User equipment and processor

Abstract

A wake-up signal scheme between a network and a user equipment (UE) operating in a discontinuous reception (DRX) state. The UE monitors wake-up signal (WUS) occasions to determine whether a WUS is received during the WUS occasion; when the WUS is received, determines whether the WUS identifies the UE; when the WUS is received and identifies the UE, monitors 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, remains in a sleep state during the on-duration corresponding to the WUS.

Description

Technical Field

[0001] The present application generally relates to wireless communication and, more particularly, to wake-up signals for discontinuous reception operations. Background Art

[0002] A user equipment (UE) may be configured with a discontinuous reception cycle (DRX) that includes a scheduling time window during which the UE monitors network communication. Outside of the scheduling time window, the UE may have the opportunity to sleep and conserve power. Conventionally, the UE monitors network communication during the scheduling time window regardless of whether there will actually be any communication for the UE. This is an inefficient use of the UE's limited power source. Accordingly, a mechanism is needed to mitigate the inefficient power consumption associated with receiving network communication while in DRX mode. Summary of the Invention

[0003] 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) 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 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, remaining in a sleep state during the on-duration corresponding to the WUS.

[0004] Other exemplary embodiments relate to a processor configured to perform operations. The operations include: monitoring a wake-up signal (WUS) occasion to determine whether a WUS is received during the WUS occasion; 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, remaining in a sleep state during the on-duration corresponding to the WUS.

[0005] Additional exemplary embodiments relate to a processor configured to perform operations. The operations include: determining whether to wake up a user equipment (UE) during an on-duration of a discontinuous reception (DRX) cycle; when waking up the UE, transmitting the WUS to the UE during a wake-up signal (WUS) occasion corresponding to the on-duration; and when not waking up the UE, omitting transmission of the WUS during the WUS occasion corresponding to the on-duration. Brief Description of the Drawings

[0006] Figure 1 Illustrates an exemplary network arrangement according to various exemplary embodiments.

[0007] Figure 2 Illustrates an exemplary user equipment (UE) according to various exemplary embodiments.

[0008] Figure 3 Illustrates an exemplary timing diagram of a DRX cycle including a WUS occasion according to various exemplary embodiments.

[0009] Figure 4 Illustrates an exemplary timing diagram of a DRX cycle including a WUS occasion corresponding to multiple on durations according to various exemplary embodiments.

[0010] Figure 5A Illustrates an example of a wake-up signal (WUS) spanning multiple time slots according to various exemplary embodiments.

[0011] Figure 5B Illustrates an example of a WUS configured within a single time slot according to various exemplary embodiments.

[0012] Figure 6 Illustrates an exemplary timing diagram of a DRX cycle including a WUS including a triggered tracking reference signal (TRS) according to various exemplary embodiments.

[0013] Figure 7 Illustrates an exemplary timeline for tapering the modulation and coding scheme (MCS) during an on duration according to various exemplary embodiments. Detailed Description

[0014] The exemplary embodiments can be further understood with reference to the following description and the related drawings, in which like elements are denoted with the same reference numerals. The exemplary embodiments relate to using wake-up signaling between a network and a user equipment (UE).

[0015] The exemplary embodiments are described with reference to a UE. However, the reference to the UE is provided for illustrative purposes only. The exemplary embodiments can 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. Thus, the UE described herein is used to represent any electronic component.

[0016] Exemplary embodiments are described with reference to a network that is a fifth generation (5G) new radio (NR) network. A 5G NR network and a UE may utilize discontinuous reception (DRX) cycles in combination with a wake-up signal (WUS). However, any reference to a 5G NR network or WUS is provided for illustrative purposes only. Exemplary embodiments may be applied to any type of network that utilizes wake-up signaling in combination with any suitable type of power saving cycle.

[0017] When the UE is in the radio resource control (RRC) idle state or the RRC inactive state, the UE may be configured with a DRX cycle. Those skilled in the art will understand that a DRX cycle refers to a power saving mechanism that includes an active mode for data exchange processing and an inactive sleep mode. The UE can perform scheduled operations, such as performing measurements related to network conditions, transmitting (e.g., requests, measurement reports, uplink data, etc.), and receiving (e.g., control channel information, reference signals, synchronization signals, downlink data, etc.), using the active mode of processing at defined intervals. The time period during which the UE may be scheduled to receive control channel information may be referred to as an on-duration. This on-duration relates to the duration during which the UE can perform operations that enable the UE to receive data that may be transmitted to the UE, such data including but not limited to control channel information, uplink grants, downlink grants, reference signals, synchronization signals, payload data, paging information, etc. During the DRX cycle, when no on-duration is scheduled, the UE has the opportunity to utilize the inactive sleep mode and save power.

