CONTROLLING INTERFERENCE CAUSED BY SECONDARY SYSTEMS

摘要

There is provided a method comprising: obtaining, at a base station of a secondary user system utilizing shared radio communication resources with a coexisting primary user system, channel state information with respect to both a propagation channel between the secondary user and the base station and a propagation channel between the secondary user and a primary user; jointly determining power allocation and transmit coefficients for at least one data stream which is to be transmitted from the secondary user to the base station; and causing communication of information indicating the determined power allocation and transmit coefficients to the secondary user.