Determination of requirement of UE processing time in NR
A method of providing a relaxed UE processing time for uplink transmission in NR is proposed. The UE processing time of uplink transmission is required for HARQ-ACK after the reception of downlink data over physical data shared channel (PDSCH). The UE processing time is also required for physical uplink share channel (PUSCH) transmission after the reception of an uplink grant. Under non-co-located carrier aggregation, the timing difference between the signals received at the UE in different cells could be up to 30.26 us, which increases the UE processing time for uplink transmission. In accordance with one novel aspect, the UE processing time requirement is relaxed according to the timing difference requirement for carrier aggregation, when CA is operated. In addition, the UE processing time requirement also depends on the applied subcarrier spacing (SCS) in NR systems.
1. A method comprising:
establishing a primary connection in a primary cell with a primary base station by a user equipment (UE) in a wireless communication network, wherein the primary cell comprises a first downlink (DL) component carrier (CC) and a first uplink (UL) CC;
establishing a second connection in a secondary cell under either intra-band non-contiguous carrier aggregation (CA) or inter-band CA, wherein the secondary cell comprises a second downlink CC; and
receiving a physical-layer signaling for transmitting an UL transmission after a time period in response to a DL transmission, wherein the UE performs the UL transmission when the time period provided by the primary base station is at least equal to a UE processing time that is relaxed according to a timing difference requirement of the CA, wherein the relaxed UE processing time is included in the time period for a hybrid automatic repeat request (HARQ) ACK or for a scheduled uplink transmission.
2. The method of claim 1 , wherein the physical-layer signaling schedules the DL transmission over the second DL CC, and wherein the UL transmission is a hybrid automatic repeat request (HARQ) ACK over the first UL CC.
3. The method of claim 2 , wherein the physical-layer signaling is transmitted over the first DL CC.
4. The method of claim 2 , wherein the physical-layer signaling is transmitted over the second DL CC.
5. The method of claim 1 , wherein the DL transmission comprising an UL grant transmitted over the second DL CC, and wherein the UL transmission is scheduled by the UL grant and is transmitted over the first UL CC.
6. The method of claim 1 , wherein the time period corresponds to an end time of the DL transmission and a start time of the UL transmission.
7. The method of claim 1 , wherein the UE does not perform the UL transmission when the provided time period is shorter than the UE processing time.
8. A User Equipment (UE) comprising:
a control circuit that establishes a primary connection in a primary cell with a primary base station in a wireless communication network, wherein the primary cell comprises a first downlink (DL) component carrier (CC) and a first uplink (UL) CC;
a carrier aggregation (CA) handling circuit that establishes a second connection in a secondary cell under either intra-band non-contiguous CA or inter-band CA, wherein the secondary cell comprises a second downlink CC; and
a receiver that receives a physical-layer signaling for transmitting an UL transmission after a time period in response to a DL transmission, wherein the UE performs the UL transmission when the time period provided by the primary base station is at least equal to a UE processing time that is relaxed according to a timing difference requirement of the CA, wherein the relaxed UE processing time is included in the time period for a hybrid automatic repeat request (HARQ) ACK or for a scheduled uplink transmission.
9. The UE of claim 8 , wherein the physical-layer signaling schedules the DL transmission over the second DL CC, and wherein the UL transmission is a hybrid automatic repeat request (HARQ) ACK over the first UL CC.
10. The UE of claim 9 , wherein the physical-layer signaling is transmitted over the first DL CC.
11. The UE of claim 9 , wherein the physical-layer signaling is transmitted over the second DL CC.
12. The UE of claim 8 , wherein the DL transmission comprising an UL grant transmitted over the second DL CC, and wherein the UL transmission is scheduled by the UL grant and is transmitted over the first UL CC.
13. The UE of claim 8 , wherein the time period corresponds to an end time of the DL transmission and a start time of the UL transmission.
14. The UE of claim 8 , wherein the UE does not perform the UL transmission when the provided time period is shorter than the UE processing time.
15. A method comprising:
establishing a primary connection with a user equipment (UE) in a primary cell belonging to a primary base station in a wireless communication network, wherein the primary cell comprises a first downlink (DL) component carrier (CC) and a first uplink (UL) CC;
configuring a second connection for the UE in a secondary cell under carrier aggregation (CA), wherein the secondary cell comprises a second downlink CC, wherein the UE is configured with either intra band non-contiguous CA or inter-band CA; and
transmitting a physical-layer signaling to the UE to schedule an UL transmission after a time period in response to a DL transmission, wherein the time period is provided by the primary base station based on a UE processing time that is relaxed according to a timing difference requirement of the CA, wherein the relaxed UE processing time is included in the time period for a hybrid automatic repeat request (HARQ) ACK or for a scheduled uplink transmission.
16. The method of claim 15 , wherein the physical-layer signaling schedules the DL transmission over the second DL CC, and wherein the UL transmission is a hybrid automatic repeat request (HARQ) ACK over the first UL CC.
17. The method of claim 16 , wherein the physical-layer signaling is transmitted over the first DL CC.
18. The method of claim 16 , wherein the physical-layer signaling is transmitted over the second DL CC.
19. The method of claim 15 , wherein the DL transmission comprising an UL grant transmitted over the second DL CC, and wherein the UL transmission is scheduled by the UL grant and is transmitted over the first UL CC.
20. The method of claim 15 , wherein the time period corresponds to an end time of the DL transmission and a start time of the UL transmission.