WO2025199834A1

WO2025199834A1 - Devices, methods, and medium for communication

Info

Publication number: WO2025199834A1
Application number: PCT/CN2024/084234
Authority: WO
Inventors: Lei Chen; Gang Wang
Original assignee: NEC Corp
Current assignee: NEC Corp
Priority date: 2024-03-27
Filing date: 2024-03-27
Publication date: 2025-10-02
Anticipated expiration: 2026-09-27

Abstract

Example embodiments of the present disclosure relate to devices, methods, and computer storage medium for communication. In the solution, a terminal device receives a low power signal and determines an information block of the low power signal, the low power signal comprises a plurality of OOK symbols with a plurality of OOK-ON symbols and a plurality of OOK-OFF symbols, where the plurality of OOK symbols are generated based on a first bit sequence and the plurality of OOK-ON symbols are generated based on a second bit sequence which is determined based on an inverse order of the first bit sequence or a cyclic shift of the first bit sequence. As such, there is no need to receive/decode all OOK symbols at the terminal device and the overhead can be reduced.

Description

DEVICES, METHODS, AND MEDIUM FOR COMMUNICATION

FIELD

Example embodiments of the present disclosure generally relate to the field of communication techniques and in particular, to devices, methods, and a computer readable medium for communication.

BACKGROUND

Several technologies have been proposed for power saving of a terminal device. For example, user equipment (UE) may enter to a radio resource control (RRC) idle/inactive state to reduce power consumption. However, it is still critical for power limited devices, e.g., the Internet of Things (IoT) devices, wearable devices, etc., since periodic paging monitoring and measurement consume considerable power at UE side even in RRC idle/inactive state. Therefore, it is beneficial for UE to further reduce the power consumption.

A study item for low power wake-up signal (LP-WUS) was discussed in new radio (NR) release 18 (Rel-18) of 3rd Generation Partnership Project (3GPP) . This study item intends to study and evaluate techniques of low power signal and low power wake-up receiver, to enable extreme low power consumption and low wake-up latency, mainly in RRC idle/inactive state. A work item of LP-WUS continue being studied in release 19 (Rel-19) , and some details are still to be studied.

SUMMARY

In general, example embodiments of the present disclosure provide devices, methods, and a computer storage medium for communication.

In a first aspect, there is provided a terminal device. The terminal device comprises at least one processor configured to cause the terminal device at least to: receive, from a network device, a low power signal comprising an LP-WUS or a low power synchronization signal (LP-SS) , wherein the low power signal comprises a plurality of on-off keying (OOK) symbols with a plurality of OOK-ON symbols and a plurality of OOK-OFF symbols, wherein the plurality of OOK symbols are generated based on a first bit sequence and the plurality of OOK-ON symbols are generated based on a second bit sequence, and wherein the second bit sequence is determined based on an inverse order of the first bit sequence or a cyclic shift of the first bit sequence; and determine an information block of the low power signal.

In a second aspect, there is provided a network device. The network device comprises at least one processor configured to cause the network device at least to: determine a first bit sequence based on an information block of a low power signal to be transmitted to a terminal device, wherein the low power signal comprises an LP-WUS or an LP-SS; determine a second bit sequence based on an inverse order of the first bit sequence or a cyclic shift of the first bit sequence; generate the low power signal based on the first bit sequence and the second bit sequence, wherein the low power signal comprises a plurality of OOK symbols with a plurality of OOK-ON symbols and a plurality of OOK-OFF symbols, and wherein the plurality of OOK symbols are generated based on the first bit sequence and the plurality of OOK-ON symbols are generated based on the second bit sequence; and transmit, to the terminal device, the low power signal.

In a third aspect, there is provided a method of communication. The method comprises: receiving, at a terminal device from a network device, a low power signal comprising an LP-WUS or an LP-SS, wherein the low power signal comprises a plurality of OOK symbols with a plurality of OOK-ON symbols and a plurality of OOK-OFF symbols, wherein the plurality of OOK symbols are generated based on a first bit sequence and the plurality of OOK-ON symbols are generated based on a second bit sequence, and wherein the second bit sequence is determined based on an inverse order of the first bit sequence or a cyclic shift of the first bit sequence; and determining an information block of the low power signal.

In a fourth aspect, there is provided a method of communication. The method comprises: determining, at a network device, a first bit sequence based on an information block of a low power signal to be transmitted to a terminal device, wherein the low power signal comprises an LP-WUS or an LP-SS; determining a second bit sequence based on an inverse order of the first bit sequence or a cyclic shift of the first bit sequence; generating the low power signal based on the first bit sequence and the second bit sequence, wherein the low power signal comprises a plurality of OOK symbols with a plurality of OOK-ON symbols and a plurality of OOK-OFF symbols, and wherein the plurality of OOK symbols are generated based on the first bit sequence and the plurality of OOK-ON symbols are generated based on the second bit sequence; and transmitting, to the terminal device, the low power signal.

In a fifth aspect, there is provided a computer readable medium having instructions stored thereon, the instructions, when executed on at least one processor, causing the at least one processor to carry out the method according to the third or the fourth aspect above.

It is to be understood that the summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Through the more detailed description of some example embodiments of the present disclosure in the accompanying drawings, the above and other objects, features and advantages of the present disclosure will become more apparent, wherein:

FIG. 1 illustrates an example communication network in which some embodiments of the present disclosure can be implemented;

FIG. 2A illustrates a schematic diagram of resources occupied by an LP signal which can be used in some example embodiments of the present disclosure;

FIGS. 2B-2C illustrate schematic diagrams of OOK symbols which can be used in some example embodiments of the present disclosure;

FIGS. 3A-3B illustrate schematic diagrams of OOK-1 and OOK-4 respectively which can be used in some example embodiments of the present disclosure;

FIG. 4 illustrates a signalling chart illustrating communication process in accordance with some embodiments of the present disclosure;

FIGS. 5A-5C illustrate some example schematics of OOK based LP-WUS with overlaid sequence over OOK symbol with N=1 in accordance with some embodiments of the present disclosure;

FIGS. 6A-6E illustrate some example schematics of OOK based LP-WUS with overlaid sequence over OOK symbol with N=2 in accordance with some embodiments of the present disclosure;

FIGS. 7A-7B illustrate some example schematics of OOK based LP-WUS with overlaid sequence over OOK symbol considering a cyclic shift of the first bit sequence in accordance with some embodiments of the present disclosure;

FIGS. 8A-8E illustrate some example schematics of OOK based LP-WUS with overlaid sequence over OOK symbol at the receiver side in accordance with some embodiments of the present disclosure;

FIG. 9 illustrates a flowchart of an example method implemented at a terminal device in accordance with some embodiments of the present disclosure;

FIG. 10 illustrates a flowchart of an example method implemented at a network device in accordance with some embodiments of the present disclosure; and

FIG. 11 illustrates a simplified block diagram of a device that is suitable for implementing embodiments of the present disclosure.

Throughout the drawings, the same or similar reference numerals represent the same or similar element.

DETAILED DESCRIPTION

Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. Embodiments described herein can be implemented in various manners other than the ones described below.

In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

References in the present disclosure to “one embodiment, ” “an embodiment, ” “an example embodiment, ” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It shall be understood that although the terms “first” and “second” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and/or” includes any and all combinations of one or more of the listed terms.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a” , “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” , “comprising” , “has” , “having” , “includes” and/or “including” , when used herein, specify the presence of stated features, elements, and/or components etc., but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof.

In some examples, values, procedures, or apparatus are referred to as “best, ” “lowest, ” “highest, ” “minimum, ” “maximum, ” or the like. It will be appreciated that such descriptions are intended to indicate that a selection among many used functional alternatives can be made, and such selections need not be better, smaller, higher, or otherwise preferable to other selections.

As used herein, the term “communication network” refers to a network following any suitable communication standards or technologies, such as New Radio (NR) , Long Term Evolution (LTE) , LTE-Advanced (LTE-A) , Code Divided Multiple Address (CDMA) , Frequency Divided Multiple Address (FDMA) , Time Divided Multiple Address (TDMA) , Frequency Divided Duplexer (FDD) , Time Divided Duplexer (TDD) , Multiple-Input Multiple-Output (MIMO) , Orthogonal Frequency Divided Multiple Access (OFDMA) , cdma2000, Wideband Code Division Multiple Access (WCDMA) , High-Speed Packet Access (HSPA) , Global System for Mobile Communications (GSM) , Narrow Band Internet of Things (NB-IoT) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (1G) , the second generation (2G) , 2.5G, 2.75G, the third generation (3G) , the fourth generation (4G) , 4.5G, the fifth generation (5G) , 5.5G, 5G-Advanced networks, beyond 5G (B5G) , the sixth generation (6G) communication protocols, wireless local network communication protocols such as Institute for Electrical and Electronics Engineers (IEEE) 802.11 and the like, and/or any other protocols either currently known or to be developed in the future. The techniques described herein may be used for the wireless networks and radio technologies mentioned above as well as other wireless networks and radio technologies. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

