Wake-up signal for discontinuous reception operation

Abstract

The present disclosure relates to a wake-up signal scheme between a network and a user equipment (UE) operating in a discontinuous reception (DRX) state. The UE monitors a wakeup signal (WUS) occasion to determine whether a WUS is received during the WUS occasion; when the WUS is received, determining whether the WUS identifies the UE; when the WUS is received and identifies the UE, monitoring the opening duration of a discontinuous reception (DRX) cycle corresponding to the WUS; and when the WUS is not received or the WUS does not identify the UE, maintaining a sleep state during the turn-on duration corresponding to the WUS.

Description

[0001] This application is a divisional application of the invention patent application with an international application date of October 14, 2020 and national application number 202080106275.7 (international application number PCT / CN2020 / 120856). Technical Field

[0002] The present application relates generally to wireless communications, and more particularly to wake-up signals for discontinuous receive operations. Background Art

[0003] A user equipment (UE) may be configured with a discontinuous reception (DRX) cycle, which includes a scheduled time window during which the UE monitors network communications. Outside of the scheduled time window, the UE has the opportunity to sleep and conserve power. Conventionally, the UE monitors network communications during the scheduled time window, regardless of whether any communications will actually occur for the UE. This is an inefficient use of the UE's limited power resources. Therefore, a mechanism is needed to mitigate the inefficient power consumption associated with receiving network communications while in DRX mode. Summary of the Invention

[0004] Some exemplary embodiments relate to a user equipment (UE) having: a transceiver configured to communicate with a base station; and a processor communicatively coupled to the transceiver and configured to perform operations. The operations include: monitoring a wake-up signal (WUS) opportunity to determine whether the WUS is received during the WUS opportunity; when the WUS is received, determining whether the WUS identifies the UE; when the WUS is received and identifies the UE, monitoring an on-duration (OnDuration) of a discontinuous reception (DRX) cycle corresponding to the WUS; and when the WUS is not received or the WUS does not identify the UE, maintaining a sleep state during the on-duration corresponding to the WUS.

[0005] Other exemplary embodiments relate to a processor configured to perform operations including: monitoring a wake-up signal (WUS) opportunity to determine whether the WUS is received during the WUS opportunity; when the WUS is received, determining whether the WUS identifies a user equipment (UE) including the processor; when the WUS is received and identifies the UE, monitoring an on-duration of a discontinuous reception (DRX) cycle corresponding to the WUS; and when the WUS is not received or the WUS does not identify the UE, maintaining a sleep state during the on-duration corresponding to the WUS.

[0006] Additional exemplary embodiments relate to a processor configured to perform operations including determining whether to wake up a user equipment (UE) during an on-duration of a discontinuous reception (DRX) cycle; transmitting a wake-up signal (WUS) to the UE during a WUS opportunity corresponding to the on-duration when the UE is to be woken up; and omitting transmitting the WUS during the WUS opportunity corresponding to the on-duration when the UE is not to be woken up. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 Exemplary network arrangements are shown according to various exemplary embodiments.

[0008] Figure 2 An exemplary user equipment (UE) is shown in accordance with various exemplary embodiments.

[0009] Figure 3 An exemplary timing diagram of a DRX cycle including a WUS opportunity is shown according to various exemplary embodiments.

[0010] Figure 4 An exemplary timing diagram of a DRX cycle including WUS opportunities corresponding to multiple OnDurations according to various exemplary embodiments is shown.

[0011] Figure 5A An example of a wake-up signal (WUS) spanning multiple time slots is shown according to various exemplary embodiments.

[0012] Figure 5B An example of a WUS configured within a single time slot is shown according to various exemplary embodiments.

[0013] Figure 6 An exemplary timing diagram of a DRX cycle of a WUS including triggering a tracking reference signal (TRS) according to various exemplary embodiments is shown.

[0014] Figure 7 An exemplary timeline for tapering a modulation and coding scheme (MCS) during an on-duration is shown, according to various exemplary embodiments. DETAILED DESCRIPTION

[0015] The exemplary embodiments may be further understood with reference to the following description and associated drawings, wherein like elements have the same reference numerals.Exemplary embodiments relate to utilizing wake-up signaling between a network and a user equipment (UE).

[0016] The exemplary embodiments are described with respect to a UE. However, reference to a UE is provided for illustrative purposes only. The exemplary embodiments may be used with any electronic component that can establish a connection with a network and is configured with hardware, software, and / or firmware for exchanging information and data with the network. Therefore, UE as described herein is used to represent any electronic component.

