Out-of-group interference reduction in wireless communication systems

A multiple-input multiple-output wireless communication system comprising:

• a plurality of base stations, each of which can transmit signals to, and receive signals transmitted from, one or more user equipments, wherein the base stations are organised into a plurality of groups;
• and
• in a given group of base stations serving one or more user equipments, those serving base stations coordinate with each other to simultaneously transmit signals to the one or more served user equipments, and one or more of the served user equipments feed back information to one or more of those serving base stations, said information incorporating inter-group noise information related to interference between different base station groups;
• wherein signals are processed for simultaneous transmission from base stations of a group to one or more user equipments served by that group and said processing uses the inter-group noise information fed back to the base station(s) of that group to improve transmission capacity.

An apparatus for use in a multiple-input multiple-output wireless communication system, the system comprising:

• a plurality of base stations, each of which can transmit signals to, and receive signals transmitted from, one or more user equipments, wherein the base stations are organised into a plurality of groups;
• and
• in a given group of base stations serving one or more user equipments, those serving base stations coordinate with each other to simultaneously transmit signals to the one or more served user equipments, and one or more of the served user equipments feed back information to one or more of those serving base stations, said information incorporating inter-group noise information related to interference between different base station groups;
• wherein the apparatus processes signals for simultaneous transmission from base stations of a group to one or more user equipments served by that group and, said processing uses the inter-group noise information fed back to the base station(s) of that group to improve transmission capacity.