Abstract: A method and a network agent for providing cell assignment for a wireless device served by a network node. An input vector is created for a set of candidate cells based on measurements by the wireless device and/or by the network node related to performance and signals. A future effect of assigning the wireless device to a candidate cell is estimated for each candidate cell by applying the created input vector to an effect estimation function which may be a Q-learning function. A cell in the set of candidate cells is then determined and assigned for the wireless device, based on the estimated future effects of the candidate cells. The cell that provides the best future effect may be selected for cell assignment.

Abstract: Systems and methods for ultra-wideband Crest Factor Reduction (CFR) are provided. In some embodiments, a method performed by a wireless node for performing CFR includes performing a first CFR step on a plurality of input signals at a first sampling rate with joint peak detection and band-specific noise shaping; and performing a second CFR step on the resulting plurality of input signals at a second sampling rate with joint peak detection and joint noise shaping where the second sampling rate is higher than the first sampling rate. In this way, Peak-to-Average Power Ratio (PAPR) reduction may be increased while the computational complexity is reduced.

Abstract: Systems and methods for ultra-wideband Crest Factor Reduction (CFR) are provided. In some embodiments, a method performed by a wireless node for performing CFR includes performing a first CFR step on a plurality of input signals at a first sampling rate with joint peak detection and band-specific noise shaping; and performing a second CFR step on the resulting plurality of input signals at a second sampling rate with joint peak detection and joint noise shaping where the second sampling rate is higher than the first sampling rate. In this way, Peak-to-Average Power Ratio (PAPR) reduction may be increased while the computational complexity is reduced.

Abstract: A method and a network agent for providing cell assignment for a wireless device served by a network node. An input vector is created for a set of candidate cells based on measurements by the wireless device and/or by the network node related to performance and signals. A future effect of assigning the wireless device to a candidate cell is estimated for each candidate cell by applying the created input vector to an effect estimation function which may be a Q-learning function. A cell in the set of candidate cells is then determined and assigned for the wireless device, based on the estimated future effects of the candidate cells. The cell that provides the best future effect may be selected for cell assignment.

Abstract: There is disclosed mechanisms for calibrating a homodyne receiver in a signal distribution network for time division duplex; a corresponding method is performed by a baseband calibration module. The method comprises acquiring a transmission signal being input to a homodyne transmitter of the signal distribution network; acquiring, from a heterodyne transmitter observation receiver of the signal distribution network, a first received version of the transmission signal; acquiring, from a homodyne receiver of the signal distribution network, a second received version of the transmission signal; and, calibrating the homodyne receiver using a comparison of the first received version of the transmission signal and the second received version of the transmission signal, using the first received version of the transmission signal as a reference signal, and using the transmission signal as a calibration signal.

Abstract: There is disclosed mechanisms for calibrating a homodyne receiver in a signal distribution network for time division duplex; a corresponding method is performed by a baseband calibration module. The method comprises acquiring a transmission signal being input to a homodyne transmitter of the signal distribution network; acquiring, from a heterodyne transmitter observation receiver of the signal distribution network, a first received version of the transmission signal; acquiring, from a homodyne receiver of the signal distribution network, a second received version of the transmission signal; and, calibrating the homodyne receiver using a comparison of the first received version of the transmission signal and the second received version of the transmission signal, using the first received version of the transmission signal as a reference signal, and using the transmission signal as a calibration signal.

Abstract: An amplifier circuit is disclosed for providing a radio frequency output signal having a variable signal envelope, comprising a main amplifier device and an auxiliary amplifier and a combiner network for combining an output signal from said first amplifier device and a second output signal from said second amplifier device to provide a combined output signal of variable signal envelope to a load, and a signal processing circuit comprising an input and a non-linear processing section to provide at least said second radio frequency output signal with a signal envelope that has a non-linear dependency from an amplitude characteristic of the input signal such that the degree of non-linearity of the non-linear dependency varies dependent on the amount of change per time unit of the amplitude characteristic of the input signal. Further, a method of power amplifying a radio frequency signal having a variable signal envelope is disclosed.

Abstract: A method for compensating signal distortions in multiple transmitting branches entering a composite amplifier.

Abstract: An amplifier circuit is disclosed for providing a radio frequency output signal having a variable signal envelope, comprising a main amplifier device and an auxiliary amplifier and a combiner network for combining an output signal from said first amplifier device and a second output signal from said second amplifier device to provide a combined output signal of variable signal envelope to a load, and a signal processing circuit comprising an input and a non-linear processing section to provide at least said second radio frequency output signal with a signal envelope that has a non-linear dependency from an amplitude characteristic of the input signal such that the degree of non-linearity of the non-linear dependency varies dependent on the amount of change per time unit of the amplitude characteristic of the input signal. Further, a method of power amplifying a radio frequency signal having a variable signal envelope is disclosed.

Abstract: A method for compensating signal distortions in multiple transmitting branches entering a composite amplifier.

