User equipment and method for waking up signal process with low power consumption

Abstract

The present application discloses a method for a low power wake up signal (LP-WUS) procedure, comprising: a low power wake up receiver (LP-WUR) in a user equipment (UE) uses the LP-WUS to wake up a primary radio frequency of the UE, where a signal design of the LP-WUS comprises a sequence-based signal design with a physical broadcast channel (PBCH) and / or a signal design based on a particular UE or a group of UEs (User Equipment), and a method of using the LP-WUS to wake up the primary radio frequency of the UE by a low power wake up receiver (LP-WUR) in the UE, where the signal design of the LP-WUS comprises a sequence-based signal design with a PBCH (Physical Broadcast Channel).

Description

Technical Field

[0001] This application relates to the field of wireless communication systems. More specifically, it relates to a user equipment (UE) and a method for the low power wake up signal (LP-WUS) process in a 5G new radio (NR) communication system. More specifically, this application discusses the signal design and process of LP-WUS, as well as the architecture of a low power wake up receiver (LP-WUR), aiming to define an ultra-low power mechanism to improve the energy saving effect of the UE. Background Art

[0002] Energy efficiency is one of the basic requirements for 5G systems because 5G supports diverse application scenarios, including power-sensitive devices such as Internet of Things (e.g., industrial wireless sensors, controllers), wearable devices, etc. The power consumption of these devices depends on the configured length of the wake-up cycle, such as the paging cycle. To meet the battery life requirements, a relatively large value of the eDRX cycle is usually used, but this results in higher latency and is not suitable for services that require both long battery life and low latency. For example, in the application scenario of fire detection and extinguishing, from the moment the fire is detected by the sensor, the fire shutter must close within 1 to 2 seconds, and the fire sprinkler must also be activated immediately. Therefore, a long eDRX cycle cannot meet this latency requirement. Obviously, eDRX is not suitable for latency-sensitive scenarios. During the DRX and eDRX cycles, the UE needs to wake up periodically once per cycle, which incurs significant power consumption even when there is no signaling or data transmission. If the UE wakes up the main radio frequency module only when triggered (e.g., paging in the idle / inactive state or PDCCH monitoring in the connected state), the power consumption can be significantly reduced. This effect can be achieved by triggering the main radio frequency with a wake-up signal and by means of an independent receiver that can continuously monitor the wake-up signal with ultra-low power consumption, as mentioned in the study item description (SID) objectives: mainly providing low-power WUS / WUR for power-sensitive, small-sized devices (such as industrial sensors, controllers, and wearable devices); studying and evaluating wake-up signal design solutions that support wake-up receivers [RAN1, RAN4]; studying the potential improvements in power-saving effects, coverage capabilities, and latency impacts compared to existing Rel-15 / 16 / 17 UE power-saving mechanisms; system impacts should also be included in the study, such as network power consumption, coexistence with non-low-power WUR UEs, network coverage / capacity / resource overhead, etc. [RAN1]. In addition, the low power wake up signal (LP-WUS) will also focus on low latency requirements (e.g., lower than eDRX latency) to support diverse application scenarios.

[0003] In the prior art, several companies have proposed LP-WUS signal waveform schemes based on on-off keying (OOK) and frequency shift keying (FSK), as well as sequence-based and message-based information transmission signal designs for waking up the main radio frequency module of the UE, and have defined the listening process of LP-WUS. However, most companies have not paid sufficient attention to issues such as latency, the low complexity of LP-WUR, and synchronization-related problems of LP-WUR. Therefore, it is necessary to further study the detailed mechanism of LP-WUS and fully consider latency, synchronization, and the low complexity requirements of the LP-WUR architecture during its signal design and operation process. Summary of the Invention

[0004] The purpose of this application is to propose a user equipment (UE) and a method for a low power wake up signal (LP-WUS) process, aiming to study the detailed mechanism of LP-WUS and consider factors such as latency, synchronization, and the low complexity of the LP-WUR architecture during its signal design and operation process.

[0005] According to the first aspect of this application, a method for a low power wake up signal (LP-WUS) process includes: using the LP-WUS by the low power wake up receiver (LP-WUR) of the user equipment (UE) to wake up the main radio frequency module of the UE, where the signal design of LP-WUS includes a sequence-based signal design with a physical broadcast channel (PBCH) and / or a signal design based on a specific UE or UE group.

[0006] According to the second aspect of this application, a method for an LP-WUS process includes: using a periodic LP-WUS and / or a configured LP-WUS by the low power wake up receiver (LP-WUR) of the user equipment (UE) to wake up the main radio frequency module of the UE.

[0007] According to the third aspect of this application, a user equipment includes a memory, a transceiver, and a processor coupled to the memory and the transceiver, where the processor is configured to execute the above method.

[0008] According to the fourth aspect of the present application, instructions are stored on a non-transitory machine-readable storage medium, and when the instructions are executed by a computer, the computer is caused to execute the above method.

[0009] According to the fifth aspect of the present application, a chip includes a processor configured to call and run a computer program stored in a memory, so that a device installed with the chip executes the above method.

[0010] According to the sixth aspect of the present application, a computer-readable storage medium stores a computer program, and the computer program causes a computer to execute the above method.

