Method and apparatus for wake-up signal

Abstract

The embodiment of the invention relates to a method and equipment for waking up a signal. A method implemented at a network device includes forming an OOK subsequence having a plurality of OOK symbols, the plurality of OOK symbols including at least one OOK ON symbol and at least one OOK OFF symbol. The plurality of OOK symbols is associated with an OFDM symbol. The method further includes mapping the OOK sub-sequence to a plurality of pre-discrete Fourier transform (pre-DFT) sub-sequences to form a pre-DFT sequence, and performing transform precoding on the pre-DFT sequence. The method further includes mapping the output of the transform precoding into a frequency resource allocated to a wake-up signal (WUS) and generating the WUS, and transmitting the WUS to a terminal device.

Description

Technical Field

[0001] Embodiments of the present disclosure relate generally to the field of telecommunications, and more particularly to methods and apparatus for wake-up signals. Background Art

[0002] For a user equipment (UE) in radio resource control (RRC) idle / inactive state, periodic paging monitoring and measurement consumes considerable power on the UE side, which is critical for power-constrained devices (e.g., Internet of Things (IoT) devices, wearable devices, etc.).

[0003] Research on low-power wake-up signaling (WUS) is needed, which can study and evaluate the techniques of low-power signaling and low-power receivers to achieve extremely low power consumption and low wake-up latency. Summary of the invention

[0004] In general, example embodiments of the present disclosure provide methods and apparatus for wake-up signals.

[0005] In a first aspect, a method implemented at a network device is provided. The method includes generating at least one on-off keying (OOK) ON symbol by using a first number of frequency resources mapped with a non-zero value. The non-zero value is used for normal downlink (DL) transmission. The method also includes generating at least one OOK OFF symbol by using a second number of frequency resources mapped with a zero value or a value close to zero. The method also includes generating a wake-up signal (WUS) based on at least one OOK ON symbol and at least one OOK OFF symbol, and sending the WUS to a terminal device.

[0006] In a second aspect, a method implemented at a network device is provided. The method includes forming an OOK subsequence having a plurality of OOK symbols, the plurality of OOK symbols including at least one OOK ON symbol and at least one OOK OFF symbol. The plurality of OOK symbols are associated with an OFDM symbol. The method also includes mapping the OOK subsequence to a plurality of pre-discrete Fourier transform (pre-DFT) subsequences accordingly to form a pre-DFT sequence. The method also includes performing transform precoding on the pre-DFT sequence, and mapping the output of the transform precoding to a frequency resource allocated to a wake-up signal (WUS) and generating a WUS. The method also includes sending the WUS to a terminal device. The length of the pre-DFT subsequence in the plurality of pre-DFT subsequences is associated with at least one of the following items: the number of subcarriers used for the WUS, the number of the plurality of OOK symbols, or the index of the pre-DFT subsequence in the plurality of pre-DFT subsequences.

[0007] In a third aspect, a method implemented at a terminal device is provided. The method includes receiving a wake-up signal (WUS) from a network device. The method also includes detecting the WUS to determine a plurality of on-off keying (OOK) symbols, the plurality of OOK symbols including at least one OOK ON symbol and at least one OOK OFF symbol. At least one OOK ON symbol is generated based on a first number of frequency resources mapped with a non-zero value. The non-zero value is used for normal downlink (DL) transmission. At least one OOK OFF symbol is generated based on a second number of frequency resources mapped with a zero value or a value close to zero.

[0008] In a fourth aspect, a method implemented at a terminal device is provided. The method includes receiving a wake-up signal (WUS) from a network device. The method also includes detecting the WUS to determine a plurality of on-off keying (OOK) symbols including at least one OOK ON symbol and at least one OOK OFF symbol. The WUS is generated based on the output of the transform precoding of a pre-discrete Fourier transform (pre-DFT) sequence, and the pre-DFT sequence includes a plurality of pre-DFT subsequences. The pre-DFT sequence is generated based on an OOK subsequence, and the OOK subsequence includes a plurality of OOK symbols. A plurality of OOK symbols are associated with an OFDM symbol. In addition, the length of the pre-DFT subsequence in the plurality of pre-DFT subsequences is associated with at least one of the following items: the number of subcarriers used for the WUS, the number of the plurality of OOK symbols, or the index of the pre-DFT subsequence in the plurality of pre-DFT subsequences.

[0009] In a fifth aspect, a method implemented at a terminal device is provided. The method includes receiving a downlink (DL) signal from a network device, the DL signal including a wake-up signal (WUS) and a normal DL transmission. The LP-WUS and the normal DL transmission are generated using orthogonal frequency division multiplexing (OFDM) operation. The method also includes receiving a WUS configuration from the network device, and determining resources for the WUS indicated in the WUS configuration. The method also includes determining overlapping resources that are allocated to normal DL transmission and overlap with resources for the WUS, and determining that the overlapping resources are not available for normal DL transmission.

[0010] In a sixth aspect, a method implemented at a terminal device is provided. The method includes receiving a downlink (DL) signal from a network device, the DL signal including a wake-up signal (WUS) and a normal DL transmission. The WUS includes a plurality of on-off keying (OOK) symbols, the plurality of on-off keying (OOK) symbols including at least one OOK ON symbol and at least one OOK OFF symbol. At least one OOK ON symbol is generated based on data of a normal DL transmission. The method also includes determining an index of a plurality of PRBs assigned to the WUS, and determining that a resource unit (RE) of a plurality of PRBs of an OFDM symbol associated with the OOK ON symbol is available for normal DL transmission. The method also includes determining that the RE of a plurality of PRBs of an OFDM symbol associated with the OOK OFF symbol is not available for normal DL transmission.

[0011] In a seventh aspect, a network device is provided. The network device comprises a processor and a memory storing instructions. The memory and the instructions are configured together with the processor to enable the network device to perform the method according to the first and second aspects.

[0012] In an eighth aspect, a terminal device is provided. The terminal device includes a processor and a memory storing instructions. The memory and the instructions are configured together with the processor to enable the terminal device to execute the method according to the third, fourth, fifth and sixth aspects.

[0013] In a ninth aspect, a computer readable medium is provided, having instructions stored thereon, which, when executed on at least one processor of a device, cause the device to perform the method according to the first, second, third, fourth, fifth and sixth aspects.

[0014] It should be understood that the invention summary is not intended to identify the key or essential features of the embodiments of the present disclosure, nor is it intended to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and other objects, features and advantages of the present disclosure will become more apparent through a more detailed description of some embodiments of the present disclosure in the accompanying drawings, in which:

[0016] Figure 1 An example communication system is shown in which embodiments of the present disclosure may be implemented;

[0017] Figure 2 An example process of generating a WUS signal according to some example embodiments of the present disclosure is shown;

[0018] Figure 3An example signaling diagram illustrating an example process of a WUS according to some embodiments of the present disclosure;

[0019] Figure 4 An example signaling diagram illustrating another example process of WUS according to some embodiments of the present disclosure.

[0020] Figure 5A An example transmitter for WUS according to some embodiments of the present disclosure is shown;

[0021] Figure 5B An example receiver for WUS according to some embodiments of the present disclosure is shown;

[0022] Figure 6 An example diagram of OFDM symbols in a subframe for 15 KHz subcarrier spacing (SCS) according to some embodiments of the present disclosure is shown;

[0023] Fig. 7A shows an example diagram of OOK ON symbol generation according to some embodiments of the present disclosure;

[0024] Figure 7B Another example diagram showing OOK ON symbol generation according to some embodiments of the present disclosure;

[0025] Figure 7C Another example diagram showing OOK ON symbol generation according to some embodiments of the present disclosure;

[0026] Fig. 8A shows an example diagram of OOK OFF symbol generation according to some embodiments of the present disclosure;

[0027] Figure 8B Another example diagram of OOK OFF symbol generation according to some embodiments of the present disclosure is shown;

[0028] Fig.9A An example diagram showing OOK symbol generation based on a discrete Fourier transform spread OFDM (DFT-s-OFDM) waveform according to certain embodiments of the present disclosure;

[0029] Fig. 9B Another example diagram illustrating OOK symbol generation based on a DFT-s-OFDM waveform according to certain embodiments of the present disclosure;

[0030] Fig.10 An example diagram showing an OOK sequence that processes a cyclic prefix (CP) as a useful portion of an OOK symbol in accordance with certain embodiments of the present disclosure;

[0031] Fig.11An example diagram of the OOK sequence of FIG. 9 showing an inserted guard interval (GI) according to certain embodiments of the present disclosure;

[0032] Fig.12 An example diagram showing an OOK sequence in which CP is processed as an unused portion of an OOK symbol according to certain embodiments of the present disclosure;

[0033] Fig.13 An example diagram showing an OOK sequence in which the duration of the CP and the duration of the OOK sequence are different according to some embodiments of the present disclosure;

[0034] Fig.14A and 14B An example diagram showing an OOK sequence with padding data inserted between non-consecutive OOK symbols according to some embodiments of the present disclosure;

[0035] Fig.15 A flowchart illustrating an example method implemented at a network device according to some embodiments of the present disclosure;

[0036] Fig.16 A flowchart illustrating another example method implemented at a network device according to some embodiments of the present disclosure is shown;

[0037] Fig.17 A flowchart showing an example method implemented at a terminal device according to some embodiments of the present disclosure is shown;

[0038] Fig.18 A flowchart showing another example method implemented at a terminal device according to some embodiments of the present disclosure is shown;

[0039] Fig.19 A flowchart showing another example method implemented at a terminal device according to certain embodiments of the present disclosure; and

[0040] Fig. 20 is a simplified block diagram of a device suitable for implementing embodiments of the present disclosure.

[0041] Throughout the drawings, the same or similar reference numerals denote the same or similar elements. DETAILED DESCRIPTION

[0042] The principles of the present disclosure will now be described with reference to some example embodiments. It should be understood that these embodiments are only for illustrative purposes, and contribute to those skilled in the art to understand and implement the present disclosure, without implying any limitation to the scope of the present disclosure. The present disclosure described herein can be implemented in various ways except for the modes described below.

[0043] 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 skill in the art to which this disclosure belongs.

[0044] As used herein, the term "network equipment" refers to equipment that is capable of providing or hosting a cell or coverage with which a terminal device can communicate. Examples of network equipment include, but are not limited to, Node B (NodeB or NB), evolved Node B (eNodeB or eNB), next generation Node B (gNB), transmission reception point (TRP), remote radio unit (RRU), radio head (RH), remote radio head (RRH), IAB node, low power node (such as femto node), pico node, reconfigurable intelligent surface (RIS), etc.

[0045] As used herein, the term "terminal device" refers to any device with wireless or wired communication capabilities. Examples of terminal devices include, but are not limited to, user equipment (UE), personal computers, desktops, mobile phones, cellular phones, smartphones, 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 communications (MTC) devices, vehicle-borne devices for V2X communications (where X represents pedestrians, vehicles, or infrastructure / networks), devices for integrated access and backhaul (IAB), space-borne vehicles or airborne vehicles in non-terrestrial networks (NTNs) (including satellites and high altitude platforms (HAPs), including unmanned aerial systems (UASs), extended reality (XR) devices (including different types of reality, such as augmented reality (AR), mixed reality (MR), and virtual reality (VR) R)), unmanned aerial vehicles (UAV) (commonly known as drones, which are aircraft without any human pilots), devices on high-speed trains (HST) or image capture devices, such as digital cameras, sensors, gaming devices, music storage and playback devices, or Internet devices that support wireless or wired Internet access and browsing, etc. "Terminal device" may also have "multicast / broadcast" features to support public safety and critical missions, V2X applications, transparent IPv4 / IPv6 multicast transmission, IPTV, Smart TV, radio services, wireless software transmission, group communication and IoT applications. It may also be combined with one or more subscriber identity modules (SIMs), known as multi-SIM. The term "terminal device" may be used interchangeably with UE, mobile station, subscriber station, mobile terminal, user terminal or wireless device.

