Nokia Solutions and Networks Oy

Nokia Technologies Oy

Tian He

Shavantha Kularatna

Chad Young

Peter Y Novak

Jacob Edward Longwell

Christian Reichl

Aki Korhonen

This specification relates to digital pre-distortion of signals before power amplification during the transmission of a signal. A method comprising: receiving an input signal 1and 2subband signals associated with 1and 2centre frequencies; applying a pre-distortion to the input signal to generate a pre-distorted signal, the pre-distortion applying an inverse to a power amplification model associated with a power amplifier; and outputting the pre-distorted signal for power amplification. The power amplification model or the inverse to the power amplification model comprises a first plurality of terms and a second plurality of terms. Each of the 1and 2plurality of terms comprising a product of a complex coefficient, a power factor, and other factors depending on if it is 1or 2plurality of terms.

Dual-band digital pre-distortion system and method

As solution for predistorting a signal is presented. The solution comprises receiving () as an input a signal comprising at least two signal components on a different band, sampling () the input signal comprising linear terms, composite non-linear terms causing intermodulation outside Nyquist band of the input signal and further non-linear terms causing intermodulation inside the Nyquist band, the further non-linear terms comprising multi-band terms. Oversampling () by a given factor is applied to the signal in a first predistortion circuit for processing the linear terms and composite non-linear terms causing intermodulation outside Nyquist band; processing () the input signal without oversampling in a second predistortion circuit in parallel with the first predistortion circuit for the further non-linear terms. The rates of the output signals of the predistortion circuits are matched (), combined and filtered ().

Predistortion method

An apparatus is disclosed, comprising means for providing two or more amplifiers for amplifying signals in two or more respective frequency bands, receiving a composite signal comprising first and second predistorted input signals in first and second frequency bands and filtering the composite signal to provide (i) the first predistorted signal for input to a first amplifier of the two or more amplifiers for producing an amplified first output signal and (ii) the second predistorted signal for input to a second amplifier of the two or more amplifiers for producing an amplified second output signal. The apparatus may also comprise means for routing, at non-overlapping times, the first and second output signals to a common feedback path and for linearizing received first and second input signals based on the respective first and second output signals received on the common feedback path.

Radio apparatus

A method comprising determining a plurality of digital pre-distortion engines, determining signals for the pre-distortion engines, determining terms for a matrix and filter the matrix, based on the filtered matrix, determining correlation matrixes, obtaining pre-distorted signals from the digital pre-distortion engines, wherein the pre-distorted signals are pre-distorted based on the determined correlation matrixes, and combining the pre-distorted signals to a combined pre-distorted signal.

Interference mitigation with multi-band digital pre-distortion

A model structure modeling a power amplifier is based on at least a binomial expansion, a first building block, a second building block, and a third building block. The first building block is a first complex sub-band signal with a first delay, the second building block is a multiplication of the first complex sub-band signal with a second delay and a complex conjugate of the first complex sub-band signal with a third delay, and the third building block is a multiplication of a second complex sub-band signal with a fourth delay and a complex conjugate of the second complex sub-band signal with a fifth delay. The sum of the first complex sub-band signal and the second complex sub-band signal is a baseband signal. Terms are obtained by optimizing delay combinations for the model structure. The model structure is used to dual-band digital pre-distortion of the baseband signal.

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Plano, TX, United States of America

Tian He