METHOD AND APPARATUS FOR DETERMINING A PRECODING VECTOR FOR PRECODING DATA TO BE TRANSMITTED TO A WIRELESS DEVICE IN A WIRELESS COMMUNICATION SYSTEM.

摘要

A Method (100) for determining a precoding vector ( p i ,opt ) for precoding data to be transmitted to a wireless device in a wireless communication system comprises receiving (110) first channel state information of a channel between a first wireless device and a first base station in the wireless communication system. The first channel state information is received by the first base station from the first wireless device. Further, the method comprises receiving (120) first channel gain information (h 21 ) of a channel between a second wireless device and the first base station. The first channel gain information (h 21 ) is received from the second base station. Additionally, the method (100) comprises receiving (130) a first signal strength parameter (b i ) from the second base station indicating a signal strength at the second wireless device caused by the second base station and receiving (140) a first interference strength parameter (a i ) from the second base station indicating an interference strength at the first wireless device caused by the second base station. Further, the method (100) comprises maximizing (150) a common signal to interference noise ratio parameter (C, SINR , SINR low , SINR' ) to obtain a precoding vector ( p i ,opt ) for precoding data to be transmitted to the first wireless device. The common signal to interference noise ratio parameter (C, SINR , SINR low , SINR' ) depends on a signal to interference noise ratio (SINR 1 ) at the first wireless device and a signal to interference noise ratio (SINR 2 ) at the second wireless device and is based on the first channel state information, the first channel gain information (h 21 ), the first signal strength parameter (b i ) and the first interference strength parameter (a i ).