Transmit power control method and apparatus
A method and apparatus for controlling transmit power of a User Equipment (UE) in a mobile communication system is provided. The transmit power control method of the present invention includes determining, when the terminal's required transmit power exceeds the terminal's maximum transmit power, whether a plurality of Hybrid Automatic Repeat reQuest (HARQ) processes are running and reducing, when the plurality of HARQ processes are running, a transmit power of at least one of the plurality of HARQ processes which has not experienced transmit power reduction previously. The UE transmit power control method and apparatus of the present invention is advantageous to control the transmit power in transmit power reduction mode.
1. A transmit power control method of a terminal, the method comprising:
determining, if a required transmit power of the terminal exceeds a maximum transmit power of the terminal, whether a plurality of Hybrid Automatic Repeat reQuest (HARQ) processes are running, wherein each of the plurality of HARQ processes is an independent HARQ process managing HARQ packets;
selecting, if the plurality of HARQ processes are running, at least one of the plurality of HARQ processes which has not experienced transmit power reduction previously and reducing a transmit power of the selected at least one HARQ process; and
reducing, if each of the plurality of HARQ processes has previously experienced a transmit power reduction the transmit power of one of the plurality of HARQ processes that has experienced the fewest number of previous power reductions.
2. The method of claim 1 , further comprising increasing, if the terminal's required transmit power does not exceed the terminal's maximum transmit power, the transmit power of the one of the plurality of HARQ processes that has experienced the fewest number of previous power reductions.
3. The method of claim 2 , further comprising accumulating an amount of the transmit power reduction of each of the plurality of HARQ processes that has previously experienced the transmit power reduction,
wherein the increasing comprises incrementing the transmit power of the one of the plurality of HARQ processes that has experienced the fewest number of previous power reductions based on the amount of the accumulated power reduction in the corresponding HARQ process.
4. The method of claim 2 , further comprising accumulating an amount of the transmit power reduction of each of the plurality of HARQ processes that has previously experienced the transmit power reduction,
wherein the increasing comprises incrementing the transmit power of the one of the plurality of HARQ processes that has experienced the fewest number of previous power reductions as much as a sum of the amount of the accumulated power reduction and a required power of the corresponding process.
5. The method of claim 1 , further comprising reducing, if the terminal's required transmit power is greater than the terminal's maximum transmit power and a single HARQ process is running, the transmit power of the single HARQ process.
6. The method of claim 1 , further comprising reducing, if the terminal's required transmit power is greater than the terminal's maximum transmit power and no uplink data channel to be transmitted exists, the transmit power of an uplink control channel.
7. A terminal for controlling transmit power, the terminal comprising: a controller for determining, if a required transmit power of the terminal exceeds a maximum transmit power of the terminal, whether a plurality of Hybrid Automatic Repeat reQuest (HARQ) processes are running, wherein each of the plurality of HARQ processes is an independent HARQ process managing HARQ packets, and for selecting, if the plurality of HARQ processes are running, at least one of the plurality of HARQ processes which has not experienced transmit power reduction previously and reducing a transmit power of the selected at least one HARQ process, wherein the controller reduces, if each of the plurality of HARQ processes has previously experienced a transmit power reduction, the transmit power of one of the plurality of HARQ process that has experienced the fewest number of previous power reductions.
8. The terminal of claim 7 , wherein the controller increases, if the terminal's required transmit power does not exceed the terminal's maximum transmit power, the transmit power of the one of the plurality of HARQ processes that has experienced the fewest number of previous power reductions.
9. The terminal of claim 8 , wherein the controller accumulates an amount of the transmit power reduction of each of the plurality of HARQ processes that had previously experienced the transmit power reduction and increases the transmit power of the one of the plurality of HARQ processes that has experienced the fewest number of previous power reductions based on the amount of the accumulated power reduction in the corresponding HARQ process.
10. The terminal of claim 8 , wherein the controller accumulates an amount of the transmit power reduction of each of the plurality of HARQ processes that had previously experienced the transmit power reduction and increases the transmit power of the one of the plurality of HARQ processes that has experienced the fewest number of previous power reductions as much as sum of the amount of the accumulated power reduction and a required power of the corresponding process.
11. The terminal of claim 7 , wherein the controller reduces, if the terminal's required transmit power is greater than the terminal's maximum transmit power and a single HARQ process is running, the transmit power of the single HARQ process.
12. The terminal of claim 7 , wherein the controller reduces, if the terminal's required transmit power is greater than the terminal's maximum transmit power and no uplink data channel to be transmitted exists, the transmit power of an uplink control channel.