[0011] According to the seventh aspect of the present application, a computer program product includes a computer program, and the computer program causes a computer to execute the above method.

[0012] According to the eighth aspect of the present application, a computer program causes a computer to execute the above method. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] To more clearly illustrate the embodiments of the present application or related technologies, the drawings to be described in the embodiments are briefly introduced below. Obviously, the drawings are only some embodiments of the present application, and those of ordinary skill in the art can obtain other drawings based on these drawings without paying any cost.

[0014] Figure 1 A schematic diagram showing an example of LP-WUR in IEEE.

[0015] Figure 2 A schematic diagram showing an example of LP-WUS and PEI triggering the main radio frequency.

[0016] Figure 3 A schematic diagram showing an example of the main radio frequency turn-on time triggered by LP-WUS.

[0017] Figure 4 It is a block diagram of one or more user equipments and a network / gNB in a communication network system in an embodiment of the present application.

[0018] Figure 5 It is a flowchart of a method for a low power wake up signal (LP-WUS) process in an embodiment of the present application.

[0019] Figure 6 It is a schematic diagram of a sequence-based LP-WUS design with PBCH in an embodiment of the present application.

[0020] Figure 7 It is a schematic diagram of a UE-specific or UE-group-specific LP-WUS design in an embodiment of the present application.

[0021] Figure 8 It is a schematic diagram of LP-WUS with a relatively long period in an embodiment of the present application.

[0022] Figure 9 It is a schematic diagram of LP-WUS with a relatively short period in an embodiment of the present application.

[0023] Figure 10 It is a schematic diagram of the configured LP-WUS in an embodiment of the present application for triggering the main radio frequency to monitor PEI.

[0024] Figure 11 It is a schematic diagram of the configured LP-WUS in an embodiment of the present application for triggering the main radio frequency to monitor the paging PDCCH.

[0025] Figure 12 It is a schematic diagram of the listening process of LP-WUS in the connected state in an embodiment of the present application.

[0026] Figure 13 It is a schematic diagram of the configured LP-WUS in an embodiment of the present application for triggering the main radio frequency to perform PDCCH monitoring during the DRx on period.

[0027] Figure 14 It is a schematic diagram of the periodic LP-WUS triggering the main radio frequency during the DRx off period in an embodiment of the present application.

[0028] Figure 15 It is a schematic diagram of the configured LP-WUS triggering the main radio frequency during the DRx on period in an embodiment of the present application.

[0029] Figure 16 It is a schematic diagram of the configured LP-WUS triggering the main radio frequency during the DRx off period in an embodiment of the present application.

[0030] Figure 17 It shows a block diagram of a UE for wireless communication according to an embodiment of the present application.

[0031] Figure 18 It shows a block diagram of a system for wireless communication according to an embodiment of the present application. Detailed implementation manners

[0032] The technical content, structural features, achieved objectives and effects of the present application will be described in detail below with reference to the accompanying drawings. Specifically, the terms in the embodiments of the present application are only used for the purpose of describing specific embodiments and are not intended to limit the present application.

[0033] Figure 1It shows the basic processes and working principles of LP-WUS and LP-WUR. The main radio frequency is only used for data transmission and reception and is usually in the off or deep sleep state, unless it needs to be awakened. The low-power wake-up receiver (LP-WUR) remains on to continuously monitor for wake-up signals. The LP-WUS and LP-WUR structures shown in the figure are based on the IEEE low-power receiver architecture and can be used as a basic reference for designing the LP-WUS process and LP-WUR architecture in 3GPP cellular networks.

[0034] The core requirement of the Rel-18 ultra-low-power mechanism is to allow the UE's main radio frequency to be in the sleep state for a long time in the idle / inactive state and the connected state and only be awakened when triggered by the network. In Rel-16, a wake-up signal (WUS) was introduced for connected-state UEs as an energy-saving mechanism, and in Rel-17, a paging early indication (PEI) mechanism was introduced for idle / inactive-state UEs. These two mechanisms are used to trigger the UE's receiver before the PDCCH monitoring or paging occasion respectively. However, these old mechanisms directly wake up the main receiver and consume more power compared to the LP-WUS mechanism in Rel-18. On the other hand, the LP-WUS mechanism can trigger the main radio frequency only when the UE actually needs to receive data or signaling from the network / gNB, achieving energy savings both in the idle / inactive state and the connected state.

[0035] However, transmitting LP-WUS in the idle / inactive state may cause the LP-WUR to be triggered twice, as Figure 2 shown, triggered once by LP-WUS and once by PEI respectively. This mechanism may consume more UE power compared to the Rel-17 PEI-based energy-saving mechanism. In addition, if LP-WUS is sent too early in the time domain to trigger the main radio frequency before PEI, the main radio frequency may remain on for a long time, as Figure 3 shown, which will further increase the UE's power consumption.

[0036] In addition, due to the limitations of the low-cost LP-WUR architecture, its receiving sensitivity may not be sufficient to detect LP-WUS and cannot wake up the main radio frequency in time to receive data or signaling from the network / gNB, especially for UEs located at the cell edge. This missed detection of LP-WUS will cause the main radio frequency to remain in the sleep mode, thus missing the reception of data or signaling. Therefore, it is necessary to further study how to enhance the coverage ability of LP-WUS to avoid the main radio frequency missing critical data or signaling transmissions due to missed detection.

