Wake-up signal waveform design

Abstract

The invention provides a system and a method for generating a wake-up signal. The method comprises the following steps: receiving a plurality of input samples; performing, on the plurality of input samples, a subcarrier mapping that maps the plurality of input samples to a set of subcarriers, thereby generating a subcarrier mapper output; generating a first orthogonal frequency division multiplexing (OFDM) signal by mapping at least a portion of the subcarrier mapper output to a first frequency band, wherein the first frequency band corresponds to a first wake-up signal symbol; generating a second OFDM signal by mapping at least a portion of the subcarrier mapper output to a second frequency band, wherein the second frequency band corresponds to a second wake-up signal symbol; and generating a wake-up signal comprising at least a portion of the first OFDM signal for representing the first wake-up symbol and at least a portion of the second OFDM signal for representing the second wake-up signal.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is based upon and claims priority to U.S. patent application No. 63 / 411,292 filed on September 29, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0003] Apparatus and methods consistent with example embodiments of the present disclosure relate to orthogonal frequency division multiplexing (OFDM) based frequency shift keying (FSK) waveform generation. Background Art

[0004] A low-power wake-up radio (WUR) in the prior art is a receiver that can operate at a lower power than a conventional receiver. A user equipment (UE) can have both a conventional receiver and a low-power wake-up radio. In order to save power, the conventional receiver can be placed in a low-power state where applicable (for example, when the UE is in idle mode or DRX mode). In this state, the conventional receiver can be turned off (i.e., not receiving or sending any signals), or can be in an almost-off mode. When the conventional receiver is in this state, the WUR can be in an operating mode and can be monitoring a wake-up signal (WUS). If the WUS is detected and the WUS instructs the UE to turn on the conventional receiver, the UE turns on the conventional receiver and can start performing conventional send / receive processes. For example, it can detect a serving cell, obtain system information, perform random access, and so on.

[0005] Two common designs of waveforms used to generate WUS are ON-OFF keying (OOK) and frequency shift keying (FSK). OOK is used in IEEE 802.11ba. In OOK, the waveform includes ON and OFF patterns in the time domain, and a specific pattern is used to convey information. For example, (ON OFF) can be represented by a bit "1", while (OFF ON) can be represented by a bit "0". In FSK, the frequency of the waveform conveys information. For example, if a pulse is sent at or near frequency f0, a bit "0" is conveyed, and if a pulse is sent at or near frequency f1, a bit 1 is conveyed. Summary of the invention

[0006] According to an embodiment, a system and method for generating an Orthogonal Frequency Division Multiplexing (OFDM) based Frequency Shift Keying (FSK) waveform is provided.

[0007] According to one embodiment, a method for generating a wake-up signal is provided, which is performed by at least one processor. The method includes: receiving a plurality of input samples; performing subcarrier mapping on the plurality of input samples to map the plurality of input samples to a set of subcarriers, thereby generating a subcarrier mapper output; generating a first orthogonal frequency division multiplexing (OFDM) signal by mapping at least a portion of the subcarrier mapper output to a first frequency band, wherein the first frequency band corresponds to a first wake-up signal symbol; generating a second OFDM signal by mapping at least a portion of the subcarrier mapper output to a second frequency band, wherein the second frequency band corresponds to a second wake-up signal symbol; and generating a wake-up signal, the wake-up signal including at least a portion of the first OFDM signal for representing the first wake-up signal symbol and at least a portion of the second OFDM signal for representing the second wake-up signal symbol.

[0008] Mapping at least a portion of the subcarrier mapper output to the first frequency band may further include performing a first inverse discrete Fourier transform (IDFT) on the subcarrier mapper output, and mapping at least a portion of the subcarrier mapper output to the second frequency band may further include performing a second IDFT on the subcarrier mapper output.

