Abstract: A test signal for determining a frequency-dependent or any other property of a receiver path is proposed. The test signal comprises, in a time domain representation, a sequence of discrete states that may be periodically repeated and that gives rise to a plurality of discrete tones in a frequency domain representation of the test signal. The test signal can be utilized for determining a frequency-dependent imbalance (e.g., an IQ imbalance) between different signal branches of a receiver or transmitter.

Abstract: Spatial sensor data, such as position, movement and rotation, which is provided by a sensor in a wireless communication device in a wireless communication system is used. By using the spatial sensor data it is possible to calculate predicted spatial data for use in controlling antenna beams for transmission as well as reception in the wireless communication system.

Abstract: A continuous-time ??-ADC (1) is disclosed, comprising a sampled quantizer (5) arranged to generate samples y(n) of a digital output signal of the ??-ADC (1) at sample instants nT. The ??-ADC (1) further comprises two or more DACs (10a-b), each arranged to generate an analog feedback signal based on the samples of the digital output signal generated by the sampled quantizer (5), and a continuous-time analog network (20) arranged to generate an analog input signal to the quantizer (5) based on the feedback signal(s) from the two or more DACs (10a-b) and an analog input signal to the ??-ADC (1). At least a first DAC (10a) of the two or more DACs (10a-b) is adapted to generate a pulsed feedback signal that, for each n, comprises a pulse, the magnitude of which is proportional to the sample of the digital output signal at sample instant nT and which lasts between the time instants (n+a1)T and (?+?1)T, wherein 0<?1<?1<1.

Abstract: A frequency translation filter 500 is configured to receive a radio frequency (RF) signal 501 comprising first and second non-contiguous carriers or non-contiguous frequency ranges. The frequency translation filter comprises a mixer 503 configured to mix the RF signal 501 received on a first input with a local oscillator (LO) signal 505 received on a second input. A filter 507 comprises a frequency dependent load impedance, the filter having band-pass characteristics which, when frequency translated using the mixer 503, contain first and second pass-bands corresponding to the first and second non-contiguous carriers or non-contiguous frequency ranges. The first and second pass-bands are centered about the local oscillator frequency.

Abstract: A complex intermediate frequency mixer (IFM) for frequency translating a received complex intermediate frequency, IF, signal, wherein the received complex IF signal comprises at least two frequency bands located at upper-side and lower-side of 0 Hz, is provided. The complex intermediate frequency mixer comprises a first, second, third and fourth mixer (M1, M2, M3, M4). The complex intermediate frequency mixer further comprises a first, second, third and fourth gain adjusting component (?1, ?2, ?2, ?1), connected to a first, second, third and fourth mixer output (M1-out, M2-out, M3-out, M4-out), respectively. Moreover, a first summing unit (S1), connected to a first gain output (?1-out), a fourth gain output (?1-out) and a third mixer output (M3-out) negated, and second summing unit (S2), connected to the second gain output (?2-out), the third gain output (?2-out) and the fourth mixer output (M4-out), are configured to output a first baseband complex signal of the received complex IF signal.

Abstract: In a dual-carrier, double-conversion Orthogonal Frequency Division Multiplexing (OFDM) receiver a frequency synthesizer generates a first local oscillator signal for the first down-conversions stage of the receiver. A frequency divider is used to derive a second local oscillator signal from the first local oscillator signal, thus eliminating the need for a separate frequency synthesizer for the second down-conversion stage. A controller determines the frequency of the first local oscillator signal and a divisor M to align subcarrier grids for said first and second baseband signals with DC.

Abstract: The present disclosure relates to a technique for performing physical layer measurements on a frequency resource relative to other frequency resources in a telecommunications system operable to communicate over multiple frequency resources.

Abstract: A complex intermediate frequency mixer (IFM) for frequency translating a received complex intermediate frequency, IF, signal, wherein the received complex IF signal comprises at least two frequency bands located at upper-side and lower-side of 0 Hz, is provided. The complex intermediate frequency mixer comprises a first, second, third and fourth mixer (M1, M2, M3, M4). The complex intermediate frequency mixer further comprises a first, second, third and fourth gain adjusting component (?1, ?2, ?2, ?1), connected to a first, second, third and fourth mixer output (M1-out, M2-out, M3-out, M4-out), respectively. Moreover, a first summing unit (S1), connected to a first gain output (?1-out), a fourth gain output (?1-out) and a third mixer output (M3-out) negated, and second summing unit (S2), connected to the second gain output (?2-out), the third gain output (?2-out) and the fourth mixer output (M4-out), are configured to output a first baseband complex signal of the received complex IF signal.

