Abstract: The teachings herein provide a number of advantages, including but not limited to improving soft-cell operation in service scenarios involving legacy devices that do not directly support carrier aggregation—i.e., devices that can transmit or receive in only one frequency band at a time. By imposing a Time Division Duplex (TDD) arrangement across two carriers operating in different frequency bands, scheduled transmissions involving the legacy device are mutually exclusive as between the two carriers. Advantageously, the TDD arrangement is imposed across first and second carriers used in the macro- and low-power layers of a soft-cell, thus imposing TDD-based coordination of scheduled transmissions between those carriers irrespective of whether the individual carriers are configured as Frequency Division Duplex (FDD) or TDD carriers, or a mix thereof.

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 network node (100) enabled to work, within a cellular communication system comprising a plurality of base stations (102), according to a device-to-device, D2D communication mode is disclosed. The network node (100) can also have backhaul (600) capability via a second communication network (602) distinct from a backbone network (502) of the cellular communication network and is enabled to provide D2D communication by direct or multi-hop communication with other nodes or terminals (104, 106) on a peer level for providing service via the second communication network (602) when operating in the D2D communication mode. The network node (100) can have backhaul (500) capability via a backbone network (502) of the cellular communication network, wherein the network node (100) is further enabled to work according to a device-to-device, D2D communication mode within and under control of the cellular communication network. Methods and computer program are also disclosed.

Abstract: A method of estimation of harmonic distortion level for a radio receiver operative in a cellular communication system enabled to receive signals from transmitters of one or more cells is disclosed. The method comprises measuring, within a bandwidth of operation, a total received signal power; measuring, within the bandwidth of operation, a received signal power of signals received from the one or more cells, respectively; and estimating a level of harmonic receiver distortions by: determining whether a fraction of the total received signal power and a theoretical noise floor is below or above a first threshold; or determining whether a remaining part of the total received signal power, said remaining part not including said fraction, is above or below a second threshold. A such radio receiver, and a computer program for implementing the method are also disclosed.

Abstract: A down-conversion circuit for a receiver circuit is disclosed. It comprises a first mixer arranged to down-convert an RF signal with a first LO signal (LO1), thereby generating a first down-converted signal. It further comprises a second mixer arranged to down-convert the RF signal with a second LO signal (LO2) having the same LO frequency as the first LO signal (LO1), but a different and a second duty cycle, thereby generating a second down-converted signal. The second mixer has an enabled and a disabled mode. The down-conversion circuit also comprises a third mixer arranged to down-convert the RF signal with the second LO signal (LO2), thereby generating a third down-converted signal.

Abstract: The present invention relates to scheduling of uplink and downlink resources between mobile terminals (110, 120) and a base station (130). To reduce the power leakage between the transmitter and the receiver of the mobile terminal (110), the scheduler allocates uplink frequency carriers and downlink frequency carriers with a large duplex distance to those mobile terminals (110, 120) that have to transmit with high power. This means that the requirements on the external SAW filter could be reduced.

Abstract: A technique of suppressing noise in a transmitter device (300) is provided, wherein the transmitter device (300) comprises a baseband signal processing stage (301) operating at baseband frequency and comprising a modulator (316, 320) for converting a baseband signal into an RF signal, and an RF signal processing stage (301) operating at RF and comprising an amplifier (330).

Abstract: A method of frequency down-converting an input signal to an output signal, a first local oscillator signal is generated as a square wave having a duty cycle of 1/3 or 2/3, and the input signal is mixed with first oscillator signal to achieve a first down-converted signal, a second local oscillator signal is generated as a modified square wave having the same period time as the first oscillator signal and a duty cycle of 2/3, of which one part has a positive amplitude and another part has a negative amplitude. The input signal is mixed with the second oscillator signal to achieve a second down-converted signal. The first oscillator signal has a delay of 1/4 of the period time to achieve a phase shift of ?/2 between the oscillator signals, and at least one down-converted signal is multiplied by a pre-calculated factor. The resulting down-converted signals are added to achieve the output signal.

Abstract: The teachings herein provide a number of advantages, including but not limited to improving soft-cell operation in service scenarios involving legacy devices that do not directly support carrier aggregation—i.e., devices that can transmit or receive in only one frequency band at a time. By imposing a Time Division Duplex (TDD) arrangement across two carriers operating in different frequency bands, scheduled transmissions involving the legacy device are mutually exclusive as between the two carriers. Advantageously, the TDD arrangement is imposed across first and second carriers used in the macro- and low-power layers of a soft-cell, thus imposing TDD-based coordination of scheduled transmissions between those carriers irrespective of whether the individual carriers are configured as Frequency Division Duplex (FDD) or TDD carriers, or a mix thereof.

Abstract: In a method of frequency down-converting an input signal to an output signal, a first local oscillator signal is generated as a square wave having a duty cycle of 1/3 or 2/3, and the input signal is mixed with the first oscillator signal to achieve a first down-converted signal, A second local oscillator signal is generated as a modified square wave having the same period time and a duty cycle of 2/3, of which one part has a positive amplitude and another part has a negative amplitude. The input signal is mixed with the second oscillator signal to achieve a second down-converted signal. The first oscillator signal has a delay of 1/4 of the period time to achieve a phase shift of ?/2 between the oscillator signals, and at least one down-converted signal is multiplied by a pre-calculated factor. The resulting down-converted signals are added to achieve the output signal.