[0009] According to one embodiment, a wake-up signal waveform generator is provided, which includes: at least one memory configured to store computer program code; and at least one processor configured to access the at least one memory and operate according to the instructions of the computer program code, wherein the computer program code includes: a receiving code configured to cause the at least one processor to receive a plurality of input samples; an executing code configured to cause the at least one processor to perform subcarrier mapping on the plurality of input samples to map the plurality of input samples to a set of subcarriers, thereby generating a subcarrier mapper output; a first generating code configured to cause the at least one processor to generate a first orthogonal frequency division multiplexing (OFDM) signal by mapping at least a portion of the subcarrier mapper output to a first frequency band, wherein the first frequency band corresponds to a first wake-up signal symbol; a second generating code configured to cause the at least one processor to generate a second OFDM signal by mapping at least a portion of the subcarrier mapper output to a second frequency band, wherein the second frequency band corresponds to a second wake-up signal symbol; and a third generating code configured to cause the at least one processor to generate a wake-up signal, the wake-up signal including at least a portion of the first OFDM signal for representing the first wake-up symbol and at least a portion of the second OFDM signal for representing the second wake-up signal.

[0010] According to one embodiment, a non-transitory computer-readable medium having instructions stored therein is provided, which, when executed by a processor in a wake-up signal waveform generator, causes the processor to perform a method, the method comprising: receiving a plurality of input samples; performing subcarrier mapping on the plurality of input samples to map the plurality of input samples to a set of subcarriers, thereby generating a subcarrier mapper output; generating a first orthogonal frequency division multiplexing (OFDM) signal by mapping at least a portion of the subcarrier mapper output to a first frequency band, wherein the first frequency band corresponds to a first wake-up signal symbol; generating a second OFDM signal by mapping at least a portion of the subcarrier mapper output to a second frequency band, wherein the second frequency band corresponds to a second wake-up signal symbol; and generating a wake-up signal, the wake-up signal comprising at least a portion of the first OFDM signal for representing the first wake-up signal symbol and at least a portion of the second OFDM signal for representing the second wake-up signal symbol.

[0011] Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be achieved by practice of the presented embodiments of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Features, aspects, and advantages of certain exemplary embodiments of the present disclosure will be described below with reference to the accompanying drawings, in which like reference numerals represent like elements, and in which:

[0013] Figure 1 illustrates WUS generation using an OFDM transmitter according to an embodiment;

[0014] Figure 2 illustrates a WUS symbol generated using an OFDM transmitter according to an embodiment;

[0015] Figure 3 is a diagram of an example network device according to various embodiments of the present disclosure;

[0016] Figure 4 is a schematic diagram of an example wireless communication system according to various embodiments of the present disclosure; and

[0017] Figure 5 is a flowchart illustrating a method of generating a WUS according to various embodiments of the present disclosure. DETAILED DESCRIPTION

[0018] The following detailed description of the exemplary embodiments refers to the accompanying drawings. The above disclosure provides illustrations and descriptions, but is not intended to be exhaustive or to limit the implementation to the precise form disclosed. Modifications and variations are possible based on the above disclosure, or can be obtained from the practice of implementation. In addition, one or more features or components of an embodiment can be incorporated into another embodiment (or one or more features of another embodiment) or combined with it. In addition, in the flowcharts and operational descriptions provided below, it can be understood that one or more operations can be omitted, one or more operations can be added, one or more operations can be performed simultaneously (at least in part), and the order of one or more operations can be switched.

[0019] It is obvious that the system and / or method described herein can be implemented with different forms of hardware, firmware, or a combination of hardware and software. The actual dedicated control hardware or software code for implementing these systems and / or methods does not limit these implementations. Therefore, the operation and behavior of the system and / or method are described herein without reference to specific software codes. It should be understood that software and hardware can be designed to implement these systems and / or methods based on the description herein.

[0020] Even though particular combinations of features are recited in the claims and / or disclosed in the specification, these combinations are not intended to limit the disclosure of possible implementations. In fact, many of these features may be combined in ways not specifically recited in the claims and / or disclosed in the specification. Although each dependent claim listed below may directly depend on only one claim, the disclosure of possible implementations includes each dependent claim in combination with every other claim in the claim set.