[0046] Terminal devices or network devices can have artificial intelligence (AI) or machine learning capabilities. It usually includes a model that has been trained from a large amount of collected data for a specific function and can be used to predict some information.

[0047] The terminal or network device can operate in several frequency ranges, such as FR1 (410MHz to 7125MHz), FR2 (24.25GHz to 71GHz), frequency bands greater than 100GHz, and terahertz (THz). It can also operate on licensed / unlicensed / shared spectrum. In the multi-radio dual connectivity (MR-DC) application scenario, the terminal device can have more than one connection with the network device. The terminal device or network device can operate in full-duplex, flexible duplex, and cross-duplex modes.

[0048] The embodiments of the present disclosure may be executed in a test device, such as a signal generator, a signal analyzer, a spectrum analyzer, a network analyzer, a test terminal device, a test network device, or a channel simulator.

[0049] 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 "including" and its variations are to be understood as open-ended terms, meaning "including but not limited to". The term "based on" is to be understood as "based at least in part on". The terms "some embodiments" and "embodiments" are to be understood as "at least some embodiments". The term "another embodiment" is to be understood as "at least one other embodiment". The terms "first", "second", etc. may refer to different or the same objects. Other explicit and implicit definitions may be included below.

[0050] In some examples, values, processes, or devices are referred to as "best," "lowest," "highest," "minimum," "maximum," etc. It should be understood that such descriptions are intended to indicate that a selection may be made among a number of functional alternatives for use, and that such selection is not necessarily better, lesser, higher, or more preferred than other selections.

[0051] As mentioned above, research on low-power wake-up signals (WUS) is needed. OOK modulation has been widely considered in research due to its very simple receiver architecture and extremely low power consumption. With OOK modulation, the receiver may only need to detect the envelope / energy of the time domain signal at a relatively low sampling rate without complex baseband processing.

[0052] IEEE 802.11ba introduces a low-power wake-up mechanism for WiFi systems using multi-carrier OOK modulation. In 802.11ba, OOK on and off symbols are generated based on CP-OFDM symbols, and the duration of CP-OFDM is 4us.

[0053] However, New Radio (NW) systems may have different requirements from Wi-Fi systems. For example, NR may focus mainly on idle / inactive mode, requiring a good balance between power saving and wake-up latency, and may not provide the same coverage as normal DL / uplink (UL) transmissions.

[0054] In addition, the existing NR channels / signals are based on OFDM waveforms, which cannot coexist directly with OOK. Therefore, the WUS signal can be generated independently of other OFDM-based channels / signals. However, considering the complexity and spectrum efficiency, it would be beneficial to reuse the OFDM framework to generate the WUS signal. For example, if the WUS is synchronized with normal DL channels (e.g., physical downlink control channel (PDCCH), physical downlink shared channel (PDSCH)) and uses the same OFDM parameter set, they are orthogonal in the frequency domain, so the guard band can be avoided or reduced. In addition, the time boundaries of the WUS and other DL symbols can be well aligned, which is conducive to obtaining good resource utilization.

[0055] If we use the same method as IEEE 802.11ba, there will be some problems. For example, the CP-OFDM symbol of NR is much longer than that of WIFI (e.g., about 71us for NR 15KHz SCS), and using such a long OOK symbol may cause low spectrum efficiency; multiple SCS are supported by NR, and the duration of the CP-OFDM symbol may depend on the parameter set; and the CP length of OFDM symbols in one slot may not be the same, for example, for 15KHz SCS, the 0th and 7th symbols may have longer CP than other symbols.

[0056] In the present disclosure, OOK modulation is only an example, and other amplitude modulations (e.g., amplitude shift keying (ASK)) may also be used. The term "OOK symbol" may also be replaced by "modulation symbol", "OOK ON-symbol" may be replaced by "symbol with higher amplitude", and "OOK OFF-symbol" may be replaced by "symbol with lower amplitude or zero amplitude".

[0057] An embodiment of the present disclosure proposes a method for generating a low-power wake-up signal. In this solution, common OFDM operation is used for both WUS and other DL transmissions. WUS only occupies part of the channel bandwidth and is multiplexed with other DL transmissions in the frequency domain, and then the spectrum efficiency can be improved.

[0058] The principles and implementations of the present disclosure will be referred to below Figures 1 to 20In some embodiments, a general configuration (e.g., time / frequency resources) for a WUS is described. Some embodiments describe how to generate an OOK symbol if one CP-OFDM symbol is considered as one OOK symbol. In addition, some embodiments describe how to generate an OOK symbol if one CP-OFDM symbol is considered as multiple OOK symbols.

[0059] Figure 1 An example communication system 100 in which embodiments of the present disclosure may be implemented is shown. System 100 includes terminal devices (e.g., UE) 120 and 121 and network devices (e.g., base station (BS)) 110 serving terminal devices 120 and 121. The service area of ​​network device 110 is referred to as cell 102. It should be understood that the number of network devices and terminal devices is only for illustrative purposes and does not represent any limitation. System 100 may include any suitable number of network devices and terminal devices suitable for implementing embodiments of the present disclosure.

[0060] In some embodiments, terminal device 120 may be in an RRC idle / inactive state and monitor for a WUS from network device 110, while terminal device 121 may be in an RRC connected / active state and receive DL transmissions from network device 110. In some embodiments, terminal device 121 may be indicated resources for the WUS to avoid potential resource conflicts between the WUS and other DL transmissions.

[0061] Communications in the communication system 100 may be implemented according to any generation of communication protocols currently known or to be developed in the future. Examples of communication protocols include, but are not limited to, first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, fifth generation (5G) communication protocols, 5.5G, 5G-Advanced networks, or sixth generation (6G) networks.

[0062] Figure 2 An example process 200 of generating a WUS signal according to some example embodiments of the present disclosure is shown. Some terms will refer to Figure 2 is described. By way of example, Figure 2An OOK subsequence containing four OOK symbols "1010" is shown, where the OOK symbol can be an OOK ON symbol (represented by "1") or an OOK OFF symbol (represented by "0"), the OOK sequence is a sequence of OOK symbols, and the OOK subsequence is a continuous portion of the OOK sequence. In some embodiments, the OOK sequence is mapped into multiple OFDM symbols, and the OOK subsequence is a portion of the OOK sequence and is mapped into one of the multiple OFDM symbols. In some embodiments, the term "mapping" indicates transformation or association, for example, mapping the OOK sequence into multiple OFDM symbols may mean that the OOK sequence is transformed into multiple OFDM symbols (i.e., multiple OFDM symbols are generated based on the OOK sequence), or the OOK sequence is associated with multiple OFDM symbols.

[0063] like Figure 2 As shown, a pre-discrete Fourier transform (pre-DFT) sequence is obtained by performing sequence mapping 210 on the OOK subsequence. After sequence mapping 210, each OOK symbol in the OOK subsequence is mapped to a pre-DFT subsequence, and a plurality of pre-DFT subsequences associated with the OOK symbols in the OOK subsequence are concatenated into a pre-DFT sequence.

[0064] After transform precoding and inverse fast Fourier transform (IFFT) operation 220, the pre-DFT sequence is transformed into a post-IFFT sequence. The post-IFFT subsequence is a continuous part of the post-IFFT sequence. The post-IFFT subsequence can be approximately regarded as a transformation from the corresponding pre-DFT subsequence. The post-IFFT subsequence associated with the OOK OFF symbol has a relatively small power, while the post-IFFT subsequence associated with the OOK ON symbol has a relatively large power. In some embodiments, the IFFT operation can be replaced by an inverse discrete Fourier transform (IDFT).

[0065] In addition, after the DFT (also known as transform precoding) operation, the pre-DFT sequence is transformed into a post-DFT sequence. It is an intermediate stage between the pre-DFT sequence and the post-IFFT sequence and is Figure 2 Not shown.

[0066] Thereafter, the WUS signal may include at least one post-IFFT sequence, and optionally have other signals (eg, CP, GI, padding data, or a signal generated based on the padding data, etc.).

[0067] To summarize, the post-IFFT sequence, pre-DFT sequence and OOK subsequence are correlated with each other; the post-IFFT subsequence, pre-DFT subsequence and OOK symbols are correlated with each other; the post-IFFT subsequence can be regarded as an oversampled version of the associated pre-DFT subsequence, and the post-IFFT sequence can be regarded as an oversampled version of the associated pre-DFT sequence.

[0068] Please note that in this disclosure, if not specifically stated, the term "OFDM symbol" refers to a CP-OFDM symbol, or any variant of an OFDM symbol, e.g., GI-OFDM, zero CP OFDM, unique word OFDM, etc. And the term "OFDM without CP" refers to the output of IFFT, and the CP or guard interval has not yet been inserted.

[0069] Figure 3 An example signaling diagram of an example process 300 of a WUS according to some embodiments of the present disclosure is shown. For ease of discussion, the process 300 will refer to Figure 1 Process 300 may involve Figure 1 The network (NW) device 110 and the terminal devices 120 and 121 (ie, UE 120 and UE 121) are shown. Although the process 300 has been Figure 1 The process is described in the communication system 100, but the process can also be applied to other communication scenarios.

[0070] like Figure 3 As shown, NW 110 generates 310 at least one OOK ON symbol and generates 320 at least one OOK OFF symbol. In some embodiments, the OOK ON symbol or the OOK OFF symbol is generated based on OFDM symbols that are also used for normal DL transmission (e.g., PDCCH, PDSCH, channel state information reference signal (CSI-RS), etc.).

[0071] In some embodiments, multiple subcarriers can be used for OOK symbol generation. For example, a first number of subcarriers mapped with non-zero values ​​can be used to generate OOK ON symbols. The non-zero value can be a complex-valued symbol dedicated to WUS, or the non-zero value can be a value also used for normal DL channels or DL ​​signals (e.g., PDCCH, PDSCH, demodulation reference signal (DMRS), CSI-RS, positioning RS, etc.). In addition, a second number of subcarriers mapped with zero values ​​or near zero values ​​can be used to generate OOK OFF symbols. A value close to zero has a power less than the non-zero value used for the OOK ON symbol. The number of the first plurality of subcarriers and the number of the second plurality of subcarriers may be different.

[0072] After at least one OOK ON symbol and at least one OOK OFF symbol are generated, the NW 110 generates 330 a WUS based on the generated OOK ON symbol and OOK OFF symbol.

[0073] Using this OOK symbol generation mechanism, WUS can occupy only part of the channel bandwidth and can be multiplexed with other DL transmissions in the frequency domain. Therefore, spectral efficiency can be improved. In addition, common OFDM operation can be used for both WUS and other DL transmissions, and WUS can be orthogonal to normal DL transmissions, so the guard band between WUS and normal DL transmissions can be reduced. For example, at least for OOK ON symbols, there may be no guard band because the inter-carrier interference from normal DL transmissions to WUS is actually useful for OOK symbol detection because it increases the power level of the OOK ON symbols on the receiver side. There may be no interference from WUS to normal DL transmissions because they are generated by common OFDM operations.

[0074] Frequency domain resources for WUS will be described. In some embodiments, WUS may occupy multiple subcarriers or physical resource blocks (PRBs), for example, 100 subcarriers or 200 subcarriers, or 4PRBs, 8PRBs, 16PRBs, 24PRBs or 32PRBs, etc.

[0075] Reference now Figure 5A and Figure 5B . Figure 5A An example transmitter 500 for a WUS that may be included in a network device 110 is shown. Figure 5B An example receiver 450 of a WUS that may be included in terminal devices 120 and 121 is shown.

