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EP-4187997-B1 - METHODS AND DEVICES FOR CONTROL CHANNEL RECEPTION IN POWER SAVE MODE

EP4187997B1EP 4187997 B1EP4187997 B1EP 4187997B1EP-4187997-B1

Inventors

  • KWON, YOUNG HOON
  • XIA, PENGFEI

Dates

Publication Date
20260506
Application Date
20190522

Claims (15)

  1. A method implemented by a user equipment UE, the method comprising: determining that a media access control, MAC, entity of the UE is in Active Time at an expected transmission time of a wake up signal, WUS, wherein the WUS indicates if a physical downlink control channel, PDCCH, transmission is expected during a discontinuous reception, DRX, ON period associated with the WUS; and deactivating WUS reception of the UE during the expected transmission time of the WUS before the DRX ON period, based on the determining.
  2. The method according to claim 1, wherein the WUS is transmitted within a predetermined time window before the DRX ON period.
  3. The method according to claim 1 or 2, comprising: receiving a first WUS using a first beam, wherein the first WUS is associated with a first DRX ON period; receiving a first control channel during the associated first DRX ON period, wherein the first control channel is received on a first control resource set(s), CORESET, using a second beam, wherein the first WUS and the first control channel share a common quasi collocated, QCL, source; receiving a second WUS using a third beam, wherein the second WUS indicates if a PDCCH transmission is expected during a second DRX ON period; failing to successfully receive a second control channel during the second DRX ON period; and transmitting a packet to indicate a request for a beam update procedure.
  4. The method according to claim 3, wherein the second WUS is received at a predetermined time window before the second DRX ON period.
  5. The method according to any one of claims 1 to 4, wherein the Active Time includes a time while: one of a drx-onDurationTimer, a drx-InactivityTimer, a drx-RetransmissionTimerDL, a drx-RetransmissionTimerUL, or a ra-ContentionResolutionTimer is running.
  6. The method according to any one of claims 1 to 5, wherein the Active Time includes a time while a Scheduling Request is sent on physical uplink control channel, PUCCH, and is pending.
  7. The method according to any one of claims 1 to 6, wherein the Active Time includes a time while the PDCCH indicating a new transmission addressed to a cell-radio network temporary identifier, C-RNTI, of the MAC entity has not been received after successful reception of a Random Access Response for a Random Access Preamble not selected by the MAC entity among a contention-based Random Access Preamble.
  8. The method according to any one of claims 1 to 7, wherein the Active Time is before the first DRX ON period.
  9. A user equipment, UE, comprising: at least one processor; and a non-transitory computer readable storage medium storing programming for execution by the processor, the programming including instructions to cause the UE to implement the method according to any one of claims 1 to 8.
  10. A method implemented by an access node, the method comprising: determining that a media access control, MAC, entity of a user equipment, UE, is in Active Time during a predetermined time window for transmitting a wake up signal, WUS, prior to a discontinuous reception, DRX, ON period; and not transmitting the WUS to the UE during the predetermined time window prior to the DRX ON period, based on the determining.
  11. The method according to claim 10, wherein the WUS is transmitted within the predetermined time window before the DRX ON period.
  12. The method according to claim 10 or 11, wherein the Active Time includes a time while: one of a drx-onDurationTimer, a drx-InactivityTimer, a drx-RetransmissionTimerDL, a drx-RetransmissionTimerUL, or a ra-ContentionResolutionTimer is running.
  13. The method according to any one of claims 10 to 12, wherein the Active Time includes a time while a Scheduling Request is sent on physical uplink control channel, PUCCH, and is pending.
  14. The method according to any one of claims 10 to 13, wherein the Active Time includes a time while a PDCCH indicating a new transmission addressed to a cell-radio network temporary identifier, C-RNTI, of the MAC entity has not been received after successful reception of a Random Access Response for a Random Access Preamble not selected by the MAC entity among a contention-based Random Access Preamble.
  15. An access node comprising: at least one processor; and a non-transitory computer readable storage medium storing programming for execution by the processor, the programming including instructions to cause the access node to implement the 30 method according to any one of claims 10 to 14.