[0017] Example embodiments are also described with reference to a network that is a fifth generation (5G) New Radio (NR) network. The 5G NR network and UE may utilize a discontinuous reception (DRX) cycle in conjunction with a wake-up signal (WUS). However, any reference to a 5G NR network or WUS is provided for illustrative purposes only. The example embodiments are applicable to any type of network that utilizes wake-up signaling in conjunction with any suitable type of power saving cycle.

[0018] When a UE is in a Radio Resource Control (RRC) idle state or an RRC inactive state, the UE may be configured with a DRX cycle. Those skilled in the art will appreciate that a DRX cycle refers to a power-saving mechanism that includes an active mode of processing that utilizes data exchange and an inactive sleep mode. The UE may use the active mode of processing at defined intervals to perform scheduled operations, such as measurements related to network conditions, transmissions (e.g., requests, measurement reports, uplink data, etc.), and receptions (e.g., control channel information, reference signals, synchronization signals, downlink data, etc.). The period during which the UE may be scheduled to receive control channel information may be referred to as an on-duration. The on-duration refers to the duration during which the UE may perform operations that enable the UE to receive data transmittable to the UE, such as, but not limited to, control channel information, uplink grants, downlink grants, reference signals, synchronization signals, payload data, paging information, etc. During a DRX cycle, when an on-duration is not scheduled, the UE may have the opportunity to utilize the inactive sleep mode and save power.

[0019] A DRX cycle may have a predetermined duration N, such as 100 milliseconds (ms), 50 ms, 40 ms, 20 ms, and so on. For example, at time 0, there may be an on-duration during which active mode processing is used. Subsequently, at the end of the on-duration, the UE has the opportunity to utilize an inactive sleep mode. Then, at time N, there may be another on-duration. Subsequently, sleep mode is used until time 2N. This process continues for the duration of the cycle. Reference to an inactive sleep mode does not necessarily imply that the UE's processor, transmitter, and receiver are put to sleep, hibernated, or otherwise disabled. For example, the processor (e.g., baseband and / or application) may continue to execute other applications or processes. Sleep mode involves conserving power by interrupting the continuous processing functions associated with enabling the UE to receive data for transmission to the UE and transmit data to the network. Reference to the term DRX cycle is for illustrative purposes only; different networks may use different names to refer to similar concepts. Furthermore, reference to a cycle configured in milliseconds is for illustrative purposes only; exemplary embodiments may utilize a DRX cycle based on subframes or any other suitable time unit.

[0020] Under normal circumstances, the UE may wake up during one or more On Durations, regardless of whether the network will send information to the UE during the On Duration. However, utilizing an active mode of data exchange processing during an On Duration that does not include any network communications for the UE is an inefficient use of the UE's limited power resources. As will be described below, if there is no network communication intended for the UE during the On Duration, an exemplary embodiment may allow the UE to omit the active mode of data exchange processing during the On Duration. The exemplary embodiment is directed to utilizing wake-up signaling between the UE and the network during a DRX cycle. Throughout this specification, the term "wake-up signal" or "WUS" may refer to a signal transmitted by the network to the UE that includes information about a subsequent time window during which the UE will monitor network communications. The WUS may allow the UE to mitigate inefficient power consumption associated with a traditional DRX cycle.

[0021] However, because the UE may remain in a sleep state for extended periods of time, e.g., without waking up for a certain on-duration, when the UE wakes up and enters an active mode for data exchange processing, the UE may experience frequency and / or timing errors. This may negatively impact the processing of subsequent control information and / or data. Therefore, exemplary embodiments also relate to operations for illustrating potential frequency and / or timing errors that a UE may experience when waking up.

[0022] Figure 1An exemplary network arrangement 100 according to various exemplary embodiments is shown. Exemplary network arrangement 100 includes a UE 110. Those skilled in the art will appreciate that UE 110 may be any type of electronic component configured to communicate via a network, such as a mobile phone, tablet computer, desktop computer, smartphone, phablet, embedded device, wearable device, Internet of Things (IoT) device, etc. It should also be appreciated that a practical network arrangement may include any number of UEs used by any number of users. Therefore, for illustrative purposes, an example with a single UE 110 is provided.

[0023] UE 110 can be configured to communicate with one or more networks. In the example of network configuration 100, the networks with which UE 110 can wirelessly communicate are 5G NR radio access network (RAN) 120 and WLAN 122. However, it should be understood that UE 110 can also communicate with other types of networks (e.g., 5G cloud RAN, LTE-RAN, traditional cellular networks, etc.), and UE 110 can also communicate with networks via wired connections. Referring to the exemplary embodiment, UE 110 can establish a connection with 5G NR RAN 120 and / or WLAN 122. Thus, UE 110 can have a 5G NR chipset for communicating with NG-RAN 120 and an ISM chipset for communicating with WLAN 122.