[0018] The DRX cycle may have a predetermined duration N, such as 100 milliseconds (ms), 50 ms, 40 ms, 20 ms, etc. For example, at time 0, there may be an on-duration during which the active mode of processing is used. Subsequently, at the end of the on-duration, the UE has the opportunity to utilize the inactive sleep mode. Then at time N, there may be another on-duration. Subsequently, the sleep mode is used until time 2N. This process continues for the duration of the cycle. Referring to the inactive sleep mode does not necessarily mean putting the UE's processor, transmitter, and receiver to sleep, hibernate, or deactivate. For example, the processor (e.g., baseband and / or application) may continue to execute other applications or processes. The sleep mode involves saving power by interrupting continuous processing functions related to operations that enable the UE to receive data that may be transmitted to the UE and transmit data to the network. The reference to the term DRX cycle is for illustrative purposes, and different networks may use different names to refer to similar concepts. Additionally, the reference to a cycle configured in ms units is for illustrative purposes only, and exemplary embodiments may utilize a DRX cycle based on subframes or any other suitable time unit.

[0019] 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 that on duration. However, an active mode that utilizes data exchange processing during an on duration that does not include any network communication for the UE is an inefficient use of the UE's limited power source. 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 that utilizes data exchange processing during the on duration. The exemplary embodiment relates 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 from the network to the UE that includes information about a subsequent time window during which the UE will monitor network communication. The WUS may allow the UE to mitigate inefficient power consumption associated with traditional DRX cycles.

[0020] However, since the UE may remain in a sleep state for a relatively long period of time, e.g., not wake up during a certain on duration, when the UE wakes up and enters the active mode of data exchange processing, the UE may experience frequency and / or timing errors. This may have a negative impact on the processing of subsequent control information and / or data. Therefore, the exemplary embodiment also relates to operations for illustrating the potential frequency and / or timing errors that the UE may experience when waking up.

[0021] Figure 1 An exemplary network arrangement 100 according to various exemplary embodiments is shown. The exemplary network arrangement 100 includes a UE 110. Those skilled in the art will understand that the UE 110 may be any type of electronic component configured to communicate via a network, e.g., a mobile phone, a tablet computer, a desktop computer, a smart phone, a phablet, an embedded device, a wearable device, an Internet of Things (IoT) device, etc. It should also be understood that an actual network arrangement may include any number of UEs used by any number of users. Therefore, for illustrative purposes, only an example with a single UE 110 is provided.

[0022] The UE 110 can be configured to communicate with one or more networks. In an example of network configuration 100, the networks with which the UE 110 can communicate wirelessly are the 5G NR radio access network (RAN) 120 and the WLAN 122. However, it should be understood that the UE 110 can also communicate with other types of networks (e.g., 5G cloud RAN, LTE-RAN, traditional cellular networks, etc.), and the UE 110 can also communicate with the network via a wired connection. Referring to the exemplary implementation, the UE 110 can establish a connection with the 5G NR RAN 120 and / or the WLAN 122. Thus, the UE 110 can have a 5G NR chipset for communicating with the NG-RAN 120 and an ISM chipset for communicating with the WLAN 122.

[0023] The 5G NR RAN 120 can be part of a cellular network deployable by a network operator (e.g., Verizon, AT&T, T-Mobile, etc.). The 5G NR RAN 120 can include, for example, cells or base stations (node B, eNodeB, HeNB, eNBS, gNB, gNodeB, macro cell base station, micro cell base station, small cell base station, femto cell base station, etc.) configured to send and receive communication traffic from UEs equipped with appropriate cellular chipsets. The WLAN 122 can include any type of wireless local area network (WiFi, hotspot, IEEE 802.11x network, etc.).

[0024] A base station (e.g., gNB 120A) can include one or more communication interfaces to exchange data and / or information with the pre-empted UEs, the corresponding RAN, the cellular core network 130, the Internet 140, etc. In addition, the base station can include a processor configured to perform various operations. For example, the processor of the base station can be configured to perform operations related to the exemplary wake-up signaling described herein. However, the reference to the processor is for illustrative purposes only. The operations of the base station can also be represented as stand-alone combined components of the base station, or can be modular components coupled to the base station, e.g., integrated circuits with or without firmware. For example, an integrated circuit can include an input circuitry for receiving signals and a processing circuitry for processing signals and other information. In addition, in some base stations, the functionality of the processor is shared between two or more processors such as a baseband processor and an application processor. The exemplary implementation can be realized according to any of these or other configurations of the base station.

