US 2026/0066928 A1 · REDUCED COMPLEXITY FREQUENCY SELECTIVE LINEARIZATION

Abstract

In various embodiments of the present disclosure, provided is a system to perform reduced complexity frequency selective linearization. In an embodiment, multistage digital predistortion (DPD) can linearize different parts of the spectrum differently. The first stage captures the signal across the entire linearization bandwidth where the least stringent linearization requirement and general unwanted emission requirements are targeted. Second stage pre-distorts a down-sampled signal where second least stringent requirements across the linearization bandwidth are aimed for. This “peel-off” process continues until the final stage which pre-distorts the portion of the spectrum with the most stringent linearization requirements. Consequently, earlier stages run at higher rates to linearize wider spectrum while later stages run at lower rates to selectively further linearize portions of spectrum that have already passed through earlier stages.

Claims22

Dependent claims

A method performed by a digital predistortion system for a wireless transmission node, comprising:

receiving a digital input signal for a transmission, the digital input signal having a sampling rate that is based on a linearization bandwidth of the digital input signal;
performing, at the sampling rate of the digital input signal, a first stage digital predistortion on the digital input signal to thereby provide a first pre-distorted digital signal;
and
for a particular sub-band of two or more sub-bands of the first pre-distorted digital signal:
down-sampling either the particular sub-band of the first pre-distorted digital signal or a frequency-shifted version of the particular sub-band of the first pre-distorted digital signal at a reduced sampling rate to provide a down-sampled digital signal, wherein the reduced sampling rate is based on a bandwidth of the particular sub-band and is lower than the sampling rate of the digital input signal;
performing, at the reduced sampling rate, a second stage digital predistortion on the down-sampled digital signal to thereby provide a second pre-distorted digital signal;
and
further processing the first pre-distorted digital signal and the second pre-distorted signal to provide a pre-distorted output signal for transmission by the wireless transmission node.

5 more elements

A transmitting node configured to implement a digital predistortion system, the transmitting node comprising a radio interface and processing circuitry configured to:

receive a digital input signal for a transmission, the digital input signal having a sampling rate that is based on a linearization bandwidth of the digital input signal;
perform, at the sampling rate of the digital input signal, a first stage digital predistortion on the digital input signal to thereby provide a first pre-distorted digital signal;
and
for a particular sub-band of two or more sub-bands of the first pre-distorted digital signal:
down-sample the particular sub-band of the first pre-distorted digital signal or a frequency-shifted version of the particular sub-band of the first pre-distorted digital signal at a reduced sampling rate to provide a down-sampled digital signal, wherein the reduced sampling rate is based on a bandwidth of the particular sub-band and is lower than the sampling rate of the digital input signal;
perform, at the reduced sampling rate, a second stage digital predistortion on the down-sampled digital signal to thereby provide a second pre-distorted signal;
and
further process the first pre-distorted digital signal and the second pre-distorted digital signal to provide a pre-distorted output signal for transmission by the transmission node.

5 more elements

Dependencies are inferred from the claim text.

Reduced complexity frequency selective linearization

Life of this patent

Reduced complexity frequency selective linearization

Life of this patent

Abstract

Claims22