Cellular vehicle-to-everything design principles

1. A method for wireless communication, comprising:

identifying, by a first user equipment (UE) configured to communicate using a first radio access technology (RAT), a shared radio frequency spectrum band that is shared between the first UE and a second UE that is configured to communicate using a second RAT different from the first RAT;

identifying resources for a transmission from the first UE to a third UE using the first RAT based at least in part on detecting one or more control channel transmissions from the second UE;

generating, based at least in part on the second RAT, a preamble for transmission on the shared radio frequency spectrum band using the second RAT, the preamble configured to be decodable by the second UE of the second RAT and conveying an indication of the transmission from the first UE to the third UE using the first RAT, the transmission communicated using the first RAT; and

transmitting the preamble using the second RAT prior to the transmission from the first UE to the third UE using the first RAT, wherein the transmission is communicated via the identified resources.

2. The method of claim 1 , further comprising:

configuring at least one of a network allocation vector (NAV) or a transmission opportunity (TxOP) parameter in the preamble to convey an indication of a transmission duration for the transmission by the first UE using the first RAT.

3. The method of claim 1 , wherein the first RAT has a higher transmission priority than the second RAT.

4. The method of claim 1 , wherein the first RAT comprises a vehicle-to-everything (V2X) RAT, and wherein the second RAT comprises one or more of a Wi-Fi RAT, a long term evolution (LTE) license assisted access (LTE-LAA) RAT, an enhanced LTE-LAA RAT, or a multi-fire RAT.

5. The method of claim 1 , further comprising:

selecting a bandwidth for the transmission by the first UE using the first RAT; and

configuring the preamble to convey an indication of the bandwidth.

6. The method of claim 1 , further comprising:

performing a listen-before-talk (LBT) procedure prior to the transmission by the first UE using the first RAT; and

performing a backoff procedure when the LBT procedure indicates that the shared radio frequency spectrum band is occupied.

7. The method of claim 1 , wherein the transmission by the first UE using the first RAT comprises a unicast transmission or a broadcast transmission, or both.

8. The method of claim 1 , wherein the transmission by the first UE using the first RAT comprises a vehicle-to-everything (V2X) transmission.

9. A first user equipment (UE) for wireless communication, comprising:

one or more memories storing processor-executable code a processor; and

one or more processors coupled with the one or more memories and individually or collectively operable to execute the code to cause the first UE to:

identify, by the first UE configured to communicate using a first radio access technology (RAT), a shared radio frequency spectrum band that is shared between the first UE and a second UE that is configured to communicate using a second RAT different from the first RAT;

identify resources for a transmission from the first UE to a third UE using the first RAT based at least in part on detecting one or more control channel transmissions from the second UE;

generate, based at least in part on the second RAT, a preamble for transmission on the shared radio frequency spectrum band using the second RAT, the preamble configured to be decodable by the second UE of the second RAT and conveying an indication of the transmission from the first UE to the third UE using the first RAT, the transmission communicated using the first RAT; and

transmit the preamble using the second RAT prior to the transmission from the first UE to the third UE using the first RAT, wherein the transmission is communicated via the identified resources.

10. The first UE of claim 9 , wherein the one or more processors are individually or collectively operable to execute the code to cause the first UE to:

configure at least one of a network allocation vector (NAV) or a transmission opportunity (TxOP) parameter in the preamble to convey an indication of a transmission duration for the transmission by the first UE and communicated using the first RAT.

11. The first UE of claim 9 , wherein the first RAT has a higher transmission priority than the second RAT.

12. The first UE of claim 9 , wherein the first RAT comprises a vehicle-to-everything (V2X) RAT, and wherein the second RAT comprises one or more of a Wi-Fi RAT, a long term evolution (LTE) license assisted access (LTE-LAA) RAT, an enhanced LTE-LAA RAT, or a multi-fire RAT.

13. The first UE of claim 9 , wherein the one or more processors are individually or collectively operable to execute the code to cause the first UE to:

select a bandwidth for the transmission by the first UE communicated using the first RAT; and

configure the preamble to convey an indication of the bandwidth.

14. The first UE of claim 9 , wherein the one or more processors are individually or collectively operable to execute the code to cause the first UE to:

perform a listen-before-talk (LBT) procedure prior to the transmission by the first UE communicated using the first RAT; and

perform a backoff procedure when the LBT procedure indicates that the shared radio frequency spectrum band is occupied.

15. The first UE of claim 9 , wherein the transmission by the first UE communicated using the first RAT comprises a unicast transmission or a broadcast transmission, or both.

16. The first UE of claim 9 , wherein the transmission by the first UE communicated using the first RAT comprises a vehicle-to-everything (V2X) transmission.