[0025] Those skilled in the art will understand that any relevant process can be executed for the UE 110 to connect to the 5G NR RAN 120. For example, as described above, the 5G NR RAN 120 can be associated with a specific network operator where the UE 110 and / or its user have protocol and credential information (e.g., stored on the SIM card). When the presence of the 5G NR RAN 120 is detected, the UE 110 can transmit the corresponding credential information to be associated with the 5G NR RAN 120. More specifically, the UE 110 can be associated with a specific cell (e.g., gNB 120A). As described above, the use of the 5G NR RAN 120 is for illustrative purposes, and any type of network can be used. For example, the UE 110 can also be connected to an LTE-RAN (not shown) or a legacy RAN (not shown).

[0026] In addition to the networks 120 and 122, the network arrangement 100 further includes a cellular core network 130, the Internet 140, an IP Multimedia Subsystem (IMS) 150, and a network service backbone 160. The cellular core network 130 can be regarded as an interconnected collection of components that manage the operations and traffic of the cellular network. The cellular core network 130 also manages the traffic flowing between the cellular network and the Internet 140. The IMS 150 can generally be described as an architecture for delivering multimedia services to the UE 110 using IP protocols. The IMS 150 can communicate with the cellular core network 130 and the Internet 140 to provide multimedia services to the UE 110. The network service backbone 160 communicates directly or indirectly with the Internet 140 and the cellular core network 130. The network service backbone 160 can generally be described as a set of components (e.g., servers, network storage arrangements, etc.) that implement a set of services that can be used to extend the functions for the UE 110 to communicate with various networks.

[0027] Figure 2 An exemplary UE 110 is shown in accordance with various exemplary embodiments. The UE 110 will be described with reference to Figure 1 the network arrangement 100. The UE 110 can represent any electronic device and can 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 can 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, etc.

[0028] 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 a WUS.

[0029] The above engines are merely exemplary as applications (e.g., programs) executed by the processor 205. The functions associated with the engines may also be represented as separate integrated components of the UE 110, or may be modular components coupled to the UE 110, e.g., integrated circuits with or without firmware. For example, an integrated circuit may include input circuitry for receiving signals and processing circuitry for processing the signals and other information. The engines may also be embodied as one application or separate multiple applications. Additionally, in some UEs, the functionality described for the 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 the UE.

[0030] 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 a user to make inputs. The display device 215 and the I / O device 220 may be separate components or may be integrated together (such as a touchscreen). The transceiver 225 may be a hardware component configured to establish connections with the 5G NR-RAN 120, WLAN 122, etc. Thus, the transceiver 225 may operate on multiple different frequencies or channels (e.g., a continuous frequency band).

[0031] When connected to a network, the UE 110 may be configured to be in one of a variety of different operating states. One operating state may be characterized as the RRC idle state, and another operating state may be characterized as the RRC connected state. RRC refers to the Radio Resource Control (RRC) protocol. Those skilled in the art will understand that when the UE 110 is in the RRC connected state, the UE 110 and the network may be configured to exchange information and / or data. The exchange of information and / or data may allow the UE 110 to perform functionality available via the network connection. Additionally, those skilled in the art will understand that when the UE 110 is connected to the network and in the RRC idle state, the UE 110 generally is not exchanging data with the network, and within the network, radio resources are not being allocated to the UE 110. However, when the UE 110 is in the RRC idle state, the UE 110 may monitor information and / or data transmitted by the network (e.g., WUS, paging, etc.).

[0032] Another operating state can be characterized as the RRC Inactive state. In the RRC Inactive state, the UE 110 maintains the RRC connection while minimizing signaling and power consumption. Similar to the RRC Idle state, when the UE 110 is connected to the network and in the RRC Inactive state, the UE 110 is generally not exchanging data with the network. When the UE 110 is in the RRC Inactive state, the UE 110 can still monitor information and / or data transmitted by the network (e.g., WUS, paging, etc.). However, any reference to the RRC connected state, the RRC Idle state, and the RRC Inactive state is provided for illustrative purposes only, and the exemplary embodiments can be applied to any suitable operating state of the UE 110.

[0033] When the UE 110 camps on a cell in the RRC Idle state or the RRC Inactive state, the UE 110 may not be able to exchange data with the network. To exchange data with the network, the UE 110 can transition from the RRC Idle state to the RRC connected state. For example, when in the RRC Idle state or the Inactive state, the UE 110 can listen for information such as but not limited to: Primary Synchronization Signal (PSS) and Secondary Synchronization Signal (SSS), Master Information Block (MIB), broadcast message, System Information Block (SIB), WUS, paging message, etc. In response, the UE 110 can send a request to the network that indicates that the UE 110 wishes to transition to the RRC connected state. A successful transition from the RRC Idle state or the RRC Inactive state to the RRC connected state can include message exchange between the UE 110 and the cell of the network. In the RRC connected state, a network context can be established between the cell of the first network and the UE 110. Thus, the UE 110 can be allocated radio resources and the UE 110 can be able to exchange data with the network.

