Siemens Aktiengesellschaft

Nokia Solutions and Networks Oy

Nokia Siemens Networks Gmbh & Co Kg

Nokia Technologies Oy

Nokia Solutions and Networks Gmbh & Co. Kg

Björn Jelonnek

Gunter Wolff

Armin Splett

Radoslaw Ceszkiel

Grzegorz Haza

Marko Fleischer

Jan Hellmann

Michael Weber

Helmut Heinz

Rene Röschke

Armin Fuchs

Hans Dieterich

Jürgen Hellstab

Andre Baumgart

Lukasz Skomra

Disclosed is a method comprising selecting a mathematical model associated with a nonlinear component, determining an error signal associated with the nonlinear component, wherein the error signal indicates a difference between a first signal and a second signal, estimating one or more parameters that minimize the error signal based on the mathematical model, and estimating and/or linearizing the nonlinear component based on the estimated one or more parameters.

Parameter estimation for linearization of nonlinear component

Example embodiments provide a method for compensating transmitter distortions. The compensation can be performed with tapered antenna elements. The method comprises determining a first subset of antennas of an antenna array, wherein the first subset of antennas operate without a power headroom in relation to one or more thresholds; determining a second subset of antennas of the antenna array, wherein the second subset of antennas comprise one or more antennas that operate with a power headroom in relation to the one or more thresholds; calculating compensation signals for distortions of wanted signals to be transmitted with the first subset of antennas to one or more user devices; combining the compensation signals with wanted signals to be transmitted with the second subset of antennas to the one or more user devices; and transmitting, with the second subset of antennas, the compensation signals combined with the wanted signals. An apparatus, a method, and a computer program are disclosed.

Apparatuses and methods for compensation of transmitter distortions

An apparatus comprises a digital processing device configured to generate a digital transmission signal, a digital-to-analog converter connected to the digital processing device and configured to convert the digital transmission signal into an analog transmission signal, and a power amplifier connected to the digital-to-analog converter and configured to amplify the analog transmission signal. An antenna filter is connected to the power amplifier and configured to filter the amplified analog transmission signal; the antenna filter is configured to pass frequencies in at least one passband and to attenuate frequencies in at least one stopband. The digital processing device is configured to perform a process of reducing peak power in the digital transmission signal; in this process error components having different frequencies are produced. A frequency spectrum of the error components is manipulated such that a part of the error components is deposited in the stopband of the antenna filter.

CFR error deposition out of the transmission band

An apparatus includes an estimation circuitry configured to receive a first set of one or more digital signals of transmitters of a communication system, and capture a set of one or more radio frequency signals that have been generated from the first set of digital signals The set of radio frequency signals being input of an antenna system of the communication system. Based on the first set of digital signals and the corresponding set of radio frequency signals, a set of weights related to a distortion effect caused by the generation of the radio frequency signals is derived. A received second set of digital signals is weighted using the set of weights, resulting in filtered signals. Using the filtered signals, a correction signal indicative of an interference caused by transmission of the second set of digital signals at a receiver of the communication system is estimated.

Method for processing of passive intermodulation products

A method comprising: obtaining a first radio signal and a second radio signal, determining a first envelope signal based on the first radio signal and a second envelope signal based on the second radio signal, determining a preview envelope signal based on the first envelope signal and the second envelope signal, determining a common clipping gain signal based on the preview envelope signal, determining a first clipping gain signal based on the common clipping gain signal and a first weighing factor, determining a second clipping gain signal based on the common clipping gain signal and a second weighing factor, performing a first crest factor reduction for the first radio signal utilizing the first clipping gain signal, and performing a second crest factor reduction for the second radio signal utilizing the second clipping gain signal.

Distribution of clipping noise between bands

A system and a method create a pre-distorted signal y(k) from an interpolated broadband baseband signal x(k) for a transmitter power amplifier having at least three branches to which the signal x(k) is respectively connected on the input side. A first branch contains a distortion device for taking into account memory effects of the transmitter power amplifier to which the signal x(k) is supplied on the input side. Where 2=j=n, each other j-th branch contains the following serially mounted elements: a deceleration device with a signal x(k) supplied on the input side, a first adder, a digital low-pass filter, and a second adder, the output signal formed by the second adder being used to create the pre-distorted signal y(k). The distortion device pertaining to the first branch is connected, on the input side, to another input of the second adder of the second branch, and on the output side, to another input of the first adder of the second branch.