[0021] Unless explicitly stated, no element, act, or instruction used herein should be construed as critical or essential. In addition, as used herein, the terms "a" and "an" are intended to include one or more items and can be used interchangeably with "one or more". Figure 1 items, the term "one" or similar language is used. In addition, as used herein, the terms "has," "have," "having," "include," "including," and the like are intended to be open-ended terms. Furthermore, unless expressly stated otherwise, the term "based on" means "based at least in part on." Furthermore, expressions such as "at least one of [A] and [B]" or "at least one of [A] or [B]" should be understood to include only A, only B, or both A and B.

[0022] The prior art does not propose how to generate WUS based on FSK using an OFDM transmitter, where one OFDM symbol can be used to generate multiple WUS symbols. At the same time, one or more example embodiments provide an OFDM-based FSK waveform generation scheme that enables WUS generation using a conventional 5G NR transmitter. Therefore, power saving can be achieved on the UE side, thereby extending battery life, and a conventional 5G NR transmitter can be used for WUS generation.

[0023] Waveform Generation

[0024] In one method, the WUS can be generated using the prior art FSK modulation. In another method, the WUS can be generated using the prior art FSK modulation. Figure 1 The OFDM transmitter shown is used to generate WUS.

[0025] According to an example embodiment, a set of M input samples 110 x are mapped using a subcarrier mapping (SM) block 120. 0 to x M-1 Mapped to a group of M subcarriers. The input samples 110 can be symbols modulated by binary phase shift keying (BPSK) and / or symbols modulated by quadrature phase shift keying (QPSK). The input samples 110 can be scaled to have different power levels. Before mapping the input samples 110 to the subcarriers, they can be processed using a frequency domain window. The input samples 110 can also undergo a phase change operation, for example, to maintain phase continuity.

[0026] The frequency (e.g., a frequency band consisting of one or more subcarriers) to which the samples 110 are mapped may correspond to one or more WUS symbols. For example, an OFDM signal generated by mapping the input 110 to a frequency band at or near f0 (frequency band 0) may indicate symbol 0, while an OFDM signal generated by mapping the input to a frequency band at or near f1 (frequency band 1) may indicate symbol 1. f0 and f1 may be midpoint frequencies in their respective frequency bands. For example, a frequency band may include 12 resource blocks with a subcarrier spacing of 15 kHz, corresponding to a 2.160 MHz bandwidth. Here, a cyclic prefix (CP) and / or a guard interval (GI) (e.g., a guard interval consisting of zeros) may also be prepended to the inverse discrete Fourier transform (IDFT) output. After the CP / GI is added, the signal may be modulated to the carrier frequency and processed by digital-to-analog conversion before transmission.

[0027] In a method according to an example embodiment, a subset of the IDFT outputs (rather than all of the IDFT outputs) may be used to indicate one or more WUS symbols. For example, the IDFT outputs may be represented by Figure 1 The N samples 150 shown are composed of, and n output samples (e.g., n=24 and N=512) can be used to indicate a symbol 0 or 1. An example is shown in Figure 2 and described below.

[0028] The OFDM signal is generated by mapping input samples 210 to frequency bands (in one embodiment, input samples 210 are equivalent to input samples 110). The signal 220 generated using frequency band 0 is represented as d 0 , and the signal 230 generated using frequency band 1 is represented as d 1 Each signal can contain N samples. Figure 2 As shown, sample indices are represented by subscripts.

[0029] To send symbol 0, select d 0 To send symbol 1, select d 1 A cyclic prefix or guard interval may be added to the n-point signal. The signal may then be modulated and converted to an analog signal.

[0030] To send the next symbol, the same set of n samples or another set of n samples can be selected. Figure 2 In one method, the index of the n samples can be calculated as mod(n×k+of:n×(k+1)-1+of,N), where mod represents the modulo operation, k is a symbolic index starting from 0, and of is an integer offset between 0 and N (including 0 and N).

[0031] In one method, if all N samples of the IDFT output are used to indicate a WUS symbol, a new set of N samples can be generated using a new set of M input samples, and the new N samples can be used to indicate a new symbol. In another method, the same N samples can be used to send the entire WUS. The M input samples mapped to different frequency bands can be different.