[0037] The main objectives of some embodiments of the present invention are to define and develop an ultra-low power LP-WUS mechanism, with a focus on low latency, low resource overhead, and the synchronization issue between the LP-WUR and the network. To achieve the above objectives, a series of solutions are proposed in this paper, and the summary is as follows.

[0038] This application proposes two different LP-WUS signal design schemes, which are as follows: 1. Sequence-based LP-WUS signal design, combined with the physical broadcast channel (PBCH), is used to broadcast LP-WUS to all UEs within the cell coverage to trigger the main radio frequency wake-up; 2. UE-specific and UE-group-specific LP-WUS signal design can meet the latency requirements of latency-sensitive services.

[0039] In addition, this application also proposes two alternative working mechanisms applicable to the LP-WUS process in the idle / inactive state and the connected state, which are as follows: 1. Periodic LP-WUS working mechanism, aiming to reduce the resource overhead and decoding complexity of LP-WUS and support a low-cost LP-WUR architecture; 2. Configurable LP-WUS working mechanism, used to meet the strict requirements of latency-sensitive services.

[0040] Some embodiments of this application explore the signal design and processes of LP-WUS in the idle / inactive state and the connected state, and have one or more of the following advantages: ultra-low power mechanism, low resource overhead, low latency, and LP-WUS coverage enhancement ability.

[0041] As Figure 4 shown, in some embodiments of this application, the communication network system 40 includes one or more user equipments (UEs) 10 and a network / gNB 20. The communication network system 40 includes one or more UEs 10 and a network / gNB 20. Each UE 10 may include a memory 12, a transceiver 13, and a processor 11 connected to the memory 12 and the transceiver 13; the network / gNB 20 may include a memory 22, a transceiver 23, and a processor 21 connected to the memory 22 and the transceiver 23. The processor 11 or 21 may be configured to execute the functions, processes, and / or methods described in this application. Each layer of the radio interface protocol may also be implemented in the processor 11 or 21. The memory 12 or 22 is operatively connected to the processor 11 or 21 and is used to store various information for the operation of the processor 11 or 21. The transceiver 13 or 23 is operatively connected to the processor 11 or 21 and is used to send and / or receive wireless signals.

[0042] The processor 11 or 21 may include an application-specific integrated circuit (ASIC), other chip sets, logic circuits, and / or data processing devices. The memory 12 or 22 may include a read-only memory (ROM), a random access memory (RAM), a flash memory, a memory card, a storage medium, and / or other storage devices. The transceiver 13 or 23 may include a baseband circuit for processing radio frequency signals. When the present embodiment is implemented in software, the technologies described herein may be implemented by modules (such as processes, functions, etc.) that execute related functions. These modules may be stored in the memory 12 or 22 and executed by the processor 11 or 21. The memory 12 or 22 may be integrated inside the processor 11 or 21, or may exist independently outside, and is communicatively connected to the processor 11 or 21 in various ways known in the art.

[0043] Figure 5 Method 500 illustrates the low power wake up signal (LP-WUS) process in an embodiment of the present application. In some embodiments, method 500 includes: In step 502, a low power wake up receiver (LP-WUR) of a user equipment (UE) uses the LP-WUS to wake up the main radio frequency module of the UE, where the signal design of the LP-WUS includes a sequence-based signal design with a physical broadcast channel (PBCH), and / or a UE-specific or UE group-specific LP-WUS signal design. In addition, the processor 11 is configured to execute the above method 500 and execute this method in some of the following embodiments.

[0044] In some embodiments, in the sequence-based signal design with PBCH, the LP-WUS is a sequence-based LP-WUS, information is broadcast to multiple UEs through the sequence-based LP-WUS, and the amount of information transmitted to multiple UEs has a predefined length, where each UE is assigned a single-bit information for the wake-up function of the main radio frequency and / or the function of maintaining the sleep mode. In some embodiments, in the sequence-based design, the length of the information transmitted to the UE depends on the number of UEs entering the LP-WUS mode and is adjusted according to this number.

[0045] In some embodiments, in a sequence-based signal design with PBCH, the UE detects its corresponding information according to the symbol assigned to it by the base station when the UE enters the LP-WUS mode. In some embodiments, in a UE-specific / UE-group-specific LP-WUS signal design, LP-WUS is a UE-specific / UE-group-specific signal and is configured for a certain UE or a group of UEs. This signal design includes a low power synchronization signal (LP-SS), a WUS message part, and payload information. In some embodiments, the LP-SS synchronizes the LP-WUR before receiving the WUS message part, and the WUS message part contains trigger information bits for the UE or UE group, as well as payload information containing the target UE identifier (UE ID) or UE group identifier.