[0034] When in the RRC Idle state or the RRC Inactive state, the UE 110 can be configured with a DRX cycle. As noted above, the DRX cycle can include an on-duration during which the UE 110 can monitor network communication. The exemplary embodiments reduce the power consumption associated with waking up by implementing wake-up signaling that can be used to control the monitoring behavior of the UE 110.

[0035] Figure 3 An exemplary timing diagram 300 of a DRX cycle including WUS opportunities according to various exemplary embodiments is shown. Reference will be made to Figure 1 the network arrangement 100 of Figure 2 and the UE 110 of Figure 3 . The timing diagram 300 provides a general overview of how wake-up signaling can be used in conjunction with the DRX cycle.

[0036] The timing diagram 300 includes a line 305 representing time. Initially, consider a scenario where the UE 110 pre-empts the gNB 120A and operates in the RRC idle state or the RRC inactive state. In the first DRX cycle, a WUS occasion 315 is scheduled during a time period 310. The UE 110 is configured to monitor the WUS during the WUS occasion 315. The WUS occasion 315 corresponds to an on-duration 325 that occurs during a time period 320. The network may transmit the WUS during the WUS occasion 315. In this example, it can be considered that the network does not transmit the WUS during the WUS occasion 315. This means that the network does not have any communication for the UE 110 during the corresponding on-duration 325. Therefore, after monitoring the WUS in the WUS occasion 315, the UE 110 may return to the sleep state and remain asleep within the corresponding on-duration 325.

[0037] Although Figure 3 the sizes of the WUS occasion 315 and the on-duration 325 in do not imply any specific time period for transmission, these sizes imply that the time period 310 for transmitting the WUS occasion 315 is much smaller than the time period 320 of the on-duration 325. Therefore, although the UE 110 will wake up during the WUS occasion 315 to listen for the WUS, the amount of time it will be woken up is much shorter than the amount of time it will remain awake within the time period 320 of the on-duration 325 when there is no network communication designated for the UE 110.

[0038] In the second DRX cycle, a WUS occasion 335 is scheduled during a time period 330. The UE 110 is configured to monitor the WUS during the WUS occasion 335. The WUS occasion 335 corresponds to an on-duration 345 that occurs during a time period 340. The network may transmit the WUS during the WUS occasion 335. In this example, it can be considered that the network transmits the WUS during the WUS occasion 335. This means that there will be network communication during the on-duration 345, and the UE 110 should wake up during the on-duration 345 to receive the network communication and perform corresponding operations. Therefore, from Figure 3 the two DRX cycles shown in it can be seen that using the WUS allows the UE 110 to remain in the sleep state for a longer time period during the DRX cycle (e.g., during the on-duration when there is no network communication scheduled for the UE 110).

[0039] In some exemplary embodiments, the UE 110 may skip multiple ON durations based on the absence of a WUS in a single WUS occasion. For example, the UE 110 may be configured such that a WUS occasion corresponds to more than one ON duration. When configured in this manner, in the case where the UE 110 does not receive a WUS during a WUS occasion, the UE 110 may remain asleep for all corresponding ON durations.

[0040] Figure 4 An exemplary timing diagram 400 of a DRX cycle including a WUS occasion corresponding to multiple ON durations is shown according to various exemplary embodiments. The timing diagram 400 includes a line 405 representing time. Initially, consider a scenario where the UE 110 camps on the gNB 120A and operates in the RRC idle state or the RRC inactive state. A WUS occasion 415 is scheduled during a time period 410. The UE 110 is configured to monitor for a WUS during the WUS occasion 415. In this example, the WUS occasion 415 corresponds to an ON duration 425 that occurs during a time period 420 and an ON duration 445 that occurs during a time period 440. In this example, it may be considered that the network does not transmit a WUS during the WUS occasion 415. This means that the network does not have any communication for the UE 110 during the corresponding ON duration 425 or ON duration 445. Therefore, after monitoring for a WUS in the WUS occasion 415, the UE 110 may return to the sleep state and remain asleep during the corresponding ON duration 425 and ON duration 445. In this example, since the WUS occasion 415 corresponds to both the ON duration 425 and the ON duration 445, there may be no WUS occasion between the ON duration 425 and the ON duration 445, for example, similar to Figure 3 the WUS occasion 335.

