Patent ID: 8761092

Claim:
A method for receiving, at a mobile station, a signal by a collaborative multiple-input multiple-output (Co-MIMO) scheme in a multi-cell environment, the method comprising: configuring a sounding zone for the Co-MIMO scheme; transmitting a sounding signal to a serving base station via the sounding zone for the Co-MIMO scheme, wherein one or more adjacent base stations receive the sounding signal; and receiving signals precoded by using a multiuser precoding matrix via the sounding zone for the Co-MIMO scheme, wherein according to the Co-MIMO scheme, one or more mobile stations including the mobile station are served jointly by a plurality of base stations including the serving base station and the one or more adjacent base stations, wherein the serving base station and the one or more adjacent base stations determine the multiuser precoding matrix for the one or more mobile stations based on the sounding signal, wherein the serving base station calculates channel state information of a downlink channel between the serving base station and the one or more mobile stations based on an uplink channel, and the obtained channel state information is used for the Co-MIMO scheme and for beamforming.