Method and apparatus for adjusting sound reference signal transmission power
Provided are a method and apparatus for adjusting sounding reference signal transmission power. A terminal a plurality of transmit powers used for transmitting a plurality of sounding reference signals (SRSs) in a sounding reference symbol. If a total transmission power for the plurality of SRSs exceeds a maximum transmission power, the terminal scales each transmission power by the same scale factor.
1. A method of adjusting a transmit power for sounding reference signals in a wireless communication system, performed by a user equipment, comprising:
determining a plurality of transmit powers for transmitting a plurality of sounding reference signals (SRSs) in a sounding reference symbol; and
if a total transmit power for the plurality of SRSs exceeds a maximum transmit power, scaling each of the plurality of transmit powers with a same scaling factor.
2. The method of claim 1 , wherein each of the plurality of SRSs corresponds to respective serving cell.
3. The method of claim 2 , wherein each transmit power for respective SRS is determined based on a bandwidth of each SRS transmission.
4. The method of claim 3 , wherein each transmit power P SRS,c (i) for respective SRS which is transmitted on subframe i for serving cell c is determined as shown:
P SRS,c ( i )=min{ P CMAX,c ( i ), P SRS — OFFSET,c ( m )+10 log 10 ( M SRS,c )+ P O — PUSCH,c ( j )+α c ( j ) PL c +f c ( i )}
where P CMAX,c is a configured transmit power for serving cell c,
P SRS — OFFSET,c (m) is a parameter configured by higher layer for serving cell c,
M SRS,c is the bandwidth of each SRS transmission for serving cell c, and
P O — PUSCH,c (j), α c (j), PL c , f c (i) are parameters.
5. The method of claim 1 , wherein the sounding reference symbol is a last orthogonal frequency division multiplexing (OFDM) symbol of a subframe.
6. The method of claim 5 , wherein the subframe is one of subframes satisfying a SRS configuration including a SRS periodicity and a SRS subframe offset.
7. A user equipment of adjusting a transmit power for sounding reference signals in a wireless communication system, comprising:
a radio frequency unit configured to transmit a radio signal; and
a processor operatively coupled with the radio frequency unit and configured to:
determine a plurality of transmit powers for transmitting a plurality of sounding reference signals (SRSs) in a sounding reference symbol; and
if a total transmit power for the plurality of SRSs exceeds a maximum transmit power, scale each of the plurality of transmit powers with a same scaling factor.
8. The user equipment of claim 7 , wherein each of the plurality of SRSs corresponds to respective serving cell.
9. The user equipment of claim 8 , wherein each transmit power for respective SRS is determined based on a bandwidth of each SRS transmission.
10. The user equipment of claim 9 , wherein each transmit power SRS,c (i) for respective SRS which is transmitted on subframe i for serving cell c is determined as shown:
P SRS,c ( i )=min{ P CMAX,c ( i ), P SRS — OFFSET,c ( m )+10 log 10 ( M SRS,c )+ P O — PUSCH,c ( j )+α c ( j ) PL c +f c ( i )}
where P CMAX,c is a configured transmit power for serving cell c,
P SRS — OFFSET,c (m) is a parameter configured by higher layer for serving cell c,
M SRS,c is the bandwidth of each SRS transmission for serving cell c, and
P O — PUSCH,c (j), α c (j), PL c (i) are parameters.
11. The user equipment of claim 7 , wherein the sounding reference symbol is a last orthogonal frequency division multiplexing (OFDM) symbol of a subframe.
12. The user equipment of claim 11 , wherein the subframe is one of subframes satisfying a SRS configuration including a SRS periodicity and a SRS subframe offset.