Abstract: A method for compensating signal distortions in multiple transmitting branches (3, 5; 43, 45, 46) entering a composite amplifier (1; 1?). According to the invention the method comprises the steps of: —providing (S1) one or more input signals (x) to the composite amplifier. —observing (S2) an output signal (z) from the composite amplifier (1; 1?) for each provided input signal; —deriving (S5) an error in each output signal (z) by comparing the output signal with an ideal output signal, said error being caused by said signal distortions; —deriving (S11) the individual contribution from each transmitting branch (3, 5; 43,45,46) to the error by utilizing a composite amplifier model, said composite amplifier model comprising information about the contribution from each constituent amplifier (23, 25; 103a,103b,103c) to the output signal for each provided input signal: —compensating the signal distortions in the transmitting branches (3, 5; 43,45,46) accordingly.

Abstract: A circuit (200, 400, 500, 600, 700) for use in a transmitter in a base station in a wireless cellular access system, comprising a main line with a first filter (210) arranged in the main line with an input side (220) and an output side (230) in the main line. The circuit additionally comprises a feed forward cancellation loop with a second filter (240), the cancellation loop also having an input point (250) and an output point (260). The cancellation loop is connected to the main line with the output point (260) of the cancelation loop being connected to the main line on the output side (230) of the first filter (210). Suitably, the first filter (210) i.e. the main line filter, is a bandpass filter.

Abstract: A detuned composite amplifier includes a nonlinear drive function (22) that has a phase that varies with the composite amplifier output voltage amplitude. The nonlinear drive function (22) is configured to transform the output voltage transition point of the prior art into an extended output voltage transition region to increase the efficiency of the composite amplifier.

Abstract: The present invention relates to a predistorter for reducing memory effects in RF power amplifiers. The invention also relates to a method for reducing memory effects in RF power amplifiers and to a base station including such a predistorter. A predistorter according to the invention includes first means (1) for generating a first signal component, which is an estimate of a drain current of said amplifier, which means (1) for generating said first signal component comprises a linear filter, second means (8) for generating a second signal component as a function of said first signal component and at least one first gain function; third means (9) for generating a third signal component as a function of a conjugate of said first signal component and at least one second gain function, and fourth means (7) for combining at least said second signal component and said third signal component to form an output signal.

Abstract: A circuit (200, 400, 500, 600, 700) for use in a transmitter in a base station in a wireless cellular access system, comprising a main line with a first filter (210) arranged in the main line with an input side (220) and an output side (230) in the main line. The circuit additionally comprises a feed forward cancellation loop with a second filter (240), the cancellation loop also having an input point (250) and an output point (260). The cancellation loop is connected to the main line with the output point (260) of the cancelation loop being connected to the main line on the output side (230) of the first filter (210). Suitably, the first filter (210) i.e. the main line filter, is a bandpass filter.

Abstract: A radio transmitter with IQ-modulator error compensation includes a homodyne observation receiver (42) producing a first real baseband (S5) signal from a real radio frequency signal (S2). A real-value extracting element (44) and a down-sampler (46) convert a complex baseband signal (S1) into a second real baseband signal. An adapter (40) determines parameters controlling an IQ-error compensator (12) by minimizing the error between the two real baseband signals. In a preferred embodiment he transmitter also includes a phase shifter (56) providing three different phase shifts to compensate for the fact that the homodyne observation receiver produces a real and not a complex signal.

Abstract: The present invention relates to a predistorter for reducing memory effects in RF power amplifiers. The invention also relates to a method for reducing memory effects in RF power amplifiers and to a base station including such a predistorter. A predistorter according to the invention includes first means (1) for generating a first signal component, which is an estimate of a drain current of said amplifier, which means (1) for generating said first signal component comprises a linear filter, second means (8) for generating a second signal component as a function of said first signal component and at least one first gain function; third means (9) for generating a third signal component as a function of a conjugate of said first signal component and at least one second gain function, and fourth means (7) for combining at least said second signal component and said third signal component to form an output signal.

Abstract: An adaptive predistortion arrangement includes means (26, 40, 42, 44, 46) for up-converting a baseband signal (S1) into an intermediate frequency signal (S12) having frequency aliazing and means (18, 20, 220, 24, 26) for down-converting a radio frequency signal (S4) into an intermediate frequency signal (S7) having the same frequency aliazing as the up-converted baseband signal. An adapter (34) adapts predistortion parameters to keep the up-converted baseband signal equal to the down-converted radio frequency signal.

Abstract: A multiple input multiple output power amplifier system includes multiple main amplifiers for amplifying corresponding independent input signals. A common control unit forms a composite signal from the independent input signals. The composite signal is amplified by a peaking amplifier and forwarded to an output network where main amplifier output signals are combined with amplified composite signals into multiple power amplifier output signals.

Abstract: A method for compensating signal distortions in multiple transmitting branches (3, 5; 43, 45, 46) entering a composite amplifier (1; 1?). According to the invention the method comprises the steps of: —providing (S1) one or more input signals (x) to the composite amplifier, —observing (S2) an output signal (z) from the composite amplifier ( 1; 1?) for each provided input signal; —deriving (S5) an error in each output signal (z) by comparing the output signal with an ideal output signal, said error being caused by said signal distortions; —deriving (S11) the individual contribution from each transmitting branch (3, 5; 43,45,46) to the error by utilising a composite amplifier model, said composite amplifier model comprising information about the contribution from each constituent amplifier (23, 25; 103a,103b,103c) to the output signal for each provided input signal: —compensating the signal distortions in the transmitting branches (3, 5; 43,45,46) accordingly.