[0041] When the UE 110 wakes up during an ON duration (e.g., Figure 3 the ON duration 345) because the UE 110 detects the corresponding WUS, the UE 110 may perform various operations during that ON duration. These operations may include, for example, decoding paging DCI, performing camped cell quality measurements, performing neighboring cell quality measurements, performing inter-frequency measurements, etc. As described above, when there is communication for the UE 110 during the corresponding ON duration, the network will transmit a WUS. Based on the above example, it should be understood that the general term network communication may include operations such as receiving transmissions specifically designated for the UE 110, receiving general transmissions from the network, performing measurements, transmitting data to the network, etc.

[0042] As described above, the UE 110 may be configured to monitor WUS occasions. In some exemplary embodiments, configuring the UE 110 to monitor WUS occasions may include providing an offset to the UE 110. The offset indicates when the corresponding WUS occasion will occur relative to the on-duration. For example, referring to Figure 3 , in this example, the time period 350 may be the configured offset. For example, the UE 110 expects the WUS occasion 315 to occur an 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 the UE 110 and the network, etc. The offset may be configured in terms of time (e.g., milliseconds) or in units of time slots, symbols, etc. In some exemplary embodiments, the UE 110 may report a preferred WUS offset to the network after RRC connection establishment.

[0043] With respect to the WUS design, in some exemplary embodiments, the WUS may be encoded by a polar error correction code. In some exemplary embodiments, the WUS may be encoded with 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. The new RNTI may be configured via RRC signaling, SIB, or a hash function based on a UE ID (such as a temporary mobile subscriber identity (TMSI) or an international mobile subscriber identity (IMSI)). This type of WUS may be similar to downlink control information (DCI).

[0044] 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. An N-bit bitmap in the WUS may be used to indicate which group of UEs is to be woken up within the DRX cycle. In the example above, it was stated that if the WUS is not detected during the WUS occasion, 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 occasion, but the WUS may include information indicating that the WUS is not for the UE 110. For example, the WUS includes group information and the UE 110 is not part of the identified group. Thus, this example shows that the absence of the WUS or a WUS 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.

[0045] In some exemplary embodiments, the WUS may also include the location / trigger of a reference signal that may be used by the UE 110 for timing and frequency tracking. This timing and frequency tracking will be described in more detail below with reference to Figure 6 More detailed descriptions of this timing and frequency tracking will be provided.

[0046] In some exemplary embodiments, the WUS can be designed based on sequence detection. For example, there can be a single sequence, e.g., a single sequence is allocated to UE 110, and if the UE detects the corresponding sequence allocated to itself, the UE performs wake-up; otherwise, the UE skips the corresponding on-duration. As another example, the WUS can have a one-to-one mapping with the P-RNTI. As understood by those skilled in the art, multiple UEs can share the P-RNTI. Therefore, if a UE sharing the P-RNTI detects the P-RNTI in the WUS, the UE performs wake-up; otherwise, the UE skips the corresponding on-duration. As yet another example, a group of UEs sharing the same P-RNTI can be further divided into N groups, where each group has its own sequence. In this example, the WUS can include the P-RNTI and a sequence indicating which one of the UEs sharing the P-RNTI should wake up.

[0047] When the WUS is designed based on sequence detection, this design can be used to facilitate time and frequency tracking. For example, the WUS can represent multiple symbols carried in one or more time slots. There are various different combinations of symbols and time slots that can be used for the 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.

[0048] In the frequency domain, the WUS can include a broadband transmission for frequency and timing tracking, e.g., at least 52 physical resource blocks (PRBs). In the time domain, various designs can be used, such as a fixed number of symbols between two WUS symbols, multiple WUS symbols in one time slot, multiple time slots of WUS symbols, with or without the same pattern, etc. Below with respect to Figure 5A and Figure 5B Examples of WUS configurations are provided.

[0049] Figure 5A Shows an example of a WUS spanning multiple time slots. In this example, the first time slot 510 includes two WUS symbols 512, 514, and there are three symbols between these two WUS symbols 512, 514. The WUS also includes a second adjacent time slot 320, which also includes two WUS symbols 522, 524, and there are three symbols between these two WUS symbols 522, 524.

[0050] Figure 5B Shows an example of a WUS configured within a single time slot. 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. Although in Figure 5Bis not shown, but in some WUS configurations, there may be three symbols between the first WUS symbol and the third WUS symbol within the same time slot. Compared with Figure 5A compared, 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 described above, the exemplary embodiments are not limited to a specific WUS configuration.

[0051] Accordingly, because UE 110 understands the time and / or frequency pattern of WUS, UE 110 may use the detected WUS to perform timing and / or frequency tracking of gNB 120A that transmits the WUS. In this example, detecting the WUS and performing the 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.

[0052] In some exemplary embodiments, WUS may be used to trigger a Tracking Reference Signal (TRS) before a DRX cycle. The TRS may refer to a downlink reference signal configured to be used by UE 110 for timing and / or frequency tracking. Thus, different from the above example, WUS is not used for timing and / or frequency tracking. Instead, WUS may trigger a separate reference signal that UE 110 may use for timing and / or frequency tracking.

