Fast wake-up signal detector

Abstract

Aspects of the present disclosure relate to a user equipment (UE) for wireless communication. The UE wakes up to monitor a wake-up signal (WUS) having a maximum WUS duration, and the WUS is configured to indicate an upcoming transmission of a paging signal corresponding to the WUS. The UE detects reference signal tone energy from a tone carrying a reference signal, detects WUS tone energy from a tone designated to carry the WUS, and determines whether the WUS is present or absent based on the WUS tone energy and the reference signal tone energy. Then, when it is determined that the WUS is missing, the UE switches to a sleep state before the maximum WUS duration ends. Alternatively, when it is determined that the WUS exists, the UE remains awake and receives a paging signal corresponding to the WUS. Other aspects, features, and embodiments are also claimed and described.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Non-Provisional Application Serial No. 16 / 938609 filed in the U.S. Patent Office on July 24, 2020 and Indian Application Serial No. 202041020398 filed in the Indian Patent Office on May 14, 2020, the entire contents of which are incorporated herein by reference as if fully set forth below in their entirety and for all applicable purposes. Technical Field

[0003] The techniques discussed below relate generally to wireless communication systems, and more particularly to wake-up signal configuration for wireless communication. Embodiments may provide and enable techniques for detecting the absence of a wake-up signal before the maximum wake-up signal monitoring duration has expired. Background Art

[0004] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, broadcast, etc. These systems can support communication with multiple users by sharing available system resources (e.g., time, frequency, and power). A wireless multiple-access communication system may include several base stations or network access nodes, each of which simultaneously supports communication for multiple communication devices, which may also be referred to as user equipment (UE).

[0005] In some wireless communication systems (e.g., Internet of Things (IoT) or enhanced machine type communication (eMTC)), a base station may send data to a UE. The base station may signal to the UE that data and / or control information is available for the UE by sending a paging message in a downlink channel before the data and / or system information transmission. In some cases, the base station and the UE may utilize power saving signals such as a wake-up signal (WUS) for idle mode paging. The UE may wake up from a sleep state after receiving the WUS and monitor downlink transmissions (such as paging messages) from the base station. The WUS may have a maximum duration in which the UE may monitor the WUS before returning to the sleep state (e.g., if no paging message is received). Waiting for the maximum duration may shorten the battery life of the UE. Summary of the invention

[0006] An overview of one or more aspects of the present disclosure is presented below in order to provide a basic understanding of these aspects. This overview is not an extensive review of all expected features of the present disclosure, and is neither intended to identify the key or important elements of all aspects of the present disclosure, nor is it intended to describe the scope of any or all aspects of the present disclosure. Its sole purpose is to present some concepts of one or more aspects of the present disclosure in some form as a preface to a more detailed description presented later.

[0007] Various aspects of the present disclosure relate to a user equipment (UE) for wireless communication. The UE wakes up to monitor for a wake-up signal (WUS) having a maximum WUS duration and configured to indicate an upcoming transmission of a paging signal. The UE detects reference signal tone energy from one or more tones carrying a reference signal, detects WUS tone energy from one or more tones designated for carrying the WUS, and determines whether the WUS is present or absent based on the WUS tone energy and the reference signal tone energy (e.g., by comparing the WUS tone energy with a threshold based on the reference signal tone energy). If the UE determines that the WUS is absent, the UE transitions to a sleep state before the maximum WUS duration ends. If the UE determines that the WUS is present, the UE remains awake and receives a paging signal including control information for receiving an upcoming data transmission.

[0008] In one example, a method for wireless communication at a user equipment (UE) is disclosed. The method includes waking up to monitor a wake-up signal (WUS) having a maximum WUS duration and configured to indicate an upcoming transmission of a paging signal corresponding to the WUS; detecting a reference signal tone energy from one or more tones carrying a reference signal; detecting a WUS tone energy from one or more tones designated to carry the WUS; determining whether the WUS is present or absent based on the WUS tone energy and the reference signal tone energy (e.g., by comparing the WUS tone energy with a threshold determined based on the reference signal tone energy); when it is determined that the WUS is absent, transitioning to a sleep state before the maximum WUS duration ends; when it is determined that the WUS is present, remaining awake; and receiving a paging signal corresponding to the WUS, wherein the paging signal includes control information for receiving an upcoming data transmission.

[0009] In another example, a user equipment (UE) for wireless communication is disclosed. The UE includes at least one processor, a transceiver communicatively coupled to the at least one processor, and a memory communicatively coupled to the at least one processor. The at least one processor and the memory are configured to wake up to monitor a wake-up signal (WUS), the WUS having a maximum WUS duration and configured to indicate an upcoming transmission of a paging signal corresponding to the WUS; detect reference signal tone energy from one or more tones carrying a reference signal; detect WUS tone energy from one or more tones designated for carrying the WUS; determine whether the WUS is present or absent based on the WUS tone energy and the reference signal tone energy (e.g., by comparing the WUS tone energy with a threshold determined based on the reference signal tone energy); when it is determined that the WUS is absent, transition to a sleep state before the maximum WUS duration ends; when it is determined that the WUS is present, remain awake; and receive a paging signal corresponding to the WUS, wherein the paging signal includes control information for receiving an upcoming data transmission.

[0010] In another example, a user equipment (UE) for wireless communication is disclosed. The UE includes a component for waking up to monitor a wake-up signal (WUS) having a maximum WUS duration and configured to indicate an upcoming transmission of a paging signal corresponding to the WUS; a component for detecting a reference signal tone energy from one or more tones carrying a reference signal; a component for detecting a WUS tone energy from one or more tones designated for carrying the WUS; a component for determining whether the WUS is present or absent based on the WUS tone energy and the reference signal tone energy (e.g., by comparing the WUS tone energy with a threshold determined based on the reference signal tone energy); a component for transitioning to a sleep state before the maximum WUS duration ends when it is determined that the WUS is absent; a component for staying awake when it is determined that the WUS is present; and a component for receiving a paging signal corresponding to the WUS, wherein the paging signal includes control information for receiving an upcoming data transmission.

[0011] In another example, a non-transitory computer-readable medium storing computer executable code for wireless communication at a user equipment (UE) is disclosed. The non-transitory computer-readable medium includes code for causing a computer to perform the following operations: wake up to monitor a wake-up signal (WUS) having a maximum WUS duration and configured to indicate an upcoming transmission of a paging signal corresponding to the WUS; detect reference signal tone energy from one or more tones carrying a reference signal; detect WUS tone energy from one or more tones designated for carrying the WUS; determine whether the WUS is present or absent based on the WUS tone energy and the reference signal tone energy (e.g., by comparing the WUS tone energy with a threshold determined based on the reference signal tone energy); when it is determined that the WUS is absent, transition to a sleep state before the maximum WUS duration ends; when it is determined that the WUS is present, remain awake; and receive a paging signal corresponding to the WUS, wherein the paging signal includes control information for receiving an upcoming data transmission.

[0012] Various method, system, device and apparatus embodiments may also include additional features. For example, if the WUS tone energy is greater than or equal to a threshold, the WUS is present, and if the WUS tone energy is less than the threshold, the WUS is absent. In another example, the reference signal is a narrowband reference signal (NRS) or a cell-specific reference signal (CRS).

[0013] In some examples, the UE detects the reference signal tone energy by accumulating the reference signal tone. The signal tone may be accumulated across a number of repeated subframe transmissions. The energy of the accumulated reference signal tone may be combined. In another example, the UE detects the reference signal tone energy by pre-multiplying the received reference signal with a locally generated reference signal replica to form a coherently combined reference signal symbol, and determining the energy of the coherently combined reference signal symbol as the reference signal tone energy.

[0014] In another example, the UE detects the WUS tone energy by accumulating the tones designated to carry the WUS across several repeated subframe transmissions and combining the energy of the accumulated tones designated to carry the WUS. In another example, the UE detects the WUS tone energy by pre-multiplying the received WUS with a locally generated WUS replica to form a coherently combined WUS symbol and determining the energy of the coherently combined WUS symbol as the WUS tone energy.

[0015] In some examples, the threshold is at least equal to the accumulated energy of the combination of reference signal tones. In another example, the maximum WUS duration is proportional to the maximum number of repetitions for sending the paging signal.

[0016] By reading the following detailed description, these and other aspects of the present invention will be more fully understood. After reading the following description of specific exemplary embodiments in conjunction with the accompanying drawings, other aspects, features and embodiments will become apparent to those of ordinary skill in the art. Although features may be discussed relative to certain embodiments and accompanying drawings below, all embodiments may include one or more of the advantageous features discussed herein. In other words, although one or more embodiments may be discussed as having certain advantageous features, one or more of such features may also be used according to the various embodiments discussed herein. In a similar manner, although exemplary embodiments may be discussed below as equipment, system or method embodiments, it should be understood that such exemplary embodiments may be implemented in various equipment, systems and methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of a wireless communication system according to some aspects.

[0018] Figure 2 is a conceptual illustration of an example of a radio access network in accordance with some aspects.

[0019] Figure 3 is a block diagram illustrating a wireless communication system supporting multiple-input multiple-output (MIMO) communications in accordance with some aspects.

[0020] Figure 4 is a diagram of radio resource organization in an air interface utilizing orthogonal frequency division multiplexing (OFDM) according to some aspects.

[0021] Figure 5

[0013] An example of a wireless communication system supporting wake-up signal (WUS) configuration for wireless communication in accordance with some aspects is shown.

[0022] Figure 6 A first network configuration when a UE is paged and a second network configuration when the UE is not paged are shown according to some aspects.

[0023] Figure 7 A time-frequency resource structure is shown describing a scheme for detecting the presence or absence of a wake-up signal (WUS) according to some aspects.

[0024] Figure 8 is a block diagram conceptually illustrating an example of a hardware implementation for a UE according to some aspects.

[0025] Fig. 9 is a flow chart illustrating an example process for wireless communications at a UE in accordance with some aspects. DETAILED DESCRIPTION

[0026] The detailed description set forth below in conjunction with the accompanying drawings is intended as a description of various configurations and is not intended to represent the only configuration in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the various concepts. However, it is apparent to those skilled in the art that these concepts may be practiced without these specific details. In some cases, well-known structures and components are shown in block diagram form to avoid obscuring these concepts.

