公开(公告)号：US20220060220A1

公开(公告)日：2022-02-24

申请号：US17407698

申请日：2021-08-20

Applicant: Nokia Technologies Oy

Inventor： Olli PIIRAINEN ,  Jaakko VIHRIÄLÄ ,  Ori SHENTAL ,  Sivarama VENKATESAN ,  Juha MYLLYLÄ

IPC: H04B7/0426 ,  H04B7/0456 ,  H04B17/345

Abstract: A method comprising obtaining a noise and interference covariance matrix, performing scaling of the noise and interference covariance matrix, determining a sum of diagonal elements of the scaled noise and interference covariance matrix, performing a first spectral shift by the sum to the scaled noise and interference covariance matrix to obtain a first spectral shifted matrix, performing eigenvalue decomposition to the first spectral shifted matrix to obtain an eigenvalue matrix, performing a second spectral shift by the sum to the eigenvalue matrix, limiting the eigenvalue matrix to a diagonal matrix, and obtaining a new noise and interference covariance matrix adding the scaled noise and interference covariance matrix and eigenvalue pairs that are obtained based, at least partly, on the performed eigenvalue decomposition.

公开(公告)号：US20220021426A1

公开(公告)日：2022-01-20

申请号：US17378285

申请日：2021-07-16

Applicant: NOKIA TECHNOLOGIES OY

Inventor： Olli PIIRAINEN ,  Jari YLIOINAS

IPC: H04B7/0456 ,  H04W52/24 ,  H04B7/024

Abstract: According to an aspect, there is provided an apparatus for performing beamforming optimization for a MIMO architecture. The apparatus maintains, in a database, channel state information of a plurality of radio channels comprising first and second order statistics. The apparatus calculates, separately for each of two or more remote radio units using an eigenbeamforming scheme, first sets of beamforming weights based on the second order statistics. Then, the apparatus performs, for each terminal device, single-user MIMO optimization between the two or more remote radio units to maximize a pre-defined metric, being a mutual information metric or signal-to-interference-plus-noise, based on first sets of beamforming weights and the first order statistics. The result, for each terminal device, is a second set of beamforming weights. The apparatus causes transmitting data using beams formed by applying both first and second sets of optimized beamforming weights at the two or more remote radio units.