[0046] In some embodiments, UE-specific / UE-group-specific LP-WUS is only transmitted to the UEs that need to be woken up, and a single-bit information is assigned to each UE for the wake-up function of the primary radio frequency and / or the function of maintaining the sleep mode. In some embodiments, when the primary radio frequency of the UE is in the radio resource control (RRC) idle or inactive state, the network / gNB initiates a transmission to the UE through a paging occasion, and uses LP-WUS as a trigger signal before this paging occasion to wake up the primary radio frequency of the UE or UE group to listen for this paging occasion. In some embodiments, when the primary radio frequency of the UE is in the RRC connected state, the primary radio frequency remains on and performs PDCCH monitoring according to the detection of LP-WUS. In some embodiments, LP-WUS is used to indicate whether to enter the discontinuous reception (DRX) on state, and / or is used to indicate the start of PDCCH monitoring during the DRX on period.

[0047] In some embodiments, the periodic LP-WUS sent by the network / gNB can be used by the UE's LP-WUR to trigger the main radio frequency for paging monitoring; or the LP-WUS can be configured at a specific timing to trigger the main radio frequency for paging when the UE is in the RRC idle / inactive state or the RRC connected state. In some embodiments, the UE or UE group uses the LP-WUS to trigger the main radio frequency according to the sequence-based signal design with PBCH, and the LP-WUR uses the periodic LP-WUS to trigger the UE's main radio frequency only when the network / gNB sends a paging early indication (PEI) or the paging physical downlink control channel (PDCCH) for a specific UE. In some embodiments, the periodic LP-WUS is not targeted at a specific UE or UE group, but is broadcast by the network / gNB throughout the cell or sent in different beam directions. In some embodiments, the period of the periodic LP-WUS is defined within the range of the periodicity of the 5G new radio (NR) synchronization signal burst, such as {5, 10, 20, 40, 80, 160} milliseconds. In some embodiments, the UE's LP-WUR uses the LP-WUS to trigger the main radio frequency to respond close to the PEI in the time domain. In some embodiments, the configured LP-WUS is used as an indication to notify the UE or UE group to monitor the target paging PDCCH and replace the PEI as the paging trigger mechanism.

[0048] In some embodiments, when the UE's main radio frequency is in the RRC connected state, the main radio frequency is in the on state and performs PDCCH monitoring based on the detection of the LP-WUS. In some embodiments, the LP-WUS is used to indicate whether to enter the discontinuous reception (DRX) on state and / or indicate the start of PDCCH monitoring during the DRX on period. In some embodiments, the UE or UE group uses the periodic LP-WUS to trigger the main radio frequency according to the sequence-based signal design with PBCH, and the LP-WUR uses the periodic LP-WUS to trigger the main radio frequency and indicate entering the DRX on state to monitor the PDCCH during the DRX on period and / or during the DRX off period. In some embodiments, the UE or UE group uses the configured LP-WUS to trigger the main radio frequency according to the UE-specific or UE-group-specific LP-WUS signal design, and the LP-WUR uses the configured LP-WUS to trigger the main radio frequency and indicate entering the DRX on state to monitor the PDCCH during the DRX on period and / or during the DRX off period.

[0049] This application explores the signal design and process of a low-power wake-up signal (LP-WUS), with a focus on the low-power mechanisms of the UE in the RRC idle / inactive state and the RRC connected state. Example 1 illustrates the LP-WUS signal design with a focus on a low-resource-overhead and low-complexity LP-WUR architecture; Example 2 focuses on the LP-WUS process and illustrates the periodic LP-WUS and configured LP-WUS in the RRC idle / inactive state; Example 3 focuses on the LP-WUS process and illustrates the periodic LP-WUS and configured LP-WUS in the RRC connected state.

[0050] Example 1: Signal Design of LP-WUS

[0051] This example discusses the signal design of LP-WUS. According to the objectives described in the research project in the background section, the design of LP-WUS should take low power consumption as the main feature to simplify the detection process at the UE receiver and support a low-complexity LP-WUR architecture. In this application, we propose the following two signal design schemes for LP-WUS.

[0052] Example 1.1: Sequence-Based Signal Design Combined with the Physical Broadcast Channel

[0053] Figure 6 For this application, it is a schematic diagram of the sequence-based LP-WUS signal design combined with the PBCH. As Figure 6 shown, the sequence-based design can be combined with the physical broadcast channel to broadcast LP-WUS information to multiple UEs. Through this design, the amount of information transmitted to multiple UEs can have a predefined length, and each UE will be assigned a single-bit information for the "wake-up" function and / or "stay in sleep" function of the main radio frequency. The UE can implicitly detect the assigned information based on the symbol assigned to it. In this signal design, when the UE enters the LP-WUS mode, a specific symbol position should be assigned in the time domain of a sequence of length X. The LP-WUR can implicitly detect the symbol assigned to the UE based on the position of the symbol in the received sequence and determine whether the main radio frequency needs to be awakened accordingly.

[0054] For example, when the bit information transmitted in the LP-WUS sequence is '0', it means "stay in sleep"; when it is '1', it means "wake up". Based on this information, when the LP-WUR detects that the corresponding information of the UE is '1', it will wake up the main radio frequency; if the information is '0', the main radio frequency will be kept in the sleep state. In addition, the length of the information transmitted to the UE depends on the number of UEs entering the LP-WUS mode, and this length will be dynamically adjusted according to the number of UEs in this mode.