[0027] Although various aspects and embodiments are described in this application by illustrating some examples, it will be understood by those skilled in the art that other implementations and use cases may occur in many different arrangements and scenarios. The innovations herein may be implemented on many different platform types, devices, systems, shapes, sizes, and packaging arrangements. For example, embodiments and / or uses may be implemented via integrated chip embodiments and / or other non-module component-based devices (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail / purchase devices, medical devices, AI-enabled devices, etc.). However, some examples may or may not be specifically targeted at use cases or applications, and a wide range of applicability of the described innovations may occur. The range of implementations may range from chip-level or modular components to non-modular, non-chip-level implementations, and further aggregated, distributed, or OEM devices or systems that incorporate one or more aspects of the described innovations. In some practical settings, the device in combination with the described aspects and features may also necessarily include additional components and features for implementing and practicing the claimed and described embodiments. For example, the transmission and reception of wireless signals must include several components for analog and digital purposes (e.g., hardware components including antennas, RF chains, power amplifiers, modulators, buffers, processors, interleavers, adders / summers, etc.) The innovations described herein are intended to be practiced in a wide variety of devices, chip-level components, systems, distributed arrangements, end-user devices, etc., of various sizes, shapes, and configurations.

[0028] Aspects of the present disclosure provide and enable techniques for quickly detecting the absence of a wake-up signal (WUS). The WUS can be configured to indicate an upcoming paging signal transmission. The WUS can help transition to a sleep state before the maximum WUS duration ends to consume less power and extend the battery life of a communication device.

[0029] The various concepts presented throughout this disclosure may be implemented across a variety of telecommunication systems, network architectures and communication standards. Figure 1, various aspects of the present disclosure are described with reference to a wireless communication system 100 as an illustrative example and not as a limitation. The wireless communication system 100 includes three interacting domains: a core network 102, a radio access network (RAN) 104, and a user equipment (UE) 106. By means of the wireless communication system 100, the UE 106 may be enabled to communicate data with an external data network 110, such as (but not limited to) the Internet.

[0030] The RAN 104 may implement any suitable wireless communication technology or techniques to provide wireless access to the UE 106. As an example, the RAN 104 may operate in accordance with the 3rd Generation Partnership Project (3GPP) New Radio (NR) specification, commonly referred to as 5G. As another example, the RAN 104 may operate in a hybrid 5G NR and Evolved Universal Terrestrial Radio Access Network (eUTRAN) standard, commonly referred to as LTE. 3GPP refers to this hybrid RAN as the Next Generation RAN or NG-RAN. Of course, many other examples may be utilized within the scope of the present disclosure.

[0031] As shown, the RAN 104 includes a number of base stations 108. Broadly, a base station is a network element in a radio access network that is responsible for radio transmission and reception to or from a UE in one or more cells. In different technologies, standards, or contexts, a base station may be referred to differently by those skilled in the art as a base transceiver station (BTS), a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), an access point (AP), a Node B (NB), an eNode B (eNB), a gNode B (gNB), or some other appropriate terminology.

[0032] The wireless access network 104 is also illustrated as supporting wireless communications for multiple mobile devices. A mobile device may be referred to as a user equipment (UE) in the 3GPP standard, but those skilled in the art may also refer to such devices as a mobile station (MS), a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communication device, a remote device, a mobile user station, an access terminal (AT), a mobile terminal, a wireless terminal, a remote terminal, a mobile phone, a terminal, a user agent, a mobile client, a client, or some other suitable term. A UE may be a device (e.g., a mobile device) that provides access to network services to a user. In some examples, a UE may also refer to a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or an MTC device, etc., which may be implemented in various articles such as appliances, vehicles, meters, etc.

[0033] In this document, a "mobile" device does not necessarily have the ability to move, and may be stationary. The term mobile device or mobile device refers broadly to a wide array of devices and technologies. A UE may include several hardware structural components that are sized, shaped, and arranged to facilitate communication; such components may include antennas, antenna arrays, RF chains, amplifiers, one or more processors, etc. that are electrically coupled to each other. For example, some non-limiting examples of mobile devices include mobile devices, cellular (cellular / cell) phones, smart phones, session initiation protocol (SIP) phones, laptops, personal computers (PCs), notebooks, netbooks, smartbooks, tablets, personal digital assistants (PDAs), and, for example, a wide array of embedded systems corresponding to the "Internet of Things" (IoT). A mobile device may additionally be a car or other transportation vehicle, a remote sensor or actuator, a robot or robotic device, a satellite radio, a global positioning system (GPS) device, an object tracking device, a drone, a multicopter, a quadcopter, a remote control device, a consumer and / or wearable device, such as glasses, a wearable camera, a virtual reality device, a smart watch, a health or fitness tracker, a digital audio player (e.g., an MP3 player), a camera, a game console, etc. The mobile device may also be a digital home or smart home device, such as home audio, video and / or multimedia equipment, appliances, vending machines, smart lighting, home security systems, smart meters, etc. In addition, the mobile device may be a smart energy device, security device, solar panel or solar array, municipal infrastructure equipment (e.g., smart grid) that controls power, lighting, water, etc.; industrial automation and enterprise equipment; logistics controller; agricultural equipment, etc. In addition, the mobile device may provide remote connected medical or telemedicine support, such as health care. Telemedicine devices may include telemedicine monitoring devices and telemedicine management devices, whose communications may be given priority treatment or priority access over other types of information, for example, in terms of priority access for the delivery of critical service data, and / or in terms of associated QoS for the delivery of critical service data.

[0034] Wireless communication between RAN 104 and UE 106 can be described as utilizing an air interface. Transmissions over the air interface from a base station (e.g., base station 108) to one or more UEs (e.g., UE 106) can be referred to as downlink (DL) transmissions. According to certain aspects of the present disclosure, the term downlink can refer to point-to-multipoint transmissions initiated at a scheduling entity (further described below; e.g., base station 108). Another way to describe the scheme can be to use the term broadcast channel multiplexing. Transmissions from a UE (e.g., UE 106) to a base station (e.g., base station 108) can be referred to as uplink (UL) transmissions. According to further aspects of the present disclosure, the term uplink can refer to point-to-point transmissions initiated at a scheduled entity (further described below; e.g., UE 106).

[0035] In some examples, access to the air interface may be scheduled, wherein a scheduling entity (e.g., a base station 108) allocates resources for communications between some or all devices and equipment within its service area or cell. Within the present disclosure, as further discussed below, a scheduling entity may be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more scheduled entities. That is, for scheduled communications, a UE 106, which may be a scheduled entity, may utilize resources allocated by the scheduling entity 108.

[0036] Base station 108 is not the only entity that can act as a scheduling entity. That is, in some examples, a UE can act as a scheduling entity to schedule resources for one or more scheduled entities (e.g., one or more other UEs).

[0037] like Figure 1 As shown, the scheduling entity 108 may broadcast downlink traffic 112 to one or more scheduled entities 106. Broadly speaking, the scheduling entity 108 is a node or device responsible for scheduling traffic in the wireless communication network, which includes downlink traffic 112 and, in some examples, uplink traffic 116 from one or more scheduled entities 106 to the scheduling entity 108. On the other hand, the scheduled entity 106 is a node or device that receives downlink control information 114, which includes but is not limited to scheduling information (e.g., grants), synchronization or timing information, or other control information from another entity in the wireless communication network (such as the scheduling entity 108).

[0038] Typically, the base stations 108 may include a backhaul interface for communicating with a backhaul portion 120 of the wireless communication system. The backhaul 120 may provide a link between the base stations 108 and the core network 102. Additionally, in some examples, the backhaul network may provide interconnections between the various base stations 108. Various types of backhaul interfaces may be employed, such as a direct physical connection, a virtual network, the like using any suitable transport network.

[0039] The core network 102 may be part of the wireless communication system 100 and may be independent of the radio access technology used in the RAN 104. In some examples, the core network 102 may be configured according to 5G standards (e.g., 5GC). In other examples, the core network 102 may be configured according to 4G Evolved Packet Core (EPC) or any other suitable standard or configuration.

[0040] Reference now Figure 2 , a schematic diagram of RAN 200 is provided as an example and not a limitation. In some examples, RAN 200 may be used in conjunction with the Figure 1 The geographic area covered by the RAN 200 may be divided into cellular areas (cells) that may be uniquely identified by a user equipment (UE) based on an identity broadcast from an access point or base station. Figure 2 Macro cells 202, 204, and 206 and small cells 208 are illustrated, each of which may include one or more sectors (not shown). A sector is a sub-area of ​​a cell. All sectors within a cell are served by the same base station. A radio link within a sector may be identified by a single logical identifier belonging to the sector. In a cell divided into sectors, multiple sectors within a cell may be formed by antenna groups, each antenna being responsible for communicating with a UE in a portion of the cell.

[0041] exist Figure 2 , two base stations 210 and 212 are shown in cells 202 and 204; a third base station 214 is shown controlling a remote radio head (RRH) 216 in cell 206. That is, the base station may have an integrated antenna or may be connected to an antenna or RRH by a feeder cable. In the example shown, cells 202, 204, and 126 may be referred to as macro cells because base stations 210, 212, and 214 support cells with large sizes. In addition, base station 218 is shown in a small cell 208 (e.g., a micro cell, a pico cell, a femto cell, a home base station, a home Node B, a home eNode B, etc.), which may overlap with one or more macro cells. In this example, cell 208 may be referred to as a small cell because base station 218 supports a cell with a relatively small size. Cell size determination may be performed based on system design and component constraints.

[0042] It should be understood that the radio access network 200 may include any number of wireless base stations and cells. In addition, relay nodes may be deployed to extend the size or coverage area of ​​a given cell. Base stations 210, 212, 214, 218 provide wireless access points to the core network for any number of mobile devices. In some examples, base stations 210, 212, 214, and / or 218 may be configured as described above and in conjunction with a base station. Figure 1 The base station / scheduling entity 108 is the same as shown in .

[0043] Figure 2 Also included is a quadcopter or drone 220 that can be configured to act as a base station. That is, in some examples, the cell may not necessarily be stationary, and the geographic area of ​​the cell may move based on the location of a mobile base station (such as a quadcopter 220).

[0044] Within the RAN 200, a cell may include UEs that may communicate with one or more sectors of each cell. In addition, each base station 210, 212, 214, 218, and 220 may be configured to provide access to the core network 102 (see FIG. 1 ) for all UEs in the corresponding cell. Figure 1 ) access point. For example, UEs 222 and 224 may communicate with base station 210; UEs 226 and 228 may communicate with base station 212; UEs 230 and 232 may communicate with base station 214 via RRH 216; UE 234 may communicate with base station 218; and UE 236 may communicate with mobile base station 220. In some examples, UEs 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, and / or 242 may communicate with the above-described and Figure 1 The UE / scheduled entity 106 shown in FIG. 1 is the same as that shown in FIG.