[0053] Figure 6 FIG. 600 shows an exemplary timing diagram of a DRX cycle including WUS that triggers a TRS according to various exemplary embodiments. The timing diagram 600 includes a line 605 representing time. Initially, consider a scenario where UE 110 camps on gNB 120A and operates in the RRC idle state or the RRC inactive state. In the DRX cycle, a WUS occasion 615 is scheduled during a time period 610. UE 110 is configured to monitor the WUS during the WUS occasion 615. The WUS occasion 615 corresponds to an on-duration 635 that occurs during a time period 630. The network may transmit the WUS during the WUS occasion 615. In this example, it may be considered that the network transmits the WUS during the WUS occasion 615. This means that the network has communication for UE 110 during the corresponding on-duration 635.

[0054] The WUS received at the WUS occasion 615 may also trigger the TRS 625 during the time period 620. Thus, after monitoring the WUS at the WUS occasion 615, the UE 110 will also wake up during the time period 620 to monitor the TRS 625. The UE 110 may receive the TRS 625 and then use the TRS to obtain frequency and / or timing estimates for the gNB 120A. Then, the UE 110 may wake up within the on-duration 635 and perform operations with the gNB 120A based on the TRS with improved frequency and / or timing during the on-duration 635.

[0055] The network may configure a TRS timing offset 640 between the WUS 615 and the TRS 625 such 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, in the SIB or may be defined by a standard (e.g., 3GPP standard). In some exemplary embodiments, the UE may report the minimum TRS offset. Similarly, the network may also configure a DRX timing offset 650 between the TRS 625 and the on-duration 635 such that the UE 110 has sufficient time to perform accurate timing and frequency tracking. Again, the UE 110 may report the minimum DRX timing offset or it may be defined by a standard.

[0056] As described above, when the UE 110 sleeps for a long time period, the UE may experience frequency and / or timing errors. This may have a negative impact on 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 WUS or TRS for frequency and / or timing tracking.

[0057] Additional exemplary embodiments for handling these frequency and / or timing errors are described below. In these examples, it may be considered that the UE 110 receives the WUS during the WUS occasion and wakes up during the corresponding on-duration.

[0058] In some exemplary embodiments, the modulation and coding scheme (MCS) during the on-duration of the physical downlink shared channel (PDSCH) for scheduling may be tapered. Figure 7 An exemplary timeline 700 for tapering the MCS during the on-duration according to various exemplary embodiments is shown. Figure 7 A line 705 representing time including the on-duration 710 is shown. As Figure 7As shown, the activation duration 710 may include three MCSs for the PDSCH: MCS(1) 720, MCS(2) 730, and MCS(3) 740. The characteristics of MCS(1) 720, MCS(2) 730, and MCS(3) 740 will be described in more detail below. Thus, during the activation duration 710, gNB 120A may schedule PDSCH data for UE 110. gNB 120A may encode the PDSCH data for a corresponding time period using MCS(1) 720, as Figure 7 shown. gNB 120A may then encode the PDSCH data for a corresponding time period using MCS(2) 730, as Figure 7 shown. Finally, gNB 120A may encode the PDSCH data for a corresponding time period using MCS(3) 730, as Figure 7 shown. Correspondingly, UE 110 may be configured to decode the PDSCH data using an appropriate MCS.

[0059] In this example, MCS(1) 720 may be considered a more robust encoding than MCS(2) 730 (e.g., a lower coding rate and / or a lower modulation order), and this MCS(2) is a more robust encoding than MCS(3) 740. As will be understood by those skilled in the art, a lower coding rate and / or a lower modulation order generally means that UE 110 is more likely to successfully decode the encoded data. A lower coding rate and / or a lower modulation order results in a lower throughput than a lower coding rate. Thus, the purpose of initially having a lower coding rate and / or a lower modulation order is to enable UE 110 to more likely successfully decode the data received on the PDSCH while having a lower throughput if there are large frequency and / or timing errors due to a long sleep cycle of UE 110. As more data is received and the frequency and / or timing errors are resolved, the MCS may be increased (e.g., a higher coding rate and / or a higher modulation order), resulting in a higher throughput. This is Figure 7 the three (3)-MCS scheme shown. The exemplary embodiments are not limited to three levels of MCS, as the ramp may have any number of MCS levels of 2 or greater.