[0024] The 5G NR RAN 120 may be part of a cellular network that may be deployed by a network operator (e.g., Verizon, AT&T, T-Mobile, etc.). The 5G NR RAN 120 may include, for example, cells or base stations (Node B, eNodeB, HeNB, eNBS, gNB, gNodeB, macrocell base stations, microcell base stations, small cell base stations, femtocell base stations, etc.) configured to send and receive communication traffic from UEs equipped with appropriate cellular chipsets. The WLAN 122 may include any type of wireless local area network (WiFi, hotspot, IEEE 802.11x network, etc.).

[0025] A base station (e.g., gNB 120A) may include one or more communication interfaces for exchanging data and / or information with a camped UE, a corresponding RAN, cellular core network 130, the Internet 140, and the like. Furthermore, the base station may include a processor configured to perform various operations. For example, the base station's processor may be configured to perform operations related to the exemplary wake-up signaling described herein. However, reference to a processor is for illustrative purposes only. The operations of the base station may also be represented as independently incorporated components of the base station, or as modular components coupled to the base station, such as integrated circuits with or without firmware. For example, an integrated circuit may include input circuitry for receiving signals and processing circuitry for processing signals and other information. Furthermore, in some base stations, processor functionality is shared between two or more processors, such as a baseband processor and an application processor. The exemplary embodiments may be implemented in any of these or other configurations of a base station.

[0026] Those skilled in the art will appreciate that any relevant procedures may be performed for UE 110 to connect to 5G NR RAN 120. For example, as described above, 5G NR RAN 120 may be associated with a specific network operator, for which UE 110 and / or its user has protocol and credential information (e.g., stored on a SIM card). Upon detecting the presence of 5G NR RAN 120, UE 110 may transmit corresponding credential information to associate with 5G NR RAN 120. More specifically, UE 110 may associate with a specific cell (e.g., gNB 120A). As described above, the use of 5G NR RAN 120 is for illustrative purposes only, and any type of network may be used. For example, UE 110 may also connect to an LTE RAN (not shown) or a legacy RAN (not shown).

[0027] In addition to networks 120 and 122, network arrangement 100 includes a cellular core network 130, the Internet 140, an IP Multimedia Subsystem (IMS) 150, and a network services backbone 160. Cellular core network 130 can be considered an interconnected collection of components that manage the operation and traffic of a cellular network. Cellular core network 130 also manages traffic flowing between the cellular network and the Internet 140. IMS 150 can generally be described as an architecture for delivering multimedia services to UE 110 using IP protocols. IMS 150 can communicate with cellular core network 130 and the Internet 140 to provide multimedia services to UE 110. Network services backbone 160 communicates directly or indirectly with the Internet 140 and cellular core network 130. Network services backbone 160 can generally be described as a set of components (e.g., servers, network storage arrangements, etc.) that implement a suite of services that can be used to extend the functionality of UE 110 to communicate with various networks.

[0028] Figure 2 An exemplary UE 110 is shown according to various exemplary embodiments. Figure 1 100 is used to describe the UE 110. The UE 110 may represent any electronic device and may include a processor 205, a memory arrangement 210, a display device 215, an input / output (I / O) device 220, a transceiver 225, and other components 230. The other components 230 may include, for example, an audio input device, an audio output device, a battery providing a limited power source, a data acquisition device, a port for electrically connecting the UE 110 to other electronic devices, and the like.

[0029] The processor 205 may be configured to execute multiple engines of the UE 110. For example, the engines may include a WUS engine 235. The WUS engine 235 may be configured to perform operations associated with detecting a WUS and determining the content of the WUS. The WUS engine 235 may be further configured to control the behavior of the UE 110 in response to receiving the WUS.

[0030] The engine described above as an application (e.g., a program) executed by processor 205 is merely exemplary. The functionality associated with the engine may also be represented as a standalone, integrated component of UE 110, or may be a modular component coupled to UE 110, such as an integrated circuit with or without firmware. For example, an integrated circuit may include input circuitry for receiving signals and processing circuitry for processing signals and other information. The engine may also be embodied as a single application or as separate applications. Furthermore, in some UEs, the functionality described with respect to processor 205 is shared between two or more processors, such as a baseband processor and an application processor. The exemplary embodiments may be implemented in any of these or other configurations of a UE.

[0031] The memory 210 may be a hardware component configured to store data related to operations performed by the UE 110. The display device 215 may be a hardware component configured to display data to a user, while the I / O device 220 may be a hardware component that enables user input. The display device 215 and the I / O device 220 may be separate components or may be integrated together (such as a touch screen). The transceiver 225 may be a hardware component configured to establish a connection with the 5G NR-RAN 120, WLAN 122, etc. Thus, the transceiver 225 can operate on multiple different frequencies or channels (e.g., a contiguous group of frequencies).