[0076] On the transmitter 500 side, the NW 110 generates WUS and normal DL transmissions through a common OFDM generation operation. Figure 3 As shown, NW 110 sends 340 WUS to UE 120. In some embodiments, NW 110 sends 350 a DL signal including WUS and normal DL transmission to UE 121. In some embodiments, NW 110 may also send WUS to UE 120 in a DL signal including normal DL transmission. On the receiver 550 side, UE 120 may use filter 551 (e.g., a bandpass filter) to suppress interference from other DL transmissions to WUS, and then use OOK detector 452 to detect WUS symbols.

[0077] In some embodiments, the WUS may occupy frequency resources at the edge of the bandwidth, in other words, the PRBs allocated for the WUS may be the first M PRBs (i.e., the lower bandwidth edge) or the last M PRBs (i.e., the upper bandwidth edge) of the channel bandwidth, where M is an integer. Additionally or alternatively, a subset of the subcarriers of the M PRBs is located in a guard band of the channel bandwidth, in other words, a subset of the subcarriers of the M PRBs is a subcarrier that is not available for other DL transmissions.

[0078] The benefit of allowing the WUS to be located at the edge of the bandwidth or in the guard band is at least to save potential guard bands between the WUS and other DL transmissions, as only one side guard band may be needed between the WUS and other DL transmissions.

[0079] In some embodiments, UE 120 may be instructed with bandwidth configuration to monitor WUS. If UE 120 does not receive bandwidth configuration, UE 120 may assume that the frequency resources of WUS are the center / upper edge / lower edge M PRBs of a default bandwidth part (BWP) (e.g., an initial BWP or a preconfigured BWP). Additionally or alternatively, the frequency resources of WUS may be the center / upper edge / lower edge M PRBs of a channel bandwidth, where the channel bandwidth may be indicated by NW 110 in system information.

[0080] The time domain resources used for WUS will be described. In some embodiments, the duration of WUS may be equal to or not greater than N consecutive OFDM symbols (a guard duration may be reserved before or after the WUS signal, and the guard duration may also be in N OFDM symbols), where N is an integer, and N may be associated with the parameter set configuration for the OFDM symbol, for example, N may be equal to s*2^u, where u is a parameter set parameter that is an integer, and s is an integer.

[0081] In some embodiments, the WUS may start from an OFDM symbol with an index from 0, 1, 2, 3, ..., 7*2^u in a subframe, and end at an OFDM symbol no later than the OFDM symbol with an index of 7*2^u in the subframe. In other words, the WUS signal may be within the first half subframe, or within the first OFDM symbol of the first half subframe plus the second half subframe. Alternatively, the WUS signal may start from an OFDM symbol with an index from 7*2^u, (7*2^u)+1, (7*2^u)+2, ..., (14*2^u)-1 in a subframe, and end at an OFDM symbol no later than the OFDM symbol with an index of (14*2^u)-1 in the subframe. In other words, the WUS signal may be within the second half subframe.

[0082] This may be because symbol 0 and symbol 7*2^u have longer CPs than other OFDM symbols in the subframe. If the WUS signal spans symbol 0 or symbol 7*2^u, the duration of the OOK symbol may not be unique, which may degrade receiver performance.

[0083] Reference now Figure 6 , Figure 6 An example diagram 600 of OFDM symbols in a subframe for 15 KHz SCS (ie, u=0,) is shown in accordance with some embodiments of the present disclosure.

[0084] In some embodiments, for 15KHz SCS, the WUS signal may contain 7 OOK symbols, and the duration of each OOK symbol may be equal to the duration of an OFDM symbol, and the 7 OOK symbols may be aligned with OFDM symbols 7 to 13 accordingly.

[0085] like Figure 6 As shown, symbol 7 is longer than the other symbols. However, this has no effect on the WUS detector because the detector can determine the duration of the first OOK symbol based on the boundary between the first and second OOK symbols.

[0086] In some embodiments, if the parameter set is 30KHz SCS, in order to align with the 15KHz case, the WUS signal can still contain 7 OOK symbols, and the duration of each OOK symbol can be equal to the duration of two OFDM symbols. As an example, the first OOK symbol can be aligned with OFDM symbol 14 and OFDM symbol 15, and the second OOK symbol can be aligned with OFDM symbol 16 and OFDM symbol 17, and so on. Figure 6 As shown, T1=T2+16*Ts, where Ts is the reference sampling duration.

[0087] Alternatively, for 15KHz SCS, the WUS signal may contain N OOK symbols, where N is less than 7, and the duration of each OOK symbol may be equal to an OFDM symbol, and the N OOK symbols may be aligned with N consecutive OFDM symbols in the last 7 OFDM symbols of the subframe.

[0088] Now return to reference Figure 3 For a UE (eg, UE 120) in an RRC idle / inactive state, NW 110 may send 360 a WUS configuration to UE 120 in system information.

[0089] In some embodiments, the WUS configuration may include a frequency domain resource configuration. The frequency domain resource configuration may indicate a plurality of PRBs or subcarriers occupied by the WUS signal. For example, the frequency domain resource configuration may indicate the index of the first PRB / subcarrier of the WUS and the number of PRBs / subcarriers of the WUS. If the number of PRBs / subcarriers is not indicated, a predefined / default value may be used by the UE 120. Additionally or alternatively, the frequency domain resource configuration may indicate one of the following candidate resource configurations: the WUS occupies the first M PRBs of the BWP or channel bandwidth, the WUS occupies the last M PRBs of the BWP or channel bandwidth, the WUS occupies the middle M PRBs of the BWP or channel bandwidth, or the BWP or channel bandwidth is a default or preconfigured BWP or channel bandwidth.

[0090] In some embodiments, the WUS configuration may include a sequence configuration. The sequence configuration may indicate one of the following: sequence length (ie, the number of OOK symbols in a sequence), duration of an OOK symbol, or a sequence ID indicating an OOK sequence from a plurality of predefined OOK sequences.

[0091] In some embodiments, the WUS configuration may further include a time domain resource configuration. The time domain resource configuration may indicate one of the following: a period of the WUS, a duty cycle of the WUS, or the number of OOK symbols mapped to an OFDM symbol.

[0092] In some embodiments, for a UE in an RRC connected state (e.g., UE 121), it may not be necessary to monitor the WUS. However, the resources used for the WUS may still be indicated to avoid potential resource conflicts between the WUS and other DL transmissions. Therefore, the NW 110 may send 360 the WUS configuration to the UE 121 via an RRC information element. The above information for idle / inactive UEs may be reused for connected UEs. In addition, the time domain resource configuration may also indicate N consecutive OFDM symbols in a time slot or subframe that may be used for the WUS.

[0093] In some embodiments, the OOK ON symbol or the OOK OFF symbol may be mapped into a single OFDM symbol. Specifically, a portion of the subcarriers of the OFDM symbol may be used to generate the OOK symbol, and the other subcarriers may be used for other DL transmissions. Using these methods, it is very simple to generate the OOK symbol by utilizing the existing OFDM signal generation. In addition, it is easy to achieve symbol / time slot / subframe alignment between the WUS signal and other DL transmissions.

[0094] Now back to Figure 3UE 120 detects 370 WUS using, for example, detector 552 to determine a plurality of OOK symbols including at least one OOK ON symbol and at least one OOK OFF symbol.

[0095] In some embodiments, UE 121 determines 380 resources for the WUS. For example, UE 121 may determine resources for the WUS indicated in the WUS configuration. UE 121 may be indicated with time and frequency resources for the WUS. If resources for other DL transmissions overlap with the resources allocated to the WUS, UE 121 may determine that the overlapping resources are not available for other DL transmissions.

[0096] Additionally or alternatively, if the OOK ON symbol is generated based on data of other DL transmissions, the UE 121 may determine the indexes of the multiple PRBs allocated to the WUS. For a particular time slot to which the WUS is mapped, the UE 121 may determine the WUS sequence (i.e., the OOK sequence) in the time slot. The UE 121 may determine that the resource elements (REs) of the M PRBs of the OFDM symbol associated with the OOK ON symbol are available for other DL transmissions, and determine that the REs of the M PRBs in the OFDM symbol associated with the OOK OFF symbol are not available for other DL transmissions.

[0097] In some embodiments, the OOK sequence may be indicated by a downlink control information (DCI) format (e.g., by DCI format 1-0, 1-1, or 1-2), the DCI format scheduling the PDSCH for UE 121. Additionally or alternatively, UE 121 may determine the OOK sequence based on a preemption indication (e.g., by DCI format 2-1). Wherein S bits of preemption indication may be used, and each of the S bits may represent a symbol group, wherein the symbol group may include at least one consecutive OFDM symbol. A bit value of "0" / "1" may indicate that the corresponding symbol group is associated with an OOK ON symbol (i.e., the corresponding symbol group and the M PRBs may be available for other DL transmissions), and a bit value of "1" / "0" may indicate that the corresponding symbol group is associated with an OOK OFF symbol (i.e., the corresponding symbol group and the M PRBs may not be available for other DL transmissions).

[0098] Fig. 7A An example diagram 700 of OOK ON symbol generation according to some embodiments of the present disclosure is shown. Fig. 7A In the example, NW 110 may generate OOK ON symbols based on other DL transmissions.

[0099] In this case, the M PRBs allocated for WUS are actually mapped with data of other DL transmissions (e.g., PDSCH, PDCCH, CSI-RS, DMRS, etc.), and these DL transmissions may be sent, for example, to UE 121. The feasibility of this method may be that the OOK detector only detects the envelope or energy of the OOK symbol and is not affected by the value of the data mapped to the M PRBs.

[0100] Figure 7B An example diagram 730 of OOK ON symbol generation according to some embodiments of the present disclosure is shown. Figure 7B In the example, NW 110 may generate OOK ON symbols based on a dedicated sequence for WUS.

[0101] In this case, a sequence (e.g., {S0, S1, S2, ..., Sn-1}) may be mapped to M PRBs to generate OOK ON symbols. The elements of the sequence may be complex-valued symbols, such as binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), 16 quadrature amplitude modulation (QAM), or 64QAM symbols, or the sequence may be a Zadoff-Chu (ZC) sequence or a computer-generated sequence.

[0102] Figure 7C An example diagram 760 of OOK ON symbol generation according to some embodiments of the present disclosure is shown. Figure 7C In the example, NW 110 may generate OOK ON symbols based on a dedicated sequence with transform precoding 761 for WUS.

[0103] In this case, the sequence (e.g., {S0, S1, S2, ..., Sn-1}) can first be transformed precoded 761 (e.g., DFT processing), and then the output of the transform precoding can be mapped to M PRBs to generate OOK ON symbols.

[0104] for Figures 7A to 7C Due to the OOK ON symbol generation method in, a guard band may not be required between WUS and other DL transmissions. For the OOK ON symbol, any signal component that increases the power is beneficial to detection. Therefore, at the receiver side, power leakage from other DL transmissions to WUS has no harmful effect on the envelope or energy detector. On the contrary, the leakage may increase the detection power of the WUS ON symbol. On the other hand, for UEs receiving other DL transmissions, since the WUS and other DL transmissions are generated using common OFDM operation, there may be no interference from the WUS to other DL transmissions at the receiver side.

[0105] As described above, a zero value or a near-zero value (i.e., a value with less power than other DL transmissions or a dedicated sequence for the OOK ON symbol) is mapped to the M PRBs allocated for the WUS to generate the OOK OFF symbol. Unlike the OOK ON symbol, power leakage from other DL transmissions may have a negative impact on the OOK OFF symbol detection at the receiver side.

[0106] Fig. 8A An example diagram 800 of OOK OFF symbol generation according to some embodiments of the present disclosure is shown. Fig. 8A In this case, how to handle the interference from other DL transmissions to WUS can be implemented at the receiver side, for example, using a narrower bandpass filter, using an interference suppression algorithm, etc.