As used herein, the term “terminal device” refers to any device having wireless or wired communication capabilities. Examples of terminal device include, but not limited to, user equipment (UE) , personal computers, desktops, mobile phones, cellular phones, smart phones, personal digital assistants (PDAs) , portable computers, tablets, wearable devices, internet of things (IoT) devices, Ultra-reliable and Low Latency Communications (URLLC) devices, Internet of Everything (IoE) devices, machine type communication (MTC) devices, device on vehicle for V2X communication where X means pedestrian, vehicle, or infrastructure/network, devices for Integrated Access and Backhaul (IAB) , Space borne vehicles or Air borne vehicles in Non-terrestrial networks (NTN) including Satellites and High Altitude Platforms (HAPs) encompassing Unmanned Aircraft Systems (UAS) , eXtended Reality (XR) devices including different types of realities such as Augmented Reality (AR) , Mixed Reality and Virtual Reality (VR) , the unmanned aerial vehicle (UAV) commonly known as a drone which is an aircraft without any human pilot, devices on high speed train (HST) , or image capture devices such as digital cameras, sensors, gaming devices, music storage and playback appliances, or Internet appliances enabling wireless or wired Internet access and browsing and the like. The ‘terminal device’ can further has ‘multicast/broadcast’ feature, to support public safety and mission critical, V2X applications, transparent IPv4/IPv6 multicast delivery, IPTV, smart TV, radio services, software delivery over wireless, group communications and IoT applications. It may also be incorporated one or multiple Subscriber Identity Module (SIM) as known as Multi-SIM. The term “terminal device” can be used interchangeably with a UE, a mobile station, a subscriber station, a mobile terminal, a user terminal or a wireless device.

As used herein, the term “network device” refers to a device which is capable of providing or hosting a cell or coverage where terminal devices can communicate. Examples of a network device include, but not limited to, a satellite, an unmanned aerial systems (UAS) platform, a Node B (NodeB or NB) , an evolved NodeB (eNodeB or eNB) , a next generation NodeB (gNB) , a transmission reception point (TRP) , a remote radio unit (RRU) , a radio head (RH) , a remote radio head (RRH) , an IAB node, a low power node such as a femto node, a pico node, a reconfigurable intelligent surface (RIS) , and the like.

In one embodiment, the terminal device may be connected with a first network device and a second network device. One of the first network device and the second network device may be a master node (MN) and the other one may be a secondary node (SN) . The first network device and the second network device may use different radio access technologies (RATs) . In one embodiment, the first network device may be a first RAT device and the second network device may be a second RAT device. In one embodiment, the first RAT device is eNB and the second RAT device is gNB. Information related with different RATs may be transmitted to the terminal device from at least one of the first network device and the second network device. In one embodiment, first information may be transmitted to the terminal device from the first network device and second information may be transmitted to the terminal device from the second network device directly or via the first network device. In one embodiment, information related with configuration for the terminal device configured by the second network device may be transmitted from the second network device via the first network device. Information related with reconfiguration for the terminal device configured by the second network device may be transmitted to the terminal device from the second network device directly or via the first network device.

The terminal device or the network device may have Artificial intelligence (AI) or machine learning capability. It generally includes a model which has been trained from numerous collected data for a specific function, and can be used to predict some information.

The terminal device or the network device may work on several frequency ranges, e.g. frequency range 1 (FR1) (410 MHz –7125 MHz) , frequency range 2 (FR2) (24.25GHz to 71GHz) , frequency band larger than 100GHz as well as Tera Hertz (THz) . It can further work on licensed/unlicensed/shared spectrum. The terminal device may have more than one connection with the network device under Multi-Radio Dual Connectivity (MR-DC) application scenario. The terminal device or the network device can work on full duplex, flexible duplex and cross division duplex modes.

The embodiments of the present disclosure may be performed in test equipment, e.g., signal generator, signal analyzer, spectrum analyzer, network analyzer, test terminal device, test network device, or channel emulator.

The embodiments of the present disclosure may be performed according to any generation communication protocols either currently known or to be developed in the future. Examples of the communication protocols include, but not limited to, the 1G, 2G, 2.5G, 2.75G, 3G, 4G, 4.5G, 5G, 5.5G, 5G-Advanced networks, or 6G networks.

The term “circuitry” used herein may refer to hardware circuits and/or combinations of hardware circuits and software. For example, the circuitry may be a combination of analog and/or digital hardware circuits with software/firmware. As a further example, the circuitry may be any portions of hardware processors with software including digital signal processor (s) , software, and memory (ies) that work together to cause an apparatus, such as a terminal device or a network device, to perform various functions. In a still further example, the circuitry may be hardware circuits and or processors, such as a microprocessor or a portion of a microprocessor, that requires software/firmware for operation, but the software may not be present when it is not needed for operation. As used herein, the term circuitry also covers an implementation of merely a hardware circuit or processor (s) or a portion of a hardware circuit or processor (s) and its (or their) accompanying software and/or firmware.

As used herein, the singular forms “a” , “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. The term “includes” and its variants are to be read as open terms that mean “includes, but is not limited to. ” The term “based on” is to be read as “based at least in part on. ” The term “one embodiment” and “an embodiment” are to be read as “at least one embodiment. ” The term “another embodiment” is to be read as “at least one other embodiment. ” The terms “first, ” “second, ” and the like may refer to different or same objects. Other definitions, explicit and implicit, may be included below.

A low power wake-up signal (LP-WUS) was proposed in NR Rel-18. A study item for LP-WUS has studied and evaluated techniques of low power signal and low power wake-up receiver (LP-WUR) , to enable extreme low power consumption and low wake-up latency, mainly in RRC idle or inactive state. A new work item of LP-WUS is ongoing in Rel-19. An LP-WUS will be introduced into the NR system which is used to wake up a UE whose main radio (MR) is staying in ultra-deep-sleep mode. Power consumption of UE MR can be saved because it can stay in ultra-deep-sleep mode in a relatively long time.

It is proposed that on-off keying (OOK) modulation can be used for LP-WUS generation. An objective may include specifying OOK based LP-WUS with overlaid OFDM sequence (s) over OOK symbol. However, details on the overlaid OFDM sequence (s) are still needed for further study.

Embodiments of the present disclosure provide a solution of communication. In the solution, a low power signal may be generated based on a first bit sequence and the OOK-ON symbols may be generated based on a second bit sequence which is associated with an inverse order or a cyclic shift of the first bit sequence. As such, there is no need to receive/decode all OOK symbols at the terminal device and the overhead can be reduced. Principles and implementations of the present disclosure will be described in detail below with reference to the figures.

FIG. 1 illustrates an example communication network 100 in which some embodiments of the present disclosure can be implemented. The communication network 100 may also be called as a network environment, a network system, a communication system, a communication environment, or the like, the present disclosure does not limit this aspect. The communication network 100 includes a network device 110 and a terminal device 120 which may communicate with each other. The communication network 100 may also include a core network (CN) which may involve a variety of network functions or entities.

In the communication network 100, the network device 110 and the terminal device 120 can communicate data and control information to each other, and the communications in the communication network may be implemented according to any proper communication protocol (s) .

Embodiments of the present disclosure can be applied to any suitable scenarios. For example, embodiments of the present disclosure can be implemented at reduced capability NR devices. Alternatively, embodiments of the present disclosure can be implemented in one of the followings: NR multiple-input and multiple-output (MIMO) , NR sidelink enhancements, NR systems with frequency above 52.6GHz, an extending NR operation up to 71GHz, narrow band-Internet of Thing (NB-IOT) /enhanced Machine Type Communication (eMTC) over non-terrestrial networks (NTN) , NTN, UE power saving enhancements, NR coverage enhancement, NB-IoT and LTE-MTC, Integrated Access and Backhaul (IAB) , NR Multicast and Broadcast Services, or enhancements on Multi-Radio Dual-Connectivity.

It is to be understood that the numbers of devices and their connection relationships and types shown in FIG. 1 are only for the purpose of illustration without suggesting any limitation. For example, there may be multiple terminal devices connecting to the network device 110, for example the network 100 may include any suitable numbers of devices adapted for implementing embodiments of the present disclosure.

In some example embodiments, the terminal device 120 may be equipped with an LP-WUR and a main radio (MR) , where the LP-WUR is used to receive the LP signal, where the MR is used to transmit/receive other channel or signal other than the LP signal. For ease of description, the channel or signal transmitted/received by the MR may be referred to as an MR signal, including but not limited to receiving PDCCH, PDSCH, SSB, or transmitting PUCCH, PUSCH, sounding reference signal (SRS) , etc.

In some embodiments, the terminal device 120 may be in a main mode to receive the MR signal. In some embodiments, the terminal device 120 may be in a low power mode to receive the LP signal. In some embodiments, the terminal device 120 may receive the MR signal and the LP signal at a same time.

In some embodiments, the terminal device 120 may be in a main mode. The terminal device 120 may receive/transmit normal DL/UL transmission (e.g., PDSCH, PDCCH, PUSCH, PUCCH, etc. ) in the main mode with a main radio or a main receiver. In the context of the present disclose, the terms “main radio” , “main receiver” can be used interchangeably. In the present disclosure, the term “MR” may refer to the main radio and/or the main receiver.

