Telefonaktiebolaget Lm Ericsson (publ)

Fredrik Tillman

Bengt Lindoff

Stefan Parkvall

Fredrik Gunnarsson

Leif Wilhelmsson

Lars Sundström

Henrik Sjöland

Fenghao Mu

Magnus Åström

Stefan Mikael Andersson

Christian Elgaard

Christian Bergljung

Imad Ud Din

Bo Hagerman

Sven Erik Mattisson

Johan Nilsson

Fredrik Nordström

Anders Rosenqvist

Johan Wernehag

Mattias Palm

Henrik Fredriksson

Daniel Eckerbert

Kirill Kozmin

Fabien Mesquita

Magnus ÅSTRÖM

Fredrik NORDSTRÖM

Henrik SJÖLAND

Lars SUNDSTRÖM

Stefan Andersson

A configurable passive mixer is described herein. According to one exemplary embodiment, a passive mixer for a wireless receiver comprises a plurality of passive mixer cores coupled in parallel with each mixer core configured to receive a same set of radio frequency input signals and a separately driven set of local oscillator input signals. Further, each mixer core is configured to be separately enabled or disabled so that the passive mixer can be selectively configured during operation to convert the same set of radio frequency input signals to a set of downconverted output signals that satisfy a certain performance requirement or performance parameter of the passive mixer.

Re-configurable passive mixer for wireless receivers

The disclosure concerns controlling circuitry operably connectable to a plurality of constituent analog-to-digital converters (sub-ADCs) of an asynchronous time-interleaved analog-to-digital converter (TI-ADC). The controlling circuitry is configured to maintain a set of a number of sub-ADCs currently available for processing of an input sample, wherein the set is a subset of the plurality. Maintenance of the set is achieved by reception, from each of one or more of the sub-ADCs of the plurality, of an availability signal indicative of availability of the corresponding sub-ADC, and (responsive to the reception of the availability signal) addition of the corresponding sub-ADC to the set. Maintenance of the set is further achieved by (for each new input sample) selection of a sub-ADC of the set for processing of the new input sample, and (responsive to the selection) removal of the selected sub-ADC from the set and causing of the selected sub-ADC to process the new input sample. Corresponding TI-ADC, wireless communication receiver, wireless communication node, method and computer program product are also disclosed.

Control of a time-interleaved analog-to-digital converter

An analog-to-digital conversion circuit () is disclosed. It comprises a switched-capacitor SAR-ADC, () arranged to receive an analog input signal (x(t)) and a clock signal, to sample the analog input signal (x(t)), and to generate a sequence (W(n)) of digital output words corresponding to samples of the analog input signal (x(t)), wherein the SAR-ADC () is arranged to generate a bit of the digital output word per cycle of the clock signal. It further comprises a clock-signal generator () arranged to supply the clock signal to the SAR-ADC (), and a post-processing unit () adapted to receive the sequence (W(n)) of digital output words and generate a sequence of digital output numbers (y(n)), corresponding to the digital output words, based on bit weights assigned to the bits of the digital output words. The bit weights are selected to compensate for a decay of a signal internally in the SAR-ADC ().

Leakage compensation for a successive approximation analog-to-digital converter

An integrated circuit (-) is disclosed, which is configured to be connected to an antenna module () having multiple antenna elements (). The integrated circuit (-) comprises a plurality of communications circuits (), each of which is configured to be connected to an antenna element () of the antenna module (). It also comprises a first clock input terminal () configured to receive a reference clock signal from outside the integrated circuit (-) and a first clock-distribution network () connected between the first clock input terminal () and a first subset () of the communication circuits (). Furthermore, it comprises a second clock input terminal () configured to receive a reference clock signal from outside the integrated circuit (-) and a second clock-distribution network () connected between the second clock input terminal () and a second subset () of the communication circuits ().

Integrated circuit with clock distribution

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.

Timing for radio reconfiguration in a mobile communications network

A configurable passive mixer is described herein. According to one exemplary embodiment, the passive mixer comprises a clock generator, a controller, and a plurality of passive mixer cores connected in parallel. The clock generator comprises a local oscillator drive unit for each passive mixer core. The controller varies an effective transistor size of the passive mixer by separately configuring each of the passive mixer cores to enable/disable each passive mixer core. For example, the controller may selectively enable one or more of the passive mixer cores to vary the effective transistor width of the passive mixer. As the performance requirements and/or the operating communication standard change, the controller may re-configure each passive mixer core.

There is provided a method of handling interference caused by inter-modulation in a network node. The method comprises detecting an interference level on an uplink carrier frequency band for stations, and determining whether the interference level indicates probable inter-modulation interference. If the interference level indicates probable inter-modulation interference, the method proceeds with scheduling an uplink transmission grant for at least one of the stations. The uplink transmission grant is valid for a first transmission time interval. The uplink transmission grant is transmitted to the station. A transmit level on the downlink carrier frequency band is assigned at the first transmission time interval such that inter-modulation interference is reduced on the uplink carrier frequency band at the first transmission time interval. An uplink transmission from the station is received at the first transmission time interval. Further methods, computer programs, a network node and a network node site are also disclosed.

Method and apparatus for handling inter-modulation interference in a network node capable of FDD communications

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.

Method and radio receiver enabling harmonic distortion estimation

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 (LO), 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 (LO) having the same LO frequency as the first LO signal (LO), 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 (LO), thereby generating a third down-converted signal. A passive output combiner network is used to combine the first and the second down-converted signals such that harmonically down-converted signal content present in the first down-converted signal and harmonically down-converted signal content present in the second down-converted signal cancel in a combined output signal of the down-conversion circuit. The down-conversion circuit further comprises a detection unit adapted to detect interference based on the first and third down-converted signals and to selectively set the second passive switching mixer in the enabled mode, for counteracting the interference, or in the disabled mode, for saving power compared with the enabled mode, based on the detection. A corresponding receiver circuit, a corresponding communication device, and a corresponding method are also disclosed.

Down-conversion circuit with interference detection

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&#x2014;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.

Method and apparatus for carrier aggregation

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

OFDMA scheduling method for avoiding leakage at the mobile stations

A technique of suppressing noise in a transmitter device () is provided, wherein the transmitter device () comprises a baseband signal processing stage () operating at baseband frequency and comprising a modulator () for converting a baseband signal into an RF signal, and an RF signal processing stage () operating at RF and comprising an amplifier (). A method implementation of this technique comprises the steps performed in a feedback loop () coupled around the amplifier () of tapping the RF signal processing stage downstream of the amplifier () to obtain an amplified RF signal comprising a baseband signal component and a noise component, downconverting the tapped RF signal to baseband frequency, removing the baseband signal component from the downconverted signal, upconverting the resulting signals still comprising the noise component to RF frequency and feeding the upconverted signal back to the RF signal processing stage upstream of the amplifier () thereby suppressing the noise component.

Technique for suppressing noise in a transmitter device

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 &#x3c0;/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.

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Lund, Sweden

Fredrik Tillman