[0032] When connected to a network, UE 110 may be configured to operate in one of a number of different operating states. One operating state may be characterized as an RRC idle state, and another operating state may be characterized as an RRC connected state. RRC refers to the Radio Resource Control (RRC) protocol. Those skilled in the art will appreciate that when UE 110 is in the RRC connected state, UE 110 and the network may be configured to exchange information and / or data. The exchange of information and / or data may allow UE 110 to perform functionality available via the network connection. Furthermore, those skilled in the art will appreciate that when UE 110 is connected to a network and in the RRC idle state, UE 110 is generally not exchanging data with the network, and no radio resources are being allocated to UE 110 within the network. However, while in the RRC idle state, UE 110 may monitor for information and / or data transmitted by the network (e.g., WUS, paging, etc.).

[0033] Another operating state can be characterized as an RRC inactive state. In the RRC inactive state, UE 110 maintains an RRC connection while minimizing signaling and power consumption. Similar to the RRC idle state, when UE 110 is connected to the network and in the RRC inactive state, UE 110 is generally not exchanging data with the network. When UE 110 is in the RRC inactive state, UE 110 can still monitor information and / or data (e.g., WUS, paging, etc.) transmitted by the network. However, any reference to the RRC connected state, RRC idle state, and RRC inactive state is provided for illustrative purposes only, and the exemplary embodiments are applicable to any suitable operating state of UE 110.

[0034] When UE 110 is camped on a cell in the RRC Idle state or the RRC Inactive state, UE 110 may not be able to exchange data with the network. To exchange data with the network, UE 110 may transition from the RRC Idle state to the RRC Connected state. For example, while in the RRC Idle state or the RRC Inactive state, UE 110 may monitor information such as, but not limited to, the Primary Synchronization Signal (PSS) and Secondary Synchronization Signal (SSS), the Master Information Block (MIB), broadcast messages, the System Information Block (SIB), the WUS, paging messages, and the like. In response, UE 110 may issue a request to the network indicating that it wishes to transition to the RRC Connected Deactivated state. A successful transition from the RRC Idle state or the RRC Inactive state to the RRC Connected state may include message exchanges between UE 110 and a cell of the network. In the RRC Connected state, a network context may be established between the cell of the first network and UE 110. Consequently, radio resources may be allocated to UE 110, and UE 110 may be able to exchange data with the network.

[0035] When in the RRC idle state or the RRC inactive state, the UE 110 may be configured with a DRX cycle. As noted above, the DRX cycle may include an on-duration during which the UE 110 may monitor network communications. Example embodiments reduce power consumption associated with wake-up by implementing wake-up signaling that may be used to control the monitoring behavior of the UE 110.

[0036] Figure 3 An exemplary timing diagram 300 of a DRX cycle including a WUS opportunity is shown according to various exemplary embodiments. Figure 1 The network arrangement 100 and Figure 2 UE 110 is described Figure 3 Timing diagram 300 provides a general overview of how wake-up signaling may be used in conjunction with a DRX cycle.

[0037] Timing diagram 300 includes line 305 representing time. Initially, consider a scenario in which UE 110 is camped on gNB 120A and operating in an RRC idle state or an RRC inactive state. In a first DRX cycle, a WUS opportunity 315 is scheduled during time period 310. UE 110 is configured to monitor for a WUS during WUS opportunity 315. WUS opportunity 315 corresponds to an on-duration 325 occurring during time period 320. The network may transmit a WUS during WUS opportunity 315. In this example, it can be considered that the network does not transmit a WUS during WUS opportunity 315. This means that the network does not have any communications with UE 110 during the corresponding on-duration 325. Therefore, after monitoring for a WUS during WUS opportunity 315, UE 110 may return to a sleep state and remain asleep for the corresponding on-duration 325.

[0038] Although Figure 3 The sizes of the WUS opportunity 315 and the on-duration 325 in do not imply any particular time period for transmission, but rather these sizes imply that the time period 310 for transmitting the WUS opportunity 315 is much smaller than the time period 320 for the on-duration 325. Thus, while the UE 110 will wake up during the WUS opportunity 315 to listen for the WUS, it will be awake for a much shorter amount of time than it would have remained awake during the time period 320 for the on-duration 325 when there is no network communication destined for the UE 110.

[0039] In the second DRX cycle, a WUS opportunity 335 is scheduled during time period 330. UE 110 is configured to monitor for WUS during WUS opportunity 335. WUS opportunity 335 corresponds to on-duration 345 occurring during time period 340. The network may transmit a WUS during WUS opportunity 335. In this example, it can be considered that the network transmits a WUS during WUS opportunity 335. This means that there will be network communication during on-duration 345, and UE 110 should wake up during on-duration 345 to receive network communication and perform corresponding operations. Therefore, from Figure 3 As can be seen from the two DRX cycles shown in FIG, using WUS may allow UE 110 to remain in the sleep state for a longer period of time during a DRX cycle (eg, during an on-duration when there are no network communications scheduled for UE 110).