In some embodiments, the terminal device 120 may be in a low power mode. The terminal device 120 may receive the LP signal in the low power mode with a low power wake-up radio or a low power wake-up receiver. In the context of the present disclose, the terms “low power mode” , “deep sleeping mode” , “ultra-deep sleeping mode” , “ultra-low power mode” can be used interchangeably, and the terms “low power radio” , “ultra-low power radio” , “low power receiver” , “ultra-low power receiver” , “wake-up receiver” , “low power wake-up receiver” , “low power wake-up radio” can be used interchangeably. In the present disclosure, the term “LP-WUR” may refer to the low power wake-up receiver and/or the low power wake-up radio.

In the present disclosure, the term “low power mode” may refer to a mode that the terminal device 120 is not required to perform at least one of: paging monitoring, cell selection and re-selection, measurement based on an SSB or channel state information -reference signal (CSI-RS) , PDCCH monitoring, UL transmission, etc., and the terminal device 120 is required to perform LP signal monitoring and/or detection.

In the present disclosure, the term “LP-WUR” may refer to a radio used in the low power mode for transmission/reception. In an embodiment, the LP-WUR may be independent to the MR, and it is not used for transmission/reception of the normal DL/UL transmissions. In another embodiment, the LP-WUR may share at least a part of the components of the MR, and it may have lower power consumption than the MR.

In some embodiments, the terminal device 120 may perform, by using the MR, at least one of: paging monitoring, cell selection and re-selection, measurement based on SSB or CSI-RS, PDCCH monitoring, or UL transmission.

In some embodiments, the LP-WUR may be turned off or on. For a UE in RRC idle/inactive state, it may turn off its MR or switch the MR into an ultra-deep sleep mode. The UE utilizes the LP-WUR to monitor the LP-WUS signal, and determines whether to wake-up the MR based on the detection of LP-WUS. The LP-WUR is low-cost and low power consuming, it can be independent to the MR, or it may share some components with the MR.

In the present disclosure, the terminal device 120 may be equipped with an LR with OFDM receiver (i.e., the LR is capable of receiving OFDM signal, e.g., an OFDM sequence) , which may be called as an OFDM-LR, or an OOK-LR for LR with OOK receiver. In some examples, the OFDM-LR can receive the bits carried by the OOK symbols and the overlaid sequences.

As mentioned above, the LP-WUR is used to receive LP signal. In the present disclosure, there may be two types of LP signals: a low power synchronization signal (LP-SS) and a low power wake-up signal (LP-WUS) .

The LP-SS may also be called as a low power reference signal (LP-RS) , which is used for synchronization, measurement, and/or beam measurement. The LP-SS may be cell specific, or cell group specific (e.g., multiple cells associated with a same tracking area code (TAC) , may have a same configuration for LP-SS) . In some examples, the terminal device 120 may expect that the LP-SS will always be transmitted in each LP-SS occasion.

The LP-WUS is used for informing the terminal device of the wake-up information, e.g., to inform the terminal device to wake-up from the LP mode, or inform the terminal device to stay in the LP mode, or to inform the terminal device of a configuration for LP signal. For example, the LP-WUS may be used for indicating to the terminal device 120 to wake up from the LP mode, e.g., start to monitor a paging occasion for paging downlink control information (DCI) .

In some examples, the LP-WUS may include a preamble part and a payload part, where the preamble part is used for synchronization or measurement and the payload part contains the wake-up information.

In some embodiments, the LP signal (such as LP-WUS) may be based on at least one amplitude modulation sequence, where the sequence may include a symbol with higher amplitude and a symbol with lower amplitude. In some examples, the amplitude modulation may include any of: amplitude shift keying (ASK) , frequency shift keying (FSK) , or on-off keying (OOK) modulation. Specifically, the OOK modulation is widely considered due to its very simple receiver architecture and ultra-low power consumption. With OOK modulation, the receiver may detect envelop or energy of the time domain signal with a relatively low sampling rate, and without complicated baseband processing. As an example, the OOK modulation is considered in the following disclosure as one of the amplitude modulation. An OOK modulation sequence may include at least one OOK ON symbol and at least one OOK OFF symbol. In some examples, the terms “OOK symbol” , “OOK ON symbol” and “OOK OFF symbol” can be replaced by “OOK chip” , “OOK pulse” , “OOK ON pulse” and “OOK OFF pulse” , respectively. For example, the ON symbol and the OFF symbol may represent symbols or pulses with higher and lower amplitude respectively.

For FSK, there may be multiple frequency components (e.g., two frequency components) , and the information may be conveyed by selecting a subset of the frequency components to transmit signal. For example, the information which is transmitted in a first component may represent information bit “0” , and the information which is transmitted in a second component may represent information bit “1” .

For ease of description, the following description will be discussed with reference to OOK modulation, however it is to be understood that ASK or FSK is still applicable and the present disclosure does not limit this aspect. For example, an OOK ON symbol is equivalent to a non-zero symbol which is transmitted in a frequency component of FSK modulation, an OOK OFF symbol is equivalent to a symbol with zero power in a frequency component of FSK modulation.

In some embodiments, the LP signal may occupy a set of time/frequency resources for a serving cell. FIG. 2A illustrates a schematic diagram of resources 210 occupied by an LP signal which can be used in some example embodiments of the present disclosure. In frequency domain, the resources allocated to the LP signal 212 may be overlapped with a set of PRBs or subcarriers, i.e., the terminal device 120 may be indicated a set of PRBs or subcarriers, and the frequency resources of the set of PRBs or subcarriers are used by the LP signal 212. In time domain, the resources allocated to the LP signal 212 may be overlapped with a set of OFDM symbols, i.e., the terminal device 120 may be indicated a set of OFDM symbols, and the time resources of the set of OFDM symbols are used by the LP signal 212.

In some examples, OOK modulation is proposed for the LP signal, such as LP-WUS. An OOK signal may be generated based on the OFDM signal generation, e.g., an OFDM with zero power can be an OOK-OFF symbol (i.e., a logical value “0” ) , and an OFDM symbol with non-zero power can be an OOK-ON symbol (i.e., a logical value “1” ) . In other words, the OOK ON symbol has a relatively high power, and the OOK OFF symbol has zero power or relatively low power.

It is to be understood that an OOK symbol may be equal to or may be not equal to an OFDM symbol. FIG. 2B illustrates a schematic diagram of OOK symbols 220 which can be used in some example embodiments of the present disclosure. As shown in FIG. 2B, an OOK ON symbol or an OOK OFF symbol may have a duration which equals to the duration of an OFDM symbol. In this case, an OOK ON symbol and an OOK OFF symbol are realized by a non-zero power OFDM symbol and a zero power OFDM symbol respectively. FIG. 2C illustrates a schematic diagram of OOK symbols 230 which can be used in some example embodiments of the present disclosure. As shown in FIG. 2C, an OOK ON symbol or an OOK OFF symbol may have a duration which is shorter than an OFDM symbol. In this case, the OOK ON symbol and OOK OFF symbol can be realized by DFT-s-OFDM, or by independent time domain generation.

For example, several options for OOK signal generation based on OFDM waveform were proposed. FIGS. 3A-3B illustrate schematic diagrams of OOK-1 310 and OOK-4 320 respectively which can be used in some example embodiments of the present disclosure. For example, a number of SCs used by LP-WUS including potential guard-bands may be represented as N.

Option OOK-1: Single-bit in 1 OFDM symbol, SCs of LP-WUS are:

● OOK=1 means all SCs are modulated;

● OOK=0 means all SCs are zero power (from base-band point of view) .

Option OOK-4: Transform M-bit OOK in time domain

● N SCs of OOK-1 are generated by a transformation (DFT/Least square)

- N’samples are generated from M-bits;

- signal modification may or may NOT be used;

- truncation or other additional modification may or may NOT be used, if not used, N is the same as N’ ;

● N’ can be the same as K.

It is to be noted that, in the present disclosure, if not specified otherwise, the term “OFDM symbol” indicates CP-OFDM symbol, or any variant of OFDM symbol, e.g., DFT-s-OFDM, GI-OFDM, zero CP OFDM, unique word OFDM, etc.

In some cases, the OFDM sequence used for generating an OOK symbol (i.e., OOK-ON symbol) can also convey information bit. For example, there may be Ns OFDM sequences which can convey maximum log2 (Ns) information bits, and the UE may try to detect which sequence is used by gNB and then determine the information bits conveyed by the sequence.

In the work item on LP-WUS for Rel-19, one objective is proposed to specify an LP-WUS design commonly applicable to both idle/inactive and connected modes. The objective includes to specify OOK (OOK-1 and/or OOK-4) based LP-WUS with overlaid OFDM sequence (s) over OOK symbol, where the LP-WUS design shall ensure that for idle/inactive operation, the same information is delivered irrespective of LP-WUR type. The OFDM sequence can carry information, and at least duty-cycled monitoring of LP-WUS is supported. One objective is to specify LP-SS with periodicity with Y ms for LP-WUR, for synchronization and/or RRM for serving cell. The objective specifies that the LP-SS is based on OOK-1 and/or OOK-4 wave form with or without overlaid OFDM sequences.

It is proposed that an OFDM sequence can be used to generate an OOK-ON symbol (denoted as an overlaid OFDM sequence) , and the overlaid OFDM sequence may also carry information bits which can be utilized by the LR with an OFDM receiver. Therefore, how to carry the information by the overlaid OFDM sequence should be addressed.