Arrangement and method for digital predistortion of a complex baseband input signal

A radio signal in a radio communication system may be filtered to prepare an EDGE-signal. In this case, the signal-to-noise-ratios are calculated according to a first operation in addition to previously known methods for detecting a neighboring channel interference. In addition, other variously tuned filters are activated when a corresponding threshold is reached, where the thresholds are associated with correspondingly intense interferences from neighboring channel influences. A filtering method or filter module can be mounted in an existing station behind an existing receiving filter. In the first filtering operation, the previous filter effect is reduced to the smallest amount possible before new filtering is carried out to produce a desired signal. The EDGE signals can also be produced in a simple manner from GMSK signals.

Adaptive filtering method and filter for filtering a radio signal in a mobile radio-communication system

Partial signals of a basic frequency band are used to form a carrier frequency output signal. Each of n partial signals is attributed as an input signal to a representative main branch and the corresponding partial signal is limited in amplitude, filtered and converted into an intermediate frequency partial signal. As output signals of the main branch, the n partial signals are assembled into a common sum signal. Moreover, each partial signal reaches an auxiliary branch, whereby expected peak values of the partial signal can be determined as estimated values. Using the estimated values, the amplitude limitations of the corresponding partial signals, executed in the main branch, can be regulated in the branch.

Method for limiting amplitude of a carrier frequency output signal

An arrangement for runtime compensation of a runtime difference, arising through emulation of a high frequency signal, is disclosed, with a signal x(t), for emulation by a signal processing device, which emulates the signal x(t) with a signal x(t) and a device for determining a difference signal between the signals x(t) and x(t). The arrangement is characterized in that the emulated signal x(t) is conducted via filter with a negative group runtime for certain frequency ranges.

Arrangement for runtime compensation of a runtime difference arising through emulation of a high frequency signal

A system reduces non-linear distortions in an output signal of an amplifier stage that is configured according to the feed forward principle. An amplifier stage input signal arrives at a main branch of an amplifier. The output signal of the amplifier, which is distorted in a non-linear manner, arrives at an adder. An output of the adder forms the amplifier stage output signal. The output signal which is distorted in a non-linear manner and the amplifier stage input signal are fed to a secondary branch that comprises an error signal device. The error signal device generates an error signal from the delayed amplifier stage input signal and the output signal of the amplifier, which is distorted in a non-linear manner. The error signal is fed to the adder in order to reduce distortions in the amplifier stage output signal. The error signal device comprises at least one transmission device that is provided with a negative group delay time.

Arrangement for reducing non-linear distortions in an output signal of an amplifier stage

A delay device has at least one first delay element and optional additional delay elements connected downstream from the first in a serially consecutive manner. The digital input signal is connected to an input of the first delay element and is connected to an input of a first D/A converter. The output of the first delay element is connected to an input of another D/A converter assigned thereto. The optional additional delay elements each have outputs connected to an input of another D/A converter assigned to the respective delay elements. All D/A converters are combined on the output side in a step-by-step manner so that output signals of all D/A converters form the analog output signal or the device. A specific coefficient is assigned to each D/A converter, and a specific delay time is assigned to each delay element for realizing a filter characteristic.

Configuration for digital-analog conversion of high-frequency digital input signal into carrier-frequency analog output signal

A sigma-delta modulator converting digital input signals x(k) includes a first feedback loop of a spectrally formed output signal y(k) of the sigma-delta modulator and a second feedback loop of a spectrally formed differential signal e(k), obtained from an intermediate signal u(k) and the output signal y(k). The intermediate signal u(k) constitutes the differential signal of the input signal x(k) and the total signal r(k) of the first and second feedback loops. A quantizer determines the output signal y(k) based on the intermediate signal u(k), whereby k is the discrete independent time variable. The sigma-delta converter generates a skew between the output signal y(k) and the input signal x(k).

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Ulm, Germany

Björn Jelonnek