Abstract: A radio transceiver circuit for FDD communication is disclosed. It comprises a transmitter for FDD signal transmission in a first frequency band, a first receiver for FDD signal reception in a second frequency band, separate from the first frequency band, and a duplexer. An output port of the transmitter is operatively connected to a first port of the duplexer for transmitting, through the duplexer, signals in said first frequency band. An input port of the first receiver is operatively connected to a second port of the duplexer for receiving, through the duplexer, signals in said second frequency band. The radio transceiver circuit comprises a second receiver, separate from the first receiver, for reception in said first frequency band. An input port of the second receiver is operatively connected to said first port of the duplexer for receiving, through the duplexer, signals in said first frequency band. A related radio communication apparatus is also disclosed.

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: A radio circuit comprises an interface unit for communicating data and commands over a communication link between a digital baseband circuit and the radio circuit. Furthermore, the radio circuit comprises an event-scheduling unit, a local time-reference unit, a synchronization unit, and an execution-control unit. The event-scheduling unit is arranged to receive event-request commands specifying an event to be executed in the radio circuit and a time instant at which the specified event is to be executed, from the digital baseband circuit. Furthermore, the event-scheduling unit is arranged to, in response to receiving an event request-command, schedule the specified event to be executed on the specified time instant. The execution-control unit is arranged to issue execution of each scheduled event at the scheduled time instant based on time information from the local time reference unit.

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: The disclosure relates to a Complex Intermediate Frequency (CIF)-based receiver adapted to process a received signal comprising a signal component at a desired frequency and a signal component as an image frequency. The CIF-based receiver determines the power of the received signal by calibrating the receiver to minimize the power of the signal component at the image frequency that interferes with the signal component at the desired frequency, introduces signal leakage from the image frequency to intentionally degrade the quality of the signal component at the desired frequency, and determines the power of the signal component at the image frequency based on the amount of degradation.

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: 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 radio-receiver circuit. The radio receiver circuit comprises an analog-to-digital conversion unit. The analog-to-digital conversion unit comprises an analog-to-digital converter, ADC, and a filter operatively connected to an input terminal of the ADC in a receive path of the radio-receiver circuit. The radio-receiver circuit further comprises a control unit adapted to receive control data and determine, based on the control data, a frequency band in which data is to be transmitted to the radio-receiver circuit during a subsequent time interval. Furthermore, the control unit is adapted to adapt at least one frequency characteristic of the analog-to-digital conversion unit to the determined frequency band for receiving said data transmitted in said subsequent time interval.

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.