Some embodiments in the present disclosure may involve one or more operators, such as floor [] , ceil [] , mod () , etc. The operator floor [x] , i.e. the floor function, may return the greatest integer value less than or equal to x. The operator ceil [x] , i.e. the ceiling function, may return the smallest integer value greater than or equal to x. The operator mod (x, y) , also represented as x mod y, returns the reminder or singed reminder of a division, after x is divided by y.

Reference is now made to FIG. 4, which illustrates a signalling chart illustrating communication process 400 in accordance with some example embodiments of the present disclosure. The process 400 may involve a network device 110 and a terminal device 120 as shown in FIG. 1. It would be appreciated that the process 400 may be applied to other communication scenarios, which will not be described in detail.

In the process 400, the network device 110 determines 410 an information block. In some implementations, the information block may be generated based on a payload of an LP-WUS or a binary sequence of an LP-SS. In some embodiments, in case there is a low power signal to be transmitted to the terminal device 120, the network device 110 can determine an information for the low power signal.

In some examples, the low power signal comprises an LP-WUS, the network device 110 may determine an information block for the LP-WUS. The information block may be generated based on a payload of the LP-WUS, where the payload may include multiple information bits which can indicate the terminal device 120 to wake up or not. For example, the multiple information bits can be used for a wake-up indication field which may carry a wake-up indication or a non-wake-up indication. In some instances, the information block may be the payload sequence and a cyclic redundancy check (CRC) , or may be the payload only. In some instances, the information block may be a bit sequence before channel coding, e.g. before Manchester coding if used. In some instances, the information block may be determined based on bit processing of the payload, for example, the bit processing may include one or more of the following: CRC adding, segmentation, truncation, padding, interleaving, or scrambling.

In some examples, the low power signal comprises an LP-SS, and the information block may be a binary sequence that is used to generate the LP-SS. For ease of description, some of the following embodiments are discussed with reference to LP-WUS, however, it is to be noted that the LP-SS is also applied unless indicated otherwise.

In the process 400, the network device 110 determines 420 a first bit sequence based on the information block. In some implementations, the first bit sequence may include a plurality of bits, such as k bits, in other words, the first bit sequence has a length which can be represented as k . In some examples, the first bit sequence may be represented as (a₀, a₁, …, a_k-1) .

In some examples, the first bit sequence may be the same as the information block. In some other examples, the first bit sequence may be part of the information block. It is to be noted that the first bit sequence may be generated based on the information block by using other method, which will not be listed herein.

In addition or alternatively, the network device 110 may generate multiple OOK symbols based on the first bit sequence. Specifically, the multiple OOK symbols may include one or multiple OOK-ON symbols and one or multiple OOK-OFF symbols.

In some example embodiments, a bit in the first bit sequence may be mapped to a set of OOK symbols. In some examples, a set of OOK symbols may include one OOK symbol or more than one OOK symbol. In other words, a bit in the first bit sequence may be mapped to one OOK symbol or more than one OOK symbol.

In some instances, a bit “0” in the first bit sequence may be mapped to an OOK-OFF symbol (or an OOK-ON symbol) , and a bit “1” in the first bit sequence may be mapped to an OOK-ON symbol (or an OOK-OFF symbol) . In some other instances, a bit “0” in the first bit sequence may be mapped to a first set of OOK symbols, and a bit “1” in the first bit sequence may be mapped to a second set of OOK symbols. For example, the first set of OOK symbols may be [OOK-ON symbol, OOK-OFF symbol] , and the second set of OOK symbols may be [OOK-OFF symbol, OOK-ON symbol] . For example, the first set of OOK symbols may be [OOK-ON symbol, OOK-OFF symbol, OOK-ON symbol, OOK-OFF symbol] , and the second set of OOK symbols may be [OOK-ON symbol, OOK-OFF symbol, OOK-OFF symbol, OOK-ON symbol] .

In some embodiments, the mapping from the first bit sequence to the multiple OOK symbols may be performed by a method similar with Manchester encoding, for example, the Manchester encoding with a code rate 1/2 or 1/4 may be applied. It is to be noted that some other method may be used for the mapping, and the present disclosure does not limit for this aspect.

In some examples, the first bit sequence is represented as (a₀, a₁, …, a_k-1) , and a₀ is mapped to a first OOK symbol or a first OOK symbol set, a₁ is mapped to a second OOK symbol or a second OOK symbol set, …, a_k-1 is mapped to a k-th OOK symbol or a k-th OOK symbol set.

In the process 400, the network device 110 determines 430 a second bit sequence based on the first bit sequence. In some implementations, the second bit sequence is generated based on an inverse order of the first bit sequence. In some other implementations, the second bit sequence is generated based on a cyclic shift of the first bit sequence.

In addition or alternatively, the network device 110 may generate the multiple OOK-ON symbols based on the second bit sequence. In some implementations, the network device 110 may generate a plurality of overlaid sequences based on the second bit sequence, and further determine the multiple OOK-ON symbols based on the plurality of overlaid sequences.

In some implementations, the second bit sequence may include a plurality of bits, such as l bits, in other words, the second bit sequence has a length which can be represented as l. In some examples, the second bit sequence may be represented as (b₀, b₁, …, b_l-1) .

In some implementations, an overlaid sequence is also called as an overlaid OFDM sequence, and may carry one or more than one bit information, such as N bit (s) . In some example embodiments, a number of bits that carried by an overlaid sequence may be a second number, which is represented as N. In other words, an overlaid sequence may be generated based on N bits, N is an integer, for example, N may be one value in a range of {1, 2, 3, 4, …, 8}.

In some example embodiments, an overlaid sequence may be a Zadoff-Chu (ZC) sequence. In some other example embodiments, an overlaid sequence may be a pseudo random sequence. For example, the overlaid sequence may be generated based on a m-sequence, a gold sequence, or other pseudo random sequence.

In some example embodiments, an overlaid sequence may have good cross-correlation property and/or auto-correlation property.

In some example embodiments, an overlaid sequence may be a time domain sequence. In some examples, OOK-4 is used to generate an OOK-ON symbol, for example, a DFT processing is applied to the time domain sequence, and then IFFT is performed to generate the OOK-ON symbol. In some other example embodiments, an overlaid sequence may be a frequency domain sequence, for example, the OOK-ON symbol is generated based on an IFFT processing of the frequency domain sequence.

In some example embodiments, an overlaid sequence may be selected from a sequence set which contains multiple sequences, such as 2^N sequences, then N bit information can be conveyed by an index of a selected sequence. In some example embodiments, an overlaid sequence may be generated based on a parameter (e.g., a variable in the formula for pseudo random sequence or ZC sequence generation) , and the parameter may have 2^N values. In some example embodiments, the second number (i.e. N) may be determined by the network device 110, for example, the network device 110 may indicate the second number (i.e. N) to the terminal device 120 through system information or an RRC message.

In some implementations, the plurality of overlaid sequences may be generated by mapping N bits in the second bit sequence to an overlaid sequence. In some implementations, the first N bits in the second bit sequence can be mapped into the first overlaid sequence, the second N bits in the second bit sequence can be mapped into the second overlaid sequence, and so on.

As an example, the second bit sequence is represented as (b₀, b₁, …, b_l-1) , and N =1, then b₀ is mapped to an overlaid sequence for the first OOK-ON symbol, b₁ is mapped to an overlaid sequence for the second OOK-ON symbol, …and so on.

An another example, the second bit sequence is represented as (b₀, b₁, …, b_l-1) , and N =2, then (b₀, b₁) are mapped to an overlaid sequence for the first OOK-ON symbol, (b₂, b₃) are mapped to an overlaid sequence for the second OOK-ON symbol, …and so on.

Regarding the second bit sequence, in some implementations, the second bit sequence may be determined based on an inverse order of the first bit sequence. In some examples, a length of the second bit sequence may equal to a length of the first bit sequence, i.e., l=k . For example, the second bit sequence (b₀, b₁, …, b_l-1 ) = (a_k-1, a_k-2, …, a₀ ) . For example, a bit in the second bit sequence is: b_i=a_k-i-1, with i is a value of 0 ～ l-1.

In some examples, a length of the second bit sequence may be smaller than a length of the first bit sequence, i.e., l<k. For example, the second bit sequence may be generated based on an inverse order of a rear part of the first bit sequence. For example, the second bit sequence (b₀, b₁, …, b_l-1) = (a_k-1, a_k-2, …, a_k-l) , i.e., b_i=a_k-i-1, with i is a value of 0 ～ l-1. For example, the length of the second bit sequence (l) may be associated with a first number (which may be represented as s) and a second number (N, as discussed above) . In some instances, the first number may be regarded as a number of OOK symbols or OOK symbol sets for receiving the low power signal. For example, the length of the second bit sequence (l) may be associated with a length of the first bit sequence (k) and the second number (N) .

For instance, the first number (s) may be determined based on the length of the first bit sequence (k) and the second number (N) , e.g., k/ (N+1) . One of the following may be used for determining the first number: s=k/ (N+1) , s=floor [k/ (N+1) ] , s=ceil [k/ (N+1) ] , s=floor [k/ (N+1) ] +p, or s=ceil [k/ (N+1) ] +q, where each of p and q may be a positive or negative integer. As one example, p (or q) may be 1 or -1. It should be noted that some other manners may be used for determining the first number, and the present disclosure does not limit for this aspect.