[0045] In some examples, a mobile network node (eg, quadcopter 220 ) may be configured to function as a UE. For example, quadcopter 220 may operate within cell 202 by communicating with base station 210 .

[0046] In another aspect of RAN 200, sidelink signals can be used between UEs without having to rely on scheduling or control information from a base station. For example, two or more UEs (e.g., UEs 226 and 228) can use peer-to-peer (P2P) or sidelink signals 227 to communicate with each other without relaying the communication through a base station (e.g., base station 212). In another example, UE 238 communicating with UE 240 and 242 is illustrated. Here, UE 238 can be used as a scheduling entity or a primary sidelink device, and UE 240 and 242 can be used as a scheduled entity or a non-primary (e.g., secondary) sidelink device. In yet another example, a UE can be used as a scheduling entity in a device-to-device (D2D), peer-to-peer (P2P) or vehicle-to-vehicle (V2V) network and / or in a mesh network. In the mesh network example, in addition to communicating with the scheduling entity 238, UE 240 and 242 can optionally communicate directly with each other. Therefore, in a wireless communication system having scheduled access to time-frequency resources and having a cellular configuration, a P2P configuration, or a mesh configuration, a scheduling entity and one or more scheduled entities may communicate using the scheduled resources.

[0047] In the radio access network 200, the ability of a UE to communicate independently of its location while moving is called mobility. The various physical channels between the UE and the radio access network are usually managed by an access and mobility management function (AMF, not shown). Figure 1 The AMF is established, maintained, and released under the control of the core network 102 (part of the core network 102 in the AMF). In some scenarios, the AMF may include a security context management function (SCMF). The SCMF may manage the security context of the control plane and user plane functionalities in whole or in part, and perform the security anchor function (SEAF) for authentication.

[0048] In various aspects of the present disclosure, the radio access network 200 can utilize DL-based mobility or UL-based mobility to implement mobility and switching (i.e., the transfer of a UE's connection from one radio channel to another). In a network configured for DL-based mobility, during a call with a scheduling entity, or at any other time, the UE can monitor various parameters of the signal from its serving cell and various parameters of neighboring cells. Based on the quality of these parameters, the UE can maintain communication with one or more neighboring cells. During this time, if the UE moves from one cell to another, or if the signal quality from a neighboring cell exceeds the signal quality from the serving cell for a given time, the UE can perform a handover or handover from the serving cell to the neighboring (target) cell. For example, a UE 224 (illustrated as a vehicle, but any suitable form of UE can be used) can move from a geographic area corresponding to its serving cell 202 to a geographic area corresponding to a neighboring cell 206. When the signal strength or quality from a neighboring cell 206 exceeds the signal strength or quality of its serving cell 202 for a given amount of time, the UE 224 can send a report message indicating this condition to its serving base station 210. In response, UE 224 may receive a handover command, and the UE may handover to cell 206 .

[0049] In a network configured for UL-based mobility, the UL reference signal from each UE can be used by the network to select a serving cell for each UE. In some examples, base stations 210, 212, and 214 / 216 can broadcast a unified synchronization signal (e.g., a unified primary synchronization signal (PSS), a unified secondary synchronization signal (SSS), and a unified physical broadcast channel (PBCH)). UEs 222, 224, 226, 228, 230, and 232 can receive the unified synchronization signal, derive carrier frequency and slot timing from the synchronization signal, and send an uplink pilot or reference signal in response to the derived timing. The uplink pilot signal sent by a UE (e.g., UE 224) can be received simultaneously by two or more cells (e.g., base stations 210 and 214 / 216) within the radio access network 200. Each cell may measure the strength of the pilot signal, and the radio access network (e.g., one or more of base stations 210 and 214 / 216 and / or a central node within a core network) may determine a serving cell for UE 224. As UE 224 moves through radio access network 200, the network may continue to monitor uplink pilot signals sent by UE 224. When the signal strength or quality of the pilot signal measured by a neighboring cell exceeds the signal strength or quality measured by the serving cell, network 200 may handover UE 224 from the serving cell to the neighboring cell, with or without notifying UE 224.

[0050] Although the synchronization signals sent by base stations 210, 212 and 214 / 216 may be uniform, the synchronization signals may not identify a specific cell, but may identify a region of multiple cells at the same frequency and / or with the same timing. The use of regions in 5G networks or other next generation communication networks may implement an uplink-based mobility framework and improve the efficiency of both the UE and the network. Efficiency may be achieved because the number of mobility messages that need to be exchanged between the UE and the network may be reduced.

[0051] In various implementations, the air interface in the radio access network 200 can utilize licensed spectrum, unlicensed spectrum, or shared spectrum. Licensed spectrum provides exclusive use of a portion of the spectrum, typically through the purchase of a license by a mobile network operator from a government regulator. Unlicensed spectrum provides shared use of a portion of the spectrum without the need for a government-authorized license. Although it is still generally necessary to comply with some technical rules to access the unlicensed spectrum, generally, any operator or device can obtain access. Shared spectrum can fall between licensed and unlicensed spectrum, where access to the spectrum may require technical rules or restrictions, but the spectrum can still be shared by multiple operators and / or multiple RATs. For example, the holder of a license for a portion of the licensed spectrum can provide licensed shared access (LSA) to share the spectrum with other parties, for example, using conditions determined by the appropriate license holder to obtain access.

[0052] In order to transmit on the radio access network 200 to obtain a low block error rate (BLER) while still achieving very high data rates, channel decoding can be used. That is, wireless communication can usually utilize appropriate error correction block codes. In a typical block code, an information message or sequence is divided into code blocks (CBs), and then an encoder (e.g., CODEC) at the transmitting device mathematically adds redundancy to the information message. Utilizing this redundancy in the encoded information message can improve the reliability of the message, making it possible to correct any bit errors that may occur due to noise.

[0053] Data encoding and decoding can be implemented in a variety of ways. In the early 5G NR specifications, quasi-cyclic low-density parity check (LDPC) with two different basemaps (one basemap for large code blocks and / or high code rates and another basemap for other cases) is used to encode and decode user data. Polar decoding is used based on nested sequences to encode and decode control information and physical broadcast channel (PBCH). For these channels, puncturing, shortening, and repetition are used for rate matching.

[0054] Aspects of the present disclosure may be implemented utilizing any suitable channel codes. Various implementations of the scheduling entity 108 and the scheduled entity 106 may include appropriate hardware and capabilities (eg, encoders, decoders, and / or CODECs) to utilize one or more of these channel codes for wireless communications.

[0055] The air interface in the radio access network 200 can utilize one or more multiplexing and multiple access algorithms to enable simultaneous communication of various devices. For example, the 5G NR specification utilizes orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) to provide multiple access to UL transmissions from UEs 222 and 224 to base station 210, as well as multiplexing of DL transmissions from base station 210 to one or more UEs 222 and 224. In addition, for UL transmissions, the 5G NR specification provides support for discrete Fourier transform spread OFDM (DFT-s-OFDM) with CP (also known as single carrier FDMA (SC-FDMA)). However, within the scope of the present disclosure, multiplexing and multiple access are not limited to the above schemes, but can be provided using time division multiple access (TDMA), code division multiple access (CDMA), frequency division multiple access (FDMA), sparse code multiple access (SCMA), resource extension multiple access (RSMA) or other suitable multiple access schemes. In addition, multiplexing of DL transmissions from base station 210 to UEs 222 and 224 may be provided using time division multiplexing (TDM), code division multiplexing (CDM), frequency division multiplexing (FDM), orthogonal frequency division multiplexing (OFDM), sparse code multiplexing (SCM), or other suitable multiplexing schemes.

[0056] The air interface in the radio access network 200 can utilize one or more duplex algorithms. Duplex refers to a point-to-point communication link in which two endpoints can communicate with each other in two directions. Full-duplex means that two endpoints can communicate with each other at the same time. Half-duplex means that only one endpoint can send information to the other endpoint at a time. In a wireless link, a full-duplex channel usually relies on the physical isolation of the transmitter and the receiver and appropriate interference cancellation techniques. Full-duplex simulation is often implemented for a wireless link by utilizing frequency division duplex (FDD) or time division duplex (TDD). In FDD, transmissions in different directions operate at different carrier frequencies. In TDD, transmissions in different directions on a given channel are separated from each other using time division multiplexing. That is, at certain times, the channel is dedicated to transmissions in one direction, and at other times, the channel is dedicated to transmissions in the other direction, where the direction can change very quickly, for example, several times per time slot.

[0057] In some aspects of the present disclosure, the scheduling entity and / or the scheduled entity may be configured for beamforming and / or multiple-input multiple-output (MIMO) techniques. Figure 3An example of a wireless communication system 300 supporting MIMO is illustrated. In a MIMO system, a transmitter 302 includes multiple transmit antennas 304 (e.g., N transmit antennas), and a receiver 306 includes multiple receive antennas 308 (e.g., M receive antennas). Therefore, there are N×M signal paths 310 from the transmit antennas 304 to the receive antennas 308. Each of the transmitter 302 and the receiver 306 can be implemented, for example, in the scheduling entity 108, the scheduled entity 106, or any other suitable wireless communication device.

[0058] The use of this multi-antenna technology enables wireless communication systems to exploit the spatial domain to support spatial multiplexing, beamforming, and transmit diversity. Spatial multiplexing can be used to send different data streams (also called layers) simultaneously on the same time-frequency resources. The data stream can be sent to a single UE to increase the data rate, or to multiple UEs to increase the total system capacity, the latter of which is called multi-user MIMO (MU-MIMO). This is achieved by spatially precoding each data stream (i.e., multiplying the data stream by different weights and phase shifts) and then sending each spatially precoded stream on the downlink through multiple transmit antennas. The spatially precoded data stream arrives at the UE with a different spatial signature, which enables each of the UEs to recover one or more data streams destined for the UE. On the uplink, each UE sends a spatially precoded data stream, which enables the base station to identify the source of each spatially precoded data stream.

