converting circuit arranged to convert the processed input signal to generate an output signal according to an oscillating signal; and an arithmetic circuit arranged to generate the compensating signal according to the power of a predetermined component in the output signal, wherein the signal processing circuit uses the compensating signal to update the input signal, and the signal converting circuit converts the updated input signal to reduce the power of the predetermined component in the output signal.

Abstract: A wireless communication device (400) is arranged to transmit a transmission signal in an assigned channel bandwidth. The wireless communication device (400) comprises: a local oscillator (460) arranged to generate a local oscillator signal at a local oscillator frequency and a modulator (434) arranged for converting in-phase and quadrature-phase components of a modulation signal at a modulation frequency to a radio frequency by mixing the in-phase and quadrature-phase components with the local oscillator signal. The local oscillator frequency is arranged to place a third order intermodulation product having a frequency equal to the local oscillator frequency minus three times the modulation frequency within the assigned channel bandwidth.