Sounding reference signal transmissions in different frequency bands

1. A method comprising:

receiving, by a wireless device, configuration parameters of:

one or more first cells in a first frequency band; and

one or more second cells in an unlicensed frequency band;

transmitting, via the one or more first cells, a physical uplink shared channel (PUSCH) signal in the first frequency band;

determining, independently of transmissions of the PUSCH signal in the first frequency band, whether to transmit or to drop a configured transmission of at least one sounding reference signal (SRS) via the one or more second cells of the unlicensed frequency band, wherein the configured transmission of the at least one SRS overlaps with the PUSCH signal; and

based on the determining:

transmitting the at least one SRS via a second cell of the one or more second cells; or

dropping the at least one SRS.

2. The method of claim 1 , further comprising:

determining, based on transmissions of the PUSCH signals in the first frequency band, whether to transmit or to drop a second configured transmission of at least one second SRS via a third cell of the one or more first cells, wherein the second configured transmission of the at least one second SRS overlaps with the PUSCH signal; and

based on the determining whether to transmit or to drop the second configured transmission:

transmitting the at least one second SRS via the third cell; or

dropping the at least one second SRS.

3. The method of claim 1 , wherein the wireless device is uplink power limited during PUSCH transmission.

4. The method of claim 1 , wherein the determining is based on transmissions of second PUSCH signals in the unlicensed frequency band.

5. The method of claim 1 , wherein the one or more first cells and one or more second cells are in a same physical uplink control channel (PUCCH) group.

6. The method of claim 1 , further comprising transmitting to a base station a message comprising one or more parameters, the one or more parameters indicating that the wireless device supports an enhanced SRS transmission procedure.

7. The method of claim 1 , further comprising transmitting to a base station a message comprising one or more parameters, the one or more parameters indicating that the wireless device supports configuration of an uplink for the second cell.

8. The method of claim 1 , wherein the configuration parameters further comprise SRS configuration parameters comprising an SRS bandwidth parameter and an SRS subframe configuration parameter.

9. The method of claim 1 , wherein the transmitting the at least one SRS is in response to receiving downlink control information from a base station.

10. A wireless device comprising:

one or more processors; and

memory storing instructions that, when executed by the one or more processors, cause the wireless device to:

receive configuration parameters of:

one or more first cells in a first frequency band; and

one or more second cells in an unlicensed frequency band;

transmit, via the one or more first cells, a physical uplink shared channel (PUSCH) signal in the first frequency band;

determine, independently of transmissions of the PUSCH signals in the first frequency band, whether to transmit or to drop a configured transmission of at least one sounding reference signal (SRS) via the one or more second cells of the unlicensed frequency band, wherein the configured transmission of the at least one SRS overlaps with the PUSCH signal; and

based on the determination whether to transmit or to drop the configured transmission:

transmit the at least one SRS via a second cell of the one or more second cells; or

drop the at least one SRS.

11. The wireless device of claim 10 , wherein the instructions, when executed by the one or more processors, further cause the wireless device to:

determine, based on the transmissions of the PUSCH signals in the first frequency band, whether to transmit or to drop a second configured transmission of at least one second SRS via a third cell of the one or more first cells, wherein the second configured transmission of the at least one second SRS overlaps with the PUSCH signal; and

based on the determination whether to transmit or to drop the second configured transmission:

transmit the at least one second SRS via the third cell; or

drop the at least one second SRS.

12. The wireless device of claim 10 , wherein the wireless device is uplink power limited during PUSCH transmission.

13. The wireless device of claim 10 , wherein the determining whether to transmit or to drop the configured transmission is based on transmissions of second PUSCH signals in the unlicensed frequency band.

14. The wireless device of claim 10 , wherein the one or more first cells and the one or more second cells are in a same physical uplink control channel (PUCCH) group.

15. The wireless device of claim 10 , wherein the instructions, when executed by the one or more processors, further cause the wireless device to transmit to a base station a message comprising one or more parameters, the one or more parameters indicating that the wireless device supports an enhanced SRS transmission procedure.

16. The wireless device of claim 10 , wherein the instructions, when executed by the one or more processors, further cause the wireless device to transmit to a base station a message comprising one or more parameters, the one or more parameters indicating that the wireless device supports configuration of an uplink for the second cell.

17. The wireless device of claim 10 , wherein the configuration parameters further comprise SRS configuration parameters comprising an SRS bandwidth parameter and an SRS subframe configuration parameter.

18. A system comprising:

a base station comprising:

one or more first processors; and

first memory storing first instructions that, when executed by the one or more first processors, cause the base station to transmit configuration parameters of:

one or more first cells in a first frequency band; and

one or more second cells in an unlicensed frequency band; and

a wireless device comprising:

one or more second processors; and

second memory storing instructions that, when executed by the one or more processors, cause the wireless device to:

receive the configuration parameters;

transmit, via the one or more first cells, a physical uplink shared channel (PUSCH) signal in the first frequency band;

determine, independently of transmissions of the PUSCH signals in the first frequency band, whether to transmit or to drop a configured transmission of at least one sounding reference signal (SRS) via the one or more second cells of the unlicensed frequency band, wherein the configured transmission of the at least one SRS overlaps with the PUSCH signal; and

based on the determination whether to transmit or to drop the configured transmission:

transmit the at least one SRS via a second cell of the one or more second cells; or

drop the at least one SRS.

19. The method of claim 1 , further comprising determining whether a first SRS is scheduled for transmission independently of the PUSCH signal transmitted in the first frequency band.

20. The wireless device of claim 10 , wherein the instructions, when executed by the one or more processors, further cause the wireless device to determine whether a first SRS is scheduled for transmission independently of the PUSCH signal transmitted in the first frequency band.