Repetition schemes for URLLC operating in unlicensed spectrum
An apparatus and system to enable URLLC PUSCH repetitions in the unlicensed spectrum are described. The number of consecutive PUSCH repetitions indicated in the RRC parameter is reinterpreted as the number of transmission occasions over which the UE is able to attempt CCA. An orphan symbol is used to provide a DMRS transmission or cyclic prefix of the PUSCH transmission causing the orphan symbol. Whether a CG-UCI is piggybacked in a PUSCH transmission, and whether DCI-DFI is used, is dependent on whether cg-RetransmissionTimer is configured.
1. An apparatus for a user equipment (UE), the apparatus comprising:
processing circuitry configured to:
decode, from a 5th generation NodeB (gNB), radio resource control (RRC) signaling that contains an RRC parameter of repetitions for at least one of configured grant (CG) physical uplink shared channel (PUSCH) type A transmissions or CG PUSCH type B transmissions for Ultra-Reliable Low-Latency Communication (URLLC) PUSCH transmissions in an Unlicensed Spectrum;
reinterpret a number of consecutive PUSCH repetitions in the RRC parameter as a number of transmission occasions over which the UE is able to attempt a listen-before-talk (LBT) procedure, the number of consecutive PUSCH repetitions for a CG-PUSCH type A transmission being a number of slots over which the consecutive PUSCH repetitions span;
attempt the LBT procedure based on the RRC parameter; and
encode, for transmission to the gNB, a set of consecutive PUSCH repetitions in accordance with the RRC parameter in response to the LBT procedure being successful; and
a memory configured to store the RRC parameter,
wherein at least one of the set of consecutive PUSCH repetitions is a PUSCH transmission with repetition type B.
2. The apparatus of claim 1 , wherein the processing circuitry is configured to decode, from the gNB, a higher layer parameter that configures channel access parameters for operation in a semi-static channel access mode.
3. The apparatus of claim 2 , wherein the higher layer parameter configures channel access parameters for UE-initiated semi-static channel access.
4. The apparatus of claim 3 , wherein the higher layer parameter includes a predetermined period.
5. The apparatus of claim 3 , wherein the processing circuitry is configured to:
decode, from the gNB, a channelAccessMode-r16 information element (IE) configured to semiStatic; and
determine that the UE is to operate in the semi-static channel access mode based on the higher layer parameter and the channelAccessMode-r16 IE.
6. The apparatus of claim 5 , wherein the processing circuitry is configured to decode the channelAccessMode-r16 IE from system information block1 (SIB1).
7. The apparatus of claim 5 , wherein the processing circuitry is configured to decode the channelAccessMode-r16 IE from a dedicated configuration from higher layer signaling.
8. The apparatus of claim 1 , wherein the processing circuitry is configured to, in response to a determination that all symbols during an idle duration are invalid symbols, drop a repetition.
9. The apparatus of claim 1 , wherein the processing circuitry is configured to, in response to a determination that all symbols during an idle duration are invalid symbols, drop a repetition after the idle duration.
10. The apparatus of claim 1 , wherein the processing circuitry is configured to:
decode, from the gNB, an uplink grant; and
determine that the UE is to transmit at least one of the set of consecutive PUSCH repetitions using the uplink grant after accessing a channel.
11. A non-transitory computer-readable storage medium that stores instructions for execution by one or more processors of a user equipment (UE), the one or more processors configured to, when the instructions are executed:
determine that the UE is to operate in semi-static channel access mode during a channel access procedure performed on a channel in a shared spectrum;
determine, while sensing to evaluate availability of the channel during the channel access procedure, that a repetition of a physical uplink shared channel (PUSCH) is associated with a channel occupancy corresponding to a predetermined period has been initiated and overlaps with an idle duration corresponding to the predetermined period; and
in response to a determination that the PUSCH is associated with the channel occupancy corresponding to the predetermined period and overlaps with the idle duration corresponding to the predetermined period, determine that all symbols during the idle duration are invalid symbols.
12. The non-transitory computer-readable storage medium of claim 11 , wherein the PUSCH is a PUSCH transmission with repetition type B.
13. The non-transitory computer-readable storage medium of claim 11 , wherein the one or more processors are configured to, when the instructions are executed, decode, from a 5 th generation NodeB (gNB), a higher layer parameter that configures channel access parameters for operation in the semi-static channel access mode.
14. The non-transitory computer-readable storage medium of claim 13 , wherein the higher layer parameter configures channel access parameters for UE-initiated semi-static channel access.
15. The non-transitory computer-readable storage medium of claim 11 , wherein the one or more processors are configured to, when the instructions are executed, in response to a determination that all symbols during the idle duration are invalid symbols, drop the repetition.
16. The non-transitory computer-readable storage medium of claim 11 , wherein the one or more processors are configured to, when in response to a determination that all symbols during the idle duration are invalid symbols, drop the repetition after the idle duration.
17. The non-transitory computer-readable storage medium of claim 11 , wherein the one or more processors are configured to, when:
decode, from a 5 th generation NodeB (gNB), an uplink grant; and
determine that the UE is to transmit the PUSCH using the uplink grant after accessing a channel.
18. An apparatus for a user equipment (UE), the apparatus comprising:
processing circuitry configured to:
determine, for a semi-static channel access mode operation while sensing to evaluate availability of a channel in a shared spectrum during a channel access procedure performed on the channel, that a repetition of a physical uplink shared channel (PUSCH) is associated with a channel occupancy corresponding to a predetermined period has been initiated and overlaps with an idle duration corresponding to the predetermined period; and
in response to a determination that the PUSCH is associated with the channel occupancy corresponding to the predetermined period and overlaps with the idle duration corresponding to the predetermined period, determine that all symbols during the idle duration are invalid symbols and drop the repetition after the idle duration; and
a memory configured to store the predetermined period.
19. The apparatus of claim 18 , wherein the PUSCH is a PUSCH transmission with repetition type B.