[0040] In some exemplary embodiments, UE 110 may skip multiple On-Durations based on the absence of a WUS in a single WUS opportunity. For example, UE 110 may be configured such that a WUS opportunity corresponds to more than one On-Duration. When configured in this manner, if UE 110 does not receive a WUS during a WUS opportunity, UE 110 may remain asleep for all corresponding On-Durations.

[0041] Figure 4 An exemplary timing diagram 400 of a DRX cycle including WUS opportunities corresponding to multiple OnDurations according to various exemplary embodiments is shown. Timing diagram 400 includes line 405 representing time. Initially, consider a scenario in which UE 110 is camped on gNB 120A and operating in an RRC Idle state or an RRC Inactive state. A WUS opportunity 415 is scheduled during time period 410. UE 110 is configured to monitor for WUS during WUS opportunity 415. In this example, WUS opportunity 415 corresponds to OnDuration 425 occurring during time period 420 and OnDuration 445 occurring during time period 440. In this example, it can be assumed that the network does not transmit a WUS during WUS opportunity 415. This means that the network does not have any communications with UE 110 during the corresponding OnDuration 425 or OnDuration 445. Therefore, after monitoring for WUS during WUS opportunity 415, UE 110 can return to a sleep state and remain asleep for the corresponding OnDuration 425 and OnDuration 445. In this example, because the WUS opportunity 415 corresponds to both the on-Duration 425 and the on-Duration 445, there may be no WUS opportunity between the on-Duration 425 and the on-Duration 445, for example, similar to Figure 3 WUS Timing 335.

[0042] When the UE 110 is on for an on-duration (e.g., Figure 3 When UE 110 wakes up during an on-duration (e.g., an on-duration 345), it may perform various operations during the on-duration. These operations may include, for example, decoding paging DCI, performing camped cell quality measurements, performing neighbor cell quality measurements, performing inter-frequency measurements, etc. As described above, the network transmits a WUS when there is communication for UE 110 during the corresponding on-duration. Based on the above examples, it should be understood that the general term "network communication" may include operations such as receiving transmissions specifically intended for UE 110, receiving general transmissions from the network, performing measurements, transmitting data to the network, etc.

[0043] As described above, UE 110 may be configured to monitor for WUS opportunities. In some exemplary embodiments, configuring UE 110 to monitor for WUS opportunities may include providing an offset to UE 110. The offset indicates when the corresponding WUS opportunity will occur relative to the on-duration. For example, referring to Figure 3 In this example, time period 350 may be a configured offset, e.g., UE 110 expects WUS opportunity 315 to occur offset time period 350 before the on-duration. The offset may be configured, for example, via a system information block (SIB) transmitted by the network, via RRC signaling between UE 110 and the network, or the like. The offset may be configured in units of time (e.g., milliseconds) or in units of slots, symbols, or the like. In some exemplary embodiments, UE 110 may report the preferred WUS offset to the network after RRC connection establishment.

[0044] With respect to the WUS design, in some exemplary embodiments, the WUS may be encoded using a polar error correction code. In some exemplary embodiments, the WUS may be encoded as a cyclic redundancy check (CRC) error detection code scrambled by a radio network temporary identifier (RNTI). The RNTI may be, for example, a paging RNTI (P-RNTI). As another example, a new RNTI may be configured to be the same for a group of UEs. This new RNTI may be configured based on a UE ID (such as a temporary mobile subscriber identity (TMSI) or an international mobile subscriber identity (IMSI)) through RRC signaling, SIBs, or a hash function. This type of WUS may be similar to downlink control information (DCI).

[0045] In some exemplary embodiments, the WUS may include group information. For example, all UEs configured to wake up during the same DRX cycle may be divided into N groups. The N-bit bitmap in the WUS may be used to indicate which group of UEs to wake up during the DRX cycle. In the example above, it is stated that if no WUS is detected during the WUS opportunity, the UE 110 will not wake up. However, it should be clear from this example that the WUS may be received by the UE 110 during the WUS opportunity, but the WUS may include information indicating that the WUS is not intended for the UE 110, for example, the WUS includes group information and the UE 110 is not part of the identified group. Therefore, this example shows that the absence of a WUS or a WUS that is not intended for a particular UE may be used to indicate to the UE that the UE does not need to wake up during a particular on-duration.

