Coverage enhancement with frequency selective transmission

1. A method comprising:

receiving, by a wireless device, a downlink control information indicating:

a transmission via uplink resources comprising sub-bands; and

a sounding reference signal resource indicator (SRI);

selecting, based on the SRI, one or more sounding reference signal (SRS) resources;

determining uplink precoders for the transmission, wherein the uplink precoders comprise an uplink precoder determined, for each respective sub-band of the sub-bands, based on a transmission precoder of the one or more SRS resources transmitted via the respective sub-band; and

transmitting, based on the determined uplink precoders, a transport block of the transmission via the uplink resources.

2. The method of claim 1 , further comprising:

transmitting, to a base station, the one or more SRS resources before receiving the downlink control information.

3. The method of claim 1 , wherein selecting the one or more SRS resources comprises:

selecting the one or more SRS resources indicated by the SRI.

4. The method of claim 1 , wherein selecting the one or more SRS resources comprises:

determining, based on the SRI, one or more transmission occasions of the one or more SRS resources.

5. The method of claim 4 , wherein the one or more transmission occasions comprise one or more occasions in which the one or more SRS resources are transmitted via the sub-bands.

6. The method of claim 5 , wherein the one or more occasions comprise a plurality of occasions, and each occasion is associated with one of the sub-bands.

7. The method of claim 1 , further comprising:

transmitting the one or more SRS resources via the sub-bands, wherein the one or more SRS resources transmitted via a respective sub-band of the sub-bands is transmitted in a transmission occasion with a respective transmission precoder.

8. The method of claim 7 , wherein the transmission occasion comprises one or more symbols, one or more mini slots, or one or more slots.

9. The method of claim 1 , wherein each of the sub-bands has a same sub-band bandwidth.

10. The method of claim 1 , wherein the uplink precoder determined for each sub-band, of the sub-bands, comprises a transmission precoder transmitted with the one or more SRS resources via the sub-band.

11. 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 a downlink control information indicating:

a transmission via uplink resources comprising sub-bands; and

a sounding reference signal resource indicator (SRI);

select, based on the SRI, one or more sounding reference signal (SRS) resources;

determine uplink precoders for the transmission, wherein the uplink precoders comprise an uplink precoder determined, for each respective sub-band of the sub-bands, based on a transmission precoder of the one or more SRS resources transmitted via the respective sub-band; and

transmit, based on the determined uplink precoders, a transport block of the transmission via the uplink resources.

12. The wireless device of claim 11 , wherein the instructions further cause the wireless device to:

transmit, to a base station, the one or more SRS resources before receiving the downlink control information.

13. The wireless device of claim 11 , wherein to select the one or more SRS resources, the instructions further cause the wireless device to:

select the one or more SRS resources indicated by the SRI.

14. The wireless device of claim 11 , wherein to select the one or more SRS resources, the instructions further cause the wireless device to:

determine, based on the SRI, one or more transmission occasions of the one or more SRS resources.

15. The wireless device of claim 14 , wherein the one or more transmission occasions comprise one or more occasions in which the one or more SRS resources are transmitted via the sub-bands.

16. The wireless device of claim 15 , wherein the one or more occasions comprise a plurality of occasions, and each occasion is associated with one of the sub-bands.

17. The wireless device of claim 11 , wherein the instructions further cause the wireless device to:

transmit the one or more SRS resources via the sub-bands, wherein the one or more SRS resources transmitted via a respective sub-band of the sub-bands is transmitted in a transmission occasion with a respective transmission precoder, wherein the transmission occasion comprises one or more symbols, one or more mini slots, or one or more slots.

18. The wireless device of claim 11 , wherein each of the sub-bands has a same sub-band bandwidth.

19. The wireless device of claim 11 , wherein the uplink precoder determined for each sub-band, of the sub-bands, comprises a transmission precoder transmitted with the one or more SRS resources via the sub-band.

20. A system comprising:

a base station; and

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, from the base station, a downlink control information indicating:

a transmission via uplink resources comprising sub-bands; and

a sounding reference signal resource indicator (SRI);

select, based on the SRI, one or more sounding reference signal (SRS) resources;

determine uplink precoders for the transmission, wherein the uplink precoders comprise an uplink precoder determined, for each respective sub-band of the sub-bands, based on a transmission precoder of the one or more SRS resources transmitted via the respective sub-band; and

transmit, to the base station and based on the determined uplink precoders, a transport block of the transmission via the uplink resources.