As a specific example, if N=1, then the length of the second bit sequence (l) may be determined as l=s×N , which may be k/2 or ceil [k/2] , and the second bit sequence may be (b₀, b₁, …, b_l-1) = (a_k-1, a_k-2, …, a_k/2) with l=k/2 and k is an even number.

In some examples, a length of the second bit sequence may be larger than a length of the first bit sequence, i.e., l>k. For example, the length of the second bit sequence (l) may be associated with a length of the first bit sequence (k) and the second number (N) . Optionally, l=k×N.

For example, the second bit sequence may include N sub-sequences, and each of the sub-sequences may include k bits. As one example, each sub-sequence is an inverse order of the first bit sequence. For example, b_i=a_k-1-mod _(i, _k) , with i is an integer from 0 to l-1. As a specific example, if N=2, then the length of the second bit sequence (l) may be determined as l=2k, and the second bit sequence may be:
(b₀, b₁, …, b_l-1) = (a_k-1, a_k-2, …, a₀, a_k-1, a_k-2, …, a₀) (1)

It is to be understood that this may be equivalent to a repetition of the first bit sequence for N times (with an inverse order) .

As another example, for two adjacent subsequences in the second bit sequence, one sub-sequence comprises an inverse order of the first bit sequence, and another one sub-sequence comprises the first bit sequence. For example, the following may be applied:

where m is an integer not smaller than 0.

As a specific example, if N=2, then the length of the second bit sequence (l) may be determined as l=2k, and the second bit sequence may be:
(b₀, b₁, …, b_l-1) = (a_k-1, a_k-2, …, a₀, a₀, a₁, …, a_k-1) (3)

Regarding the second bit sequence, in some other implementations, the second bit sequence may be determined based on a cyclic shift of the first bit sequence. In some examples, a shift value for the cyclic shift may be determined based on the second number (N) . For example, the shift value may equal to a first number (which may be represented as s) . In some instances, the first number may be regarded as a number of OOK symbols or OOK symbol sets for receiving the low power signal.

For instance, the shift value (i.e. the first number, s) may be determined based on the length of the first bit sequence (k) and the second number (N) , e.g., k/ (N+1) . One of the following may be used for determining the first number: s=k/ (N+1) , s=floor [k/ (N+1) ] , s=ceil [k/ (N+1) ] , s=floor [k/ (N+1) ] +p , or s=ceil [k/ (N+1) ] +q, where each of p and q may be a positive or negative integer. As one example, p (or q) may be 1 or -1. It should be noted that some other manners may be used for determining the first number, and the present disclosure does not limit for this aspect.

In some examples, a length of the second bit sequence may equal to a length of the first bit sequence, i.e., l=k . For example, the second bit sequence (b₀, b₁, …, b_l-1 ) = (b₀, b₁, …, b_k-1) = (a_s, a_s+1, …, a_k-1, a₀, a₁, …, a_s-1) . For example, a bit in the second bit sequence is: b_i=a_mod _(i+s, _k) , with i is an integer from 0 to l-1.

In some examples, a length of the second bit sequence may be smaller than or be larger than the length of the first bit sequence, for example, l=ceil [k/ (N+1) ] or l=N×k. For example, a bit in the second bit sequence is: b_i=a_mod _(i+s, _k) , with i is an integer from 0 to l-1, and l is not larger than N×k.

As a specific example, if N=2, then the length of the second bit sequence (represented by l) may be determined as l=2k, and the second bit sequence may be:
(b₀, b₁, …, b_l-1) = (b₀, b₁, …, b_2k-1)
= (a_ceil _[k/3] , a_ceil _[k/3] ₊₁, …, a_k-1, a₀, a₀, a₁, …, a_k-1, a₀, a₁, …, a_ceil _[k/3] -1) (4)

It is to be understood that this may be equivalent to the following processing: repeating the first bit sequence for N times, and then performing a cyclic shift (with a shift value s) to the repeated first bit sequence.

In the process 400, the network device 110 generates 440 a low power signal, e.g., based on the first bit sequence and the second bit sequence. In some implementations, the low power signal includes a plurality of OOK symbols determined based on the first bit sequence. In some implementations, the plurality of OOK symbols include multiple OOK-ON symbols and multiple OOK-OFF symbols, and the multiple OOK-ON symbols are generated based on the second bit sequence.

In the process 400, the network device 110 transmits 450 the low power signal 452 to the terminal device 120. In some implementations, the low power signal 452 may be an LP-WUS or LP-SS. In some examples, although terminal device 120 is illustrated as a receiving entity of the low power signal, in some cases, the low power signal 452 may be transmitted to a group of terminal devices, for example, the low power signal 452 may be UE group based.

In some implementations, the length of the second bit sequence may be associated with a first number represented by s, in some examples, not all OOK symbols are transmitted by the network device 110. In some embodiments, from the perspective of the network device 110, the OOK symbols (or OOK symbol sets) after the s-th OOK symbol (or the s-th OOK symbol set) may not be transmitted. As such, the overhead can be reduced.

On the other side of communication, the terminal device 120 receives 454 the low power signal 452. In some implementations, the length of the second bit sequence may be associated with a first number represented by s, in some examples, the terminal device 120 may receive the first s OOK symbols (or OOK symbol sets) ; in some other examples, the terminal device 120 may receive all OOK symbols (or OOK symbol sets) for better performance. For example, some repeatedly transmitted bits may be utilized by the terminal device 120 so as to get better performance.

In some implementations, from UE perspective, the terminal device 120 may assume that the OOK symbols (or OOK symbol sets) after the s-th OOK symbol (or the s-th OOK symbol set) are not transmitted. In some examples, the terminal device 120 may does not assume that the OOK symbols (or OOK symbol sets) after the s-th OOK symbol (or the s-th OOK symbol set) are transmitted, or the terminal device 120 may blindly detect whether the OOK symbols (or OOK symbol sets) after the s-th OOK symbol (or the s-th OOK symbol set) are transmitted.

In addition, the terminal device 120 determines 460 the information block. In some implementations, the terminal device 120 may determine the first bit sequence and the second bit sequence, based on the received low power signal. In some implementations, the terminal device 120 may determine the information block, such as the payload of an LP-WUS, based on at least one of the first bit sequence and the second bit sequence.

Since the overlaid sequences can also carry information, the OFDM-LR of the terminal device 120 may not need to receive all the k OOK symbols used for LP-WUS, therefore power consumption can be saved. On the other hand, an overlaid sequence may carry more than one information bits (e.g. N>1) , therefore less than k OOK-ON symbols can be used to transmit all the k bits, (e.g., if an overlaid sequence carries 2 bits, then only k/2 OOK-ON symbols are needed) . Therefore, it provides an opportunity for LP-WUS repetition, i.e., the k bits may be transmitted multiple times in the k OOK-ON symbols, the detection performance may be improved.

It is to be appreciated that the operations discussed with reference to FIG. 4 are only for illustration without any limitation, for example, some operations can be reordered, combined, removed, or modified, for example, some additional operation (s) may be further included, the present disclosure does not limit for this aspect.

FIG. 5A illustrates an example schematic of OOK based LP-WUS 510 with overlaid sequence over OOK symbol with N=1. In the example shown in FIG. 5A, the length of the second bit sequence equals to the length of the first bit sequence, that is l=k, and b₀ is mapped to an overlaid sequence for the first OOK-ON symbol, b₁ is mapped to an overlaid sequence for the second OOK-ON symbol, …and so on.

In case the second bit sequence is an inverse order of the first bit sequence, FIG. 5B can be regarded as a specific example of OOK based LP-WUS 520 on the basis of FIG. 5A. specifically, the second bit sequence meets (b₀, b₁, …, b_l-1) = (a_k-1, a_k-2, …, a₀) with l=k.

FIG. 5C illustrates an example schematic of OOK based LP-WUS 530 with overlaid sequence over OOK symbol with N=1 in accordance with some embodiments of the present disclosure. In the example shown in FIG. 5A, the length of the second bit sequence is smaller than the length of the first bit sequence, such as l=k/2, with k is an even number. As illustrated, b₀=a_k-1 is mapped to an overlaid sequence for the first OOK-ON symbol, b₁=a_k-2 is mapped to an overlaid sequence for the second OOK-ON symbol, …and b_l-1=a_k/2 is mapped to an overlaid sequence for the k/2-th OOK-ON symbol. In this case, the terminal device 120 may receive the first k/2 OOK symbols (or OOK symbol sets) to determine the LP-WUS payload; or the terminal device 120 may receive the all k OOK symbols (or OOK symbol sets) for better performance.

FIG. 6A illustrates an example schematic of OOK based LP-WUS 610 with overlaid sequence over OOK symbol with N=2. In the example shown in FIG. 6A, the length of the second bit sequence equals to the length of the first bit sequence, that is l=k, and (b₀, b₁) are mapped to an overlaid sequence for the first OOK-ON symbol, (b₂, b₃) are mapped to an overlaid sequence for the second OOK-ON symbol, …and so on.

In case the second bit sequence is an inverse order of the first bit sequence, FIG. 6B can be regarded as a specific example of OOK based LP-WUS 620 on the basis of FIG. 6A. specifically, the second bit sequence meets (b₀, b₁, …, b_l-1) = (a_k-1, a_k-2, …, a₀) with l=k.