[0046] In some exemplary embodiments, the WUS may also include the location / trigger of reference signals that may be used by the UE 110 for timing and frequency tracking. Figure 6 This timing and frequency tracking is described in more detail.

[0047] In some exemplary embodiments, the WUS may be designed based on sequence detection. For example, there may be a single sequence, for example, a single sequence is assigned to UE 110, and if the UE detects the corresponding sequence assigned to itself, the UE performs a wake-up, otherwise, the UE skips the corresponding on-duration. As another example, the WUS may have a one-to-one mapping with the P-RNTI. As understood by those skilled in the art, multiple UEs may share a P-RNTI. Therefore, if a UE sharing a P-RNTI detects the P-RNTI in the WUS, the UE performs a wake-up, otherwise, the UE skips the corresponding on-duration. As another example, the group of UEs sharing the same P-RNTI may be further divided into N groups, each group having its own sequence. In this example, the WUS may include a P-RNTI and a sequence indicating which of the UEs sharing the P-RNTI should wake up.

[0048] When a WUS is designed based on sequence detection, the design can be used to facilitate time and frequency tracking. For example, a WUS can represent multiple symbols carried in one or more time slots. There are many different combinations of symbols and time slots that can be used for a WUS. Figure 5A and Figure 5B Each provides an example of a WUS configuration. However, any reference to a WUS configured with a specific number of symbols or a specific number of time slots is provided for illustrative purposes only. The exemplary embodiments are not limited to any specific WUS configuration.

[0049] In the frequency domain, WUS may include a wideband transmission for frequency and timing tracking, for example, at least 52 physical resource blocks (PRBs). In the time domain, various designs may be used, for example, a fixed number of symbols between two WUS symbols, multiple WUS symbols in one slot, multiple slots of WUS symbols, with or without the same pattern, etc. Figure 5A and Figure 5B Provides an example of WUS configuration.

[0050] Figure 5A An example of a WUS spanning multiple time slots is shown. In this example, a first time slot 510 includes two WUS symbols 512, 514 with three symbols between them. The WUS also includes a second adjacent time slot 320, which also includes two WUS symbols 522, 524 with three symbols between them.

[0051] Figure 5B An example of a WUS configured within a single time slot is shown. In this example, the time slot 550 is configured to include four WUS symbols 552-558 with two or three symbols between each of the WUS symbols 552-558. Figure 5B Not shown, but in some WUS configurations, there may be three symbols between the first WUS symbol and the third WUS symbol in the same slot. Figure 5A compared to, Figure 5B The WUS configuration shown in provides more WUS symbols in the same time slot. This WUS configuration may provide power saving benefits to UE 110 because there are fewer time slots and symbols for UE 110 to process. As mentioned above, the exemplary embodiments are not limited to a particular WUS configuration.

[0052] Therefore, because UE 110 understands the time and / or frequency pattern of the WUS, UE 110 can use the detected WUS to perform timing and / or frequency tracking of gNB 120A that transmitted the WUS. In this example, detecting the WUS and performing corresponding timing and / or frequency tracking may allow UE 110 to better align with gNB 120A when UE 110 wakes up during the corresponding on-duration.

[0053] In some exemplary embodiments, the WUS may be used to trigger a tracking reference signal (TRS) prior to a DRX cycle. A TRS may refer to a downlink reference signal configured for use by UE 110 for timing and / or frequency tracking. Thus, unlike the above examples, the WUS is not used for timing and / or frequency tracking. Instead, the WUS may trigger a separate reference signal that UE 110 may use for timing and / or frequency tracking.

[0054] Figure 6 An exemplary timing diagram 600 of a DRX cycle including a WUS that triggers a TRS is shown, according to various exemplary embodiments. Timing diagram 600 includes a line 605 representing time. Initially, consider a scenario in which UE 110 is camped on gNB 120A and operating in an RRC idle state or an RRC inactive state. In the DRX cycle, a WUS opportunity 615 is scheduled during time period 610. UE 110 is configured to monitor for a WUS during WUS opportunity 615. WUS opportunity 615 corresponds to an on-duration 635 occurring during time period 630. The network may transmit a WUS during WUS opportunity 615. In this example, the network may be considered to transmit a WUS during WUS opportunity 615. This means that the network has communications for UE 110 during the corresponding on-duration 635.

[0055] The WUS received in WUS opportunity 615 may also trigger TRS 625 during time period 620. Thus, after monitoring for WUS in WUS opportunity 615, UE 110 may also wake up during time period 620 to monitor for TRS 625. UE 110 may receive TRS 625 and then use the TRS to obtain a frequency and / or timing estimate for gNB 120A. UE 110 may then wake up during OnDuration 635 and perform operations with gNB 120A at an improved frequency and / or timing based on the TRS during OnDuration 635.