[0032] The above can be extended to more than two frequency bands. When the number of frequency bands is K, every n samples can be used to indicate log2K bits.

[0033] Figure 2 The example in includes a symbol 230 shown as [0; 0; 0; 1; 1; 0]. Assuming n=12, the IDFT output samples 220 and 230 for indicating the symbol can be determined as [d 0 0 to d 0 11 ;d 0 12 to d 0 23 ;d 0 24 to d 0 35;d 1 0 to d 1 11 ;d 1 12 to d 1 24 ;d 0 36 to d 0 47 ]. Note that when n<N, the symbol duration is less than the OFDM symbol duration. One or more symbols can be used to encode an information bit. For example, an information bit "0" can be encoded by the symbol [1 0], and an information bit "1" can be encoded by the symbol [0 1].

[0034] A similar approach can be used to generate an on-off keying (OOK) signal. In an OOK signal, symbol 1 can be indicated using a subset of the IDFT output, and symbol 0 can be indicated in the absence of a signal. The frequency band of the OFDM signal used to generate OOK can be different from the frequency band used for FSK. For example, the frequency band used for OOK can be a combination of band 0 and band 1.

[0035] In another method according to an example embodiment, both FSK and OOK can be used to indicate a WUS symbol. In this method, in order to represent symbol 1 in the time domain as in OOK, a signal can be generated using band 0 or band 1. Symbol 0 can be represented as no signal. At the wake-up receiver, the first time domain energy of the received signal can be detected. If the energy is above a threshold, WUS determines a signal representing symbol 1. The frequency of the signal can then be determined to be f0 or f1 (e.g., by filtering and energy detection), where f0 can indicate symbol 0 and f1 can indicate symbol 1 as in FSK. If the received signal energy is below the threshold, it is determined to represent symbol 0, and no further frequency domain analysis is required. Typically, as shown in this example, a symbol can be represented by the time domain energy and / or frequency content of the signal.

[0036] WUS can be sent in the same channel as other legacy channels. For example, the gNB can allocate 4 MHz of a 20 MHz channel to WUS and use the rest of the channel for legacy NR channels, such as a downlink shared channel. Since WUS frames can be sent with a certain duty cycle, 4 MHz may not always be allocated to WUS, but only when WUS frames are sent. The subcarrier spacing (SCS) used to generate WUS can be different, for example, based on the SCS of the channel in which the WUS is sent. For example, the SCS can be 15 kHz or 30 kHz in frequency range 1 (FR1).

[0037] In one method according to an example embodiment, the WUS input samples 210 to the IDFT can be determined based on at least the SCS. Assume that when the SCS is 30kHz, a set of input samples 210 is given by a vector x. When the SCS is 15kHz, the number of subcarriers used to map the input (assuming that the WUS bandwidth remains unchanged) will become more than twice. In this case, the input (denoted as x') can be determined by one of the following ways: (i) upsampling x by a ratio of the SCS (i.e., 30kHz / 15kHz=2), x'=upsample(x,2); (ii) x' is a repetition of x, for example x'=[xx]; and (iii) = x'=[xx*], where * represents conjugation.

[0038] An information bit may be composed of multiple WUS symbols, i.e., an information bit may be encoded using WUS symbols. For example, an information bit "0" may be represented by a WUS symbol [1 0], and an information bit "1" may be represented by a WUS symbol [0 1]. In another example, "0": [10 1 0] and "1": [0 1 0 1].

[0039] Go to Figure 3 , the methods and processes described herein may be performed on a device 300, which may correspond to any type of known computer, server, or data processing device. For example, the device 300 may include a processor, a personal computer (PC), a printed circuit board (PCB) including a computing device, a minicomputer, a mainframe computer, a microcomputer, a telephone computing device, a wired / wireless computing device (e.g., a smartphone, a personal digital assistant (PDA)), a laptop, a tablet computer, a smart device, or any other similarly functional device.

[0040] In some embodiments, Figure 3 As shown, device 300 may include a set of components such as a processor 320 , a memory 330 , a storage component 340 , an input component 350 , an output component 360 , and a communication interface 370 .