[0107] Figure 8B An example diagram 850 of OOK OFF symbol generation according to some embodiments of the present disclosure is shown. Figure 8B In some embodiments, the guard band is reserved between the WUS and other DL transmissions. In some embodiments, the guard band may be filled with a zero value or a value close to zero. Additionally or alternatively, the guard band may be filled with a non-zero value, and the non-zero value may be based on data of other DL transmissions, for example, the guard band may be filled with data related to frequency domain spectrum shaping for other DL transmissions.

[0108] In some embodiments, the OOK ON and OFF symbols may be generated based on a DFT-s-OFDM waveform and may be orthogonal to other DL transmissions. In some embodiments, a single OFDM symbol may be mapped into multiple OOK symbols. In some embodiments, the CP may be treated as a useful portion of the OOK symbol. Alternatively, the CP may be treated as a useless portion of the OOK symbol.

[0109] Using these methods, WUS and normal DL transmissions can be frequency-division multiplexed, so that spectrum efficiency can be improved. In addition, multiple OOK symbols can be mapped into a single OFDM symbol, so longer OOK sequences can be used within a specific duration, which may benefit detection performance.

[0110] Reference now Figure 4 . Figure 4 An example signaling diagram of another example process 400 of a WUS according to some embodiments of the present disclosure is shown. For the purpose of discussion, the process 400 will refer to Figure 1 Process 400 may involve a network (NW) device 110 and a terminal device 120 (ie, UE 120), such as Figure 1 Although process 400 is already Figure 1 is described in the communication system 100, but the process can equally be applied to other communication scenarios.

[0111] As Figure 4 shown, NW 110 forms 410 an OOK subsequence having a plurality of OOK symbols, the plurality of OOK symbols including at least one OOK ON symbol and at least one OOK OFF symbol. The plurality of OOK symbols may be associated with one OFDM symbol. NW 110 correspondingly maps 420 the OOK subsequence into a plurality of pre-DFT subsequences to form a pre-DFT sequence. Then, NW 110 performs 430 transform precoding on the pre-DFT sequence. In addition, NW110 maps 440 the output of the transform precoding into the frequency resources allocated to the WUS and generates the WUS. The length of the pre-DFT subsequence in the plurality of pre-DFT subsequences may be associated with at least one of the following: the number of subcarriers used for the WUS, the number of the plurality of OOK symbols, or the index of the pre-DFT subsequence in the plurality of pre-DFT subsequences.

[0112] In addition, NW 110 transmits 450 the WUS to the UE 120. The UE 120 detects 460 the WUS to determine a plurality of OOK symbols including at least one OOK ON symbol and at least one OOK OFF symbol. In some embodiments, the WUS is generated based on the output of the transform precoding of the pre-DFT sequence, and the pre-DFT sequence includes a plurality of pre-DFT subsequences. The pre-DFT sequence is generated based on the OOK subsequence, and the OOK subsequence includes a plurality of OOK symbols. The plurality of OOK symbols are associated with one OFDM symbol. In addition, the length of the pre-DFT subsequence in the plurality of pre-DFT subsequences is associated with at least one of the following: the number of subcarriers used for the WUS, the number of the plurality of OOK symbols, or the index of the pre-DFT subsequence in the plurality of pre-DFT subsequences.

[0113] Figure 4 The details of the WUS generation and detection shown in Figures 9A to 14B will be described with reference to Fig.9A and 9B shows the generation of OOK symbols based on the DFT-s-OFDM waveform according to some embodiments of the present disclosure. Fig.9A are collectively referred to as 900 in Fig. 9B and are collectively referred to as 950 in

[0114] As Fig.9A and9B As shown, the OOK subsequence can be mapped 901 to a pre-DFT sequence, ie, {S0, S1, S2, ..., Sn-1}, and the pre-DFT sequence can include k pre-DFT subsequences. In other words, each OOK symbol in the OOK subsequence can be mapped 901 to a pre-DFT subsequence.

[0115] Then, pre-DFT sequence may be performed using transform precoding 902 (ie, DFT transform), and the output of the transform precoding may be mapped into M PRBs allocated to the WUS.

[0116] In some embodiments, Fig.9A As shown, other DL transmissions and WUS may be performed using a single IFFT operation 903 and may then be inserted into the CP 904.

[0117] In some embodiments, Fig. 9B As shown, WUS can be performed using an independent IFFT operation 905, and then the GI can be inserted in front of the output of the IFFT 906. The length of the GI can be the same as the length of the CP used for other DL transmissions. The GI can be a zero-valued sample, a dedicated sequence, a copy or transformation of a specific part of the output of the IFFT, or a CP.

[0118] We now discuss the case where CP is treated as the useful part of the OOK symbol. Fig.10 An example diagram 1000 of an OOK sequence is shown that processes the CP of an OFDM symbol as the useful portion of the OOK symbol.

[0119] exist Fig.10 In the example, it is assumed that the number of subcarriers used for WUS is N. wus , the length of the OFDM symbol without CP is N ofdm samples, and the length of CP is N cp samples. Then the ideal length of each OOK symbol should be: (N ofdm +N cp ) / k, which is 1 / k of the length of the OFDM symbol. However, after IFFT transformation, there may be only N ofdm samples, so CP can be considered in OOK sequence mapping.

[0120] As described above, the OOK subsequence can be mapped to k pre-DFT subsequences. Specifically, each OOK symbol in the OOK subsequence is mapped to a pre-DFT subsequence, but the lengths of the pre-DFT subsequences can be different. Specifically, the first pre-DFT subsequence can be shorter than the other pre-DFT subsequences. The lengths of the k pre-DFT subsequences can be based on N ofdm 、N cp , k and Nwus The length of the first pre-DFT subsequence may be determined, and the difference between the length of the first pre-DFT subsequence and any pre-DFT subsequence may be associated with the length of the CP.

[0121] For example, the length of the pre-DFT subsequence other than the first pre-DFT subsequence (denoted by N 1 It can be represented by the aforementioned ideal length ((N ofdm +N cp ) / k) and the scaling factor (N wus / N ofdm ) OK. 1 Can be provided as:

[0122] N 1 =(N ofdm +N cp ) / k*N wus / N ofdm (1) or

[0123] N 1 =floor[(N ofdm +Ncp) / k*N wus / N ofdm ] (2) or

[0124] N 1 = ceil[(N ofdm + N cp ) / k * N wus / N ofdm ] (3).

[0125] Where floor[] is a function that returns the largest integer less than or equal to the input, and ceil[] is a function that returns the smallest integer greater than or equal to the input.

[0126] In addition, the length of the first pre-DFT subsequence (denoted by N 0 It can be represented by the ideal length ((N ofdm +N cp ) / k), CP length and scaling factor (N wus / N ofdm ) is determined. Alternatively, N 0 Can be directly based on N wus and N 1 . N 0 Can be provided as:

[0127] N 0 =N wus -(k-1)*N 1 (4) or

[0128] N0 =[(N ofdm +N cp ) / kN cp ]*N wus / N ofdm (5) or

[0129] N 0 =floor{[(N ofdm +N cp ) / kN cp ]*N wus / N ofdm}(6), or

[0130] N 0 =ceil{[(N ofdm + N cp ) / k - N cp ] * N wus / N ofdm} (7).

[0131] After IFFT and before CP insertion, an OFDM symbol without CP may be generated and may include k post-IFFT subsequences, and each of the k post-IFFT subsequences may be associated with an OOK symbol.

[0132] Fig.11 FIG. 1 shows an example of inserting a GI according to some embodiments of the present disclosure. Fig.10 An example diagram of an OOK sequence is shown in FIG1100. Fig.11 In the example, the length of the first post-IFFT subsequence may be shorter than that of other subsequences, and the first post-IFFT subsequence is represented as {P0, P1, ..., Pj}, where j = (N ofdm +N cp ) / kN cp -1. Then, GI can be inserted before the front of IFFTd output, assuming that the GI sequence is {Q0, Q1, ..., Qi}, and i = N cp -1.

[0133] In some embodiments, the GI sequence may be generated based on the first post-IFFT subsequence. For example, if i<=j, {Q0, Q1, ..., Qi} may be equal to the first (i+1) samples or the last (i+1) samples of {P0, P1, ..., Pj}. Alternatively, if i>j, {P0, P1, ..., Pj} may be repeated and truncated to (i+1) samples to generate {Q0, Q1, ..., Qi}.

[0134] In some embodiments, the GI sequence may be generated based on the first post-IFFT subsequence with reverse order. For example, if i<=j, {Q0', Q1', ..., Qi'} may be equal to the first (i+1) samples or the last (i+1) samples of {P0, P1, ..., Pj}, and {Q0, Q1, ..., Qi} = {Qi', Qi-1', ..., Q0'}. Alternatively, if i>j, {P0, P1, ..., Pj} may be repeated and truncated to (i+1) samples to generate {Q0', Q1', ..., Qi'}, and {Q0, Q1, ..., Qi} = {Qi', Qi-1', ..., Q0'}.

[0135] Alternatively, the above GI sequence generation can be performed only if the first OOK symbol among the k OOK symbols is an OOK ON symbol. If the first OOK symbol among the k OOK symbols is an OOK OFF symbol, all elements of the GI sequence may be zero or close to zero.

[0136] Additionally or alternatively, if the first OOK symbol and the last OOK symbol are the same, i.e., both are OOKOFF symbols or OOKON symbols, then {Q0, Q1, ..., Qi} can be the last (i+1) samples of the last post-IFFT subsequence. In other words, GI can be inserted as normal CP processing. In some embodiments, the OOK sequence can be designed to have the same value for the first and last OOK symbols in the OOK subsequence.

[0137] For illustration without imposing any limitation, an example is given below. Assuming the SCS is 15KHz, and 24 PRBs (i.e., 288 subcarriers) are used for WUS, and 4 OOK symbols are mapped into OFDM symbols. Assuming the IFFT size is 2048 and the CP length is 144 samples, for the last 3 symbols of the OOK subsequence, each symbol can be mapped to a pre-DFT sequence with a length of:

[0138] floor{[(2048+144) / 4]*288 / 2048}=77.

[0139] The first symbol of the OOK subsequence may be mapped into a pre-DFT sequence having a length of: 288-3*77=57.

[0140] In this case, the generation of OOK symbols can be generated as follows:

[0141] Step 1: Generate four pre-DFT subsequences based on four OOK symbols with the above length, and concatenate them into a pre-DFT sequence with a length of 288 points;

[0142] Step 2: The 288-point pre-DFT sequence may be subjected to a 288-point DFT process, and then a 288-point post-DFT sequence may be generated;

[0143] Step 3: The 288 elements of the post-DFT sequence can then be mapped to 288 subcarriers of 24 PRBs accordingly, and then a 2048-point IFFT can be performed to generate a CP-free OFDM symbol with 2048 samples;

[0144] Step 4: A 144-point GI can be generated and inserted in front of the 2048 samples.

[0145] Based on this method, the duration of one OFDM symbol (ie, 2048+144=2192 samples) can be roughly equally divided into 4 parts (ie, ˜2192 / 4=548 samples), and each of the four parts can represent an OOK symbol.

[0146] Now discuss the case where CP is treated as a useless part of the OOK symbol. In this case, it is assumed that the WUS receiver (e.g., receiver 550) is able to identify and remove the CP / GI, and the OOK symbol is only mapped to the useful part of the OFDM symbol, that is, the CP / GI is not a useful part of the OOK symbol.

[0147] Fig.12 An example diagram 1200 of an OOK sequence is shown in which CP is treated as a useless part of an OOK symbol according to some embodiments of the present disclosure. Still assuming that the number of subcarriers used for WUS is N wus , the length of the OFDM symbol without CP is N ofdm samples, and the length of CP is N cp .

[0148] like Fig.12 As shown, the lengths of the k pre-DFT subsequences are the same, and the length (denoted by N 2 ) can be given as:

[0149] N 2 = N wus / k (8).