[0059] The number of data streams or layers corresponds to the rank of the transmission. Typically, the rank of the MIMO system 300 is limited by the number of transmit or receive antennas 304 or 308 (whichever is lower). In addition, channel conditions at the UE and other considerations such as available resources at the base station may also affect the transmission rank. For example, the rank (and therefore the number of data streams) allocated to a specific UE on the downlink can be determined based on a rank indicator (RI) sent from the UE to the base station. The RI can be determined based on the antenna configuration (e.g., the number of transmit antennas and receive antennas) and the signal to interference and noise ratio (SINR) measured on each receive antenna. The RI can indicate, for example, the number of layers that can be supported under current channel conditions. The base station can use the RI and resource information (e.g., available resources and the amount of data to be scheduled for the UE) to allocate a transmission rank to the UE.

[0060] In a time division duplex (TDD) system, UL and DL are reciprocal because each of them uses different time slots of the same frequency bandwidth. Therefore, in a TDD system, the base station can assign a rank for DL ​​MIMO transmission based on UL SINR measurements (e.g., based on a sounding reference signal (SRS) or other pilot signal sent from the UE). Based on the assigned rank, the base station can then send a CSI-RS with a separate C-RS sequence for each layer to provide multi-layer channel estimation. From the CSI-RS, the UE can measure the channel quality across layers and resource blocks, and feed back CQI and RI values ​​to the base station for updating the rank and allocating REs for future downlink transmissions.

[0061] In the simplest case, Figure 3 As shown, a rank-2 spatial multiplexing transmission on a 2×2 MIMO antenna configuration may transmit one data stream from each transmit antenna 304. Each data stream follows a different signal path 310 to each receive antenna 308. The receiver 306 may then reconstruct the data stream using the signal received from each receive antenna 308.

[0062] Reference Figure 4 Various aspects of the present disclosure are described using the OFDM waveforms schematically illustrated in . Still other aspects of the present disclosure may be applied to DFT-s-OFDMA waveforms in substantially the same manner as described herein below. That is, although some examples of the present disclosure may focus on OFDM links for clarity, it should be understood that the same principles may also be applied to DFT-s-OFDMA waveforms as well as other waveforms.

[0063] In this disclosure, a frame refers to a duration of 10 ms used for wireless transmission, where each frame consists of 10 subframes of 1 ms each. On a given carrier, there may be a set of frames in the UL and another set of frames in the DL. Now referring to Figure 4 , illustrates an expanded view of an exemplary DL subframe 402 showing an OFDM resource grid 404. However, as will be readily appreciated by those skilled in the art, the PHY transmission structure for any particular application may differ from the examples described herein depending on any number of factors. Here, time is in the horizontal direction, in units of OFDM symbols; and frequency is in the vertical direction, in units of subcarriers or tones.

[0064] Resource grid 404 can be used to schematically represent the time-frequency resources for a given antenna port. That is, in a MIMO implementation with multiple available antenna ports, a corresponding number of resource grids 404 can be used for communication. Resource grid 404 is divided into multiple resource elements (RE) 406. RE, which is 1 subcarrier × 1 symbol, is the smallest discrete part of the time-frequency grid and contains a single complex value representing data from a physical channel or signal. Depending on the modulation used in a specific implementation, each RE can represent one or more bits of information. In some examples, RE blocks can be referred to as physical resource blocks (PRBs) or more simply resource blocks (RBs) 408, which contain any suitable number of consecutive subcarriers in the frequency domain. In one example, an RB can include 12 subcarriers, the number of which is independent of the numerology used. In some examples, depending on the numerology, an RB can include any suitable number of consecutive OFDM symbols in the time domain. In the present disclosure, it is assumed that a single RB such as RB 408 corresponds entirely to a single direction of communication (transmission or reception for a given device).

[0065] A UE typically utilizes only a subset of the resource grid 404. An RB may be the smallest resource unit that can be allocated to a UE. Thus, the more RBs are scheduled for a UE and the higher the modulation scheme selected for the air interface, the higher the data rate for the UE.

[0066] In this illustration, RB 408 is shown as occupying less than the entire bandwidth of subframe 402, with some subcarriers illustrated above and below RB 408. In a given implementation, subframe 402 may have a bandwidth corresponding to any number of one or more RBs 408. Furthermore, in this illustration, RB 408 is shown as occupying less than the entire duration of subframe 402, although this is only one possible example.

[0067] Each subframe 402 (eg, a 1 ms subframe) may be composed of one or more adjacent time slots. Figure 4 In the example shown, as an illustrative example, a subframe 402 includes four time slots 410. In some examples, a time slot can be defined according to a specified number of OFDM symbols with a given cyclic prefix (CP) length. For example, a time slot can include 7 or 14 OFDM symbols with a marked CP (nominal CP). Other examples may include mini-slots with shorter durations (e.g., 1, 2, 4, or 7 OFDM symbols). In some cases, these mini-slots can be sent occupying resources scheduled for ongoing time slot transmissions of the same or different UEs.

[0068] An expanded view of one of the time slots 410 illustrates the time slot 410 including a control region 412 and a data region 414. In general, the control region 412 may carry a control channel (e.g., PDCCH), and the data region 414 may carry a data channel (e.g., PDSCH or PUSCH). Of course, a time slot may contain all DL, all UL, or at least one DL portion and at least one UL portion. Figure 4 The simple structure shown in is merely exemplary in nature, and different slot structures may be utilized and may include one or more of each of the control region and the data region.

[0069] Despite Figure 4 Not shown in the figure, each RE 406 within the RB 408 can be scheduled to carry one or more physical channels, including a control channel, a shared channel, a data channel, etc. Other REs 406 within the RB 408 can also carry pilot or reference signals. These pilot or reference signals can be provided to a receiving device to perform channel estimation of the corresponding channel, which can achieve coherent demodulation / detection of the control and / or data channels within the RB 408.

[0070] In a DL transmission, a transmitting device (e.g., a scheduling entity 108) may allocate one or more REs 406 (e.g., within a control region 412) to carry DL control information 114 to one or more scheduled entities 106, the DL control information including one or more DL control channels, which typically carry information originating from higher layers, such as a physical broadcast channel (PBCH), a physical downlink control channel (PDCCH), etc. In addition, DL REs may be allocated to carry DL physical signals, which typically do not carry information originating from higher layers. These DL physical signals may include a primary synchronization signal (PSS); a secondary synchronization signal (SSS); a demodulation reference signal (DM-RS); a phase tracking reference signal (PT-RS); a channel state information reference signal (CSI-RS); etc.

[0071] The synchronization signals PSS and SSS (collectively referred to as SS), and in some examples, the PBCH can be sent in an SS block, which includes 4 consecutive OFDM symbols, which are numbered in increasing order from 0 to 3 via the time index. In the frequency domain, the SS block can extend to 240 consecutive subcarriers, where the subcarriers are numbered in increasing order from 0 to 239 via the frequency index. Of course, the present disclosure is not limited to this particular SS block configuration. Other non-limiting examples may utilize more or less than two synchronization signals; include one or more supplemental channels in addition to the PBCH; omit the PBCH; and / or use non-contiguous symbols for the SS block within the scope of the present disclosure.

[0072] The PDCCH may carry downlink control information (DCI) for one or more UEs in the cell. This may include, but is not limited to, power control commands, scheduling information, grants, and / or allocation of REs for DL ​​and UL transmissions.

[0073] In an UL transmission, a transmitting device (e.g., a scheduled entity 106) may utilize one or more REs 406 to carry UL control information 118 (UCI). The UCI may originate from a higher layer via one or more UL control channels (such as a physical uplink control channel (PUCCH), a physical random access channel (PRACH), etc.) to the scheduling entity 108. In addition, the UL REs may carry UL physical signals that typically do not carry information originating from higher layers, such as a demodulation reference signal (DM-RS), a phase tracking reference signal (PT-RS), a sounding reference signal (SRS), etc. In some examples, the control information 118 may include a scheduling request (SR), i.e., a request to the scheduling entity 108 to schedule an uplink transmission. Herein, in response to the SR transmitted on the control channel 118, the scheduling entity 108 may send downlink control information 114 that may schedule resources for uplink packet transmission.

[0074] The UL control information may also include hybrid automatic repeat request (HARQ) feedback, such as an acknowledgement (ACK) or negative acknowledgement (NACK), channel state information (CSI), or any other suitable UL control information. HARQ is a technology well known to those of ordinary skill in the art, where the integrity of the packet transmission can be checked for accuracy at the receiving side, for example, using any appropriate integrity check mechanism (such as a checksum or a cyclic redundancy check (CRC)). If the integrity of the transmission is confirmed, an ACK may be transmitted, and if the integrity of the transmission is not confirmed, a NACK may be transmitted. In response to the NACK, the transmitting device may send a HARQ retransmission, which may implement catch-up combining, incremental redundancy, etc.

[0075] In addition to control information, one or more REs 406 (e.g., within data region 414) may be allocated for user data or traffic data. Such traffic may be carried on one or more traffic channels, such as a physical downlink shared channel (PDSCH) for DL ​​transmissions or a physical uplink shared channel (PUSCH) for UL transmissions.

[0076] In order for the UE to obtain initial access to a cell, the RAN may provide system information (SI) that characterizes the cell. The system information may be provided using minimum system information (MSI) and other system information (OSI). The MSI may be broadcast periodically on the cell to provide the most basic information required for initial cell access and to obtain any OSI that may be broadcast periodically or sent on demand. In some examples, the MSI may be provided on two different downlink channels. For example, the PBCH may carry a master information block (MIB) and the PDSCH may carry a system information block type 1 (SIB1). In the art, SIB1 may be referred to as remaining minimum system information (RMSI).

[0077] OSI may include any SI not broadcast in MSI. In some examples, PDSCH may carry multiple SIBs, not limited to SIB1 discussed above. Here, OSI may be provided in these SIBs, for example, SIB2 and above.

[0078] Described above and in Figure 1 and Figure 4 The channels or carriers illustrated in the figure are not necessarily all channels or carriers that may be utilized between the scheduling entity 108 and the scheduled entity 106, and those skilled in the art will recognize that other channels or carriers may be utilized in addition to the channels or carriers illustrated, such as other traffic, control, and feedback channels.

[0079] These physical channels are typically multiplexed and mapped to transport channels for processing at the medium access control (MAC) layer. Transport channels carry blocks of information called transport blocks (TBs). The transmit block size (TBS) may correspond to the number of bits of information and may be a controlled parameter based on the modulation and coding scheme (MCS) and the number of RBs in a given transmission.

[0080] Various aspects of the present disclosure implement and provide techniques for quickly detecting the presence or absence of a wake-up signal (WUS). The WUS may be configured to indicate an upcoming paging signal transmission. By detecting the absence of the WUS, the communication device may transition to a sleep state before the maximum WUS duration ends. Therefore, the communication device may consume less power and extend battery life. Various types of communication devices such as user equipment (UE) and network components (e.g., base stations) may utilize various aspects to detect the presence or absence of a WUS.

