Patent ID: 11936343
Assignee: TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
Field: Basic communication processes (Electrical engineering)
Classification: CPC H | IPC H

Claim 6:
7. A method of performing Digital Predistortion, DPD, in a Multiple-Input Multiple-Output, MIMO, transmitter comprising a plurality of antenna branches comprising a respective plurality of power amplifiers coupled to a respective plurality of antenna elements, the method comprising:
for each group of antenna branches of two or more groups of antenna branches, the two or more groups of antenna branches being a disjoint subset of the plurality of antenna branches:
determining one or more model parameters for a combined MIMO DPD scheme for the group of antenna branches, the combined MIMO DPD scheme being an Iterative Learning Control, ILC, combined MIMO DPD scheme with kernel regression, wherein determining the one or more model parameters comprises:
obtaining a number, N, of samples of each of a plurality of input signals in a respective one of two or more respective groups of input signals;
determining a desired combined input signal, Us, for the respective one of the two or more groups of antenna branches;
generating a kernel regression matrix, θs, for the respective one of the two or more groups of antenna branches based on the number, N, of samples of each of the plurality of input signals in the respective one of the two or more respective groups of input signals; and
computing the one or more model parameters for a DPD model utilized by a DPD system to predistort the plurality of input signals in the respective one of the two or more respective groups of input signals based on the kernel regression matrix, θs, and the desired combined input signal, Us, for the respective one of the two or more groups of antenna branches; and

predistorting the two or more respective groups of input signals for the group of antenna branches to provide two or more respective groups of predistorted input signals for the two or more groups of antenna branches, respectively, based on the respective determined one or more model parameters in accordance with the combined MIMO DPD scheme for the group of antenna branches;

wherein each group of antenna branches comprises at least two of the plurality of antenna branches.