[0060] The maximum MCS that can be decoded by UE 110 may be reported as UE capability. For example, a basic report may include a single MCS. Over time, an advanced report may include a sequence of MCSs, e.g., as Figure 7The sequences MCS(1) 720, MCS(2) 730, and MCS(3) 740 shown above. As described above, the maximum MCS that can be decoded by the UE 110 can increase as the UE 110 has more accurate timing and frequency tracking. The UE 110 can update its UE capabilities via, for example, RRC signaling. This capability can be partially based on network configurations, such as the periodicity of the synchronization signal block (SSB), the availability of the TRS, etc. From the example of the TRS, it should be seen that the exemplary embodiments can implement more than one operation to handle frequency and / or timing errors.

[0061] In some exemplary embodiments, PDSCH repetition can be configured for the PDSCH in the idle mode. Before the UE 110 enters the inactive or idle mode, the number of repetitions can be configured in, for example, the SIB, RRC configuration signaling, etc. The repetition can follow an inter-slot repetition scheme. For example, the same time-domain and frequency-domain resource allocation can be repeated N times in N consecutive time slots. The redundancy version (RV) for each repetition can be defined by a standard (e.g., 3GPP standard), configured by the SIB, or configured via RRC signaling.

[0062] In some exemplary embodiments, when one of these repetitions conflicts with an uplink (UL) symbol, the transmission of the corresponding PDSCH is omitted. In other exemplary embodiments, when one of these repetitions conflicts with an uplink (UL) symbol, the transmission of the corresponding PDSCH is postponed to the next available time slot that does not conflict with the UL symbol.

[0063] Those skilled in the art will understand that the above-described exemplary embodiments can be implemented with any suitable software configuration, hardware configuration, or a combination thereof. An exemplary hardware platform for implementing the exemplary embodiments can include, for example, an Intel x86-based platform with a compatible operating system, Windows OS, Mac platform, and MAC OS, a mobile device with an operating system such as iOS, Android, etc. An exemplary embodiment of the above method can be embodied as a program including lines of code stored on a non-transitory computer-readable storage medium, which, when compiled, can be executed on a processor or a microprocessor.

[0064] Although this patent application describes various combinations of various embodiments each having different features, those skilled in the art will understand that any feature of one embodiment can be combined with the features of other embodiments in any manner not negated by the disclosure or features that are not functionally or logically inconsistent with the operation of the devices of the embodiments disclosed in the present invention or the described functions.

[0065] As is well known, the use of personally identifiable information should comply with privacy policies and practices that are recognized as meeting or exceeding industry or government requirements for maintaining user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of inadvertent or unauthorized access or use, and the nature of the authorized use should be clearly explained to users.

[0066] It will be apparent to those skilled in the art that various modifications can be made to the present disclosure without departing from the essence or scope of the present disclosure. Accordingly, 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 user equipment (UE), comprising: a transceiver configured to communicate with a base station; and a processor communicatively coupled to the transceiver and configured to perform operations including: monitoring a wake-up signal (WUS) occasion to determine whether the 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 an active duration of a discontinuous reception (DRX) cycle corresponding to the WUS, wherein the WUS includes information identifying a tracking reference signal (TRS) to be transmitted by the base station, the information including a time and a frequency position of the TRS, and the operations further include: monitoring for the time and frequency position of the TRS; and performing one of time or frequency tracking based on the TRS; and when the WUS is not received or the WUS does not identify the UE, remaining in a sleep state during the active duration corresponding to the WUS.

2. The UE according to claim 1, wherein the WUS corresponds to more than one active duration.

3. The UE according to claim 1, wherein monitoring the active duration includes one of the following: decoding a paging downlink control information (DCI); performing a serving cell quality measurement; performing a neighbor cell quality measurement; or performing an inter-frequency measurement.

4. The UE according to claim 1, wherein the operations further include: receiving a timing offset value indicating a time between the WUS and a corresponding active duration.

5. The UE according to claim 1, wherein the WUS is encoded with a cyclic redundancy check (CRC) error detection code scrambled by a radio network temporary identifier (RNTI).

6. The UE according to claim 5, wherein the encoded WUS identifies the UE at least based on a bitmap indicating a UE group to which the UE belongs.

7. The UE according to claim 5, wherein after the CRC error detection encoding, the WUS is encoded with a polar error correction code.

8. The UE according to claim 1, wherein the WUS identifies the UE based on at least one of the following: (i) a sequence corresponding to the UE; (ii) a paging radio network temporary identity (P-RNTI) corresponding to the UE; or (iii) the P-RNTI and another sequence including an identification of a group including the UE.

9. The UE according to claim 1, wherein the WUS includes at least one of the following: (i) more than two WUS symbols in a single time slot; (ii) two WUS symbols in a single time slot with a fixed number of non-WUS symbols between the two WUS symbols; or (iii) WUS symbols in multiple time slots, each time slot having the same WUS symbol pattern.

