Wireless communication device and method for controlling transmission power
Disclosed is a wireless communication device that can suppress an increase in power consumption of a terminal while preventing the degradation of SINR measurement precision resulting from TPC errors in a base station. A terminal controls the transmission power of a second signal by adding an offset to the transmission power of a first signal; an offset-setting unit sets an offset correction value in response to a transmission time gap between a third signal transmitted the previous time and the second signal transmitted this time; and a transmission power control unit controls the transmission power of the second signal using the correction value.
1. A communication apparatus comprising:
reference signal generating circuitry, which, in operation, generates a first Sounding Reference Signal (SRS) which is to be transmitted periodically and a second SRS which is to be transmitted with a time interval between triggering and transmission that is different from a transmission time interval of the first SRS, both of the first SRS and the second SRS being reference signals for channel-quality estimation;
offset setting circuitry, which, in operation, sets a first offset to control transmission power used to transmit the first SRS and sets a second offset to control transmission power used to transmit the second SRS, the second offset being different from the first offset; and
a transmitter, which, in operation, transmits the first SRS with the transmission power controlled based on the first offset and to transmit the second SRS with the transmission power controlled based on the second offset.
2. The communication apparatus according to claim 1 , wherein
the offset setting circuitry sets a greater offset for a longer transmission time interval.
3. The communication apparatus according to claim 2 , wherein
the offset setting circuitry sets each of the first and the second offsets by adding a correction value to a transmission power offset specified by a base station apparatus.
4. The communication apparatus according to claim 1 , wherein
the offset setting circuitry sets each of the first and the second offsets by adding a correction value to a transmission power offset specified by a base station apparatus.
5. The communication apparatus according to claim 1 , wherein
the first SRS is a periodic SRS, and the second SRS is an aperiodic SRS which is transmitted aperiodically.
6. The communication apparatus according to claim 5 , wherein
the offset setting circuitry sets the second offset to be greater than the first offset.
7. A communication method comprising:
generating a first Sounding Reference Signal (SRS) which is to be transmitted periodically and a second SRS which is to be transmitted with a time interval between triggering and transmission that is different from a transmission time interval of the first SRS, both of the first SRS and the second SRS being reference signals for channel-quality estimation;
setting a first offset to control transmission power used to transmit the first SRS and setting a second offset to control transmission power used to transmit the second SRS, the second offset being different from the first offset; and
transmitting the first SRS with the transmission power controlled based on the first offset and transmitting the second SRS with the transmission power controlled based on the second offset.
8. The communication method according to claim 7 , wherein
a greater offset is set for a longer transmission time interval.
9. The communication method according to claim 8 , wherein
each of the first and the second offsets is set by adding a correction value to a transmission power offset specified by a base station apparatus.
10. The communication method according to claim 7 , wherein
each of the first and the second offsets is set by adding a correction value to a transmission power offset specified by a base station apparatus.
11. The communication method according to claim 7 , wherein
the first SRS is a periodic SRS, and the second SRS is an aperiodic SRS which is transmitted aperiodically.
12. The communication method according to claim 11 , wherein
the second offset is set to be greater than the first offset.