[0055] Advantages: The sequence-based LP-WUS signal design combined with PBCH is adopted, with a simple detection mechanism and very low LP-WUS overhead corresponding to each UE. When used for information transmission, simple OOK or FSK waveforms can be used. Since the sequence-based LP-WUS combined with PBCH is sent in a broadcast manner, UE ID / UE group ID or UE cell ID is not required, thus reducing the overall overhead of the LP-WUS signal design and further supporting the use of a low-cost LP-WUR architecture.

[0056] Disadvantages: When a large number of UEs enter the LP-WUS mode, the sequence-based PBCH design may lead to an increase in the amount of information, resulting in a higher total overhead on the network side.

[0057] Embodiment 1.2: UE-specific / UE-group-specific LP-WUS signal design

[0058] Figure 7 This is a schematic diagram of the UE-specific or UE-group-specific LP-WUS design in the embodiments of this application. Such LP-WUS can be configured for a certain UE or a group of UEs. This signal design includes LP-SS, which is used to synchronize the LP-WUR before receiving the WUS message part. The WUS message part may include trigger information bits for a certain UE or UE group, and a payload part, which includes the UE ID or UE group ID targeted by the sent LP-WUS, as Figure 7 shown. Such LP-WUS is only sent to the UEs that need to be woken up. Similar to the sequence-based signal, the bit "0" represents "remain in sleep", and the bit "1" represents "wake up" the main radio frequency function.

[0059] Advantages: The UE-specific / UE-group-specific LP-WUS design reduces the amount of information required to trigger the main radio frequency of the UE or UE group, and is only sent to the UEs that actually need to receive data or signaling, thus further saving resources and improving efficiency.

[0060] Disadvantages: This signal design needs to carry additional UE ID / UE group ID payload information, which will increase the complexity of the LP-WUR when decoding the UE ID / UE group ID, thus increasing the power consumption of the LP-WUR. In addition, this design may also require the LP-WUR of the UE to be synchronized with the network before decoding the main radio frequency trigger information.

[0061] Embodiment 2: LP-WUS procedure in the idle / inactive state

[0062] In the idle / inactive state, the network / gNB initiates transmissions to the UE via paging. Therefore, LP-WUS can be used as a trigger mechanism before the paging occasion to wake up the main radio frequency module of a certain UE or a group of UEs to listen for the paging occasion. This embodiment proposes that the network / gNB can send periodic LP-WUS to trigger the main radio frequency of the UE for paging, or configure LP-WUS in specific scenarios to wake up the main radio frequency of the UE in the RRC idle / inactive state, as described below.

[0063] Embodiment 2.1: Periodic LP-WUS

[0064] This embodiment proposes a periodic LP-WUS mechanism, sent by the network, for triggering the main radio frequency of a certain UE or a group of UEs for paging monitoring. For this periodic LP-WUS, this application assumes that the UE or the group of UEs will use LP-WUS to trigger the main radio frequency according to the sequence-based LP-WUS design combined with PBCH described in Embodiment 1.1. In other words, only when the gNB sends the PEI or paging PDCCH related to this specific UE, the LP-WUR of the UE or the group of UEs will use LP-WUS to trigger the main radio frequency. In addition, the periodic LP-WUS is not targeted at a specific UE or a group of UEs. The gNB can broadcast LP-WUS throughout the cell or transmit it through different beam directions, such as transmission in a specific beam direction.

[0065] The main advantages of the periodic LP-WUS are as follows: The periodic LP-WUS can ensure that each UE that the network needs to wake up can receive LP-WUS in a timely manner, thereby improving the coverage rate of LP-WUS. The periodic LP-WUS does not contain UE ID or UE group ID, thus reducing the decoding complexity of the LP-WUR.

[0066] Period setting of the periodic LP-WUS

[0067] The period of the periodic LP-WUS can be defined in the range of {5, 10, 20, 40, 80, 160} milliseconds according to the periodicity of the 5G NR synchronization signal burst. In other words, the gNB can flexibly adjust the period of LP-WUS within this range to make a reasonable choice considering the turn-on duration of the main radio frequency and the delay requirements of the transmission. In the following embodiments, we will analyze the impacts of LP-WUS with longer and shorter periods on power consumption, delay, and network overhead.

[0068] Longer period of LP-WUS

[0069] Figure 8In the embodiments of the present application, it is a schematic diagram of LP-WUS with a longer period. Using LP-WUS with a longer period helps reduce the resource overhead at the network side, but may increase the turn-on time of the main radio frequency, resulting in an increase in the power consumption of the main radio frequency, as Figure 8 shown. In addition, the longer period will force the main radio frequency of the UE to listen for PEI or paging PDCCH again after receiving each LP-WUS trigger signal. If a certain listening fails to correctly detect PEI or paging PDCCH, the UE must wait until the next opportunity to re-listen. Therefore, LP-WUS with a longer period will increase the overall system latency. Note: Here we assume that the LP-WUR of the UE will choose to use LP-WUS at a position close to PEI in the time domain to trigger the main radio frequency, so as to reduce the turn-on time of the main radio frequency and lower the power consumption.

