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

Claim 0:
1. 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; and
two or more Digital Predistortion, DPD, systems each operable to, for a respective 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:
determine 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 the DPD system is operable to determine the one or more model parameters by being operative to:
obtain 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;
determine a desired combined input signal, Us, for the respective one of the two or more groups of antenna branches;
generate 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
compute the one or more model parameters for a DPD model utilized by the 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 input signal, Us, for the respective one of the two or more groups of antenna branches; and

wherein the two or more DPD systems are further operable to predistort 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.