Abstract: A mixer unit (30) for frequency translating, based on an LO signal, an input signal having one or more input signal components is disclosed. The mixer unit has a signal processing path (50a-d, 60a-d) from each Input terminal (32+, 32?) to each output terminal (34_I+, 34_I?, 34_Q+,34_Q?) of the mixer unit (30), The LO signal has an associated LO signal component (LO_Ia-d, LO_Qa-d) for each signal processing path. The mixer unit (30) comprises a plurality of mixer switches (70a-N) and a control unit (90). The control unit (90) is adapted to, for each signal processing path (50a-d, 60a-d), dynamically select an associated subset, in the following denoted active switch subset, of the plurality of mixer switches (70a-N) for operation in the signal processing path (50a-d, 60a˜d) such that which of the plurality of mixer switches (70a-N) belong to said active switch subset varies in time.

Abstract: Levels of power reduction for signals to be transmitted from a mobile communications device via radio channels in a digital wireless communications system, where each signal is modulated according to one of a number of modulation configurations, are determined. For each modulation configuration a first estimate of a power reduction is calculated (101), and the calculated first estimates are storied (102) in the device. The method comprises the steps of determining (103) a limited set of modulation configurations, said limited set comprising modulation configurations that have been determined likely to be used in practice; calculating (104) for each modulation configuration of the limited set an optimized estimate of a power reduction; and storing (105) the calculated optimized estimates in the device. In this way the power consumption of the device is reduced while keeping a look-up table at a reasonable size.

Abstract: A continuous-time ??-ADC (1) is disclosed. It comprises a sampled quantizer (5) arranged to generate samples y(n) of a digital output signal of the ??-ADC (1) at sample instants nT, where n is an integer sequence index and T is a sampling period, based on an analog input signal to the quantizer (5). Furthermore, the ??-ADC (1) comprises one or more DACs (10a-b), each arranged to generate an analog feedback signal based on the samples of the digital output signal generated by the sampled quantizer (5). Moreover, the ??-ADC (1) comprises a continuous-time analog network (20) arranged to generate the analog input signal to the quantizer (5) based on the feedback signal(s) from the one or more DACs (10a-b) and an analog input signal to the ??-ADC (1). At least one DAC (10b) of the one or more DACs (10b) comprises two switched-capacitor DACs (40, 50) arranged to operate on the same input but with a mutual delay in time.

Abstract: A method of scheduling wireless data transmissions between a mobile terminal and a base station using multiple system carrier signals is disclosed. The method comprises the steps of receiving (101) the mobile terminal information from the base station indicating available system carriers; detecting (102) at least one dynamic parameter indicative of the mobile terminal's current capability to handle non-contiguous system carriers; determining (103) from the dynamic parameter whether a situation has occurred where the mobile terminal's capability to handle non-contiguous system carriers has been reduced; modifying (104), in such case, feedback information to be transmitted to the base station; and transmitting (105) the modified feedback information to the base station.

Abstract: The present disclosure relates to a technique for performing physical layer measurements on a frequency resource relative to other frequency resources in a telecommunications system operable to communicate over multiple frequency resources.

Abstract: Interference cancellation techniques may be implemented in a radio transceiver configured to transmit a radio-frequency transmit signal at a transmit frequency and having two or more local oscillators operative to simultaneously generate local oscillator signals, at corresponding local oscillator frequencies, for simultaneously down-converting two or more corresponding received radio-frequency signals. An example method begins with identifying one or more self-interfering frequencies, based on the local oscillator frequencies and the transmit frequency. A baseband cancellation signal is then generated by weighting and frequency-shifting a baseband representation of the transmit signal, based on the identified self-interfering frequencies. The baseband cancellation signal is then combined with a down-converted received signal, to obtain an interference-reduced baseband signal.