[0081] In some wireless communication systems, a base station (e.g., base station 108) may use certain time-frequency resources of a downlink channel (e.g., PDCCH, narrowband PDCCH (NPDCCH), or MTC PDCCH (MPDCCH)) to send a wake-up signal (WUS) to a UE (e.g., UE 106). If the UE wakes up from a sleep state and detects a WUS, the UE may remain in the wake-up state to monitor a paging message (e.g., sent by the base station) in the downlink channel during a paging occasion (PO). Alternatively, if the UE wakes up from a sleep state but does not detect a WUS, there may be no paging message for the UE in the downlink channel, and the UE may return to the sleep state.

[0082] As described in some examples of this document, the maximum duration of the WUS may extend to the end of the WUS. If the UE does not detect the WUS before the maximum duration of the WUS ends, the UE may return to a sleep state. If the UE detects the WUS before the maximum duration of the WUS ends, the UE may monitor subsequent downlink channels for scheduling information specific to the UE. Therefore, if the UE does not receive scheduling information (e.g., including the UE's UE identification (ID)) in the downlink channel, the UE may return to a sleep state. Alternatively, if the UE does receive scheduling information, the UE may monitor continuous downlink channels (e.g., physical downlink shared channel (PDSCH), narrowband PDSCH (NPDSCH) or MTC PDSCH (MPDSCH)) for data, paging messages and / or control information. The base station may configure the maximum duration of the WUS and indicate the maximum duration to the UE on a carrier (e.g., NB-IoT carrier or CaTM carrier) before sending the WUS (e.g., via SIB). In some cases, the base station may configure a maximum duration of the WUS specific to the carrier.

[0083] In some examples, the actual WUS transmission duration may be shorter than the maximum duration of the WUS. The shorter WUS transmission duration may be aligned with the beginning of the configured maximum duration of the WUS, or may be aligned with the end of the configured maximum duration of the WUS. Additionally or alternatively, there may be a non-zero time gap between the end of the maximum configured WUS duration and the associated paging occasion. In some examples, this time gap between the end of the WUS and the paging occasion may be predefined. In other examples, the time gap may be dynamically configurable. The base station may explicitly indicate the configurable time gap value to the UE. Alternatively, the base station may implicitly indicate the configurable time gap value to the UE through other configured parameters.

[0084] In some cases, a list of possible maximum durations for a WUS may be defined, and the base station may indicate to the UE an index corresponding to a particular maximum duration of the WUS in the list of possible maximum durations in a SIB (e.g., a SIB indicating maximum durations as described above). In some cases, multiple lists may be defined for possible maximum durations of a WUS. For example, the list of maximum durations may depend on a maximum number of repetitions value (R) of an associated control channel (e.g., NPDCCH). max ), and the base station may specify the number of possible maximum duration lists. Alternatively, the base station may specify the number of possible maximum duration lists for all R max A single list of values ​​defining the maximum possible durations.

[0085] R max It may indicate the maximum number of repetitions of the downlink channel in the paging occasion after the end of the WUS. Additionally or alternatively, R max In some cases, R max The R may depend on the coverage area associated with the base station. For example, a larger coverage area may correspond to a larger R max , and a smaller coverage area can correspond to a smaller R max In some examples, R max It can be configured by higher layers and indicated to the UE in a broadcast signal (e.g., SIB). max Alternatively, R max The value of may be known or indicated through conventional signaling (eg, via SIB2).

[0086] In some examples, R for a common search space (e.g., type 1-NPDCCH common search space) max It may be replaced by a higher layer configured parameter indicating the number of repetitions of the NPDCCH for paging messages. In some cases, the base station may send more than R in a given paging occasion. max Less number of repetitions (R). The UE may not know R before monitoring the paging occasion and may determine the value of R based on the possible locations of downlink channel repetitions in the monitored paging occasion. R may correspond to the number of repetitions sent by the base station and monitored by the UE, so that the value R may be less than or equal to R max The value of .

[0087] In some cases, the UE may not explicitly know the duration of the WUS and may miss one or more of the repetitions R before starting to monitor for scheduling information or paging messages, thereby reducing the chance of correctly receiving the paging message.

[0088] The wireless communication system may support efficient techniques for determining the duration of the WUS. In some cases, the UE may assume a maximum duration of the WUS based on variables associated with the base station and the WUS. For example, the maximum duration of the WUS may depend on the transmit power of the WUS, the transmit diversity used by the base station for the WUS, or whether the WUS can be detected before detecting a traditional synchronization signal, or any combination thereof.

[0089] Figure 5 An example of a wireless communication system 500 that supports WUS configuration for wireless communication according to some aspects of the present disclosure is shown. In some examples, the wireless communication system 500 can implement aspects of the wireless communication system 100. The wireless communication system 500 can include a base station 508 and a UE 506, which can be examples of the base station 108 and the UE 106, respectively, as described in reference to FIG. Figure 1 UE 506 can communicate with base station 508. In some examples, base station 508 can send WUS 515 and paging occasion 520 indicating potential data and / or control information for UE 506, where the potential data and / or control information can be sent on resources of downlink channel 505 (e.g., PDCCH, NPDCCH, or MPDCCH).

[0090] In some cases, the UE 506 may wake up and monitor the WUS 515 on the downlink channel 505 (or a different downlink channel) to monitor scheduling information specific to the UE 506 (e.g., including the UE ID of the UE 506) to monitor for a paging message during a paging occasion 520 after the maximum duration of the WUS 515 expires. If the UE 506 does not detect the WUS 515, does not receive the scheduling information, or does not detect or receive a paging message in the paging occasion 520 before the maximum duration expires, the UE 506 may revert to a sleep state. In some cases, the sleep state may be a discontinuous reception (DRX) cycle off state between two DRX cycles, in which the UE 506 is awake and monitors the WUS 515 during the DRX cycle. Alternatively, if the UE 506 detects the WUS 515 before the maximum duration expires and receives the associated scheduling information, the UE 506 may monitor the subsequent downlink channel 505 (e.g., PDSCH, NPDSCH, or MPDSCH) for data, paging messages, and / or control information. In some cases, the UE 506 may remain awake after detecting the WUS and monitor the paging messages in the downlink channel 505 in the paging occasion 520 until the maximum duration of the WUS 515 expires. The base station 506 may configure the maximum duration of the WUS 515 and indicate the maximum duration to the UE 506 on the carrier (e.g., NB-IoT carrier or CaTM carrier) before sending the WUS 515 (e.g., via SIB). The maximum duration may be indicated via a downlink message such as a WUS configuration parameter 510. In some cases, the base station 508 may configure the maximum duration of the WUS 515 dedicated to the carrier. In addition, the WUS configuration parameters 510 may also include information about the WUS 515 (eg, max ).

[0091] In some cases, UE 506 may max Or assume a maximum duration (L) of the WUS 515 based on variables associated with the base station 508 and the WUS 515 WUS_max ), rather than receiving it via a downlink message. WUS_max The dependence may depend on the transmit power of WUS 515, the transmit diversity used by base station 508 for WUS 515, whether WUS 515 can be detected before the legacy synchronization signal is detected, or any combination thereof. This dependence may be determined by the scaling factor K w In other words, this factor may be indicated by the base station 508 to the UE 506 via the SIB (eg, in the WUS configuration parameters 510).

[0092] In one example, UE 506 can max and K w The relationship between L WUS_max ,as follows:

[0093] L WUS_max =(R max / K w )

[0094] Where R max = 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, or 2048, and K w = 1, 2, 4, 8, 16, 32, 64, or 128. For example, for R max =512 and K w =8,L WUS_max =64 (ie, 512 / 8=64). In some cases, L WUS_max It may be given as a number of fixed units (eg, in time units) such as subframes, slots, mini-slots, etc.

[0095] Figure 6 A first network configuration 602 when the UE is paged and a second network configuration 604 when the UE is not paged are shown according to some aspects of the present disclosure. A wake-up signal (WUS) 606 enables an idle mode to be implemented at the UE to save power. In idle mode, the UE is required to wake up in each DRX cycle (for any DRX cycle configured by the network). In this way, the WUS 606 allows the UE to reduce unnecessary wake-ups to detect downlink channels (paging signals) in each DRX cycle, such as PDCCH, NPDCCH (for NB-IoT carriers) or MPDCCH (for CaTM carriers). In particular, the WUS provides information about whether the UE needs to search for a downlink channel (paging signal). Therefore, if the WUS is missing, the UE does not need to search for a downlink channel (paging signal).

[0096] For example, the UE wakes up from a sleep state to monitor for WUS 606. Referring to the first network configuration 602, if WUS 606 is detected, the UE remains awake to receive a paging signal 608 (e.g., PDCCH, NPDCCH, or MPDCCH) during a paging opportunity (PO) corresponding to a data transmission (e.g., PDSCH, NPDSCH, or MPDSCH). This applies to each DRX cycle. Referring to the second network configuration 604, if WUS 606 is not detected, the UE goes to sleep (e.g., until it is time to monitor for another WUS 610) because there is no upcoming paging signal to receive.

[0097] Using WUS is advantageous because it allows the duration of the paging signal to be set according to the maximum number of repetitions R set by the network. max Therefore, time can be saved by quickly determining that a WUS is missing and then avoiding waking up to monitor / receive a missing paging signal.

[0098] On the one hand, the actual duration of WUS (L WUS ) is not signaled by the network to the UE. The network may only signal the maximum number of repetitions R to the UE. max and the scaling factor K w As mentioned above, the maximum WUS duration L WUS_max and the maximum number of repetitions R max (e.g., the maximum number of repetitions of PDCCH, NPDCCH, or MPDCCH). Therefore, the UE can determine the maximum WUS duration L by the following equation: WUS_max :L WUS_max =(R max / K w However, the actual duration of WUS (L WUS ) is unknown to the UE.

[0099] On the one hand, the actual duration of WUS (L WUS ) can have 2 i The length of the value, for example, from 1ms to L WUS_max For example, Figure 1 As shown, L WUS Can be equal to L WUS_max ,L WUS_max / 2,L WUS_max / 4, or L WUS_max / 8. WUS (606, 610) only exists if the UE group is paged (i.e., if the network sends a paging signal for the UE to receive). In addition, the paging probability (the probability that the UE will be paged) can be low (approximately 10%). Therefore, about 90% of the time, the UE detects that the WUS is missing. However, the UE may still need to detect the WUS with a high probability to avoid missing the paging signal.

