Abstract: A radio transceiver is disclosed. It comprises a first transceiver circuit and a second transceiver circuit, the latter requiring an LO signal having higher LO frequency than the former. It further comprises a frequency synthesizer comprising a first clock-signal generator adapted to generate the LO signal for the first transceiver circuit based on a first reference oscillation signal and a second clock-signal generator adapted to generate the LO signal for the second transceiver circuit based on a second reference oscillation signal, which is or is derived from the LO signal for the first transceiver circuit. A radio communication apparatus comprising the radio transceiver is also disclosed.

Abstract: A technique for controlling suppression of self-interference in a relay node configured to transmit and receive simultaneously using the same frequency channel or using proximate frequency channels is provided. A method implementation of this technique comprises the steps of actively cancelling a signal transmitted from the relay node that leaks back into a receiver of the relay node to suppress self-interference, determining whether an increase of an amount of self-interference suppression is needed or whether self-interference suppression can be decreased, and increasing or decreasing, depending on the result of the determination, at least one of the transmit power of the signal transmitted from the relay node and the receive power of the relay node.

Abstract: In a multi-carrier wireless system, potential problems from reconfiguring mobile station resources to accommodate changes in component-carrier configuration are mitigated by inserting a guard period each time the configuration of component carriers changes, so that transceiver reconfiguration can be carried out without interfering with ongoing transmission. A base station is configured to transmit data to a mobile station according to a first configuration of two or more component carriers, to determine that a change of configuration to a second component-carrier configuration is required, and to signal the change of configuration to the mobile station, using the first configuration of component carriers. The base station then refrains from transmitting data to the mobile station during a pre-determined guard interval of at least one transmission-time interval subsequent to the signaling of the change of configuration.

Abstract: It is disclosed a mixer arrangement for complex signal mixing comprising a first harmonic rejection mixer, and a second harmonic rejection mixer. Each of the harmonic rejection mixers comprises mixer unit cells wherein each mixer unit cell comprises a differential input, transconductance elements corresponding to the differential input, and a switching network arranged to switch signals from the transconductance elements to a differential output, and the first and the second harmonic rejection mixers have mutual quadrature phase relationship. The first and the second rejection mixer share a plurality of mixer unit cell, each comprising an input for receiving a signal to be mixed, an input for receiving control signals derived from a local oscillator signal, and one output for each of the first and second harmonic rejection mixers. A radio circuit comprising such a mixer arrangement and a communication apparatus comprising such a radio circuit are also disclosed.

Abstract: The phase-locked loop (PLL) presented herein controls the phase of the output of the PLL. To that end, the PLL includes an oscillator that generates an output signal at an output of the PLL responsive to a comparison between a reference signal input to the PLL and a feedback signal derived from the output signal. To control the phase of the output signal, a modulation signal is applied to one input of the oscillator, separate from the reference signal input, where the modulation signal comprises one or more pulses having a total area defined based on the desired phase shift. To maintain the desired phase shift at the output of the PLL, the PLL also sets a time relationship between the reference signal and the feedback signal based on the desired phase shift.

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: 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: Methods and a receiver of positioning a spurious signal for reducing the impact of the spurious signal on a received Orthogonal Frequency Division Multiplexing, OFDM signal, are presented. The method comprises determining the frequency of a spurious signal (steps 102, 204, 404), determining the frequency for the respective sub-carrier of the OFDM signal and the difference between the frequency of a sub-carrier and the frequency of a spurious signal (steps 104, 206, 406), and adjusting at least one of: the frequency of the first oscillator (step 208) and a parameter related to the frequency of a second oscillator, to decrease the frequency difference between a sub-carrier and a spurious signal (steps 106, 212, 408). By positioning a spurious signal at or near a sub-carrier frequency, the performance impact of the spurious signal is reduced, and the receiver performance improved.

Abstract: The phase-locked loop (PLL) presented herein controls the phase of the output of the PLL. To that end, the PLL includes an oscillator that generates an output signal at an output of the PLL responsive to a comparison between a reference signal input to the PLL and a feedback signal derived from the output signal. To control the phase of the output signal, a modulation signal is applied to one input of the oscillator, separate from the reference signal input, where the modulation signal comprises one or more pulses having a total area defined based on the desired phase shift. To maintain the desired phase shift at the output of the PLL, the PLL also sets a time relationship between the reference signal and the feedback signal based on the desired phase shift.

Abstract: The phase-locked loop (PLL) presented herein controls the phase of the output of the PLL. To that end, the PLL includes an oscillator that generates an output signal at an output of the PLL responsive to a comparison between a reference signal input to the PLL and a feedback signal derived from the output signal. To control the phase of the output signal, a modulation signal is applied to one input of the oscillator, separate from the reference signal input, where the modulation signal comprises one or more pulses having a total area defined based on the desired phase shift. To maintain the desired phase shift at the output of the PLL, the PLL also sets a time relationship between the reference signal and the feedback signal based on the desired phase shift.

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 quadrature mixer arrangement is disclosed, which is adapted to translate an input signal by a translation frequency. The mixer arrangement is operated at a clock rate that equals the translation frequency times an oversampling rate, wherein the oversampling rate is not a multiple of four. The mixer arrangement comprises a sequence generator, at least one pair of mixers, and one or more correction networks. The sequence generator generates an in-phase mixer translation sequence and a quadrature-phase mixer translation sequence based on the oversampling rate. The in-phase mixer translation sequence is a time-discrete representation of a translation frequency sinusoidal function sampled at the clock rate, and the quadrature-phase mixer translation sequence is a time-discrete representation of the translation frequency sinusoidal function phase-shifted by ?/2 plus a phase deviation and sampled at the clock rate, wherein the phase deviation is a function of the oversampling rate.

Abstract: An attenuator control method of a signal processing chain comprising two or more signal processing units is disclosed. One of the two or more signal processing units is a signal attenuator adapted to apply adaptive signal attenuation of an attenuator input signal based on one or more attenuation parameters to provide an attenuator output signal. At least one of the two or more signal processing units has an associated wearout process and a corresponding wearout budget, wherein a wearout event of the wearout process occurs when a level of a wearout indication signal of the signal processing chain is in a wearout region, and wherein the wearout process is modeled by a wearout event cost associated with a corresponding wearout event. The method comprises obtaining an indication of whether a wearout event of the wearout process has occurred.

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: A mobile communications terminal comprising a radio frequency interface configured to operate at least at a first configuration, and a controller, wherein said controller is configured to determine that a reconfiguration of the radio frequency interface is to be performed, determine a timing of the reconfiguration and reconfigure said radio frequency interface to operate at a second configuration at the determined timing, wherein said controller is configured to determine said timing based on the type of reconfiguration to be made.

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: 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 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 radio transceiver is disclosed. It comprises a first transceiver circuit and a second transceiver circuit, the latter requiring an LO signal having higher LO frequency than the former. It further comprises a frequency synthesizer comprising a first clock-signal generator adapted to generate the LO signal for the first transceiver circuit based on a first reference oscillation signal and a second clock-signal generator adapted to generate the LO signal for the second transceiver circuit based on a second reference oscillation signal, which is or is derived from the LO signal for the first transceiver circuit. A radio communication apparatus comprising the radio transceiver is also disclosed.