METHOD AND ARRANGEMENT IN A WIRELESS COMMUNICATIONS SYSTEM

摘要

A method in a base station for deriving a power headroom for a first component carrier is provided. The base station is a radio base station and is comprised in a wireless communication system. The base station is configured to use carrier aggregation comprising a first component carrier and a second component carrier. The base station receives (301) a power headroom report from a user equipment. The power headroom report comprises power headroom information for the second component carrier. The base station also establishes (302) the pathloss relationship between the first component carrier and the second component carrier. The base station then derives (303) the power headroom for the first component carrier based on the received power headroom information and the established pathloss relationship between the first component carrier 1 and the second component carrier.