[0150] If only one OFDM symbol is used to generate the WUS signal, the WUS receiver only needs to detect k OOK symbols, and the CP will not cause detection confusion. However, if multiple OFDM symbols are used to generate the WUS signal, there will be (multiple) CPs between the OOK symbols, and the WUS receiver must identify which part of its received signal is the CP.

[0151] Fig.13An example diagram 1300 of an OOK sequence is shown where the duration of the CP and the duration of the OOK sequence are different. In some embodiments, multiple OOK symbols may be mapped into one OFDM symbol and the CP may be inserted normally. Therefore, the duration of the CP may be considered as a useless portion for the WUS signal and the receiver should be able to remove this portion. However, as Fig.13 As shown, the duration of the CP and the duration of the post-IFFT subsequence of the OOK symbol may be different. This may cause some difficulties for the receiver.

[0152] In some embodiments, handling this non-uniform symbol duration problem may increase the complexity of the receiver. For example, the receiver may have a relatively high oversampling rate, relatively fine time synchronization, and relatively complex baseband processing.

[0153] In addition, the OOK sequence can be designed to facilitate CP detection. For example, assuming that the two OOK subsequences are mapped to two OFDM symbols respectively, the second OOK subsequence can be a repetition of the first OOK subsequence. Alternatively, the two OOK subsequences can be generated based on the same sequence but multiplied by two coefficient sets respectively (for example, the two coefficient sets are two orthogonal cover codes (OCCs) respectively). With these two methods, since the two OOK subsequences are correlated, an autocorrelation detector can be applied to detect the CP part, which may have a relatively low complexity.

[0154] In some implementations, "padding data" may be inserted at the beginning or end of the pre-DFT sequence, in order to make the interval between two non-consecutive OOK symbols equal to an integer number of OOK symbol lengths. Fig.14A and 14B An example diagram showing an OOK sequence in which padding data is inserted between discontinuous OOK symbols. Fig.14A They are collectively referred to as 1400. Fig. 14B They are collectively referred to as 1450.

[0155] For example, in Fig.14A In , OOK3 and OOK4 are not continuous, and the interval between them is equal to the duration of one OOK symbol; OOK6 and OOK7 are also not continuous, and the interval between them is equal to the duration of two OOK symbols. Fig. 14B In the embodiment, OOK2 and OOK3 are not continuous, and the interval between them is equal to the duration of one OOK symbol; OOK5 and OOK6 are also not continuous, and the interval between them is equal to the duration of one OOK symbol.

[0156] To make the interval between two non - consecutive OOK symbols equal to an integer number of OOK symbol lengths, a padding data sequence including one or more padding data can be inserted at the initial part or the ending part of the pre - DFT sequence. The padding data can be (a) zero, or a predefined sequence, or a copy or transform of a part of the pre - DFT sequence.

[0157] In some embodiments, the length of the padding data sequence can be determined based on the CP length and the index of the OFDM symbol in the OFDM symbols used for the WUS signal. For purposes of illustration and without imposing any limitation, assume that L OFDM symbols are used for the WUS signal, and the length of the post - IFFT subsequence for the OOK symbol is N ook , then for the l - th (0 < l < L) OFDM symbol, the length of the padding data sequence at the initial part of the pre - DFT sequence (denoted by N 4 ) can be:

[0158] N’ 4 ={ceil[l*(N ofdm +N cp ) / N ook *N ook -l*(N ofdm +N cp )}*(N wus / N ofdm ), and N 4

[0159] =N’ 4 (9), or

[0160] N 4 =floor(N’ 4 )(10), or

[0161] N 4 = ceil(N’ 4 ) (11).

[0162] The length of the padding data sequence at the ending part of the pre - DFT sequence (denoted by N 5 ) can be:

[0163] N’ 5 ={[(l + 1)*N ofdm +l*N cp -floor{[(l + 1)*N ofdm +l*N cp / N ook}*N ook}*(N wus / N ofdm ), and

[0164] N 5 =N' 5 (12) or

[0165] N 5 =floor(N' 5 )(13), or

[0166] N 5 = ceil(N' 5 ) (14).

[0167] Additionally or alternatively, the offset value can be configured. In this case, the length of the padding data can also be determined based on the offset value. For example, the length value determined based on the above method can be added or subtracted from the offset value, or the offset value can be used in the above formula.

[0168] Fig.15 1 shows a flow chart of an example method 1500 according to some embodiments of the present disclosure. The method 1500 may be implemented at a network device, for example, Figure 1 A network device 110 is shown.

[0169] At block 1510, the network device 110 generates at least one OOK ON symbol by using a first number of frequency resources mapped with non-zero values. The non-zero values ​​are used for normal DL transmission.

[0170] At block 1520 , the network device 110 generates at least one OOK OFF symbol by using a second number of frequency resources mapped to have a zero value or a value close to zero.

[0171] In some embodiments, the first number of frequency resources and the second number of frequency resources may include at least one of the following items: the first multiple physical resource blocks (PRBs) or subcarriers of the channel bandwidth, the last multiple PRBs or subcarriers of the channel bandwidth, or a guard band of the channel bandwidth.

[0172] At block 1530, network device 110 generates a WUS based on at least one OOK ON symbol and at least one OOK OFF symbol. In some embodiments, network device 110 may generate the WUS by using OFDM operation. OFDM operation may be used to generate normal DL transmissions.

[0173] In some embodiments, the duration of the WUS may be associated with a parameter set for an OFDM symbol. In some embodiments, the WUS may be mapped to an OFDM symbol in a subframe, and the WUS may be within one of the first half-subframe, the first half-subframe plus the first OFDM symbol of the second half-subframe, or the second half-subframe.

[0174] In some embodiments, the network device 110 may send the WUS configuration in system information to a terminal device in an RRC idle or inactive state. Additionally or alternatively, the network device 110 may send the WUS configuration to a terminal device in an RRC connected state via RRC signaling.

[0175] In some embodiments, the WUS configuration may include a frequency domain resource configuration. The frequency domain resource configuration may indicate a plurality of frequency resources occupied by the WUS. Additionally or alternatively, the WUS configuration may include a time domain resource configuration. The time domain resource configuration may indicate at least one of the period of the WUS, the duty cycle of the WUS, and the number of OOK symbols mapped to the OFDM symbol. The OOK symbol may include at least one OOK ON symbol and at least one OOK OFF symbol, as well as a plurality of consecutive OFDM symbols in a time slot or subframe used for the WUS. Additionally or alternatively, the WUS configuration may include a sequence configuration. The sequence configuration may indicate at least one of the sequence length of the OOK symbol, the duration of the OOK symbol, and the sequence ID indicating the OOK sequence from a plurality of predefined OOK sequences.

[0176] In some embodiments, network device 110 may reserve a guard band between WUS and normal DL transmission. The guard band may be filled with one of a zero value or a near-zero value, or a value based on the data of the normal DL transmission.

[0177] In some embodiments, near-zero values ​​may have less power than non-zero values.

[0178] At block 1540, the network device 110 sends a WUS to the terminal device.

[0179] Fig.16 1600 according to some embodiments of the present disclosure. The method 1600 may be performed on a network device (e.g., Figure 1 The network device 110 is shown as an example.

[0180] At block 1610, the network device 110 forms an OOK subsequence having a plurality of OOK symbols including at least one OOK ON symbol and at least one OOK OFF symbol. The plurality of OOK symbols are associated with one OFDM symbol.

[0181] At block 1620, the network device 110 maps the OOK subsequence to a plurality of pre-DFT subsequences accordingly to form a pre-DFT sequence. The length of the pre-DFT subsequence in the plurality of pre-DFT subsequences is associated with at least one of the following items: the number of subcarriers used for the WUS, the number of the plurality of OOK symbols, or the index of the pre-DFT subsequence in the plurality of pre-DFT subsequences.

[0182] In some embodiments, the network device 110 inserts padding data at the beginning or end of the pre-DFT sequence. The padding data may be at least one of a zero, a predefined sequence, or a copy of a portion of the pre-DFT subsequence. The length of the padding data may be determined based on at least one of the following items: the CP length and the index of the OFDM symbol in a plurality of OFDM symbols, or an offset value.

[0183] At block 1630, the network device 110 performs transform precoding on the pre-DFT sequence.

[0184] At block 1640 , the network device 110 maps the output of the transform precoding into the frequency resources allocated to the WUS and generates the WUS.

[0185] In some embodiments, the network device 110 may perform an IFFT operation on the output of the transform precoding and the data for normal DL transmission, and insert the CP into the output of the IFFT operation. Alternatively, the network device 110 may perform an IFFT operation on the output of the transform precoding, and insert the GI before the front of the output of the IFFT operation. The length of the GI may be the same as the length of the CP. In addition, the GI may be a zero-valued sample, a dedicated sequence, a copy or a transform of a portion of the output of an independent IFFT operation, or one of the CPs.

[0186] In some embodiments, the length of a pre-DFT subsequence in a plurality of pre-DFT subsequences may also be associated with at least one of the following items: the length of an OFDM symbol without a CP and the length of the CP. In addition, the difference between the length of the first pre-DFT subsequence and any other pre-DFT subsequence may be associated with the length of the CP.

[0187] In some embodiments, the length of the first pre-DFT subsequence may be associated with at least one of the following items: the length of the pre-DFT subsequences other than the first pre-DFT subsequence and the number of subcarriers used for the WUS.

[0188] In some embodiments, the output of the independent IFFT operation may include multiple post-IFFT subsequences. Based on determining that the first OOK symbol of the multiple OOK symbols is an OOK ON symbol, the network device 110 may generate a GI sequence based on the first post-IFFT subsequence of the multiple post-IFFT subsequences or the first post-IFFT subsequence with a reverse order. Additionally or alternatively, based on determining that the first OOK symbol of the multiple OOK symbols is an OOK OFF symbol, the network device 110 may generate a GI sequence with a zero value or a value close to zero. Additionally or alternatively, based on determining that the first OOK symbol and the last OOK symbol of the multiple OOK symbols are the same, the network device 110 may generate a GI sequence with the last post-IFFT subsequence of the multiple post-IFFT subsequences.

[0189] In some embodiments, based on determining that the multiple OOK subsequences are associated with the multiple OFDM symbols, at least one of the multiple OOK subsequences is a repetition of a first OOK subsequence in the multiple OOK subsequences. Additionally or alternatively, the multiple OOK subsequences are generated based on the same sequence and are multiplied with two sets of coefficients accordingly.

[0190] At block 1650, the network device 110 sends a WUS to the terminal device.

[0191] Fig.17 1700 according to some embodiments of the present disclosure. The method 1700 may be implemented at a terminal device, for example, Figure 1 The terminal device 120 is shown.

[0192] At block 1710, the terminal device 120 receives a WUS from a network device.

[0193] At block 1720, the terminal device 120 detects the WUS to determine a plurality of OOK symbols including at least one OOK ON symbol and at least one OOK OFF symbol.

[0194] In some embodiments, at least one OOK ON symbol is generated based on a first number of frequency resources mapped with non-zero values. Non-zero values ​​are used for normal DL transmission. At least one OOK OFF symbol is generated based on a second number of frequency resources mapped with zero or near-zero values.

[0195] In some embodiments, the WUS may be generated based on OFDM operation. OFDM operation may be used to generate normal DL transmission.