FIG. 6C illustrates an example schematic of OOK based LP-WUS 630 with overlaid sequence over OOK symbol with N=2 in accordance with some embodiments of the present disclosure. In the example shown in FIG. 6C, the length of the second bit sequence is smaller than the length of the first bit sequence, such as l=ceil [k/3] . As illustrated, (a_k-1, a_k-2) are mapped to an overlaid sequence for the first OOK-ON symbol, (a_k-3, a_k-4) are mapped to an overlaid sequence for the second OOK-ON symbol, …and (a_k-2l+1, a_k-2l) are mapped to an overlaid sequence for the l-th OOK-ON symbol. In this case, the terminal device 120 may receive the first l OOK symbols (or OOK symbol sets) to determine the LP-WUS payload; or the terminal device 120 may receive the all k OOK symbols (or OOK symbol sets) for better performance.

FIG. 6D illustrates an example schematic of OOK based LP-WUS 640 with overlaid sequence over OOK symbol with N=2 in accordance with some embodiments of the present disclosure. In the example shown in FIG. 6D, the length of the second bit sequence is larger than the length of the first bit sequence, such as l=2*k. For example, the second bit sequence may be that presented above in Equation (1) . As illustrated, (a_k-1, a_k-2 ) are mapped to an overlaid sequence for the first OOK-ON symbol, (a_k-3, a_k-4) are mapped to an overlaid sequence for the second OOK-ON symbol, …and (a₁, a₀ ) are mapped to an overlaid sequence for the (k/2-1) -th OOK-ON symbol, (a_k-1, a_k-2) are mapped to an overlaid sequence for the k/2 -th OOK-ON symbol, …, and (a₁, a₀ ) are mapped to an overlaid sequence for the k-th OOK-ON symbol. Accordingly, the repetition is enabled, and the transmission performance can be enhanced.

FIG. 6E illustrates an example schematic of OOK based LP-WUS 650 with overlaid sequence over OOK symbol with N=2 in accordance with some embodiments of the present disclosure. In the example shown in FIG. 6E, the length of the second bit sequence is larger than the length of the first bit sequence, such as l=2*k. For example, the second bit sequence may be that presented above in Equation (3) . As illustrated, (a_k-1, a_k-2 ) are mapped to an overlaid sequence for the first OOK-ON symbol, (a_k-3, a_k-4) are mapped to an overlaid sequence for the second OOK-ON symbol, …and (a₁, a₀ ) are mapped to an overlaid sequence for the (k/2-1) -th OOK-ON symbol, (a₁, a₀) are mapped to an overlaid sequence for the k/2-th OOK-ON symbol, …, and (a_k-1, a_k-2) are mapped to an overlaid sequence for the k-th OOK-ON symbol. Accordingly, the repetition is enabled, and the transmission performance can be enhanced.

FIGS. 7A-7B illustrate some example schematics of OOK based LP-WUS with overlaid sequence over OOK symbol considering a cyclic shift of the first bit sequence in accordance with some embodiments of the present disclosure. In the example 710 with N=1 as shown in FIG. 7A, a shift value k/2 is applied for the second bit sequence. In the example 720 with N=2 as shown in FIG. 7B, a shift value ceil [k/3] is applied for the second bit sequence, for example equation (4) discussed above can be applied.

FIG. 8A illustrates an example schematic of OOK based LP-WUS 810 with overlaid sequence over OOK symbol at the receiver side. The LP-WUS 810 may be received by the terminal device 120, which is corresponding to the LP-WUS 510 transmitted by the network device 110, with N=1.

FIG. 8B illustrates an example schematic of OOK based LP-WUS 820 with overlaid sequence over OOK symbol at the receiver side. The OOK based LP-WUS 820 may be a specific example of the LP-WUS 520, e.g. k=8. As illustrated, an overlaid sequence may carry N=1 bit, and the terminal device 120 may receive 4 OOK symbols (or OOK symbol sets) , e.g. in receiver window 1, to obtain all the 8 information bits. As such, there is no need to receive all OOK symbols at the terminal device, and the power consumption can be saved.

FIG. 8C illustrates an example schematic of OOK based LP-WUS 830 with overlaid sequence over OOK symbol at the receiver side. The OOK based LP-WUS 820 may be a specific example of the LP-WUS 640, e.g. k=8. As illustrated, an overlaid sequence may carry N=2 bits, and the terminal device 120 may receive 3 OOK symbols (or OOK symbol sets) , e.g. in receiver window 1, to obtain all the 8 information bits. As such, there is no need to receive all OOK symbols at the terminal device, and the power consumption can be saved. As illustrated, an overlaid sequence may carry N=2 bits, and the terminal device 120 may receive 6 OOK symbols (or OOK symbol sets) , e.g. in receiver window 2, to obtain all the 8 information bits twice (e.g. two repetitions) . As such, the repetition of information bits can be achieved, and there is no need to receive all OOK symbols at the terminal device, and the power consumption can be saved and the reliability can be improved.

FIG. 8D illustrates an example schematic of OOK based LP-WUS 840 with overlaid sequence over OOK symbol at the receiver side. The OOK based LP-WUS 840 may be a specific example of the LP-WUS 710, e.g. k=8. As illustrated, an overlaid sequence may carry N=1 bit, and the terminal device 120 may receive 4 OOK symbols (or OOK symbol sets) , e.g. in receiver window 1 or 2 or 3, to obtain all the 8 information bits. Accordingly, if an OOK-ON symbol carries 1 bit, then the terminal device 120 can receive any k/2 consecutive OOK symbols (or OOK symbol sets) to obtain all the k information bits. In some cases, this may be used for LP-SS design, the LP-SS can be correctly received even through a synchronization has not been made.

FIG. 8E illustrates an example schematic of OOK based LP-WUS 850 with overlaid sequence over OOK symbol at the receiver side. The OOK based LP-WUS 850 may be a specific example of the LP-WUS 720, e.g. k=8. As illustrated, an overlaid sequence may carry N=2 bits, and the terminal device 120 may receive 3 OOK symbols (or OOK symbol sets) , e.g. in receiver window 1, to obtain all the 8 information bits.

According to some embodiments with reference to FIGS. 4-8E, a solution of OOK based low power signal with overlaid OFDM sequences over OOK symbol is provided. In this solution, a low power signal may be generated based on a first bit sequence and the OOK-ON symbols may be generated based on a second bit sequence which is associated with an inverse order or a cyclic shift of the first bit sequence. As such, a method for bit mapping of overlaid OFDM sequences is provided. Therefore, there is no need to receive/decode all OOK symbols for the terminal device and the overhead can be reduced.

FIG. 9 illustrates a flowchart of an example method 900 implemented at a terminal device in accordance with some embodiments of the present disclosure. For the purpose of discussion, the terminal device which may perform the method 900 can be the terminal device 120 discussed above.

At block 910, the terminal device receives, from a network device, a low power signal comprising an LP-WUS or an LP-SS, wherein the low power signal comprises a plurality of OOK symbols with a plurality of OOK-ON symbols and a plurality of OOK-OFF symbols, wherein the plurality of OOK symbols are generated based on a first bit sequence and the plurality of OOK-ON symbols are generated based on a second bit sequence, and wherein the second bit sequence is determined based on an inverse order of the first bit sequence or a cyclic shift of the first bit sequence. At block 920, the terminal device determines an information block of the low power signal.

In some example embodiments, each bit in the first bit sequence is mapped to one or more OOK symbols, wherein a first bit with a first value is mapped to a first set of OOK symbols, and a second bit with a second value is mapped to a second set of OOK symbols, wherein the plurality of OOK-ON symbols are generated based on a plurality of overlaid sequences, and the plurality of overlaid sequences are generated based on the second bit sequence.

In some example embodiments, the terminal device determines the information block based on the plurality of overlaid sequences and corresponding OOK symbols, wherein a first number of the plurality of overlaid sequences is determined based on: a length of the first bit sequence, and a second number of bits carried by an overlaid sequence of the plurality of overlaid sequences.

In some example embodiments, the second bit sequence comprises a plurality of subsequences each with a length equaling to the length of the first bit sequence, and a number of the plurality of subsequences is equal to the second number.

In some example embodiments, each of the plurality of subsequences comprises an inverse order of the first bit sequence.

In some example embodiments, for two adjacent subsequences in the second bit sequence, one subsequence comprises an inverse order of the first bit sequence, and another one subsequence comprises the first bit sequence.

In some example embodiments, a length of the second bit sequence is shorter than or equals to a length of the first bit sequence.

In some example embodiments, the second bit sequence is generated based on an inverse order of a rear part of the first bit sequence, wherein a length of the rear part equals to the length of the second bit sequence.

In some example embodiments, the second bit sequence is a cyclic shift of the first bit sequence with a shift value determined based on the second number.

In some example embodiments, the overlaid sequence with a second number is generated based on a plurality of bits from the second bit sequence.

In some example embodiments, the overlaid sequence is selected from a sequence set.

In some example embodiments, the overlaid sequence comprises a pseudo random sequence or a ZC sequence generated based on a parameter.

In some example embodiments, the overlaid sequence comprises a time domain sequence or a frequency domain sequence.

In some example embodiments, the information block is determined as a payload of the LP-WUS, and wherein the payload comprises a plurality of information bits being used as a wake-up indication field.