[0100] In one aspect, the UE may not know the signal-to-noise ratio (SNR). It is worth noting that some UEs in the paging group may have good coverage, while some UEs in the paging group may have poor coverage. max The value of is large for both types of UE (producing L WUS_max In the case of a larger value of L), even at high SNR, the UE may still have to WUS_maxThe UE may monitor the WUS (606, 610) for the entire maximum WUS duration L to detect the presence or absence of the WUS. WUS_max The internal stays awake using power to monitor the WUS even when the WUS is not present and cannot be detected.

[0101] Figure 7 A time-frequency resource structure 700 is shown for describing a scheme for detecting the presence or absence of a wake-up signal (WUS) according to some aspects of the present disclosure. In the anchor carrier for NB-IoT and CaTM systems, a reference signal (e.g., a narrowband reference signal (NRS) for NB-IoT or a cell-specific reference signal (CRS) for CaTM) may be provided along with the WUS. For example, the reference Figure 7 , the resource elements designated by the WUS may be punctured to carry reference signals. Therefore, regardless of whether the WUS is sent in a subframe, the reference signal (NRS or CRS) may be present in the resource element position that normally carries the WUS. In one aspect, the UE may utilize the reference signal (RS) in the anchor carrier to terminate the WUS detection early, resulting in reduced power consumption at the UE and extended battery life. If the NRS is present, the early termination of the WUS detection may be opportunistic in the non-anchor carrier.

[0102] exist Figure 7 In FIG. 1 , the frequency grid is shown for only one subframe. However, aspects of the present disclosure contemplate that the network may repeat the transmission of a subframe multiple times, e.g., 8 times, 16 times, 64 times, 256 times, etc. For example, to cover a deep SNR, the network may repeat the transmission of a subframe 64 times. In one aspect, the tone energies of repeated subframes may be combined.

[0103] The UE may detect the WUS in various ways. For example, in one aspect, the UE may detect energy from one or more tones carrying a reference signal (NRS tone energy (NRSE) or CRS tone energy (CRS)), detect energy from one or more tones designated for carrying the WUS (WUS tone energy (WUE)), and determine whether the WUS is present or absent by comparing the WUS tone energy with a threshold based on the NRS tone energy or the CRS tone energy. The NRS tone energy (or CRS tone energy) may be detected based on the accumulation of NRS tones (or CRS tones) across several subframes (e.g., repeated subframes), and the WUS tone energy may be detected based on the accumulation of tones designated for carrying the WUS across several subframes (e.g., repeated subframes). If the detected WUS tone energy based on the detected NRS tone energy (or CRS tone energy) is below a threshold, the UE may determine that the WUS is missing and terminate the WUS detection early (e.g., within the maximum WUS duration L). WUS_max before and end).

[0104] In one aspect, the UE utilizes the tone energy of the reference signal to quickly determine (based on a comparison between the WUS tone energy and a threshold determined based on the reference signal tone energy) whether the WUS is present or absent without having to perform the entire maximum WUS duration L. WUS_max As mentioned above, about 90% of the time no paging signal is sent, so there is no WUS for the UE to receive. Therefore, instead of the UE monitoring the WUS for the entire maximum WUS duration L WUS_max The UE monitors WUS within a certain period of time. Under appropriate SNR conditions, the UE can evaluate the reference signal tone energy to help determine whether WUS is present or absent. For example, if the accumulated reference signal tone energy is relatively high, an energy baseline or threshold can be set based on the accumulated reference signal tone energy for reliable comparison. Thereafter, the accumulated WUS tone energy is compared with the energy threshold. If the accumulated WUS tone energy is lower than the energy threshold, the UE can determine that the WUS is absent. Therefore, the UE can terminate WUS detection early to save power without waiting for the entire maximum WUS duration L. WUS_max It is worth noting that if the UE does not use the information provided by the reference signal tone energy, the UE will have to monitor the WUS until the maximum WUS duration L WUS_max to determine the presence or absence of WUS.

[0105] Aspects of the present disclosure are superior to previous methods for detecting WUS. In previous methods, the presence or absence of WUS is determined by comparing the accumulated WUS tone energy with an energy threshold determined based on background white noise. However, there may be problems in determining the energy threshold. For example, the energy threshold may not increase due to noise, or the energy threshold may only increase after some accumulation over a period of time. If the SNR is unknown, the UE will have to perform noise-based correlation / accumulation over a longer period of time to reliably detect the presence or absence of WUS, thereby adapting to the white noise variance. In contrast, various aspects of the present disclosure facilitate reliable determination of the presence or absence of WUS in a faster manner by comparing the WUS tone energy with a threshold based on the reference signal tone energy. For example, the UE knows that there is a reference signal and can determine the reference signal tone energy (RSE) (e.g., X RSEs) accumulated by the reference signal over several subframes. If the UE expects the presence of WUS, the UE may assume that the accumulated WUS tone energy (e.g., Y WUSEs) of the WUS over the several subframes should be at least equal to the RSE (threshold) of X amount. In this way, instead of comparing with noise based correlations, the UE has a better energy estimate (reference signal tone energy) to compare with the WUS tone energy and can determine the absence of a WUS in a faster manner.

[0106] In particular, if the UE knows that the reference signal (pilot) is always present, then by calculating the reference signal tone energy after combining the reference signal across subframes, the UE will have a more accurate estimate of how the signal transmission is improved. At high SNRs, the reference signal tone energy increases rapidly. If WUS is present, the WUS tone energy should also increase in a similar manner. If the WUS tone energy does not increase at a rate similar to the reference signal tone energy, the UE will know that WUS is not present and can terminate WUS detection early (at the maximum WUS duration L WUS_max before the end).

[0107] Figure 8 8 is a block diagram illustrating an example of a hardware implementation for an exemplary UE 800 employing a processing system 814. For example, the UE 800 may be such as Figure 1 , 2 and / or the scheduled entity or user equipment (UE) shown in any one or more of 5.

[0108] The UE 800 may be implemented with a processing system 814 including one or more processors 804. Examples of the processor 804 include a microprocessor, a microcontroller, a digital signal processor (DSP), a field programmable gate array (FPGA), a programmable logic device (PLD), a state machine, a gated logic, a discrete hardware circuit, and other suitable hardware configured to perform the various functions described throughout the present disclosure. In various examples, the UE 800 may be configured to perform any one or more of the functions described herein. That is, the processor 804 as used in the UE 800 may be used to implement the following and Fig. 9 Any one or more of the processes and procedures illustrated in .

[0109] In the example herein, the processing system 814 may be implemented with a bus architecture, which is generally represented by a bus 802. Depending on the specific application and overall design constraints of the processing system 814, the bus 802 may include any number of interconnected buses and bridges. The bus 802 communicatively couples various circuits including one or more processors (generally represented by a processor 804), a memory 805, and a computer-readable medium (generally represented by a computer-readable medium 806). The bus 802 may also link various other circuits known in the art (such as timing sources, peripherals, voltage regulators, and power management circuits), and therefore will not be further described. The bus interface 808 provides an interface between the bus 802 and the transceiver 810. The transceiver 810 provides a communication interface or component for communicating with various other devices via a transmission medium. Depending on the nature of the device, a user interface 812 (e.g., a keypad, a display, a speaker, a microphone, a joystick) may also be provided. Of course, such a user interface 812 is optional and may be omitted in some examples, such as a base station.

[0110] In some aspects of the present disclosure, the processor 804 may include a wake-up / sleep circuit 840 configured for various functions, including, for example, waking up to monitor for a wake-up signal (WUS) having a maximum WUS duration and configured to indicate an upcoming transmission of a paging signal corresponding to the WUS, transitioning to a sleep state before the maximum WUS duration ends when the WUS is determined to be absent, and remaining awake when the WUS is determined to be present. For example, the wake-up / sleep circuit 840 may be configured to implement the following with respect to Fig. 9 The processor 804 may further include a tone energy detection circuit 842 configured for various functions, including, for example, detecting reference signal tone energy from one or more tones carrying the reference signal, and detecting WUS tone energy from one or more tones designated for carrying the WUS. For example, the tone energy detection circuit 842 may be configured to implement the following with respect to Fig. 9 The processor 804 may further include a WUS detection circuit 844 configured for various functions, including, for example, determining whether a WUS is present or absent based on the WUS tone energy and the reference signal tone energy (e.g., by comparing the WUS tone energy to a threshold determined based on the reference signal tone energy). For example, the WUS detection circuit 844 may be configured to implement the following in conjunction with Fig. 9The processor 804 may further include a signal receiving circuit 846 configured for various functions, including, for example, receiving a paging signal corresponding to a WUS, wherein the paging signal includes control information for receiving an upcoming data transmission, and receiving the data transmission. For example, the signal receiving circuit 846 may be configured to implement the following with respect to Fig. 9 One or more functions described, including, for example, block 916.

[0111] The processor 804 is responsible for managing the bus 802 and general processing, including the execution of software stored on the computer-readable medium 806. This software, when executed by the processor 804, causes the processing system 814 to perform the various functions described below for any particular device. The computer-readable medium 806 and memory 805 may also be used to store data that is manipulated by the processor 804 when executing the software.

[0112] One or more processors 804 in the processing system can execute software. Whether it involves software, firmware, middleware, microcode, hardware description language or other, software should be broadly interpreted as representing instructions, instruction sets, codes, code segments, program codes, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, processes, functions, etc. The software can reside on a computer-readable medium 806. The computer-readable medium 806 can be a non-transitory computer-readable medium. As an example, a non-transitory computer-readable medium includes a magnetic storage device (e.g., a hard disk, a floppy disk, a magnetic strip), an optical disk (e.g., a compact disk (CD) or a digital versatile disk (DVD)), a smart card, a flash memory device (e.g., a card, a stick or a key drive), a random access memory (RAM), a read-only memory (ROM), a programmable ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), a register, a removable disk, and any other suitable medium for storing software and / or instructions that can be accessed and read by a computer. The computer readable medium 806 may reside in the processing system 814, external to the processing system 814, or distributed across multiple entities including the processing system 814. The computer readable medium 806 may be included in a computer program product. For example, a computer program product may include a computer readable medium in packaging materials. Those skilled in the art will recognize how to best implement the described functionality presented throughout this disclosure, depending on the specific application and the overall design constraints imposed on the entire system.

