CPC Class H04W

A method and a system of setting up a reference signal in a radio communication system are disclosed. The radio communication system includes a serving cell and a neighboring cell, and a mobile terminal of the serving cell uses the same temporal frequency resource to receive a serving resource block from the serving cell and an interference resource block from the neighboring cell. The method includes setting up a user-specific reference signal in the interference resource block and puncturing at the same temporal frequency position as the temporal frequency position at which the user-specific reference signal is set up on the interference resource block of the serving resource block to prevent any signal from being transmitted at the punctured temporal frequency position. When the method and the system are used and the interference power between cells is measured, it is possible to effectively reduce feedback overhead in a coordinated beamforming.

Methods and apparatus are provided for a base station to trigger transmissions of sounding reference signals (SRS) from one or multiple user equipments (UEs) on one or multiple cells and for a UE to determine a power, a time instance, and other parameters for SRS transmissions in response to the triggering. A SRS transmission can be on a cell where a UE is not configured to transmit data or control information.