In some example embodiments, the information block is determined as a binary sequence associated with the LP-SS.

FIG. 10 illustrates a flowchart of an example method 1000 implemented at a network device in accordance with some embodiments of the present disclosure. For the purpose of discussion, the network device which may perform the method 1000 can be the network device 110 mentioned above.

At block 1010, the network device determines a first bit sequence based on an information block of a low power signal to be transmitted to a terminal device, wherein the low power signal comprises an LP-WUS or an LP-SS. At block 1020, the network device determines a second bit sequence based on an inverse order of the first bit sequence or a cyclic shift of the first bit sequence. At block 1030, the network device generates the low power signal based on the first bit sequence and the second bit sequence, wherein the low power signal comprises a plurality of OOK symbols with a plurality of OOK-ON symbols and a plurality of OOK-OFF symbols, and wherein the plurality of OOK symbols are generated based on the first bit sequence and the plurality of OOK-ON symbols are generated based on the second bit sequence. At block 1040, the network device transmits, to the terminal device, the low power signal.

In some example embodiments, the network device generates the plurality of OOK symbols by mapping each bit in the first bit sequence to one or more OOK symbols, wherein a first bit with a first value is mapped to a first set of OOK symbols, and a second bit with a second value is mapped to a second set of OOK symbols; and the network device determines the plurality of OOK-ON symbols based on a plurality of overlaid sequences, wherein the plurality of overlaid sequences are generated based on the second bit sequence.

In some example embodiments, the network device determines to transmit a plurality of overlaid sequences and corresponding OOK symbols, wherein a first number of the plurality of overlaid sequences is determined based on: a length of the first bit sequence, and a second number of bits carried by an overlaid sequence of the plurality of overlaid sequences.

In some example embodiments, the information block is generated based on a payload of the LP-WUS, and wherein the payload comprises a plurality of information bits being used as a wake-up indication field.

In some example embodiments, the information block is generated based on a binary sequence associated with the LP-SS.

Details of some embodiments according to the present disclosure have been described with reference to FIGS. 1-10. Now an example implementation of the terminal device and the network device will be discussed below.

In some example embodiments, a terminal device comprises circuitry configured to: receive, from a network device, a low power signal comprising an LP-WUS or an LP-SS, wherein the low power signal comprises a plurality of OOK symbols with a plurality of OOK-ON symbols and a plurality of OOK-OFF symbols, wherein the plurality of OOK symbols are generated based on a first bit sequence and the plurality of OOK-ON symbols are generated based on a second bit sequence, and wherein the second bit sequence is determined based on an inverse order of the first bit sequence or a cyclic shift of the first bit sequence; and determine an information block of the low power signal.

In some example embodiments, the terminal device comprises circuitry configured to:determine the information block based on the plurality of overlaid sequences and corresponding OOK symbols, wherein a first number of the plurality of overlaid sequences is determined based on: a length of the first bit sequence, and a second number of bits carried by an overlaid sequence of the plurality of overlaid sequences.

In some example embodiments, a network device comprises circuitry configured to: determine a first bit sequence based on an information block of a low power signal to be transmitted to a terminal device, wherein the low power signal comprises an LP-WUS or an LP-SS; determine a second bit sequence based on an inverse order of the first bit sequence or a cyclic shift of the first bit sequence; generate the low power signal based on the first bit sequence and the second bit sequence, wherein the low power signal comprises a plurality of OOK symbols with a plurality of OOK-ON symbols and a plurality of OOK-OFF symbols, and wherein the plurality of OOK symbols are generated based on the first bit sequence and the plurality of OOK-ON symbols are generated based on the second bit sequence; and transmit, to the terminal device, the low power signal.

In some example embodiments, the network device comprises circuitry configured to:generate the plurality of OOK symbols by mapping each bit in the first bit sequence to one or more OOK symbols, wherein a first bit with a first value is mapped to a first set of OOK symbols, and a second bit with a second value is mapped to a second set of OOK symbols; and determine the plurality of OOK-ON symbols based on a plurality of overlaid sequences, wherein the plurality of overlaid sequences are generated based on the second bit sequence.

In some example embodiments, the network device comprises circuitry configured to:determine to transmit a plurality of overlaid sequences and corresponding OOK symbols, wherein a first number of the plurality of overlaid sequences is determined based on: a length of the first bit sequence, and a second number of bits carried by an overlaid sequence of the plurality of overlaid sequences.

FIG. 11 illustrates a simplified block diagram of a device 1100 that is suitable for implementing embodiments of the present disclosure. The device 1100 can be considered as a further example implementation of the terminal device and the network device as described above. Accordingly, the device 1100 can be implemented at or as at least a part of the terminal device or the network device.

As shown, the device 1100 includes a processor 1110, a memory 1120 coupled to the processor 1110, a suitable transceiver 1140 coupled to the processor 1110, and a communication interface coupled to the transceiver 1140. The memory 1120 stores at least a part of a program 1130. The transceiver 1140 may be for bidirectional communications or a unidirectional communication based on requirements. The transceiver 1140 may include at least one of a transmitter and a receiver. The transmitter and the receiver may be functional modules or physical entities. The transceiver 1140 has at least one antenna to facilitate communication, though in practice an Access Node mentioned in this application may have several ones. The communication interface may represent any interface that is necessary for communication with other network elements, such as X2/Xn interface for bidirectional communications between eNBs/gNBs, S1/NG interface for communication between a Mobility Management Entity (MME) /Access and Mobility Management Function (AMF) /SGW/UPF and the eNB/gNB, Un interface for communication between the eNB/gNB and a relay node (RN) , or Uu interface for communication between the eNB/gNB and a terminal device.

The program 1130 is assumed to include program instructions that, when executed by the associated processor 1110, enable the device 1100 to operate in accordance with the embodiments of the present disclosure, as discussed herein with reference to FIGS. 1-10. The embodiments herein may be implemented by computer software executable by the processor 1110 of the device 1100, or by hardware, or by a combination of software and hardware. The processor 1110 may be configured to implement various embodiments of the present disclosure. Furthermore, a combination of the processor 1110 and memory 1120 may form processing means 1150 adapted to implement various embodiments of the present disclosure.

The memory 1120 may be of any type suitable to the local technical network and may be implemented using any suitable data storage technology, such as a non-transitory computer readable storage medium, semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory, as non-limiting examples. While only one memory 1120 is shown in the device 1100, there may be several physically distinct memory modules in the device 1100. The processor 1110 may be of any type suitable to the local technical network, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 1100 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

In summary, embodiments of the present disclosure may provide the following solutions.

The present disclosure provides a terminal device, comprising at least one processor configured to cause the terminal device at least to: receive, from a network device, a low power signal comprising an LP-WUS or an LP-SS, wherein the low power signal comprises a plurality of OOK symbols with a plurality of OOK-ON symbols and a plurality of OOK-OFF symbols, wherein the plurality of OOK symbols are generated based on a first bit sequence and the plurality of OOK-ON symbols are generated based on a second bit sequence, and wherein the second bit sequence is determined based on an inverse order of the first bit sequence or a cyclic shift of the first bit sequence; and determine an information block of the low power signal.

In one embodiment, the terminal device as above, each bit in the first bit sequence is mapped to one or more OOK symbols, wherein a first bit with a first value is mapped to a first set of OOK symbols, and a second bit with a second value is mapped to a second set of OOK symbols, wherein the plurality of OOK-ON symbols are generated based on a plurality of overlaid sequences, and the plurality of overlaid sequences are generated based on the second bit sequence.

In one embodiment, the terminal device as above, the at least one processor is configured to cause the terminal device to: determine the information block based on the plurality of overlaid sequences and corresponding OOK symbols, wherein a first number of the plurality of overlaid sequences is determined based on: a length of the first bit sequence, and a second number of bits carried by an overlaid sequence of the plurality of overlaid sequences.

In one embodiment, the terminal device as above, the second bit sequence comprises a plurality of subsequences each with a length equaling to the length of the first bit sequence, and a number of the plurality of subsequences is equal to the second number.

In one embodiment, the terminal device as above, each of the plurality of subsequences comprises an inverse order of the first bit sequence.

In one embodiment, the terminal device as above, for two adjacent subsequences in the second bit sequence, one subsequence comprises an inverse order of the first bit sequence, and another one subsequence comprises the first bit sequence.

In one embodiment, the terminal device as above, a length of the second bit sequence is shorter than or equals to a length of the first bit sequence.

In one embodiment, the terminal device as above, the second bit sequence is generated based on an inverse order of a rear part of the first bit sequence, wherein a length of the rear part equals to the length of the second bit sequence.

In one embodiment, the terminal device as above, the second bit sequence is a cyclic shift of the first bit sequence with a shift value determined based on the second number.

In one embodiment, the terminal device as above, the overlaid sequence with a second number is generated based on a plurality of bits from the second bit sequence.

In one embodiment, the terminal device as above, the overlaid sequence is selected from a sequence set.

In one embodiment, the terminal device as above, the overlaid sequence comprises a pseudo random sequence or a ZC sequence generated based on a parameter.

In one embodiment, the terminal device as above, the overlaid sequence comprises a time domain sequence or a frequency domain sequence.

In one embodiment, the terminal device as above, the information block is determined as a payload of the LP-WUS, and wherein the payload comprises a plurality of information bits being used as a wake-up indication field.