[0070] Shorter period of LP-WUS

[0071] Figure 9 In the embodiments of the present application, it is a schematic diagram of LP-WUS with a shorter period. LP-WUS with a shorter period enables the LP-WUR of the UE to trigger the main radio frequency when it is closer to the PEI position or the paging PDCCH position in the time domain, as Figure 9 shown. This can effectively reduce the turn-on time of the main radio frequency of the UE, thereby reducing the power consumption of the main radio frequency. In addition, LP-WUS with a shorter period gives the LP-WUR more opportunities to select a closer LP-WUS in the time domain to trigger the main radio frequency, thereby reducing the probability of missed detection of PEI or paging PDCCH, and further reducing the communication latency. However, it should be noted that LP-WUS with a shorter period may increase the network resource overhead.

[0072] Embodiment 2.2: Configurable LP-WUS

[0073] This embodiment proposes that when the network needs to page the UE in the idle / inactive state, LP-WUS can be configured. In this configurable LP-WUS, the LP-WUR of the UE will trigger the main radio frequency only when it receives a trigger signal from the network, and its signal design can refer to the description in Embodiment 1.2.

[0074] Figure 10 In the embodiments of the present application, it is a schematic diagram of configurable LP-WUS for triggering the main radio frequency to listen for PEI. The main advantage of this solution is that, compared with periodic LP-WUS, it can further reduce the turn-on time of the main radio frequency of the UE in the idle / inactive state. For example, LP-WUS can be configured in the OFDM symbol before PEI to trigger the main radio frequency of a certain UE or UE group to listen for PEI. In other words, the transmission of LP-WUS and PEI is located in consecutive OFDM symbols, as Figure 10As shown, this arrangement can effectively reduce the on-time of the main radio frequency.

[0075] Figure 11 This is a schematic diagram of the configured LP-WUS triggering the main radio frequency to monitor the paging PDCCH in the embodiments of the present application. In addition, since the configured LP-WUS is designed based on the signals in Embodiment 1.2 and is UE-specific or UE-group-specific, it can also be used as an indication mechanism to notify a certain UE or UE group to monitor the target paging PDCCH and replace the PEI for paging, as Figure 11 shown. The main disadvantage of this scheme is that it needs to include the UE ID or UE group ID, which will increase the load overhead of LP-WUS, lead to an increase in decoding complexity, and make the LP-WUR architecture more complex.

[0076] Embodiment 3: LP-WUS Monitoring Process in the Connected State

[0077] Figure 12 This is a schematic diagram of the LP-WUS monitoring process in the connected state in the embodiments of the present application. This embodiment discusses the periodic LP-WUS process and the configured LP-WUS process for the UE in the RRC connected state. For a UE in the RRC connected mode, the main radio frequency is in the on state (it may be in deep sleep, light sleep, or micro sleep). In this state, the PDCCH monitoring can be triggered by the detection of LP-WUS. That is, before receiving LP-WUS, the UE does not perform PDCCH monitoring, as Figure 12 shown. Note: LP-WUS can replace the function of DCI format 2_6 in Rel-16 to indicate whether to enter the DRX on state; in addition, it can also be used to indicate the start of PDCCH monitoring during the DRX on period.

[0078] Embodiment 3.1: Periodic LP-WUS

[0079] Figure 13 This is a schematic diagram of the configured LP-WUS triggering the main radio frequency to perform PDCCH monitoring during the DRX on period in the embodiments of the present application. This embodiment proposes that the periodic LP-WUS sent by the network / gNB can be used by the LP-WUR of the UE to trigger the main radio frequency and perform PDCCH monitoring, as Figure 13 shown. In this embodiment, it is assumed that the LP-WUR of the UE will select the LP-WUS close in the time domain to trigger the main radio frequency and perform PDCCH monitoring, and the signal design adopted is the sequence-based design described in Embodiment 1.1. Figure 14 This is a schematic diagram of the periodic LP-WUS triggering the main radio frequency during the DRX off period in the embodiments of the present application. That is, the periodic LP-WUS can be used to trigger the main radio frequency during both the on and off periods of DRX, respectively, asFigure 13 as shown in Figure 14 In addition, for a UE in connected-state DRX, the monitoring of its PDCCH may completely depend on the LP-WUS trigger. Therefore, only when triggered by the LP-WUS, the main radio frequency performs monitoring, so that the main radio frequency can be in a sleep state for a long time to achieve the energy-saving effect. Although using a periodic LP-WUS with a shorter period may increase the network overhead, it can significantly reduce the monitoring latency of the PDCCH in the DRX mode, as illustrated in the foregoing embodiments. Additionally, it should be noted that the load content of the periodic LP-WUS in the connected state is the same as that in the idle / inactive state.

[0080] Embodiment 3.2: Configurable LP-WUS

[0081] Figure 15 This is a schematic diagram of the configurable LP-WUS triggering the main radio frequency during the DRX activation period in an embodiment of the present application. Similar to the configurable LP-WUS in the RRC idle / inactive state, the configurable LP-WUS can also be used to wake up the main radio frequency in the connected state to monitor the PDCCH, and the signal design can refer to Embodiment 1.2, as shown in Figure 15 as shown. The advantage of the configurable LP-WUS is that it can reduce the network resource overhead and can be configured close to the timing of PDCCH monitoring in the time domain, thereby effectively reducing the monitoring latency. However, it should be noted that using the configurable LP-WUS in the connected state also requires including the UE ID of the target UE, which will bring problems such as increased decoding complexity and complication of the LP-WUR architecture, as described in the foregoing section.

