Channel-matrix dependent step size for iterative precoding matrix calculation

A device for controlling multi-antenna transmission, the device comprising:

• at least one processor;
• and
• a memory containing program code executable by the at least one processor, whereby execution of the program code by the at least one processor causes the device to:
• determine a channel matrix representing characteristics of a multi-path channel between a transmitter device equipped with multiple transmitter antennas and at least one receiver device equipped with multiple receiver antennas, the channel matrix being organized in one or more channel vectors each associated with a corresponding one of the one or more receiver antennas;
• apply an iterative optimization algorithm to determine a precoding matrix from the channel matrix;
• set at least one step size of the iterative optimization algorithm depending on a vector norm of at least one of the one or more channel vectors;
• and
• control multi-antenna transmission by the transmitter device based on the determined precoding matrix.