Abstract: User equipment comprising a receiver obtains information about a set of channels to be sensed in a sensing process, wherein each channel is associated with a respective one of a number of radio frequencies. The receiver obtains a radio frequency signal by simultaneously sensing two or more of the channels included in the set of channels. A total power level of the sensed two or more channels is measured, and a comparison result is generated by comparing the total power level of the sensed two or more channels with a predetermined power level. The user equipment is controlled based on the comparison result. For example, if the total power level is below a threshold, then the sensed channels can be considered to not be in use by external transmission equipment.

Abstract: A quadrature connected passive mixer arrangement for frequency converting analog signals from a first to a second frequency. The arrangement comprises two parallel connected mixers provided as transistors. First and second LO signals and their inverse signals having separated phases are provided for driving the transistors. Signal path switches are provided between the RF terminals and the mixer transistors. The switches are driven by signals having a different phase than the signal driving the corresponding mixer transistor. Thus, any short circuit between IF terminals of the arrangement may be eliminated.

Abstract: The second-order inter-modulation distortion, originating in a differential passive mixer core from imbalance between devices, is reduced by compensating for the mismatch or load, by means of tuning the differential output impedance at the mixer core, or the input impedance of a filter coupled to the output of the passive mixer. Compensating for the imbalance allows greater suppression of even-order harmonics in the differential structure, which reduces second-order intermodulation at the output of the mixers. The compensation is achieved by tunable resistive elements that are calibrated by a built-in self-test architecture. The calibration circuit is deactivated during receiver operation.

Abstract: The present invention relates to scheduling of uplink and downlink resources between mobile terminals (110, 120) and a base station (130). To reduce the power leakage between the transmitter and the receiver of the mobile terminal (110), the scheduler allocates uplink frequency carriers and downlink frequency carriers with a large duplex distance to those mobile terminals (110, 120) that have to transmit with high power. This means that the requirements on the external SAW filter could be reduced.

Abstract: A quadrature connected passive mixer arrangement for frequency converting analog signals from a first to a second frequency. The arrangement comprises two parallel connected mixers provided as transistors. First and second LO signals and their inverse signals having separated phases are provided for driving the transistors. Signal path switches are provided between the RF terminals and the mixer transistors. The switches are driven by signals having a different phase than the signal driving the corresponding mixer transistor. Thus, any short circuit between IF terminals of the arrangement may be eliminated.

Abstract: According to one embodiment, a radio frequency receiver includes a quadrature mixer for converting radio frequency signals to baseband signals or intermediate frequency signals. The quadrature mixer includes an in-phase passive mixer and a quadrature-phase passive mixer. Each passive mixer includes a mixer core having a plurality of mixer input switch transistors and a plurality of output switch transistors connected to the mixer input switch transistors. Clock circuitry generates a first set of clock signals and a second set of clock signals. The first set of clock signals has a frequency twice that of the second set of clock signals. The first set of clock signals is arranged to drive the mixer input switch transistors and the second set of clock signals is arranged to drive the output switch transistors.

Abstract: A quadrature connected passive mixer arrangement for frequency converting analog signals from a first to a second frequency. The arrangement comprises two parallel connected mixers provided as transistors. First and second LO signals and their inverse signals having separated phases are provided for driving the transistors. Signal path switches are provided between the RF terminals and the mixer transistors. The switches are driven by signals having a different phase than the signal driving the corresponding mixer transistor. Thus, any short circuit between IF terminals of the arrangement may be eliminated.

Abstract: A technique of suppressing noise in a transmitter device (300) is provided, wherein the transmitter device (300) comprises a baseband signal processing stage (301) operating at baseband frequency and comprising a modulator (316, 320) for converting a baseband signal into an RF signal, and an RF signal processing stage (301) operating at RF and comprising an amplifier (330).

Abstract: User equipment comprising a receiver obtains information about a set of channels to be sensed in a sensing process, wherein each channel is associated with a respective one of a number of radio frequencies. The receiver obtains a radio frequency signal by simultaneously sensing two or more of the channels included in the set of channels. A total power level of the sensed two or more channels is measured, and a comparison result is generated by comparing the total power level of the sensed two or more channels with a predetermined power level. The user equipment is controlled based on the comparison result. For example, if the total power level is below a threshold, then the sensed channels can be considered to not be in use by external transmission equipment.

Abstract: A passive, differential RF mixer reduces second order intermodulation interference while maintaining I/Q isolation via common mode feedback wherein the I and Q error signals in the feedback path are time multiplexing using a four-phase LO signal. An RF signal is received at a differential input having a center tap. The RF signal is mixed with an in-phase differential signal of the four-phase local oscillator signal in a differential mixer (I mixer). The RF signal is also mixed with a quadrature-phase differential signal Q components of the four-phase local oscillator signal in a differential mixer (Q mixer). The common mode levels of the I and Q differential mixer outputs are compared to a reference DC voltage to generate I and Q error signals. The I and Q error signals are time-multiplexed, and fed back to the RF input center tap.