In one embodiment, the terminal device as above, the information block is determined as a binary sequence associated with the LP-SS.

The present disclosure provides a network device comprising at least one processor configured to cause the network device at least to: determine a first bit sequence based on an information block of a low power signal to be transmitted to a terminal device, wherein the low power signal comprises an LP-WUS or an LP-SS; determine a second bit sequence based on an inverse order of the first bit sequence or a cyclic shift of the first bit sequence; generate the low power signal based on the first bit sequence and the second bit sequence, wherein the low power signal comprises a plurality of OOK symbols with a plurality of OOK-ON symbols and a plurality of OOK-OFF symbols, and wherein the plurality of OOK symbols are generated based on the first bit sequence and the plurality of OOK-ON symbols are generated based on the second bit sequence; and transmit, to the terminal device, the low power signal.

In one embodiment, the network device as above, the at least one processor is configured to cause the network device to: generate the plurality of OOK symbols by mapping each bit in the first bit sequence to one or more OOK symbols, wherein a first bit with a first value is mapped to a first set of OOK symbols, and a second bit with a second value is mapped to a second set of OOK symbols; and determine the plurality of OOK-ON symbols based on a plurality of overlaid sequences, wherein the plurality of overlaid sequences are generated based on the second bit sequence.

In one embodiment, the network device as above, the at least one processor is further configured to cause the network device to: determine to transmit a plurality of overlaid sequences and corresponding OOK symbols, wherein a first number of the plurality of overlaid sequences is determined based on: a length of the first bit sequence, and a second number of bits carried by an overlaid sequence of the plurality of overlaid sequences.

In one embodiment, the network device as above, the second bit sequence comprises a plurality of subsequences each with a length equaling to the length of the first bit sequence, and a number of the plurality of subsequences is equal to the second number.

In one embodiment, the network device as above, each of the plurality of subsequences comprises an inverse order of the first bit sequence.

In one embodiment, the network device as above, for two adjacent subsequences in the second bit sequence, one subsequence comprises an inverse order of the first bit sequence, and another one subsequence comprises the first bit sequence.

In one embodiment, the network device as above, a length of the second bit sequence is shorter than or equals to a length of the first bit sequence.

In one embodiment, the network device as above, the second bit sequence is generated based on an inverse order of a rear part of the first bit sequence, wherein a length of the rear part equals to the length of the second bit sequence.

In one embodiment, the network device as above, the second bit sequence is a cyclic shift of the first bit sequence with a shift value determined based on the second number.

In one embodiment, the network device as above, the overlaid sequence with a second number is generated based on a plurality of bits from the second bit sequence.

In one embodiment, the network device as above, the overlaid sequence is selected from a sequence set.

In one embodiment, the network device as above, the overlaid sequence comprises a pseudo random sequence or a ZC sequence generated based on a parameter.

In one embodiment, the network device as above, the overlaid sequence comprises a time domain sequence or a frequency domain sequence.

In one embodiment, the network device as above, the information block is generated based on a payload of the LP-WUS, and wherein the payload comprises a plurality of information bits being used as a wake-up indication field.

In one embodiment, the network device as above, the information block is generated based on a binary sequence associated with the LP-SS.

The present disclosure provides a method of communication, comprising the operations implemented at the terminal device discussed above. The present disclosure provides a method of communication, comprising the operations implemented at the network device discussed above.

The present disclosure provides a terminal device, comprising: a processor; and a memory storing computer program codes; the memory and the computer program codes configured to, with the processor, cause the terminal device to perform the method implemented at the terminal device discussed above.

The present disclosure provides a network device, comprising: a processor; and a memory storing computer program codes; the memory and the computer program codes configured to, with the processor, cause the network device to perform the method implemented at the network device discussed above.

The present disclosure provides a computer readable medium having instructions stored thereon, the instructions, when executed by a processor of an apparatus, causing the apparatus to perform the method implemented at a terminal device or a network device discussed above.

Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representation, it will be appreciated that the blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor, to carry out the process or method as described above. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the processor or controller, cause the functions/operations specified in the flowcharts and/or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

The above program code may be embodied on a machine readable medium, which may be any tangible medium that may contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. The machine readable medium may be a machine readable signal medium or a machine readable storage medium. A machine readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the machine readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM) , a read-only memory (ROM) , an erasable programmable read-only memory (EPROM or Flash memory) , an optical fiber, a portable compact disc read-only memory (CD-ROM) , an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

Further, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination.

Although the present disclosure has been described in language specific to structural features and/or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

A terminal device comprising at least one processor configured to cause the terminal device to:

receive, from a network device, a low power signal comprising a low power wake-up signal (LP-WUS) or a low power synchronization signal (LP-SS) , wherein the low power signal comprises a plurality of on-off keying (OOK) symbols with a plurality of OOK-ON symbols and a plurality of OOK-OFF symbols, wherein the plurality of OOK symbols are generated based on a first bit sequence and the plurality of OOK-ON symbols are generated based on a second bit sequence, and wherein the second bit sequence is determined based on an inverse order of the first bit sequence or a cyclic shift of the first bit sequence; and

determine an information block of the low power signal.
The terminal device of claim 1, wherein each bit in the first bit sequence is mapped to one or more OOK symbols, wherein a first bit with a first value is mapped to a first set of OOK symbols, and a second bit with a second value is mapped to a second set of OOK symbols, wherein the plurality of OOK-ON symbols are generated based on a plurality of overlaid sequences, and the plurality of overlaid sequences are generated based on the second bit sequence.
The terminal device of claim 2, wherein the at least one processor is configured to cause the terminal device to:

determine the information block based on the plurality of overlaid sequences and corresponding OOK symbols, wherein a first number of the plurality of overlaid sequences is determined based on:

a length of the first bit sequence, and

a second number of bits carried by an overlaid sequence of the plurality of overlaid sequences.
The terminal device of claim 3, wherein the second bit sequence comprises a plurality of subsequences each with a length equaling to the length of the first bit sequence, and a number of the plurality of subsequences is equal to the second number.
The terminal device of claim 4, wherein each of the plurality of subsequences comprises an inverse order of the first bit sequence.
The terminal device of claim 4, wherein,

for two adjacent subsequences in the second bit sequence, one subsequence comprises an inverse order of the first bit sequence, and another one subsequence comprises the first bit sequence.
The terminal device of claim 1, wherein a length of the second bit sequence is shorter than or equals to a length of the first bit sequence.
The terminal device of claim 7, wherein the second bit sequence is generated based on an inverse order of a rear part of the first bit sequence, wherein a length of the rear part equals to the length of the second bit sequence.
The terminal device of claim 1, wherein the second bit sequence is a cyclic shift of the first bit sequence with a shift value determined based on the second number.
The terminal device of claim 2, wherein the overlaid sequence with a second number is generated based on a plurality of bits from the second bit sequence.
The terminal device of claim 2, wherein the overlaid sequence is selected from a sequence set.
The terminal device of claim 2, wherein the overlaid sequence comprises a pseudo random sequence or a Zadoff-Chu (ZC) sequence generated based on a parameter.
The terminal device of claim 2, wherein the overlaid sequence comprises a time domain sequence or a frequency domain sequence.
The terminal device of claim 1, wherein the information block is determined as a payload of the LP-WUS, and wherein the payload comprises a plurality of information bits being used as a wake-up indication field.
The terminal device of claim 1, wherein the information block is determined as a binary sequence associated with the LP-SS.
A network device comprising at least one processor configured to cause the network device to:

determine a first bit sequence based on an information block of a low power signal to be transmitted to a terminal device, wherein the low power signal comprises a low power wake-up signal (LP-WUS) or a low power synchronization signal (LP-SS) ;

determine a second bit sequence based on an inverse order of the first bit sequence or a cyclic shift of the first bit sequence;

generate the low power signal based on the first bit sequence and the second bit sequence, wherein the low power signal comprises a plurality of on-off keying (OOK) symbols with a plurality of OOK-ON symbols and a plurality of OOK-OFF symbols, and wherein the plurality of OOK symbols are generated based on the first bit sequence and the plurality of OOK-ON symbols are generated based on the second bit sequence; and

transmit, to the terminal device, the low power signal.
The network device of claim 16, wherein the at least one processor is configured to cause the network device to:

generate the plurality of OOK symbols by mapping each bit in the first bit sequence to one or more OOK symbols, wherein a first bit with a first value is mapped to a first set of OOK symbols, and a second bit with a second value is mapped to a second set of OOK symbols; and

determine the plurality of OOK-ON symbols based on a plurality of overlaid sequences, wherein the plurality of overlaid sequences are generated based on the second bit sequence.
The network device of claim 17, wherein the at least one processor is further configured to cause the network device to:

determine to transmit a plurality of overlaid sequences and corresponding OOK symbols, wherein a first number of the plurality of overlaid sequences is determined based on:

a length of the first bit sequence, and

a second number of bits carried by an overlaid sequence of the plurality of overlaid sequences.
The network device of claim 18, wherein the second bit sequence comprises a plurality of subsequences each with a length equaling to the length of the first bit sequence, and a number of the plurality of subsequences is equal to the second number.
The network device of claim 19, wherein each of the plurality of subsequences comprises an inverse order of the first bit sequence.