Patent ID: 8553667
Filing Date: 2013-10-08
Classification: H04B,H04L,H04W

Abstract:
1. A method of operating a base station comprising a plurality of transmit antennas, each of the plurality of transmit antennas transmitting on one or more carriers selected from a set of co-located carriers and serving each of one or more non-MIMO users by only one of the plurality of transmit antennas and each of one or more MIMO users by two or more of the plurality of transmit antennas, said method for allocating a maximum transmission power budget to each of the plurality of transmit antennas comprising: allocating by one or more processing circuits, for serving each of the one or more MIMO users, one or more carriers selected from the set of co-located carriers; allocating by one or more processing circuits, for serving each of the one or more non-MIMO users, one or more carriers selected from the set of co-located carriers; deriving a set of coefficients by using, for each carrier of the set of co-located carriers, information about an amount of allocated MIMO user resources associated with the carrier and an amount of allocated non-MIMO user resources associated with the carrier, wherein each coefficient corresponds to a unique one of the plurality of transmit antennas and represents a proportion of a maximum power budget for the carrier; deriving a maximum transmission power budget for each of the plurality of transmit antennas by using for each carrier of the set of co-located carriers said set of coefficients and the maximum transmission power budget for the carrier; deriving for each antenna of the plurality of transmit antennas a total maximum transmission power budget for the antenna by combining the derived maximum transmission power budgets of the carriers transmitted on the antenna; determining whether the total maximum transmission power budget of the antenna exceeds a transmission power limit for the antenna; and if the total maximum transmission power budget of the antenna exceeds its transmission power limit and the antenna is a primary antenna of a carrier, determining whether radio conditions for a non-MIMO user satisfy one or more predefined criteria, and causing a secondary antenna of the carrier to be used to serve the non-MIMO user, if the radio conditions of the non-MIMO user satisfy the one or more predefined criteria.