[0113] In one or more examples, the computer-readable storage medium 806 may include wake-up / sleep instructions 850 configured for various functions, including, for example, waking up to monitor for a wake-up signal (WUS) having a maximum WUS duration and configured to indicate an upcoming transmission of a paging signal corresponding to the WUS, transitioning to a sleep state before the maximum WUS duration ends when the WUS is determined to be absent, and remaining awake when the WUS is determined to be present. For example, the wake-up / sleep instructions 850 may be configured to implement the following regarding Fig. 9 The computer readable storage medium 806 may further include tone energy detection instructions 852 configured for various functions, including, for example, detecting reference signal tone energy from one or more tones carrying a reference signal, and detecting WUS tone energy from one or more tones designated for carrying a WUS. For example, the tone energy detection instructions 852 may be configured to implement the following with respect to Fig. 9 The computer-readable storage medium 806 may further include WUS detection instructions 854 configured for various functions, including, for example, determining whether a WUS is present or absent based on the WUS tone energy and the reference signal tone energy (e.g., by comparing the WUS tone energy to a threshold determined based on the reference signal tone energy). For example, the WUS detection instructions 854 may be configured to implement the following in conjunction with Fig. 9 The computer readable storage medium 806 may further include a signal receiving circuit 856 configured for various functions, including, for example, receiving a paging signal corresponding to a WUS, wherein the paging signal includes control information for receiving an upcoming data transmission, and receiving the data transmission. For example, the signal receiving instructions 856 may be configured to implement the following with respect to Fig. 9 One or more functions described, including, for example, block 916.

[0114] Fig. 9 900 is a flow chart illustrating an exemplary process 900 for wireless communication at a UE according to some aspects of the present disclosure. As described below, some or all of the illustrated features may be omitted in certain implementations within the scope of the present disclosure, and some of the illustrated features may not be required for implementations of all embodiments. In some examples, process 900 may be performed by Figure 8 In some examples, process 900 may be performed by any suitable device or component for performing the functions or algorithms described below.

[0115] At block 902, the UE wakes up to monitor for a wake-up signal (WUS). The WUS has a maximum WUS duration (e.g., L WUS_max ), and is configured to indicate an upcoming transmission of a paging signal (e.g., PDCCH, NPDCCH, or MPDCCH) corresponding to a WUS. The paging signal may include control information for receiving an upcoming data transmission (e.g., PDSCH, NPDSCH, or MPDSCH). Maximum WUS duration (L WUS_max ) can be used with the maximum number of repetitions for sending a paging signal (R max ) are proportional.

[0116] At block 904, the UE detects reference signal tone energy from one or more tones carrying a reference signal. The reference signal may be, for example, a narrowband reference signal (NRS) or a cell-specific reference signal (CRS). In one aspect, the UE detects the reference signal tone energy by transmitting accumulated reference signal tones across a number of repeated subframes and combining the accumulated reference signal tone energies. In another aspect, the UE detects (or calculates) the reference signal tone energy by coherently combining received reference signal symbols. For example, the UE may pre-multiply the received reference signal with a copy of a locally generated reference signal to form a coherently combined reference signal symbol, and determine the energy of the coherently combined reference signal symbol as the reference signal tone energy.

[0117] At block 906, the UE detects WUS tone energy from one or more tones designated for carrying the WUS. In one aspect, the UE detects the WUS tone energy by accumulating the tones designated for carrying the WUS across a number of repeated subframe transmissions and combining the energy of the accumulated tones designated for carrying the WUS. In another aspect, the UE detects (or calculates) the WUS tone energy by coherently combining received WUS symbols. For example, the UE may pre-multiply the received WUS with a locally generated WUS replica to form a coherently combined WUS symbol, and determine that the energy of the coherently combined WUS symbol is the WUS tone energy.

[0118] At block 908, the UE determines whether a WUS is present or absent based on the WUS tone energy and the reference signal tone energy. In one aspect, the UE determines whether a WUS is present or absent by comparing the WUS tone energy to a threshold determined based on the reference signal tone energy. In one aspect, the threshold is at least equal to the energy of the accumulated combination of reference signal tones.

[0119] At block 910, the UE determines whether the WUS is present or absent based on the determination at block 908. In one aspect, if the WUS tone energy is greater than or equal to the threshold, the WUS is present. If the WUS tone energy is less than the threshold, the WUS is absent. In another aspect, the UE may use other types of determination methods to determine whether the WUS is present or absent based on the WUS tone energy and the reference signal tone energy.

[0120] At block 912, if it is determined that the WUS is missing, the UE transitions to a sleep state before the maximum WUS duration ends. Note that if the UE determines that the WUS is missing, the UE may also determine that a paging signal corresponding to the WUS will not be sent from the network.

[0121] At block 914, if it is determined that the WUS exists, the UE remains awake. Thereafter, at block 916, the UE receives a paging signal corresponding to the WUS. The UE may then also receive data transmission (e.g., PDSCH, NPDSCH, or MPDSCH) based on the control information included in the paging signal.

[0122] Fig. 9 The process shown in may include other aspects, such as any single aspect or any combination of aspects described below and / or in combination with one or more other processes described elsewhere herein.

[0123] In a first aspect, the UE may detect reference signal tone energy from one or more tones carrying a reference signal, and detect a wake-up signal (WUS) tone energy from one or more tones designated to carry a WUS, the WUS having a maximum WUS duration and configured to indicate an upcoming transmission of a paging signal corresponding to the WUS. The UE may also determine whether the WUS is present or absent based on the WUS tone energy and the reference signal tone energy, and when determining that the WUS is absent, transition to a sleep state before the maximum WUS duration ends.

[0124] In a second aspect, either alone or in combination with the first aspect, the UE may wake up to monitor the WUS.

[0125] In a third aspect, alone or in combination with one or more of the first and second aspects, the UE may also remain awake upon determining that the WUS exists and receive a paging signal corresponding to the WUS, wherein the paging signal includes control information for receiving upcoming data transmission.

[0126] In a fourth aspect, either alone or in combination with one or more of the first to third aspects, the UE determines whether the WUS is present or absent by comparing the WUS tone energy with a threshold determined based on the reference signal tone energy, wherein if the WUS tone energy is greater than or equal to the threshold, the WUS is present, and if the WUS tone energy is less than the threshold, the WUS is absent.

[0127] In a fifth aspect, alone or in combination with one or more of the first to fourth aspects, the reference signal is a narrowband reference signal (NRS) or a cell-specific reference signal (CRS).

[0128] In a sixth aspect, either alone or in combination with one or more of the first to fifth aspects, a UE detects reference signal tone energy by transmitting accumulated reference signal tones across a number of repeated subframes and combining the accumulated reference signal tone energies.

[0129] In the seventh aspect, either alone or in combination with one or more of the first to sixth aspects, the UE detects the WUS tone energy by accumulating the tone designated for carrying the WUS across several repeated subframe transmissions and combining the accumulated energy of the tone designated for carrying the WUS.

[0130] In an eighth aspect, either alone or in combination with one or more of the first to seventh aspects, the threshold is at least equal to the energy of the combination of the accumulated reference signal tones.

[0131] In a ninth aspect, either alone or in combination with one or more of the first to eighth aspects, the maximum WUS duration is proportional to a maximum number of repetitions for sending the paging signal.

[0132] In one configuration, an apparatus 800 for wireless communication includes components for waking up to monitor for a wake-up signal (WUS) having a maximum WUS duration and configured to indicate an upcoming transmission of a paging signal corresponding to the WUS; components for detecting reference signal tone energy from one or more tones carrying a reference signal; components for detecting WUS tone energy from one or more tones designated for carrying the WUS; components for comparing the WUS tone energy with a threshold determined based on the reference signal tone energy; components for determining whether the WUS is present or absent based on the comparison; components for determining whether the WUS is present or absent based on the WUS tone energy and the reference signal tone energy; components for transitioning to a sleep state before the maximum WUS duration expires when it is determined that the WUS is absent; components for remaining awake when it is determined that the WUS is present, and components for receiving a paging signal corresponding to the WUS, wherein the paging signal includes control information for receiving an upcoming data transmission. In one aspect, the above components may be Figure 8 The processor 804 shown in FIG. 8 is configured to perform the functions recited by the aforementioned components. On the other hand, the aforementioned components may be a circuit or any device configured to perform the functions recited by the aforementioned components.

[0133] Of course, in the above examples, the circuits included in the processor 804 are provided only as examples, and other components for performing the described functions may be included in various aspects of the present disclosure, including but not limited to instructions stored in the computer-readable storage medium 806, or Figure 1 , 2 and / or any other suitable device or component described in any of 5, and using, for example, the present invention with respect to Fig. 9 The process and / or algorithm described.

[0134] Several aspects of wireless communication networks have been presented with reference to exemplary implementations. As those skilled in the art will readily appreciate, various aspects described throughout this disclosure may be extended to other telecommunication systems, network architectures, and communication standards.

[0135] As an example, various aspects may be implemented in other systems defined by 3GPP, such as Long Term Evolution (LTE), Evolved Packet System (EPS), Universal Mobile Telecommunications System (UMTS), and / or Global System for Mobile Communications (GSM). Various aspects may also be extended to systems defined by 3rd Generation Partnership Project 2 (3GPP2), such as CDMA2000 and / or Evolution-Data Optimized (EV-DO). Other examples may be implemented within systems employing IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE802.20, Ultra Wideband (UWB), Bluetooth, and / or other suitable systems. The actual telecommunication standard, network architecture, and / or communication standard employed will depend on the specific application and the overall design constraints imposed on the system.

[0136] Within the present disclosure, the word "exemplary" is used to mean "serving as an example, instance, or illustration." Any implementation or aspect described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects of the invention. Likewise, the term "aspect" does not require that all aspects of the present disclosure include the discussed feature, advantage, or mode of operation. The term "coupled" is used herein to refer to a direct or indirect coupling between two objects. For example, if object A physically contacts object B, and object B contacts object C, objects A and C may still be considered to be coupled to each other—even if they are not in direct physical contact with each other. For example, a first object may be coupled to a second object even if the first object never makes direct physical contact with the second object. The terms "circuit" and "circuitry" are used broadly and are intended to include hardware implementations of both electrical devices and conductors that, when connected and configured, enable the functions described in the present disclosure to be performed, without limitation to the type of electronic circuits, and software implementations that, when executed by a processor, enable the execution of information and instructions, enabling the performance of the functions described in the present disclosure.

