Transmission filter calculator, communication device and methods

摘要

A transmission filter calculator for calculating at least a transmit filter for a communication from a transmit communication device comprising a plurality of antennas to a receive communication device out of a plurality of receive communication devices comprising a plurality of antennas via a multiple-input-multiple-output channel, is configured to iteratively determine transmit filters ( v d ) for a plurality of data streams (s d ). The transmission filter calculator is configured to choose a transmit filter ( v d ) in a given iteration (d) such that the transmit filter ( v d ) chosen in the given iteration is orthogonal to one or more transmit filters ( v d ) chosen in one or more previous iterations, and such that a weighted or unweighted transmission rate (r d ) obtainable using the transmit filter ( v d ) chosen in the given iteration (d) is maximized. The transmission filter calculator is configured to choose the transmit filter ( v d ) in dependence on a matrix product term which is based on a channel matrix (H s d ) describing MIMO channel characteristics between the transmit communication device and a currently considered one (s d ) of the receive communication devices and on a distortion covariance matrix ( C ·,sd ) describing a noise, an inter-cell interference and an upper limit of an intra-cell interference.