Power headroom reporting for non-scheduled uplink component carriers

摘要

This invention relates to a proposal for power headroom reporting for uplink component carriers for which no uplink resource allocation is scheduled by the eNodeB. The user equipment (UE) calculates a virtual power headroom for the non-scheduled uplink component carrier, based on a virtual uplink resource assignment pre-configured by the UE and eNodeB. According to one embodiment the maximum transmit power of the UE is set to a pre-configured fixed value. Alternatively, the maximum transmit power is calculated by the UE considering the power reduction, while the uplink transmission power is set to zero. The virtual power headroom is then transmitted to the eNodeB, which in turn can infer therefrom the pathloss and/or power-per-resource-block for the non-scheduled uplink component carrier and may also infer the power reduction used by the UE. This allows a more accurate scheduling of future uplink transmissions on said non-scheduled uplink component carrier.

主权项

1. A method for a user equipment reporting to an eNodeB a power headroom in a mobile communication system using component carrier aggregation, wherein the method comprises the steps of:
calculating by the user equipment one or both of a normal power headroom for a scheduled uplink component carrier and a virtual power headroom for a non-scheduled uplink component carrier, the virtual power headroom being calculated based on a pre-configured virtual uplink resource assignment for said non-scheduled uplink component carrier, transmitting by the user equipment to the eNodeB a report including, one of the normal power headroom and the virtual power headroom, and a flag indicating which one of the normal power headroom and the virtual power headroom is included in the report, receiving by the user equipment from the eNodeB uplink power control information, and controlling by the user equipment uplink power based on the received power control information.