Description

TECHNICAL FIELD The present disclosure relates generally to a system and method for digital communications, and, in particular embodiments, to a system and method for control channel reception in power save mode. BACKGROUND One possible deployment scenario for fifth generation (5G) New Radio (NR) system architecture uses high frequency (HF) (6 gigahertz (GHz) and above, such as millimeter wavelength (mmWave)) operating frequencies to exploit greater available bandwidth and less interference then what is available at the congested lower frequencies. However, pathloss is a significant issue. Beamforming may be used to overcome the high pathloss. However, the beams are prone to blockage. Therefore, a beam that is being used for communications may become blocked and fail, leaving the communications device without a connection. Therefore, there is a need for systems and methods for control channel reception with discontinuous reception feature to further save power consumption. Document WO 2018/132100 A1 describes a cellular wakeup receiver (C-WuRx) for reducing power consumption of a wireless wide area network (WWAN) radio of a user equipment (UE) includes receiver circuitry to receive a wakeup signal from a base station in response to the UE performing link aggregation by which downlink communications from the base station are offloaded to a wireless local area network (WLAN). Document "Wake up signalling for efeMTC" from Sony, XP051317346, discusses the candidates in terms of eNB resource consumption, paging reliability and battery power as well as an introduction of a possible Wake -up-signal sequence. SUMMARY The present invention is defined by the attached set of claims. In the following, the thirteenth implementation form of the method according to the second aspect falls within the scope of protection of the claims. The remaining aspects, examples and embodiments are presented hereinafter for illustrative purposes, to support a better understanding of the invention. According to a first aspect, a method implemented by an access node is provided. The method includes transmitting, by the access node, a wake up signal (WUS) prior to a control channel occurring within an associated discontinuous reception (DRX) ON period, wherein the WUS is transmitted using a first beam, and transmitting, by the access node, the control channel during the associated DRX ON period, wherein the control channel is transmitted on a control resource set (CORESET) using a second beam, wherein the first and second beams share a common quasi-colocated (QCL) source. In a first implementation form of the method according to the first aspect as such, wherein the WUS is transmitted prior to the associated DRX ON period. In a second implementation form of the method according to the first aspect as such or any preceding implementation form of the first aspect, wherein the CORESET is one of a plurality of CORESETs associated with the DRX ON period, and wherein all CORESETs of the plurality of CORESETs share the common QCL source. In a third implementation form of the method according to the first aspect as such or any preceding implementation form of the first aspect, wherein the CORESET is one of a plurality of CORESETs associated with the DRX ON period, and wherein the CORESET is a predetermined CORESET. In a fourth implementation form of the method according to the first aspect as such or any preceding implementation form of the first aspect, wherein the CORESET comprises one of a first CORESET of the associated DRX ON period, a CORESET with a specified identifier, a CORESET with a lowest identifier in the plurality of CORESETs, a CORESET with a highest identifier in the plurality of CORESETs, a CORESET last successfully received by a user equipment (UE), a CORESET that is associated with a UE specific search space, a CORESET that is associated with a specified common search space, or a CORESET that is associated with a search space scheduled in the associated DRX ON period. In a fifth implementation form of the method according to the first aspect as such or any preceding implementation form of the first aspect, wherein the WUS indicates a search space where the control channel will be located or a CORESET on which the control channel will be transmitted. In a sixth implementation form of the method according to the first aspect as such or any preceding implementation form of the first aspect, wherein the WUS indicates that the control channel will be transmitted in a CORESET. In a seventh implementation form of the method according to the first aspect as such or any preceding implementation form of the first aspect, further comprising configuring, by the access node, a transmission configuration indication (TCI) state for each CORESET of the plurality of CORESETs. In an eighth implementation form of the method according to the first aspect as such or any preceding implementation form of the first aspect, further comprising configuri