Patent ID: 8274952
Filing Date: 2012-09-25
Classification: H04W

Abstract:
1. A method of adjusting transmission power on a downlink radio channel from a base station to a user equipment, the method comprises the following steps carried out at said base station: receiving an uplink power headroom indication from the user equipment; obtaining an estimate of an uplink path loss between the user equipment and the base station, said uplink path loss estimate taking account of said uplink power headroom; deriving an estimate of a downlink path loss between the user equipment and the base station, from said uplink path loss estimate; detecting errors on the downlink radio channel, wherein the step of detecting errors comprises the base station indicating by sending on the downlink radio channel a first message to the user equipment, the first message comprising an allowed traffic format combination set, the user equipment sending a second message comprising a traffic format combination identifier to the base station, the base station decoding the second message and determining whether the traffic format combination identifier belongs to the allowed traffic format combination set and in case the traffic format combination identifier does not belong to the allowed set, the base station deducing that an error has occurred on the radio channel by decoding information using a modulation coding scheme of the allowed set; and adjusting the transmission power on said downlink radio channel by taking account of said downlink path loss estimate, wherein the step of adjusting the transmission power on the downlink radio channel further takes account of the detected errors.