[0196] In some embodiments, based on determining that the terminal device is in a radio resource control (RRC) idle or inactive state, the terminal device may receive a WUS configuration in the system information from the network device to monitor the WUS. Additionally or alternatively, based on determining that the terminal device is in an RRC connected state, the terminal device may receive a WUS configuration from the network device via RRC signaling. In some embodiments, the WUS configuration may include a frequency domain resource configuration. The frequency domain resource configuration may indicate a plurality of frequency resources occupied by the WUS. Additionally or alternatively, the WUS configuration may include a time domain resource configuration. The time domain resource configuration may indicate at least one of the period of the WUS, the duty cycle of the WUS, and the number of OOK symbols mapped to the OFDM symbol. The OOK symbol may include at least one OOK ON symbol and at least one OOK OFF symbol, as well as a plurality of consecutive OFDM symbols in a time slot or subframe used for the WUS. Additionally or alternatively, the WUS configuration may include a sequence configuration. The sequence configuration may indicate at least one of the sequence length of the OOK symbol, the duration of the OOK symbol, and the sequence ID indicating the OOK sequence from a plurality of predefined OOK sequences.

[0197] In some embodiments, in response to not receiving a WUS configuration from the network device 110, the terminal device 120 may detect the WUS based on the following assumption: the multiple frequency resources used for the WUS are at least one of the following items: multiple center PRBs of a default BWP, multiple upper edge PRBs of a default BWP, multiple lower edge PRBs of a default BWP, multiple center PRBs of a channel bandwidth, multiple upper edge PRBs of a channel bandwidth, or multiple lower edge PRBs of a channel bandwidth.

[0198] In some embodiments, the terminal device 120 may determine a duration of a first OOK symbol of the plurality of OOK symbols based at least on a boundary between the first OOK symbol and a second OOK symbol of the plurality of OOK symbols.

[0199] In some embodiments, non-zero values ​​may include data for normal DL transmissions.

[0200] In some embodiments, the terminal device 120 may determine a guard band to be reserved between the WUS and the normal DL transmission. The guard band may be filled with one of the following: a zero value or a value close to zero, or a value based on the data of the normal DL transmission.

[0201] In some embodiments, values ​​close to zero may have less power than non-zero values.

[0202] In some embodiments, the WUS is generated based on the output of the transform precoding of the pre-DFT sequence, and the pre-DFT sequence includes multiple pre-DFT subsequences. The pre-DFT sequence is generated based on the OOK subsequence, and the OOK subsequence includes multiple OOK symbols. Multiple OOK symbols are associated with one OFDM symbol. In addition, the length of the pre-DFT subsequence in the multiple pre-DFT subsequences is associated with at least one of the following items: the number of subcarriers used for the WUS, the number of multiple OOK symbols, or the index of the pre-DFT subsequence in the multiple pre-DFT subsequences.

[0203] In some embodiments, the terminal device 120 may receive the WUS and normal downlink (DL) transmissions in a DL signal.

[0204] In some embodiments, the WUS and normal DL transmission may be generated by an IFFT operation, and the CP may be inserted into the output of the IFFT operation. Additionally or alternatively, the WUS may be generated by an independent IFFT operation, and the GI may be inserted into the output of the independent IFFT operation.

[0205] In some embodiments, the length of a pre-DFT subsequence in the plurality of pre-DFT subsequences may be associated with at least one of a length of an OFDM symbol without a CP and a length of the CP. The difference between the length of the first pre-DFT subsequence and the length of any other pre-DFT subsequence may be associated with the length of the CP.

[0206] In some embodiments, the length of the first pre-DFT subsequence may be associated with at least one of the following items: the length of the pre-DFT subsequences other than the first pre-DFT subsequence and the number of subcarriers used for the WUS.

[0207] In some embodiments, the output of the independent IFFT operation may include multiple post-IFFT subsequences. Based on determining that the first OOK symbol of the multiple OOK symbols is an OOK ON symbol, the GI sequence may be generated based on the first post-IFFT subsequence of the multiple post-IFFT subsequences or the first post-IFFT subsequence with a reverse order. Additionally or alternatively, based on determining that the first OOK symbol of the multiple OOK symbols is an OOK OFF symbol, the GI sequence may be generated based on a zero value or a value close to zero. Additionally or alternatively, based on determining that the first OOK symbol of the multiple OOK symbols is the same as the last OOK symbol, the GI sequence may be generated based on the last post-IFFT subsequence of the multiple post-IFFT subsequences.

[0208] In some embodiments, at least one of the plurality of OOK subsequences may be a repetition of a first OOK subsequence of the plurality of OOK subsequences. Additionally or alternatively, the plurality of OOK subsequences may be generated based on the same sequence and multiplied with two sets of coefficients accordingly.

[0209] In some embodiments, the WUS may be generated based on the output of the transform precoding of the pre-DFT sequence, the pre-DFT sequence having padding data inserted at the beginning or end of the pre-DFT sequence. The padding data may be at least one of: zero, a copy of a predefined sequence or a portion of a pre-DFT subsequence. The length of the padding data sequence may be determined based on at least one of: the CP length and the index of the OFDM symbol in a plurality of OFDM symbols, or an offset value.

[0210] Fig.18 1800 according to some embodiments of the present disclosure. The method 1800 may be implemented at a terminal device, for example, Figure 1 The terminal device 121 is shown.

[0211] At block 1810, the terminal device 121 receives a DL signal including a WUS and a normal DL transmission from a network device. The LP-WUS and the normal DL transmission are generated using OFDM operation.

[0212] At block 1820 , the terminal device 121 receives a WUS configuration from the network device.

[0213] In some embodiments, the WUS may include multiple OOK symbols. In addition, the WUS configuration may include a frequency domain resource configuration. The frequency domain resource configuration may indicate multiple frequency resources occupied by the WUS. Additionally or alternatively, the WUS configuration may include a time domain resource configuration. The time domain resource configuration may indicate at least one of the period of the WUS, the duty cycle of the WUS, and the number of OOK symbols mapped to the OFDM symbol. The OOK symbol may include at least one OOK ON symbol and at least one OOK OFF symbol, as well as multiple consecutive OFDM symbols in a time slot or subframe used for the WUS. Additionally or alternatively, the WUS configuration may include a sequence configuration. The sequence configuration may indicate at least one of the sequence length of the OOK symbol, the duration of the OOK symbol, and the sequence ID indicating the OOK sequence from multiple predefined OOK sequences.

[0214] At block 1830 , the terminal device 121 determines resources for the WUS indicated in the WUS configuration.

[0215] At block 1840 , the terminal device 121 determines overlapping resources that are allocated to normal DL transmission and overlap with resources for the WUS.

[0216] At block 1850, the terminal device 121 determines that overlapping resources are not available for normal DL transmission.

[0217] Fig.19 1 shows a flowchart of an example method 1900 according to some embodiments of the present disclosure. The method 1900 may be implemented at a terminal device, for example, as Figure 1 The terminal device 121 is shown.

[0218] At block 1910, the terminal device 121 receives a DL signal including a WUS and a normal DL transmission from a network device. The WUS may include a plurality of OOK symbols including at least one OOK ON symbol and at least one OOK OFF symbol. The at least one OOK ON symbol is generated based on data of the normal DL transmission.

[0219] At block 1920 , the terminal device 121 determines the indexes of a plurality of PRBs allocated to the WUS.

[0220] At block 1930, the terminal device 121 determines that REs of a plurality of PRBs of the OFDM symbol associated with the OOK ON symbol are available for normal DL transmission.

[0221] At block 1940 , the terminal device 121 determines that REs of a plurality of PRBs of the OFDM symbol associated with the OOK OFF symbol are unavailable for normal DL transmission.

[0222] Fig. 20 is a simplified block diagram of a device 2000 suitable for implementing some embodiments of the present disclosure. The device 2000 can be viewed as Figure 1 The network device 110 or the terminal devices 120 and 121 are shown as further example embodiments. Therefore, the device 2000 may be implemented at the network device 110 or the terminal devices 120 and 121 or as at least a part of the network device 110 or the terminal devices 120 and 121.

[0223] As shown, the device 2000 includes a processor 2010, a memory 2020 coupled to the processor 2010, a suitable transmitter (TX) and receiver (RX) 2040 coupled to the processor 2010, and a communication interface coupled to the TX / RX 2040. The memory 2020 stores at least a portion of the program 2030. The TX / RX 2040 is used for bidirectional communication. The TX / RX 2040 has at least one antenna to facilitate communication, although in practice, the access node mentioned in this application may have several antennas. The communication interface may represent any interface necessary for communication with other network elements, such as an X2 interface for bidirectional communication between gNBs or eNBs, an S1 interface for communication between a mobility management entity (MME) / serving gateway (S-GW) and a gNB or eNB, a Un interface for communication between a gNB or eNB and a relay node (RN), or a Uu interface for communication between a gNB or eNB and a terminal device.

[0224] Program 2030 is assumed to include program instructions that, when executed by associated processor 2010, enable device 2000 to operate in accordance with embodiments of the present disclosure, as described herein with reference to Figures 1 to 19 The embodiments of the present invention may be implemented by computer software, hardware, or a combination of software and hardware executable by a processor 2010 of the device 2000. The processor 2010 may be configured to implement various embodiments of the present disclosure. In addition, the combination of the processor 2010 and the memory 2020 may form a processing component 2050 suitable for implementing various embodiments of the present disclosure.

[0225] Memory 2020 can be any type suitable for a local technology network, and as a non-limiting example, can be implemented using any suitable data storage technology, such as non-transitory computer-readable storage media, semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. Although only one memory 2020 is shown in device 2000, multiple physically different memory modules can exist in device 2000. Processor 2010 can be any type suitable for a local technology network, and as a non-limiting example, can include one or more of the following: a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture. Device 2000 can have multiple processors, such as a dedicated integrated circuit chip that is timely subordinate to a clock synchronized with a main processor.

[0226] The components included in the apparatus and / or device of the present disclosure can be implemented in various ways, including software, hardware, firmware or any combination thereof. In one embodiment, one or more units can be implemented using software and / or firmware, for example, machine executable instructions stored on a storage medium. In addition to or in place of machine executable instructions, some or all of the units in the apparatus and / or device can be implemented at least in part by one or more hardware logic components. For example, but not limited to, exemplary types of hardware logic components that can be used include field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), complex programmable logic devices (CPLDs), etc.

[0227] Generally, various embodiments of the present disclosure may be implemented in hardware or dedicated 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. Although various aspects of the embodiments of the present disclosure are shown and described as block diagrams, flow charts, or using some other graphical representations, it should be understood that, as non-limiting examples, the blocks, devices, systems, techniques, or methods described herein may be implemented in hardware, software, firmware, dedicated circuits or logic, general hardware or controllers or other computing devices, or some combination thereof.

[0228] 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 a program module, which are executed in a device on a target real or virtual processor to perform the above referenced Figures 1 to 19 In any of the processes or methods described in. Typically, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform specific tasks or implement specific abstract data types. The functions of program modules can be combined or split between program modules as needed in various embodiments. Machine executable instructions for program modules can be executed in local or distributed devices. In distributed devices, program modules can be located in both local and remote storage media.

[0229] The program code for executing the method of the present disclosure can be written in any combination of one or more programming languages. These program codes can be provided to a processor or controller of a general-purpose computer, a special-purpose computer or other programmable data processing device so that the program code, when executed by the processor or controller, enables the functions / operations specified in the flow chart and / or block diagram to be implemented. The program code can be executed entirely on the machine, partially on the machine, executed as an independent software package, partially on the machine and partially on a remote machine, or completely on a remote machine or server.

[0230] 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, device, or apparatus. The machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. The machine-readable medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or equipment, or any suitable combination of the above. More specific examples of machine-readable storage media include an electrical connection with one or more wires, a portable computer disk, 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 disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0231] In addition, although the operations are depicted in a particular order, it should not be understood that these operations are required to be performed in the particular order or sequence order shown, or that all the operations shown are required to be performed to achieve the desired result. In some cases, multitasking and parallel processing may be advantageous. Similarly, although several specific embodiment details are included in the above discussion, these details should not be interpreted as limitations on the scope of the present disclosure, but should be interpreted as descriptions of features that may be specific to a particular embodiment. Certain features described in the context of separate embodiments may also be combined in a single embodiment. On the contrary, the various features described in the context of a single embodiment may also be implemented separately in multiple embodiments or implemented in any suitable sub-combination.

