Sounding in multicarrier wireless communications

1. A wireless device comprising:

a) one or more communication interfaces;

b) one or more processors; and

c) memory storing instructions that, when executed, cause said wireless device to:

i) receive at least one control message comprising configuration parameters of:

(1) a plurality of cells comprising a primary cell and at least one secondary cell, said plurality of cells being grouped into a plurality of cell groups; and

(2) sounding reference signals (SRSs); and

ii) transmit one of said SRSs on a first cell in a first cell group in said plurality of cell groups overlapping in the same first subframe with transmission of a first random access preamble, said wireless device having sufficient transmission power to transmit said one of said SRSs and said first random access preamble; and

wherein transmission of a first SRS in said SRSs is dropped if:

(1) said first SRS transmission and a second random access preamble transmission coincide in the same second subframe; and

(2) said wireless device has insufficient transmission power to transmit said first SRS in parallel with said second random access preamble.

2. The wireless device of claim 1 , wherein said first random access preamble is transmitted on a second cell in a second cell group different from said first cell group.

3. The wireless device of claim 1 , wherein said wireless device assigns a lower priority to an SRS transmission power compared to a priority of a transmission power of a random access preamble.

4. The wireless device of claim 1 , wherein transmission of said first SRS in said SRSs is dropped if:

a) said first SRS transmission and said second random access preamble transmission coincide in the same subframe; and

b) said first SRS is configured to be transmitted in the same cell group employed for transmission of said second random access preamble.

5. The wireless device of claim 1 , wherein said wireless device assigns a lower priority to an SRS transmission power compared to:

a) a priority of a transmission power of a random access preamble; and

b) a priority of a transmission power of an uplink data packet.

6. The wireless device of claim 1 , wherein transmission of said one of said SRSs and an uplink data packet in a second cell in said first cell group coincide in the same subframe, said second cell being different from said first cell.

7. The wireless device of claim 1 , wherein transmission of said one of said SRSs and an uplink control packet in a second cell in said first cell group coincide in the same subframe, said second cell being different from said first cell.

8. The wireless device of claim 1 , wherein one or more of said SRSs are transmitted on the last symbol of a plurality of subframes.

9. The wireless device of claim 1 , wherein said wireless device transmits in parallel:

a) said one of said SRSs on said first cell;

b) said first random access preamble on said second cell in a second cell group different from said first cell group;

c) an uplink data packet in a second cell in said first cell group, said second cell being different from said first cell.

10. The wireless device of claim 1 , wherein no SRS is transmitted in a subframe if said wireless device does not have sufficient transmission power to transmit all the SRSs configured for transmission in said subframe.

11. A method for use by a wireless device, the method comprising:

a) receiving at least one control message comprising configuration parameters of:

i) a plurality of cells comprising a primary cell and at least one secondary cell, said plurality of cells being grouped into a plurality of cell groups; and

ii) sounding reference signals (SRSs); and

b) transmitting one of said SRSs on a first cell in a first cell group in said plurality of cell groups overlapping in the same first subframe with transmission of a first random access preamble, said wireless device having sufficient transmission power to transmit said one of said SRSs and said first random access preamble; and

wherein transmission of a first SRS in said SRSs is dropped if:

ii) said first SRS transmission and a second random access preamble transmission coincide in the same second subframe; and

iii) said wireless device has insufficient transmission power to transmit said first SRS in parallel with said second random access preamble.

12. The method of claim 11 , wherein said first random access preamble is transmitted on a second cell in a second cell group different from said first cell group.

13. The method of claim 11 , wherein said wireless device assigns a lower priority to an SRS transmission power compared to a priority of a transmission power of a random access preamble.

14. The method of claim 11 , wherein transmission of said first SRS is said SRSs is dropped if:

a) said first SRS transmission and said second random access preamble transmission coincide in the same subframe; and

b) said first SRS is configured to be transmitted in the same cell group employed for transmission of said second random access preamble.

15. The method of claim 11 , wherein said wireless device assigns a lower priority to an SRS transmission power compared to:

a) a priority of a transmission power of a random access preamble; and

b) a priority of a transmission power of an uplink data packet.

16. The method of claim 11 , wherein transmission of said one of said SRSs and an uplink data packet in a second cell in said first cell group coincide in the same subframe, said second cell being different from said first cell.

17. The method of claim 11 , wherein transmission of said one of said SRSs and an uplink control packet in a second cell in said first cell group coincide in the same subframe, said second cell being different from said first cell.

18. The method of claim 11 , wherein one or more of said SRSs are transmitted on the last symbol of a plurality of subframes.

19. The method of claim 11 , wherein said wireless device transmits in parallel:

a) said one of said SRSs on said first cell;

b) said first random access preamble on said second cell in a second cell group different from said first cell group;

c) an uplink data packet in a second cell in said first cell group, said second cell being different from said first cell.

20. The method of claim 11 , wherein no SRS is transmitted in a subframe, if said wireless device does not have sufficient transmission power to transmit all the SRSs configured for transmission in said subframe.