Apparatus and method for transmitting a power headroom report in a wireless communication system supporting multi-carriers

摘要

An apparatus and method for transmitting a power headroom report in a communication system supporting multi-carriers are disclosed, by which a user equipment is enabled to transmit the power headroom report. According to the present invention, a user equipment calculates a power headroom for each of at least one activated serving cell using a maximum transmission power of the user equipment for each of at least one activated serving cell and transmits the power headroom report including the power headroom for each of the at least one activated serving cell and the maximum transmission power of the user equipment for each of the at least one activated serving cell to a base station. In this case, the power headroom includes an information on power status of the user equipment for each of the at least one activated serving cell.

主权项

1. A method of transmitting a power headroom report by a user equipment in a communication system supporting carrier aggregation, the user equipment being configured with a plurality of serving cells including a primary cell and at least one secondary cell, the method comprising:
determining, by the user equipment, maximum transmission powers of the user equipment for the plurality of serving cells; calculating, by the user equipment, power headroom for the plurality of serving cells using respective maximum transmission powers determined for the plurality of serving cells; and transmitting, by the user equipment to a base station, the power headroom report for the plurality of serving cells, wherein the power headroom report includes first two consecutive bytes including:
six bits of a preceding byte of the first two consecutive bytes indicating power headroom for the primary cell, andsix bits of a subsequent byte of the first two consecutive bytes indicating a maximum transmission power for the primary cell, wherein the power headroom report further includes an indication field for each of the at least one secondary cell, wherein, based on the indication field indicating that the power headroom report includes power headroom for a specific secondary cell of the at least one secondary cell, the power headroom report further includes second two consecutive bytes including:
six bits of a preceding byte of the second two consecutive bytes indicating power headroom for the specific secondary cell, andsix bits of a subsequent byte of the second two consecutive bytes indicating a maximum transmission power for the specific secondary cell, wherein, based on the indication field indicating that the power headroom report does not include the power headroom information for the specific secondary cell of the at least one secondary cell, the second two consecutive bytes are skipped in the power headroom report, and wherein a power headroom for a cell is calculated based on a difference between a maximum transmission power determined for the cell and a transmission power configured for the cell.