[0232] Although the present disclosure has been described in language specific to structural features and / or methodological acts, it should be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Instead, the specific features and acts described above are disclosed as example forms of implementing the claims.

[0233] In summary, the embodiments of the present disclosure may provide the following solutions.

[0234] A method implemented at a network device, comprising: generating at least one on-off keying (OOK) ON symbol by using a first number of frequency resources mapped with non-zero values, wherein the non-zero value is used for normal downlink (DL) transmission; generating at least one OOK OFF symbol by using a second number of frequency resources mapped with zero values ​​or values ​​close to zero; generating a wake-up signal (WUS) based on at least one OOK ON symbol and at least one OOK OFF symbol; and sending the WUS to a terminal device.

[0235] In some embodiments, generating the WUS includes generating the WUS by using an orthogonal frequency division multiplexing (OFDM) operation. The OFDM operation is used to generate normal DL transmissions.

[0236] In some embodiments, the first number of frequency resources and the second number of frequency resources include at least one of the following items: the first multiple physical resource blocks (PRBs) or subcarriers of the channel bandwidth, the last multiple PRBs or subcarriers of the channel bandwidth, or a guard band of the channel bandwidth.

[0237] In some embodiments, the duration of the WUS is associated with a parameter set for an OFDM symbol.

[0238] In some embodiments, the WUS is mapped to an OFDM symbol in a subframe. The WUS is in one of the following: the first half-subframe, the first half-subframe plus the first OFDM symbol of the second half-subframe, or the second half-subframe.

[0239] In some embodiments, the method as described above further includes one of the following items: sending a WUS configuration to a terminal device in a radio resource control (RRC) idle or inactive state in system information; or sending a WUS configuration to a terminal device in an RRC connected state via RRC signaling. The WUS configuration includes at least one of the following items: a frequency domain resource configuration indicating a plurality of frequency resources occupied by the WUS; a time domain resource configuration indicating at least one of the period of the WUS, the duty cycle of the WUS, and the number of OOK symbols mapped to the OFDM symbol, wherein the OOK symbol includes at least one OOK ON symbol and at least one OOK OFF symbol, and a plurality of consecutive OFDM symbols in a time slot or subframe used for the WUS; and a sequence configuration indicating at least one of the sequence length of the OOK symbol, the duration of the OOK symbol, and the sequence ID indicating an OOK sequence from a plurality of predefined OOK sequences.

[0240] In some embodiments, the method as described above further comprises reserving a guard band between the WUS and the normal DL transmission. The guard band is filled with one of the following: a zero value or a near-zero value, or a value based on data of the normal DL transmission.

[0241] In some embodiments, near-zero values ​​have less power than non-zero values.

[0242] In another solution, a method implemented at a network device includes: forming an OOK subsequence having multiple OOK symbols, the multiple OOK symbols including at least one OOK ON symbol and at least one OOK OFF symbol, wherein the multiple OOK symbols are associated with one OFDM symbol; mapping the OOK subsequence to multiple pre-discrete Fourier transform (pre-DFT) subsequences accordingly to form a pre-DFT sequence; performing transform precoding on the pre-DFT sequence; mapping the output of the transform precoding to a frequency resource allocated to a wake-up signal (WUS) and generating the WUS; and sending the WUS to a terminal device; wherein the length of the pre-DFT subsequence in the multiple pre-DFT subsequences is associated with at least one of the following items: the number of subcarriers used for the WUS, the number of multiple OOK symbols, or the index of the pre-DFT subsequence in the multiple pre-DFT subsequences.

[0243] In some embodiments, generating the WUS also includes one of the following items: performing an inverse fast Fourier transform (IFFT) operation on the output of the transform precoding and the data for normal DL transmission, and inserting a cyclic prefix (CP) into the output of the IFFT operation; or performing an IFFT operation on the output of the transform precoding and inserting a guard interval (GI) before the front of the output of the IFFT operation, wherein the length of the GI is the same as the length of the CP, and wherein the GI is one of a zero-valued sample, a dedicated sequence, a copy or transform of a portion of the output of an independent IFFT operation, or the CP.

[0244] In some embodiments, the length of a pre-DFT subsequence in the plurality of pre-DFT subsequences is further associated with at least one of the following: the length of an OFDM symbol without a CP and the length of the CP. The difference between the length of the first pre-DFT subsequence and the length of any other pre-DFT subsequence is associated with the length of the CP.

[0245] In some embodiments, the length of the first pre-DFT subsequence is associated with at least one of the following: the length of pre-DFT subsequences other than the first pre-DFT subsequence and the number of subcarriers used for the WUS.

[0246] In some embodiments, the output of the independent IFFT operation includes a plurality of post-IFFT subsequences. Inserting the GI includes one of the following: generating a GI sequence based on the first post-IFFT subsequence in the plurality of post-IFFT subsequences or the first post-IFFT subsequence with a reverse order based on determining that the first OOK symbol in the plurality of OOK symbols is an OOK ON symbol; generating a GI sequence with a zero value or a value close to zero based on determining that the first OOK symbol in the plurality of OOK symbols is an OOK OFF symbol; or generating a GI sequence with a last post-IFFT subsequence in the plurality of post-IFFT subsequences based on determining that the first OOK symbol in the plurality of OOK symbols is the same as the last OOK symbol.

[0247] In some embodiments, based on determining that multiple OOK subsequences are associated with multiple OFDM symbols, at least one of the multiple OOK subsequences is a repetition of the first OOK subsequence among the multiple OOK subsequences, or the multiple OOK subsequences are generated based on the same sequence and multiplied with two coefficient sets accordingly.

[0248] In some embodiments, forming the pre-DFT sequence further comprises: inserting padding data at the beginning or end of the pre-DFT sequence. The padding data is at least one of zero, a copy of a predefined sequence or a portion of the pre-DFT subsequence. The length of the padding data is determined based on at least one of the following items: the CP length and the index of the OFDM symbol in the plurality of OFDM symbols, or an offset value.

[0249] In another solution, a network device includes a processor; and a memory coupled to the processor and storing instructions, which, when executed by the processor, cause the network device to perform the method as described above.

[0250] In another solution, a method implemented at a terminal device includes: receiving a wake-up signal (WUS) from a network device; and detecting the WUS to determine a plurality of on-off keying (OOK) symbols, the plurality of on-off keying (OOK) symbols including at least one OOK ON symbol and at least one OOK OFF symbol, wherein at least one OOK ON symbol is generated based on a first number of frequency resources mapped with non-zero values, the non-zero values ​​being used for normal downlink (DL) transmission, and wherein at least one OOK OFF symbol is generated based on a second number of frequency resources mapped with zero values ​​or values ​​close to zero.

[0251] In some embodiments, the WUS is generated based on an Orthogonal Frequency Division Multiplexing (OFDM) operation. The OFDM operation is used to generate normal DL transmissions.

[0252] In some embodiments, the method further includes: based on determining that the terminal device is in a radio resource control (RRC) idle or inactive state, receiving a WUS configuration in system information from a network device to monitor the WUS; or based on determining that the terminal device is in an RRC connected state, receiving a WUS configuration from a network device via RRC signaling. The WUS configuration includes at least one of the following items: a frequency domain resource configuration indicating a plurality of frequency resources occupied by the WUS; a time domain resource configuration indicating at least one of a period of the WUS, a duty cycle of the WUS, and a number of OOK symbols mapped to an OFDM symbol, wherein the OOK symbol includes at least one OOK ON symbol and at least one OOK OFF symbol, and a plurality of consecutive OFDM symbols in a time slot or subframe used for the WUS; and a sequence configuration indicating at least one of a sequence length of the OOK symbol, a duration of the OOK symbol, and a sequence ID indicating an OOK sequence from a plurality of predefined OOK sequences.

[0253] In some embodiments, in response to not receiving a WUS configuration from the network device, detecting the WUS is based on the assumption that the multiple frequency resources used for the WUS are at least one of the following items: multiple center physical resource blocks (PRBs) of a default bandwidth part (BWP), multiple upper edge PRBs of the default BWP, multiple lower edge PRBs of the default BWP, multiple center PRBs of a channel bandwidth, multiple upper edge PRBs of a channel bandwidth, or multiple lower edge PRBs of a channel bandwidth.

[0254] In some embodiments, detecting the WUS includes determining a duration of a first OOK symbol of the plurality of OOK symbols based at least on a boundary between the first OOK symbol and a second OOK symbol of the plurality of OOK symbols.

[0255] In some embodiments, detecting the WUS comprises: determining a guard band reserved between the WUS and the normal DL transmission. The guard band is filled with one of: a zero value or a near zero value, or a value based on data of the normal DL transmission.

[0256] In some embodiments, near-zero values ​​have less power than non-zero values.

[0257] In another solution, a method implemented at a terminal device includes: receiving a wake-up signal (WUS) from a network device; and detecting the WUS to determine a plurality of on-off keying (OOK) symbols including at least one OOK ON symbol and at least one OOK OFF symbol. The WUS is generated based on the output of transform precoding of a pre-discrete Fourier transform (pre-DFT) sequence, the pre-DFT sequence including a plurality of pre-DFT subsequences, the pre-DFT sequence being generated based on an OOK subsequence, and the OOK subsequence including a plurality of OOK symbols, and wherein the plurality of OOK symbols are associated with one OFDM symbol. The length of the pre-DFT subsequence in the plurality of pre-DFT subsequences is associated with at least one of the following items: the number of subcarriers used for the WUS, the number of the plurality of OOK symbols, or the index of the pre-DFT subsequence in the plurality of pre-DFT subsequences.

[0258] In some embodiments, receiving the WUS includes receiving the WUS and a normal downlink (DL) transmission in a DL signal.

[0259] In some embodiments, the WUS and normal DL transmission are generated by an inverse fast Fourier transform (IFFT) operation and a cyclic prefix (CP) is inserted into the output of the IFFT operation; or the WUS is generated by an independent IFFT operation and a guard interval (GI) is inserted into the output of the independent IFFT operation.

[0260] In some embodiments, the length of a pre-DFT subsequence in the plurality of pre-DFT subsequences is further associated with at least one of the following: the length of an OFDM symbol without a CP and the length of the CP. The difference between the length of the first pre-DFT subsequence and the length of any other pre-DFT subsequence is associated with the length of the CP.

[0261] In some embodiments, the length of the first pre-DFT subsequence is associated with at least one of the following items: the length of the pre-DFT subsequences other than the first pre-DFT subsequence and the number of subcarriers used for the WUS.

[0262] In some embodiments, the output of the independent IFFT operation includes a plurality of post-IFFT subsequences. The GI is generated based on one of the following: based on determining that the first OOK symbol of the plurality of OOK symbols is an OOK ON symbol, the GI sequence is generated based on the first post-IFFT subsequence of the plurality of post-IFFT subsequences or the first post-IFFT subsequence with a reverse order; based on determining that the first OOK symbol of the plurality of OOK symbols is an OOK OFF symbol, the GI sequence is generated based on a zero value or a value close to zero; or based on determining that the first OOK symbol of the plurality of OOK symbols is the same as the last OOK symbol of the plurality of OOK symbols, the GI sequence is generated based on the last post-IFFT subsequence of the plurality of post-IFFT subsequences.

[0263] In some embodiments, at least one of the multiple OOK subsequences is a repetition of a first OOK subsequence in the multiple OOK subsequences; or the multiple OOK subsequences are generated based on the same sequence and are multiplied with two coefficient sets accordingly.