Abstract: A conversion circuit for converting a complex analog input signal having an in-phase (I) component and a quadrature-phase (Q) component is disclosed. It comprises a channel-selection filter configured to filter the complex analog input signal, thereby generating a channel-filtered I and Q components, and one or more processing circuits. Each processing circuit comprises four mixers for generating a first and a second frequency-translated I component, and a first and a second channel-filtered Q component based on two LO signals with equal LO frequency and a 90° mutual phase shift. Each processing circuit also comprises a combiner circuit for generating a first, a second, a third, and a fourth combined signal proportional to sums and differences between the frequency translated I and Q components. The first and the fourth combined signals form a first complex signal, and the second and the third combined signals form a second complex signal.

Abstract: The present invention relates to a method and device for performing automatic gain control of a received signal. The method comprises the steps of receiving (S101) the signal and amplifying the received signal on the basis of a difference between a power reference value and actual power of the amplified signal. The method further comprises the steps of determining (S102) signal-to-interference ratio of the received signal and controlling (S103) amplification such that the amplified signal attains a target power level by further taking into account the determined signal-to-interference ratio, which target power level is increased as the determined signal-to-interference ratio decreases.

Abstract: A technique for cancelling or reducing crosstalk signals between controlled oscillators in an integrated circuit is provided. The technique involves an arrangement adapted to reduce a crosstalk signal generated by a first controlled oscillator to a second oscillator both comprised in the integrated circuit, wherein both controlled oscillators are configured to output a respective clock signal. The arrangement comprises a detector adapted to detect the crosstalk signal generated by the first controlled oscillator to the second controlled oscillator, a crosstalk cancellation circuit adapted to generate a cancellation signal having an amplitude substantially the same as that of the crosstalk signal and a phase substantially opposite to that of the crosstalk signal, and a cancellation signal injector adapted to introduce the cancellation signal into the second controlled oscillator.

Abstract: A continuous-time ??-ADC (1) is disclosed, comprising a sampled quantizer (5) arranged to generate samples y(n) of a digital output signal of the ??-ADC (1) at sample instants nT. The ??-ADC (1) further comprises two or more DACs (10a-b), each arranged to generate an analog feedback signal based on the samples of the digital output signal generated by the sampled quantizer (5), and a continuous-time analog network (20) arranged to generate an analog input signal to the quantizer (5) based on the feedback signal(s) from the two or more DACs (10a-b) and an analog input signal to the ??-ADC (1). At least a first DAC (10a) of the two or more DACs (10a-b) is adapted to generate a pulsed feedback signal that, for each n, comprises a pulse, the magnitude of which is proportional to the sample of the digital output signal at sample instant nT and which lasts between the time instants (n+a1)T and (?+?1)T, wherein 0<?1<?1<1.

Abstract: Digital IQ imbalance estimation and compensation is facilitated by shaping the frequency response of receiver branches. In particular, in a multi-carrier receiver, the frequency response of signal processing elements in at least one receiver branch is set to not fully attenuate received signals in a frequency band of interest. The frequency band of interest is greater than the carrier bandwidth of the received signal processed by that receiver branch. In some embodiments, the received signal is not attenuated, and adjacent interfering signals are partially attenuated. This allows information regarding the interfering signals to appear in an IQ imbalance-induced, inter-carrier image of the signals in anther receiver branch, facilitating digital estimation and compensation of IQ imbalance.

Abstract: The invention relates to a complex intermediate frequency (CIF) mixer stage, methods of operation thereof, and methods of calibration thereof. The CIF mixer stage comprises numerous individual mixers driven by IF clock signals to down-convert received IF signals into a set of signals at baseband frequency which are further combined to form a lower side band signal and an upper side band signal. The IF clock signals used have a predefined phase relationship among them, which involves tuneable phase skews. By calibration of the conversion gains and the phases of the IF clock signals the gain and phase imbalance introduced in a preceding radio frequency mixer stage and/or the CIF mixer stage can be cancelled. Further, in-channel IQ leakage control can be applied to the lower side band signal and/or the upper side band signal. The CIF mixer stage can thus effectively suppress image interference and IQ leakage.