Terminal apparatus, base station and communication method
Provided is a terminal apparatus in which, a transmission control unit ( 204 ) controls the transmission power of a sounding reference signal (SRS) by use of an offset value relative to the transmission power of a data signal, and a transmission unit ( 206 ) transmits the SRS by use of the transmission power as controlled. If a subframe to be used for transmitting the SRS is a predetermined subframe, the transmission control unit ( 204 ) uses a first offset value to control the transmission power of the SRS. Otherwise, the transmission control unit ( 204 ) uses a second offset value to control the transmission power of the SRS. The second offset value is an offset value that has been established so as to be transmitted to the serving cell of the terminal ( 200 ), and the first offset value is greater than the second offset value.
1. A terminal apparatus comprising:
a transmission controller which, in operation, controls a transmission power of a sounding reference signal (SRS) using an offset value; and
a transmitter which, in operation, transmits the SRS using the controlled transmission power, wherein
the offset value used to control the transmission power is set within one of a first offset setting range having a first lower limit value and a first upper limit value and a second offset setting range having a second lower limit value and a second upper limit value, wherein a difference between the first lower limit value and the second lower limit value is equal to a difference between the first upper limit value and the second upper limit value,
a step width of the offset values within the first offset setting range equals a step width of the offset values within the second offset setting range, and
the SRS is a periodic SRS (P-SRS) or an aperiodic SRS (A-SRS).
2. The terminal apparatus according to claim 1 , wherein the first and second offset setting ranges are set for the P-SRS and for the A-SRS, respectively.
3. The terminal apparatus according to claim 1 , wherein a bit length of the offset value within the first offset setting range equals a bit length of the offset value within the second offset setting range.
4. The terminal apparatus according to claim 1 , wherein the offset value is included in higher layer control information.
5. The terminal apparatus according to claim 1 , wherein the second offset setting range is used when a path loss between the terminal apparatus and a serving cell exceeds a predetermined value.
6. The terminal apparatus according to claim 1 , wherein the first offset setting range is used during transmission to a serving cell.
7. A communication method implemented by a terminal apparatus, the method comprising:
controlling a transmission power of a sounding reference signal (SRS) using an offset value; and
transmitting the SRS using the controlled transmission power, wherein
the offset value used to control the transmission power is set within one of a first offset setting range having a first lower limit value and a first upper limit value and a second offset setting range having a second lower limit value and a second upper limit value, wherein a difference between the first lower limit value and the second lower limit value is equal to a difference between the first upper limit value and the second upper limit value,
a step width of the offset values within the first offset setting range equals a step width of the offset values within the second offset setting range, and
the SRS is a periodic SRS (P-SRS) or an aperiodic SRS (A-SRS).
8. The communication method according to claim 7 , wherein the first and second offset setting ranges are set for the P-SRS and for the A-SRS, respectively.
9. The communication method according to claim 7 , wherein a bit length of the offset value within the first offset setting range equals a bit length of the offset value within the second offset setting range.
10. The communication method according to claim 7 , further comprising receiving the offset value as higher layer control information.
11. The communication method according to claim 7 , wherein the offset value is selected from the second offset setting range when a path loss between the terminal apparatus and a serving cell exceeds a predetermined value.
12. The communication method according to claim 7 , wherein the offset value is selected from the first offset setting range during transmission from the terminal apparatus to a serving cell.
13. An integrated circuit that controls a process performed at a terminal apparatus, the process comprising:
controlling a transmission power of a sounding reference signal (SRS) using an offset value; and
transmitting the SRS using the controlled transmission power, wherein
the offset value used to control the transmission power is set within one of a first offset setting range having a first lower limit value and a first upper limit value and a second offset setting range having a second lower limit value and a second upper limit value, wherein a difference between the first lower limit value and the second lower limit value is equal to a difference between the first upper limit value and the second upper limit value,
a step width of the offset values within the first offset setting range equals a step width of the offset values within the second offset setting range, and
the SR S is a periodic SR S (P-SRS) or an aperiodic SR S (A-SRS).
14. The integrated circuit according to claim 13 , wherein the first and second offset setting ranges are set for the P-SRS and for the A-SRS, respectively.
15. The integrated circuit according to claim 13 , wherein a bit length of the offset value within the first offset setting range equals a bit length of the offset value within the second offset setting range.
16. The integrated circuit according to claim 13 , wherein the process further comprises receiving the offset value as higher layer control information.
17. The integrated circuit according to claim 13 , wherein the offset value is selected from the second offset setting range when a path loss between the terminal apparatus and a serving cell exceeds a predetermined value.
18. The integrated circuit according to claim 13 , wherein the offset value is selected from the first offset setting range during transmission from the terminal apparatus to a serving cell.