[0264] In some embodiments, the WUS is generated based on the output of the transform precoding of the pre-DFT sequence, wherein padding data is inserted at the beginning or end of the pre-DFT sequence. The padding data is at least one of the following: zero, a copy of a predefined sequence or a portion of the pre-DFT subsequence. The length of the padding data sequence is determined based on at least one of the following: the CP length and the index of the OFDM symbol in multiple OFDM symbols, or an offset value.

[0265] In another solution, a method implemented at a terminal device includes: receiving a downlink (DL) signal including a wake-up signal (WUS) and a normal DL transmission from a network device, wherein the LP-WUS and the normal DL transmission are generated using orthogonal frequency division multiplexing (OFDM) operation; receiving a WUS configuration from the network device; determining resources for the WUS indicated in the WUS configuration; determining overlapping resources that are allocated to normal DL transmission and overlap with resources for the WUS; and determining that the overlapping resources are not available for normal DL transmission.

[0266] In some embodiments, the WUS includes multiple on-off keying (OOK) symbols. The WUS configuration includes at least one of the following items: frequency domain resource configuration, indicating multiple frequency resources occupied by the WUS; time domain resource configuration, indicating at least one of the period of the WUS, the duty cycle of the WUS, and the number of OOK symbols mapped to the OFDM symbol, wherein the OOK symbol includes at least one OOK ON symbol and at least one OOK OFF symbol, and multiple consecutive OFDM symbols in the time slot or subframe used for the WUS; and sequence configuration, indicating at least one of the sequence length of the OOK symbol, the duration of the OOK symbol, and a sequence ID, the sequence ID indicating an OOK sequence from a plurality of predefined OOK sequences.

[0267] In another solution, a method implemented at a terminal device includes: receiving a downlink (DL) signal including a wake-up signal (WUS) and a normal DL transmission from a network device, wherein the WUS includes a plurality of on-off keying (OOK) symbols, the plurality of on-off keying (OOK) symbols include at least one OOK ON symbol and at least one OOK OFF symbol, and wherein the at least one OOK ON symbol is generated based on data of the normal DL transmission; determining indices of a plurality of PRBs allocated to the WUS; determining that resource elements (REs) of a plurality of PRBs of an OFDM symbol associated with the OOK ON symbol are available for the normal DL transmission; and determining that REs of a plurality of PRBs of an OFDM symbol associated with the OOK OFF symbol are not available for normal DL transmission.

[0268] In another solution, a terminal device includes a processor; and a memory coupled to the processor and storing thereon instructions, which when executed by the processor cause the terminal device to perform the method as outlined above.

[0269] In another solution, a computer readable medium has stored thereon instructions that, when executed on at least one processor, cause the at least one processor to perform the method as outlined above.

Claims

1. A method implemented at a network device, comprising: forming an OOK subsequence having a plurality of OOK symbols, the plurality of OOK symbols comprising at least one OOK ON symbol and at least one OOK OFF symbol, wherein the plurality of OOK symbols are associated with one OFDM symbol; Mapping the OOK subsequence to a plurality of pre-discrete Fourier transform (pre-DFT) subsequences accordingly to form a pre-DFT sequence; performing transform precoding on the pre-DFT sequence; Mapping the output of the transform precoding to a frequency resource allocated to a wake-up signal (WUS), and generating the WUS; as well as Sending the WUS to the terminal device; The length of the pre-DFT subsequence in the multiple pre-DFT subsequences is associated with at least one of the following items: the number of subcarriers used for the WUS, the number of the multiple OOK symbols, or the index of the pre-DFT subsequence in the multiple pre-DFT subsequences.

2. The method of claim 1, wherein generating the WUS further comprises one of the following: performing an inverse fast Fourier transform (IFFT) operation on the output of the transform precoding and data for normal DL transmission, and inserting a cyclic prefix (CP) into an output of the IFFT operation; or An IFFT operation is performed on the output of the transform precoding, and a guard interval (GI) is inserted in front of the output of the IFFT operation, wherein the length of the GI is the same as the length of the CP, and wherein the GI is one of the following items: a zero-valued sample, a dedicated sequence, a copy or a transform of a portion of the output of the independent IFFT operation, or the CP.

3. The method according to claim 2, wherein: The length of the pre-DFT subsequence in the plurality of pre-DFT subsequences is further associated with at least one of: a length of the OFDM symbol without the CP, and the length of the CP; and The difference between the length of the first pre-DFT subsequence and any pre-DFT subsequences of other pre-DFT subsequences is associated with the length of the CP.

4. The method of claim 3, wherein the length of the first pre-DFT subsequence is associated with at least one of the following items: the length of the pre-DFT subsequences other than the first pre-DFT subsequence, and the number of subcarriers used for the WUS.

5. The method of claim 2, wherein the output of the independent IFFT operation comprises a plurality of post-IFFT subsequences, and wherein inserting the GI comprises one of: According to determining that the first OOK symbol among the plurality of OOK symbols is an OOK ON symbol, generating a GI sequence based on the first post-IFFT subsequence among the plurality of post-IFFT subsequences, or the first post-IFFT subsequence having a reverse order, generating a GI sequence having a zero value or a value close to zero based on determining that the first OOK symbol among the plurality of OOK symbols is an OOK OFF symbol, or According to determining that the first OOK symbol and the last OOK symbol among the multiple OOK symbols are the same, a GI sequence having a last post-IFFT subsequence among the multiple post-IFFT subsequences is generated.

6. The method of claim 1, wherein: At least one OOK subsequence of the plurality of OOK subsequences is a repetition of the first OOK subsequence of the plurality of OOK subsequences, or The multiple OOK subsequences are generated based on the same sequence and are multiplied with two sets of coefficients accordingly.

7. The method according to claim 1, wherein forming the pre-DFT sequence further comprises: inserting padding data at the beginning or end of the pre-DFT sequence, The padding data is at least one of the following: zero, a predefined sequence, or a copy of a portion of the pre-DFT subsequence, and the length of the padding data is determined based on at least one of the following: a CP length and an index of the OFDM symbol in a plurality of OFDM symbols, or an offset value.

8. A method implemented at a network device, comprising: generating at least one On-Off Keying (OOK) ON symbol by using a first number of frequency resources mapped with non-zero values, wherein the non-zero values ​​are used for normal downlink (DL) transmission; generating at least one OOK OFF symbol by using a second number of frequency resources mapped to have a zero value or a value close to zero; generating a wake-up signal (WUS) based on the at least one OOK ON symbol and the at least one OOK OFF symbol; as well as The WUS is sent to the terminal device.

9. A method implemented at a terminal device, comprising: Receive a wake-up signal (WUS) from a network device; as well as detecting the WUS to determine a plurality of on-off keying (OOK) symbols, the OOK symbols comprising at least one OOK ON symbol and at least one OOK OFF symbol; wherein the WUS is generated based on an output of transform precoding of a pre-discrete Fourier transform (pre-DFT) sequence, the pre-DFT sequence comprising a plurality of pre-DFT sub-sequences, the pre-DFT sequence being generated based on an OOK sub-sequence, and the OOK sub-sequence comprising the plurality of OOK symbols, and wherein the plurality of OOK symbols are associated with one OFDM symbol; and The length of the pre-DFT subsequence in the multiple pre-DFT subsequences is associated with at least one of the following items: the number of subcarriers used for the WUS, the number of the multiple OOK symbols, or the index of the pre-DFT subsequence in the multiple pre-DFT subsequences.

10. The method of claim 9, wherein receiving the WUS comprises: The WUS and normal downlink (DL) transmissions are received in a DL signal.

11. The method according to claim 10, wherein: The WUS and the normal DL transmission are generated by an Inverse Fast Fourier Transform (IFFT) operation, and a cyclic prefix (CP) is inserted into the output of the IFFT operation; or The WUS is generated by an independent IFFT operation, and a guard interval (GI) is inserted into the output of the independent IFFT operation.

12. The method of claim 9, wherein the length of the pre-DFT subsequence in the plurality of pre-DFT subsequences is further associated with at least one of: a length of the OFDM symbol without a CP, and the length of the CP, and The difference between the length of the first pre-DFT subsequence and any pre-DFT subsequence of other pre-DFT subsequences is associated with the length of the CP.

13. The method of claim 12, wherein the length of the first pre-DFT subsequence is associated with at least one of the following items: the length of the pre-DFT subsequences other than the first pre-DFT subsequence, and the number of subcarriers used for the WUS.

14. The method of claim 11, wherein the output of the independent IFFT operation comprises a plurality of post-IFFT subsequences, and wherein the GI is generated based on one of: According to determining that the first OOK symbol of the plurality of OOK symbols is an OOK ON symbol, the GI sequence is generated based on the first post-IFFT subsequence of the plurality of post-IFFT subsequences, or the first post-IFFT subsequence with a reverse order, Based on determining that the first OOK symbol of the plurality of OOK symbols is an OOK OFF symbol, a GI sequence is generated based on a zero value or a value close to zero, or In response to determining that the first OOK symbol and the last OOK symbol of the plurality of OOK symbols are the same, a GI sequence is generated based on a last post-IFFT subsequence of the plurality of post-IFFT subsequences.

15. The method of claim 10, wherein: At least one OOK subsequence of the plurality of OOK subsequences is a repetition of the first OOK subsequence of the plurality of OOK subsequences; or The multiple OOK subsequences are generated based on the same sequence and are multiplied with two sets of coefficients accordingly.

16. The method according to claim 10, wherein the WUS is generated based on an output of transform precoding of a pre-DFT sequence, wherein padding data is inserted at an initial or end portion of the pre-DFT sequence, and The padding data is at least one of the following: zero, a predefined sequence, or a copy of a portion of the pre-DFT subsequence, and the length of the padding data sequence is determined based on at least one of the following: a CP length and an index of the OFDM symbol in a plurality of OFDM symbols, or an offset value.

17. A method implemented at a terminal device, comprising: Receive a wake-up signal (WUS) from a network device; as well as The WUS is detected to determine a plurality of on-off keying (OOK) symbols, the plurality of on-off keying (OOK) symbols comprising at least one OOK ON symbol and at least one OOK OFF symbol, wherein the at least one OOK ON symbol is generated based on a first number of frequency resources mapped with a non-zero value, the non-zero value being used for normal downlink (DL) transmission, and wherein the at least one OOK OFF symbol is generated based on a second number of frequency resources mapped with a zero value or a value close to zero.

18. A method implemented at a terminal device, comprising: receiving a downlink (DL) signal from a network device, the DL signal comprising a wake-up signal (WUS) and a normal DL transmission, wherein the LP-WUS and the normal DL transmission are generated using an orthogonal frequency division multiplexing (OFDM) operation; receiving a WUS configuration from the network device; determining resources for the WUS indicated in the WUS configuration; determining overlapping resources, the overlapping resources being allocated to the normal DL transmission and overlapping with the resources for the WUS; and It is determined that the overlapping resources are not available for the normal DL transmission.

19. A method implemented at a terminal device, comprising: receiving a downlink (DL) signal from a network device, the DL signal comprising a wake-up signal (WUS) and a normal DL transmission, wherein the WUS comprises a plurality of on-off keying (OOK) symbols, the plurality of on-off keying (OOK) symbols comprising at least one OOK ON symbol and at least one OOK OFF symbol, and wherein the at least one OOK ON symbol is generated based on data of the normal DL transmission; determining an index of a plurality of PRBs allocated to the WUS; determining that resource elements (REs) of a plurality of PRBs of an OFDM symbol associated with an OOK ON symbol are available for the normal DL transmission; and It is determined that REs of the plurality of PRBs of the OFDM symbol associated with the OOK OFF symbol are unavailable for the normal DL transmission.

20. A communication device, comprising: processor; as well as A memory, the memory being coupled to the processor and storing instructions thereon, wherein when the instructions are executed by the processor, the network device executes the method according to any one of claims 1 to 8 or any one of claims 9 to 19.

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