Patent Document ID: 10042852
Application ID: 15506672
Patent Flag: 1

Claim One:
1. A method of operation of a network node in a cellular communications system comprising: determining beamforming weights for a plurality of subchannels for each of a plurality of relay nodes such that a parameter is minimized for a defined channel quality, the parameter being one of the group consisting of a maximum per subchannel interference and a maximum per relay power usage, wherein determining the beamforming weights comprises: determining a dual problem of the minimization of the parameter where a solution maximizing the dual problem will minimize the parameter; reformulating the dual problem into a semidefinite programming (SDP) problem; determining if a plurality of signal-to-noise ratio (SNR) constraints are all active; if the plurality of SNR constraints are all active, solving the SDP problem and determining the beamforming weights for each of the plurality of relay nodes a first way such that the parameter is minimized; and if the plurality of SNR constraints are not all active, solving the SDP problem and determining the beamforming weights for each of the plurality of relay nodes a second way such that the parameter is minimized.