[0082] Figure 16 This is a schematic diagram of the configurable LP-WUS triggering the main radio frequency during the DRX deactivation period in an embodiment of the present application. In the connected state, the configurable LP-WUS can also wake up the main radio frequency during the DRX deactivation period to perform the monitoring of the PDCCH, as shown in Figure 16 as shown. The state transition from the deactivation period to the activation period can be completed through the LP-WUS, enabling the UE to perform PDCCH monitoring in the DRX deactivation phase, thereby meeting the service requirements for latency sensitivity.

[0083] Figure 17For an embodiment of this application, it is a block diagram of a UE for wireless communication. The UE 1700 includes a low LP-WUR 1701 and a main radio frequency module 1702, where the LP-WUR 1701 is coupled to the main radio frequency module 1702. The LP-WUR 1701 is configured to wake up the main radio frequency module using the LP-WUS, and the signal design of the LP-WUS may include: a sequence-based signal design combined with the physical broadcast channel (PBCH), and / or a UE-specific or UE group-specific signal design. In other embodiments, the LP-WUR is configured to wake up the main radio frequency module using a periodic LP-WUS and / or a configured LP-WUS. In addition, the UE 1700 is also configured to execute the related methods in the above embodiments.

[0084] Summary: This application proposes two different LP-WUS signal design schemes as follows: 1. Sequence-based LP-WUS signal design combined with the physical broadcast channel (PBCH): used to broadcast the LP-WUS to all UEs in the entire cell to wake up the main radio frequency module. 2. UE-specific or UE group-specific LP-WUS signal design: can meet the latency requirements of latency-sensitive services. In addition, for the idle / inactive state and the connected state, two alternative LP-WUS operating mechanisms are also proposed: 1. Periodic LP-WUS operating mechanism: can reduce the resource overhead and decoding complexity of the LP-WUS and support a low-cost LP-WUR architecture. 2. Configured LP-WUS operating mechanism: can meet the strict requirements of latency-sensitive services. The signal design and processing flow of the LP-WUS in the idle / inactive state and the connected state are explored in multiple embodiments of this application, and have one or more of the following advantages: ultra-low power consumption mechanism, low resource overhead, low latency, and LP-WUS coverage enhancement ability.

[0085] Figure 18 It is a block diagram of a wireless communication example system 700 according to an embodiment of this application. The embodiments described herein can be implemented into the system using any appropriately configured hardware and / or software. Figure 18System 700 is shown, which includes a radio frequency (RF) circuit 710, a baseband circuit 720, an application circuit 730, a memory / storage device 740, a display 750, a camera 760, sensors 770, and an input / output (I / O) interface 780, which are coupled to each other at least as shown. The application circuit 730 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor may include any combination of a general-purpose processor and a dedicated processor, such as a graphics processor and an application processor. The processor may be coupled to the memory / storage device and configured to execute instructions stored in the memory / storage device to enable various applications and / or operating systems to run on the system.

[0086] Although the present disclosure has been described in connection with what are considered to be the most practical and preferred embodiments, it is to be understood that the present disclosure is not limited to the disclosed embodiments, but is intended to cover various arrangements without departing from the scope of the broadest interpretation of the appended claims.

Claims

1. A method for a low-power wake-up signal LP-WUS process, characterized in that, it includes: using the low-power wake-up receiver LP-WUR of the user equipment UE to wake up the main radio frequency of the UE with LP-WUS, wherein the signal design of the LP-WUS includes sequence-based signal design and physical broadcast channel PBCH and / or UE-specific / UE-group-specific LP-WUS signal design.

2. The method for the LP-WUS process according to claim 1, characterized in that, in the sequence-based signal design with the PBCH, the LP-WUS is sequence-based LP-WUS, wherein information is broadcast to multiple UEs through the sequence-based LP-WUS, and the amount of information transmitted to the multiple UEs has a predefined length, and single-bit information for the wake-up function of the main radio frequency and / or the function of maintaining the sleep mode is assigned to each UE.

3. The method for the LP-WUS process according to claim 2, characterized in that, in the sequence-based signal design with the PBCH, the length of the information transmitted to the UE depends on the number of UEs entering the LP-WUS mode, and the information length changes according to the number of UEs in the LP-WUS mode.

4. The method for the LP-WUS process according to any one of claims 1 to 3, characterized in that, in the sequence-based signal design with the PBCH, the UE detects the corresponding information according to the assigned symbol, and the symbol is assigned to the UE by the base station when the UE enters the LP-WUS mode.

5. The method for the LP-WUS process according to any one of claims 1 to 4, characterized in that, in the UE-specific / UE-group-specific LP-WUS signal design, the LP-WUS is the UE-specific / UE-group-specific LP-WUS and is configured for a certain UE or a group of UEs, and the signal design includes a low-power synchronization signal LP-SS, a WUS message part, and payload information.

6. The method for the LP-WUS process according to claim 5, characterized in that, the LP-SS synchronizes the LP-WUR before receiving the WUS message part, the WUS message part contains trigger information bits for the UE or UE group, and the payload information, and the payload information includes the UE identifier ID or UE group ID for sending the LP-WUS.

