Repetition-based uplink for low latency communications in a new radio wireless communication system
A method and apparatus for enabling repetitive transmissions for low latency systems is disclosed. For example, a base station may determine whether an uplink coverage parameter for a UE communicating with the network entity on an uplink communication channel satisfies an uplink coverage threshold, and transmit an activation message for repetition-based uplink communications to the UE based on a determination that the uplink coverage parameter for the UE communicating with the network entity on the uplink communication channel satisfies the uplink coverage threshold. Further, a UE may receive an activation message for repetition-based uplink communications from a network entity, and perform repetitive transmissions on the uplink communication channel for the duration indicated by the one or more transmission parameters in the activation message, the repetitive transmissions being configured based on the uplink sTTI pattern.
1. A method of wireless communication, comprising:
receiving, by a user equipment (UE), an activation message for repetition-based uplink communications from a network entity, the activation message including one or more transmission parameters indicating at least a duration for transmissions on an uplink communication channel and an uplink short Transmission Time Interval (sTTI) pattern for the transmissions on the uplink communication channel; and
performing, by the UE, repetitive transmissions on the uplink communication channel for the duration indicated by the one or more transmission parameters in the activation message, the repetitive transmissions being configured based on the uplink sTTI,
wherein performing the repetitive transmissions further comprises performing the repetitive transmissions on a plurality of uplink sTTIs located in two or more subframes,
wherein performing the repetitive transmissions on the plurality of uplink sTTIs located in the two or more subframes further comprises transmitting a Demodulation Reference Signal (DMRS) within each of one or more subframes for the duration indicated by the one or more transmission parameters in the activation message
wherein the repetitive transmission comprises transmitting one packet multiple times.
2. The method of claim 1 , further comprising receiving, by the UE, a configuration message for the repetition-based uplink communications with the network entity,
the configuration message including one or more configuration parameters,
the duration and the uplink sTTI pattern being further indicated by the one or more configuration parameters.
3. The method of claim 2 , wherein the configuration message is included within either a Radio Resource Control (RRC) message or a Medium Access Control (MAC) Control Element (CE).
4. The method of claim 2 , the duration comprising a number of the plurality of TTIs.
5. The method of claim 4 , the repetitive transmissions comprising repetitive transmissions of data information.
6. The method of claim 1 , wherein the activation message is included within either a Medium Access Control (MAC) Control Element (CE) or a Downlink Control Information (DCI) message.
7. The method of claim 1 , wherein the activation message is included within a grant message, and wherein the activation message includes an indication for a number of repetitive transmissions to perform.
8. The method of claim 7 , wherein the grant corresponds to a grant for a short Physical Uplink Shared Channel (sPUSCH).
9. The method of claim 1 , wherein performing the repetitive transmissions on the plurality of sTTIs located in the two or more subframes further comprises maintaining a phase continuity parameter across one or more subframes for the duration indicated by the one or more transmission parameters in the activation message.
10. The method of claim 1 , wherein performing the repetitive transmissions further comprises transmitting a Sounding Reference Signal (SRS) over a last symbol of a subframe.
11. The method of claim 1 , wherein the uplink sTTI pattern for the transmissions on the uplink communication channel corresponds to a fixed uplink sTTI pattern configured for each starting sTTI and the duration for transmissions on the uplink communication channel.
12. An apparatus for wireless communications, comprising:
a memory; and
a processor in communication with the memory, wherein the processor is configured to:
receive an activation message for repetition-based uplink communications from a network entity, the activation message including one or more transmission parameters indicating at least a duration for transmissions on an uplink communication channel and an uplink short Transmission Time Interval (sTTI) pattern for the transmissions on the uplink communication channel; and
perform repetitive transmissions on the uplink communication channel for the duration indicated by the one or more transmission parameters in the activation message, the repetitive transmissions being configured based on the uplink sTTI pattern,
wherein the processor is configured to perform the repetitive transmissions on a plurality of uplink sTTIs located in two or more subframes,
wherein the processor is further configured to transmit a Demodulation Reference Signal (DMRS) within each of one or more subframes for the duration indicated by the one or more transmission parameters in the activation message,
wherein the repetitive transmission comprises transmitting one packet multiple times.
13. The apparatus of claim 12 , wherein the processor is further configured to receive a configuration message for the repetition-based uplink communications with the network entity, the configuration message including one or more configuration parameters,
the duration and the uplink sTTI pattern being further indicated by the one or more configuration parameters.
14. The apparatus of claim 13 , wherein the configuration message is included within either a Radio Resource Control (RRC) message or a Medium Access Control (MAC) Control Element (CE).
15. The apparatus of claim 13 , the duration comprising a number of the plurality of TTIs.
16. The apparatus of claim 15 , the repetitive transmissions comprising repetitive transmissions of data information.
17. The apparatus of claim 12 , wherein the activation message is included within either a Medium Access Control (MAC) Control Element (CE) or a Downlink Control Information (DCI) message.
18. The apparatus of claim 12 , wherein the activation message is included within a grant message, and wherein the activation message includes an indication for a number of repetitive transmissions to perform.
19. The apparatus of claim 18 , wherein the grant corresponds to a grant for a short Physical Uplink Shared Channel (sPUSCH).
20. The apparatus of claim 12 , wherein the processor configured to perform the repetitive transmissions on the plurality of uplink sTTIs located in the two or more subframes is further configured to maintain a phase continuity parameter across one or more subframes for the duration indicated by the one or more transmission parameters in the activation message.
21. The apparatus of claim 12 , wherein the processor configured to perform the repetitive transmissions is further configured to transmit a Sounding Reference Signal (SRS) over a last symbol of a subframe.
22. The apparatus of claim 12 , wherein the uplink sTTI pattern for the transmissions on the uplink communication channel corresponds to a fixed uplink sTTI pattern configured for each starting sTTI and the duration for transmissions on the uplink communication channel.