[0056] The network may configure a TRS timing offset 640 between the WUS 615 and the TRS 625 so that the UE 110 has sufficient time to detect / decode the WUS before the UE 110 receives the TRS. The TRS offset may be configured, for example, as a SIB or may be defined by a standard (e.g., a 3GPP standard). In some exemplary embodiments, the UE may report a minimum TRS offset. Similarly, the network may also configure a DRX timing offset 650 between the TRS 625 and the on-duration 635 so that the UE 110 has sufficient time to perform accurate timing and frequency tracking. Likewise, the UE 110 may report a minimum DRX timing offset or it may be defined by a standard.

[0057] As described above, when UE 110 sleeps for extended periods of time, the UE may experience frequency and / or timing errors. This may negatively impact the processing of subsequent control information and / or data. Some examples of handling these frequency and / or timing errors are described above, such as using a WUS or TRS for frequency and / or timing tracking.

[0058] Additional example embodiments for handling these frequency and / or timing errors are described below.In these examples, it may be considered that the UE 110 receives a WUS during a WUS opportunity and wakes up within the corresponding OnDuration.

[0059] In some example embodiments, a modulation and coding scheme (MCS) during an on-duration of a physical downlink shared channel (PDSCH) for scheduling may be tapered. Figure 7 An exemplary timeline 700 for tapering the MCS during the on-duration is shown, according to various exemplary embodiments. Figure 7 A line 705 representing the time including the on-duration 710 is shown. Figure 7 As shown, on-duration 710 may include three MCSs for PDSCH: MCS (1) 720, MCS (2) 730, and MCS (3) 740. The characteristics of MCS (1) 720, MCS (2) 730, and MCS (3) 740 are described in more detail below. Therefore, during on-duration 710, gNB 120A may schedule PDSCH data for UE 110. gNB 120A may use MCS (1) 720 to encode PDSCH data for a corresponding time period, as shown in FIG. Figure 7 gNB 120A may then use MCS (2) 730 to encode the PDSCH data for the corresponding time period, as shown in FIG. Figure 7 Finally, gNB 120A may use MCS (3) 730 to encode the PDSCH data for the corresponding time period, as shown in Figure 7 Correspondingly, UE 110 may be configured to use an appropriate MCS to decode PDSCH data.

[0060] In this example, MCS (1) 720 may be considered a more robust coding (e.g., lower coding rate and / or lower modulation order) than MCS (2) 730, which is a more robust coding than MCS (3) 740. As will be appreciated by those skilled in the art, a lower coding rate and / or lower modulation order generally means that UE 110 is more likely to successfully decode the coded data. A lower coding rate and / or lower modulation order results in lower throughput than a lower coding rate. Thus, the purpose of initially having a lower coding rate and / or lower modulation order is so that if there are large frequency and / or timing errors due to a long sleep cycle of UE 110, UE 110 is more likely to successfully decode the data received on the PDSCH while having a lower throughput. As more data is received and the frequency and / or timing errors are resolved, the MCS may be increased (e.g., higher coding rate and / or higher modulation order), resulting in higher throughput. This is Figure 7The three (3) MCS scheme is shown in . The exemplary embodiment is not limited to three levels of MCS, as the cone can have any number of MCS levels, 2 or greater.

[0061] The maximum MCS that can be decoded by UE 110 may be reported as a UE capability. For example, a basic report may include a single MCS. Over time, an advanced report may include a sequence of MCSs, such as Figure 7 The sequence shown is MCS (1) 720, MCS (2) 730, and MCS (3) 740. As described above, the maximum MCS that can be decoded by UE 110 may increase as UE 110 has more accurate timing and frequency tracking. UE 110 may update UE capabilities via, for example, RRC signaling. The capabilities may be based in part on network configuration, such as the periodicity of synchronization signal blocks (SSBs), the availability of TRSs, etc. From the example of TRSs, it should be seen that exemplary embodiments may implement more than one operation to handle frequency and / or timing errors.

[0062] In some exemplary embodiments, PDSCH repetitions may be configured for PDSCH in idle mode. Before UE 110 enters inactive or idle mode, the number of repetitions may be configured, for example, in an SIB, RRC configuration signaling, or the like. The repetitions may follow an inter-slot repetition scheme, for example, where the same time and frequency domain resource allocation may be repeated N times in N consecutive slots. The redundancy version (RV) used for each repetition may be defined by a standard (e.g., a 3GPP standard), configured in an SIB, or configured via RRC signaling.

[0063] In some exemplary embodiments, when one of the repetitions collides with an uplink (UL) symbol, transmission of the corresponding PDSCH is omitted. In other exemplary embodiments, when one of the repetitions collides with an uplink (UL) symbol, transmission of the corresponding PDSCH is postponed to the next valid time slot that does not collide with a UL symbol.