7. The method for the LP-WUS process according to claim 5 or 6, characterized in that, the UE-specific / UE-group-specific LP-WUS is only sent to the UEs that need to be woken up, and single-bit information is assigned to each UE for the wake-up function of the main radio frequency and / or the function of maintaining the sleep mode.

8. The method for the LP-WUS process according to any one of claims 1 to 7, characterized in that, When the primary radio frequency of the UE is in the Radio Resource Control (RRC) idle state or inactive state, the network or gNB initiates a transmission to the UE through a paging occasion, and uses the LP-WUS as a trigger before the paging occasion to activate the primary radio frequency of the UE or the UE group to monitor the paging occasion.

9. The method of the LP-WUS process according to claim 8, wherein, the periodic LP-WUS sent by the network / gNB is used by the LP-WUR of the UE to trigger the primary radio frequency of the UE for paging monitoring, or the LP-WUS is configured at a specific time to trigger the primary radio frequency for paging when the UE is in the RRC idle / inactive state or RRC connected state.

10. The method of the LP-WUS process according to claim 9, wherein, the UE or the UE group uses the LP-WUS to trigger the primary radio frequency according to the sequence-based signal design with the PBCH, and when the network / gNB sends a Paging Early Indication (PEI) or a Paging Physical Downlink Control Channel (PDCCH) for a specific UE, the LP-WUR of the UE or the UE group only uses the periodic LP-WUS to trigger the primary radio frequency of the UE.

11. The method of the LP-WUS process according to claim 9 or 10, wherein, the periodic LP-WUS is not for a specific UE or UE group, but is broadcast by the network / gNB in the cell or transmitted in different beam directions.

12. The method of the LP-WUS process according to any one of claims 9 to 11, wherein, the periodicity of the periodic LP-WUS is defined in the range of {5, 10, 20, 40, 80, 160} milliseconds according to the periodicity of the Synchronization Signal (SS) burst of 5G New Radio (NR).

13. The method of the LP-WUS process according to any one of claims 9 to 12, wherein, the LP-WUR of the UE uses the LP-WUS to trigger the primary radio frequency close to the PEI in the time domain.

14. The method of the LP-WUS process according to any one of claims 9 to 13, wherein, the configured LP-WUS is used as an indication to notify the UE or the UE group to monitor the target paging PDCCH and replace the PEI as a paging indication.

15. The method of the LP-WUS process according to any one of claims 1 to 8, wherein, when the primary radio frequency of the UE is in the RRC connected state, the primary radio frequency is in the on state, and PDCCH monitoring is performed based on the detection of the LP-WUS.

16. The method of the LP-WUS process according to claim 15, wherein, the LP-WUS is used to indicate whether to enter the Discontinuous Reception (DRX) on state, and / or the LP-WUS is used to indicate the start of the PDCCH monitoring during the on period.

17. The method of the LP-WUS process according to claims 15 to 16, wherein, the UE or the UE group uses the periodic LP-WUS to trigger the main radio frequency according to the sequence-based signal design with the PBCH, and the LP-WUR of the UE or the UE group uses the periodic LP-WUS to trigger the main radio frequency and indicates entering the DRX on state to monitor the physical downlink control channel PDCCH during the DRX on period and / or the DRX off period.

18. The method of the LP-WUS process according to claims 15 to 16, wherein, the UE or the UE group uses the configured LP-WUS to trigger the main radio frequency according to the UE-specific or UE-group-specific LP-WUS signal design, and the LP-WUR of the UE or the UE group uses the configured LP-WUS to trigger the main radio frequency and indicates entering the DRX on state to monitor the physical downlink control channel PDCCH during the DRX on period and / or the DRX off period.

19. A user equipment (UE), wherein, comprising: a low-power wake-up receiver (LP-WUR) and a main radio frequency coupled to the LP-WUR, wherein the LP-WUR is configured to wake up the main radio frequency using a low-power wake-up signal (LP-WUS), and the signal design of the LP-WUS includes a sequence-based signal design with a physical broadcast channel (PBCH) and / or a UE-specific / UE-group-specific LP-WUS signal design.

20. A user equipment (UE), wherein, comprising: a low-power wake-up receiver (LP-WUR) and the main radio frequency coupled to the LP-WUR, wherein the LP-WUR is configured to wake up the main radio frequency using the periodic LP-WUS and / or the configured LP-WUS.

21. A user equipment (UE), wherein, comprising: a memory; a transceiver; and a processor coupled to the memory and the transceiver; wherein, the processor is configured to execute the method according to any one of claims 1 to 18.

22. A non-transitory machine-readable storage medium, wherein, instructions are stored thereon, and when a computer executes the instructions, the instructions cause the computer to execute the method according to any one of claims 1 to 18.

23. A chip, wherein, comprising: a processor configured to call and run a computer program stored in a memory, so that a device installed with the chip executes the method according to any one of claims 1 to 18.

24. A computer-readable storage medium, wherein, a computer program is stored therein, and the computer program causes a computer to execute the method according to any one of claims 1 to 18.

25. A computer program product, wherein, comprising a computer program, and the computer program causes a computer to execute the method according to any one of claims 1 to 18.

26. A computer program, wherein, The computer program causes a computer to perform the method according to any one of claims 1 to 18.

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