10. The UE according to claim 1, wherein the operations further include: monitoring a physical downlink shared channel (PDSCH) during a first portion of the active duration; Decode the data received on the PDSCH during the first part of the on-duration based at least on a first modulation and coding scheme (MCS); Monitor the PDSCH during a second part of the on-duration; and Decode the data received on the PDSCH during the second part of the on-duration based at least on a second MCS, wherein the first MCS includes a lower coding rate or a lower modulation order than the second MCS.

11. The UE according to claim 10, wherein the operation further comprises: Reporting to the base station one of a maximum MCS supported by the UE or a time-related MCS sequence.

12. A processor, the processor being configured to perform operations, the operations comprising: Monitoring a wake-up signal (WUS) occasion to determine whether a WUS is received during the WUS occasion; 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, wherein the WUS includes information identifying a tracking reference signal (TRS) to be transmitted by the base station, the information including a time and a frequency position of the TRS, the operations further comprising: Monitoring the time and the frequency position for the TRS; and Performing one of time or frequency tracking based on the TRS; and When the WUS is not received or the WUS does not identify the UE, remaining in a sleep state during the on-duration corresponding to the WUS.

13. The processor according to claim 12, wherein monitoring the on-duration includes one of the following: decoding paging downlink control information (DCI); performing a pre-emptive cell quality measurement; performing an adjacent cell quality measurement; or performing an inter-frequency measurement.

14. The processor according to claim 12, wherein the WUS is encoded with a cyclic redundancy check (CRC) error detection code scrambled by a radio network temporary identifier (RNTI), and the encoded WUS identifies the UE at least based on a bitmap indicating a UE group to which the UE belongs.

15. The processor according to claim 12, wherein the WUS identifies the UE based on at least one of the following: (i) a sequence corresponding to the UE; (ii) a paging radio network temporary identity (P-RNTI) corresponding to the UE; or (iii) the P-RNTI and another sequence including an identification of a group including the UE.

16. A processor, the processor being configured to perform operations, the operations comprising: 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, transmitting a WUS to the UE during a WUS occasion corresponding to the on-duration, wherein the operations further comprise: Encode the WUS to include information identifying a Tracking Reference Signal (TRS), the information including timing and frequency information for the TRS; and Transmit the TRS based on the timing and frequency information, wherein the TRS is transmitted with a predefined offset from both the WUS and the wake-up duration; and Omit transmitting the WUS during the WUS occasion corresponding to the wake-up duration when not waking up the UE.

17. The processor according to claim 16, wherein the WUS is transmitted at a predefined timing offset value before the start of the corresponding wake-up duration.

18. The processor according to claim 16, wherein the operation further comprises one of the following: Encode the WUS as a Cyclic Redundancy Check (CRC) error detection code scrambled by a Radio Network Temporary Identifier (RNTI); and After the CRC encoding, encode the WUS using a polar error correction code.

19. The processor according to claim 18, wherein the RNTI comprises one of the following: (i) a Paging RNTI (P-RNTI); or (ii) a new RNTI corresponding to a UE group to which the UE belongs, wherein the new RNTI is configured by one of Radio Resource Control (RRC) signaling, a System Information Block (SIB), or a hash function based on the identification of the UE.

20. The processor according to claim 16, wherein the operation further comprises one of the following: Encode the WUS to include a sequence corresponding to the UE; Encode the WUS to include a Paging Radio Network Temporary Identity (P-RNTI) corresponding to the UE; or Encode the WUS to include the P-RNTI and another sequence including an identification of a group including the UE.

21. The processor according to claim 16, wherein the operation further comprises one of the following: Encode the WUS to include more than two WUS symbols in a single time slot; or Encode the WUS to include two WUS symbols in a single time slot, with a fixed number of non-WUS symbols between the two WUS symbols.

22. The processor according to claim 16, wherein the operation further comprises: Transmit first data to the UE on a Physical Downlink Shared Channel (PDSCH) during a first part of the wake-up duration, wherein the data is encoded using a first Modulation and Coding Scheme (MCS); Transmit second data to the UE on the PDSCH during a second part of the wake-up duration, wherein the data is encoded using a second MCS, wherein the first MCS includes a lower coding rate or a lower modulation order than the second MCS.

23. The processor according to claim 22, wherein transmitting the first data and the second data on the PDSCH includes transmitting a predetermined number of repetitions of the first data and the second data, wherein the repetitions are transmitted in the same time domain resources and frequency domain resources in one or more consecutive time slots.

24. The processor according to claim 23, wherein, When one of the repetitions conflicts with an uplink (UL) symbol, the operation further includes one of the following: Omitting the transmission of the one repetition among the repetitions; or Postponing the transmission of the one repetition among the repetitions to the next time slot that does not conflict with the UL symbol.

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