[0064] Those skilled in the art will appreciate that the exemplary embodiments described above may be implemented with any suitable software configuration or hardware configuration or combination thereof. Exemplary hardware platforms for implementing the exemplary embodiments may include, for example, Intel x86-based platforms with compatible operating systems, Windows OS, Mac platforms and MAC OS, mobile devices with operating systems such as iOS, Android, etc. The exemplary embodiments of the above methods may be embodied as a program comprising lines of code stored on a non-transitory computer-readable storage medium, which, when compiled, may be executed on a processor or microprocessor.

[0065] Although this patent application describes various combinations of various embodiments, each with different features, those skilled in the art will understand that any feature of one embodiment may be combined with features of other embodiments in any manner not publicly denied, or with features that are not functionally or logically inconsistent with the operation or described function of the device of the embodiments disclosed herein.

[0066] It is understood that the use of personally identifiable information should be subject to privacy policies and practices that are generally recognized to meet or exceed industry or government requirements for maintaining user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of authorized use should be clearly stated to users.

[0067] It will be apparent to those skilled in the art that various modifications may be made to the present disclosure without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure is intended to cover modifications and variations of the present disclosure provided that these modifications and variations are within the scope of the appended claims and their equivalents.

Claims

1. A device comprising a processing circuit, wherein the processing circuit is configured to: monitoring a wake-up signal (WUS) opportunity during a discontinuous reception (DRX) cycle of a radio resource control (RRC) idle state or an RRC inactive state to determine whether a WUS is received during the WUS opportunity; When the WUS is received, determining whether the WUS identifies a specific user equipment (UE); When the WUS is received and identifies the specific UE, monitoring an on-duration of the DRX cycle corresponding to the WUS; as well as Paging downlink control information (DCI) received during the on-duration is decoded. The apparatus of claim 1 , wherein the WUS corresponds to more than one on-duration. 3 . The apparatus of claim 1 , wherein the WUS is encoded as a cyclic redundancy check (CRC) error detection code scrambled by a radio network temporary identifier (RNTI). The apparatus according to claim 3 , wherein the RNTI comprises an RNTI corresponding to a UE group to which the specific UE belongs. The apparatus of claim 4 , wherein the RNTI is configured by one of radio resource control (RRC) signaling, a system information block (SIB), or a hash function based on identification of the UE. The apparatus of claim 3 , wherein the WUS is further encoded using a polar error correction code. The apparatus of claim 1 , wherein the WUS is encoded using a polar error correction code.

8. A user equipment (UE), comprising: a transceiver configured to communicate with a base station; and a processing circuit, the processing circuit being configured to: monitoring a wake-up signal (WUS) opportunity during a discontinuous reception (DRX) cycle of a radio resource control (RRC) idle state or an RRC inactive state to determine whether a WUS is received during the WUS opportunity; When the WUS is received, determining whether the WUS identifies the UE; When the WUS is received and the UE is identified, monitoring an on-duration of the DRX cycle corresponding to the WUS; as well as Paging downlink control information (DCI) received during the on-duration is decoded. The UE according to claim 8 , wherein the WUS corresponds to more than one on-duration. 10 . The UE of claim 8 , wherein the WUS is encoded as a cyclic redundancy check (CRC) error detection code scrambled by a radio network temporary identifier (RNTI). The UE according to claim 10 , wherein the RNTI comprises an RNTI corresponding to a UE group to which the UE belongs. 12 . The UE of claim 11 , wherein the RNTI is configured by one of radio resource control (RRC) signaling, a system information block (SIB), or a hash function based on identification of the UE.

13. The UE of claim 10, wherein the WUS is further encoded using a polar error correction code. The UE of claim 8 , wherein the WUS is encoded using a polar error correction code.

15. An apparatus comprising a processing circuit configured to: determining whether to wake up a user equipment (UE) during an on-duration of a discontinuous reception (DRX) cycle; When the UE is to be woken up, generating a wake-up signal (WUS) for transmission to the UE during a WUS opportunity corresponding to the on-duration; and The WUS is encoded as a cyclic redundancy check (CRC) error detection code scrambled by a radio network temporary identifier (RNTI).

16. The apparatus of claim 15, wherein the processing circuit is further configured to: After the CRC encoding, the WUS is encoded using a polar error correction code. The apparatus according to claim 15 , wherein the RNTI comprises an RNTI corresponding to a UE group to which the UE belongs.

18. The apparatus of claim 17, wherein the RNTI is configured by one of radio resource control (RRC) signaling, a system information block (SIB), or a hash function based on identification of the UE.

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