[0137] Figure 1-Figure 9 One or more components, steps, features and / or functions shown in the present invention may be rearranged and / or combined into a single component, step, feature or function, or included in several components, steps or functions. Additional elements, components, steps and / or functions may also be added without departing from the novel features disclosed herein. Figure 1-Figure 9 The apparatus, devices and / or components shown in the can be configured to perform one or more of the methods, features or steps described herein. The novel algorithms described herein can also be effectively implemented in software and / or embedded in hardware.

[0138] It should be understood that the specific order or hierarchy of steps in the disclosed methods is an illustration of an exemplary process. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the methods can be rearranged. The attached method claims present elements of the various steps in an example order and are not meant to be limited to the specific order or hierarchy presented unless specifically stated herein.

[0139] The previous description is provided to enable a person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. Therefore, the present claims are not intended to be limited to the various aspects shown herein, but to conform to the full scope consistent with the language claims, wherein, unless otherwise specified, reference to an element in the singular is not intended to mean "one and only one", but to mean "one or more". Unless otherwise expressly stated, the term "some" refers to one or more. A phrase citing "at least one of" a list of items refers to any combination of these items, including a single member. As an example, "at least one of the following: a, b, or c" is intended to cover: a; b; c; a and b; a and c; b and c; all structural and functional equivalents of the elements of the various aspects described throughout the disclosure known or to be known by a person of ordinary skill in the art are expressly incorporated herein by reference, and are intended to be covered by the claims. In addition, nothing disclosed herein is intended to be contributed to the public, whether or not such disclosure is explicitly recited in the claims.

Claims

1. A method for wireless communication at a user equipment UE, comprising: detecting reference signal tone energy from one or more tones carrying the reference signal; detecting WUS tone energy from one or more tones designated for carrying a wake-up signal WUS, the WUS having a maximum WUS duration and configured to indicate an upcoming transmission of a paging signal corresponding to the WUS; determining whether the WUS is present or absent based on the WUS tone energy and the reference signal tone energy; as well as When the WUS is determined to be missing, a transition to a sleep state is made before the maximum WUS duration ends. The method of claim 1 , further comprising waking up to monitor the WUS.

3. The method according to claim 2, further comprising: Stay awake when it is determined that the WUS exists; as well as The paging signal corresponding to the WUS is received, wherein the paging signal includes control information for receiving an upcoming data transmission.

4. The method according to claim 1, wherein: The determining whether the WUS is present or absent comprises comparing the WUS tone energy with a threshold value determined based on the reference signal tone energy, wherein: If the WUS tone energy is greater than or equal to the threshold, the WUS exists; and If the WUS tone energy is less than the threshold, the WUS is missing.

5. The method according to claim 4, wherein: The detecting the reference signal tone energy comprises at least one of the following: transmitting accumulated reference signal tones across a number of repeated subframes and combining the energy of the accumulated reference signal tones; or A received reference signal is pre-multiplied with a locally generated reference signal replica to form a coherently combined reference signal symbol, and an energy of the coherently combined reference signal symbol is determined as the reference signal tone energy.

6. The method according to claim 5, wherein: The detecting the WUS tone energy comprises at least one of the following: accumulating tones designated for carrying the WUS across the plurality of repeated subframe transmissions and combining energy of the accumulated tones designated for carrying the WUS; or The received WUS is pre-multiplied with a locally generated WUS replica to form a coherently combined WUS symbol, and the energy of the coherently combined WUS symbol is determined as the WUS tone energy.

7. The method according to claim 5, wherein: The threshold is at least equal to the energy of the combination of the accumulated reference signal tones.

8. The method according to claim 1, wherein: The maximum WUS duration is proportional to the maximum number of repetitions of sending the paging signal.

9. A user equipment UE for wireless communication, comprising: at least one processor; a transceiver communicatively coupled to the at least one processor; as well as a memory communicatively coupled to the at least one processor, wherein the at least one processor and the memory are configured to: detecting reference signal tone energy from one or more tones carrying the reference signal, detecting WUS tone energy from one or more tones designated for carrying a wake-up signal WUS, the WUS having a maximum WUS duration and configured to indicate an upcoming transmission of a paging signal corresponding to the WUS, determining whether the WUS is present or absent based on the WUS tone energy and the reference signal tone energy; as well as When the WUS is determined to be missing, a transition to a sleep state is made before the maximum WUS duration ends.

10. The UE according to claim 9, wherein: The at least one processor and the memory are further configured to wake up to monitor the WUS.

11. The UE according to claim 10, wherein: The at least one processor and the memory are further configured to: Remaining awake when determining that the WUS exists; and The paging signal corresponding to the WUS is received, wherein the paging signal includes control information for receiving an upcoming data transmission.

12. The UE according to claim 9, wherein: The at least one processor configured to determine whether the WUS is present or absent and the memory configured to compare the WUS tone energy to a threshold determined based on the reference signal tone energy, wherein: If the WUS tone energy is greater than or equal to the threshold, the WUS exists; and If the WUS tone energy is less than the threshold, the WUS is missing.

13. The UE according to claim 12, wherein: The at least one processor configured to detect the reference signal tone energy and the memory are configured to perform at least one of: transmitting accumulated reference signal tones across a number of repeated subframes and combining the energy of the accumulated reference signal tones; or The received reference signal is pre-multiplied with a locally generated replica of the reference signal to form a coherently combined reference signal symbol, and an energy of the coherently combined reference signal symbol is determined as the reference signal tone energy.

14. The UE according to claim 13, wherein: The at least one processor configured to detect the WUS tone energy and the memory are configured to perform at least one of: accumulating tones designated for carrying the WUS across the plurality of repeated subframe transmissions and combining energy of the accumulated tones designated for carrying the WUS; or The received WUS is pre-multiplied with a locally generated copy of the WUS to form a coherently combined WUS symbol, and the energy of the coherently combined WUS symbol is determined as the WUS tone energy.

15. The UE according to claim 13, wherein: The threshold is at least equal to the energy of the combination of the accumulated reference signal tones.

16. The UE according to claim 9, wherein: The maximum WUS duration is proportional to the maximum number of repetitions of sending the paging signal.

17. A user equipment UE for wireless communication, comprising: means for detecting reference signal tone energy from one or more tones carrying the reference signal; means for detecting WUS tone energy from one or more tones designated for carrying a wake-up signal WUS, the WUS having a maximum WUS duration and configured to indicate an upcoming transmission of a paging signal corresponding to the WUS, means for determining whether the WUS is present or absent based on the WUS tone energy and the reference signal tone energy; as well as Means for transitioning to a sleep state before expiration of the maximum WUS duration when the WUS is determined to be missing.

18. The UE of claim 17, further comprising means for waking up to monitor the WUS.

19. The UE according to claim 18, further comprising: means for remaining awake when it is determined that said WUS exists; and Means for receiving the paging signal corresponding to the WUS, wherein the paging signal includes control information for receiving an upcoming data transmission.

20. The UE according to claim 17, wherein: The means for determining whether the WUS is present or absent comprises means for comparing the WUS tone energy with a threshold value determined based on the reference signal tone energy, wherein: If the WUS tone energy is greater than or equal to the threshold, the WUS exists; and If the WUS tone energy is less than the threshold, the WUS is missing.

21. The UE according to claim 20, wherein: The means for detecting the reference signal tone energy is configured to perform at least one of the following: transmitting accumulated reference signal tones across a number of repeated subframes and combining the energy of the accumulated reference signal tones; or The received reference signal is pre-multiplied with a locally generated replica of the reference signal to form a coherently combined reference signal symbol, and an energy of the coherently combined reference signal symbol is determined as the reference signal tone energy.

22. The UE according to claim 21, wherein: The means for detecting the WUS tone energy is configured to perform at least one of the following: accumulating tones designated for carrying the WUS across the plurality of repeated subframe transmissions and combining energy of the accumulated tones designated for carrying the WUS; or The received WUS is pre-multiplied with a locally generated copy of the WUS to form a coherently combined WUS symbol, and the energy of the coherently combined WUS symbol is determined as the WUS tone energy.

23. The UE according to claim 21, wherein: The threshold is at least equal to the energy of the combination of the accumulated reference signal tones.

24. The UE according to claim 17, wherein: The maximum WUS duration is proportional to the maximum number of repetitions of sending the paging signal.

25. A non-transitory computer-readable medium storing computer executable code at a user equipment (UE) for wireless communication, comprising code for causing a computer to perform the following operations: detecting reference signal tone energy from one or more tones carrying the reference signal; detecting WUS tone energy from one or more tones designated for carrying a wake-up signal WUS, the WUS having a maximum WUS duration and configured to indicate an upcoming transmission of a paging signal corresponding to the WUS, determining whether the WUS is present or absent based on the WUS tone energy and the reference signal tone energy; and When the WUS is determined to be missing, a transition to a sleep state is made before the maximum WUS duration ends.

26. The non-transitory computer-readable medium of claim 25, further comprising code for waking a computer to monitor the WUS.

27. The non-transitory computer-readable medium of claim 26, further comprising code for causing a computer to: Remaining awake when determining that the WUS exists; and receiving the paging signal corresponding to the WUS, wherein: The paging signal includes control information for receiving an upcoming data transmission.

28. The non-transitory computer readable medium of claim 25, wherein: The code for causing the computer to determine whether the WUS is present or absent is configured to compare the WUS tone energy to a threshold determined based on the reference signal tone energy, wherein: If the WUS tone energy is greater than or equal to the threshold, the WUS exists; and If the WUS tone energy is less than the threshold, the WUS is missing.

29. The non-transitory computer readable medium of claim 28, wherein: The code for causing the computer to detect the reference signal tone energy is configured to perform at least one of: transmitting accumulated reference signal tones across a number of repeated subframes and combining the energy of the accumulated reference signal tones; or pre-multiplying a received reference signal with a locally generated replica of a reference signal to form a coherently combined reference signal symbol, and determining an energy of the coherently combined reference signal symbol as the reference signal tone energy; as well as The code for causing the computer to detect the WUS tone energy is configured to perform at least one of: accumulating the tones designated for carrying the WUS across the plurality of repeated subframe transmissions and combining the energy of the accumulated tones designated for carrying the WUS, or The received WUS is pre-multiplied with a locally generated copy of the WUS to form a coherently combined WUS symbol, and the energy of the coherently combined WUS symbol is determined as the WUS tone energy.

30. The non-transitory computer readable medium of claim 29, wherein: The threshold is at least equal to the energy of the combination of the accumulated reference signal tones.

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