[0041] The bus 310 may include one or more components that allow communication between the set of components of the device 300. For example, the bus 310 may be a communication bus, a cross-over bar, a network, etc. Although the bus 310 may be Figure 3 Although depicted as a single line in FIG. 3 , bus 310 may be implemented using multiple (two or more) connections between the set of components of device 300. The present disclosure is not limited in this respect.

[0042] Device 300 may include one or more processors, such as processor 320. Processor 320 may be implemented in hardware, firmware and / or a combination of hardware and software. For example, processor 320 may include a central processing unit (CPU), a graphics processing unit (GPU), an accelerated processing unit (APU), a microprocessor, a microcontroller, a digital signal processor (DSP), a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a general purpose single-chip or multi-chip processor, or other programmable logic devices, discrete gates or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described herein. A general purpose processor may be a microprocessor, or any conventional processor, controller, microcontroller or state machine. Processor 320 may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors combined with a DSP core, or any other such configuration. In some embodiments, specific processes and methods may be performed by a circuit system specific to a given function.

[0043] Processor 320 may control the overall operation of device 300 and / or the set of components of device 300 (eg, memory 330 , storage component 340 , input component 350 , output component 360 , communication interface 370 ).

[0044] Device 300 may also include memory 330. In some embodiments, memory 330 may include random access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), flash memory, magnetic memory, optical memory, and / or another type of dynamic or static storage device. Memory 330 may store information and / or instructions for use (e.g., execution) by processor 320.

[0045] The storage component 340 of the device 300 may store information and / or computer-readable instructions and / or code related to the operation and use of the device 300. For example, the storage component 340 may include a hard disk (e.g., a magnetic disk, an optical disk, a magneto-optical disk, and / or a solid-state disk), a compact disk (CD), a digital versatile disk (DVD), a universal serial bus (USB) flash drive, a Personal Computer Memory Card International Association (PCMCIA) card, a floppy disk, a cassette, a magnetic tape, and / or another type of non-transitory computer-readable medium, and a corresponding drive.

[0046] Device 300 may also include input component 350. Input component 350 may include one or more components that allow device 300 to receive information, such as via user input (e.g., a touch screen, keyboard, keypad, mouse, stylus, buttons, switches, microphone, camera, etc.). Alternatively or additionally, input component 350 may include a sensor for sensing information (e.g., a global positioning system (GPS) component, an accelerometer, a gyroscope, an actuator, etc.).

[0047] Output component 360 of device 300 may include one or more components (e.g., a display, a liquid crystal display (LCD), a light emitting diode (LED), an organic light emitting diode (OLED), a tactile feedback device, a speaker, etc.) that can provide output information from device 300.

[0048] The device 300 may also include a communication interface 370. The communication interface 370 may include a receiver component, a transmitter component and / or a transceiver component. The communication interface 370 may enable the device 300 to establish a connection and / or transmit communication with other devices (e.g., a server, another device). Communication may be achieved via a wired connection, a wireless connection, or a combination of a wired and wireless connection. The communication interface 370 may allow the device 300 to receive information from another device and / or provide information to another device. In some embodiments, the communication interface 370 may provide communication with another device via a network, such as a local area network (LAN), a wide area network (WAN), a metropolitan area network (MAN), a private network, a self-organizing network, an intranet, the Internet, a fiber-based network, a cellular network (e.g., a fifth generation (5G) network, a long-term evolution (LTE) network, a third generation (3G) network, a code division multiple access (CDMA) network, etc.), a public land mobile network (PLMN), a telephone network (e.g., a public switched telephone network (PSTN)), etc., and / or a combination of these or other types of networks. Alternatively or additionally, the communication interface 370 may provide communication with another device via a device-to-device (D2D) communication link, such as FlashLinQ, WiMedia, Bluetooth, ZigBee, Wi-Fi, LTE, 5G, etc. In other embodiments, the communication interface 370 may include an Ethernet interface, an optical interface, a coaxial interface, an infrared interface, a radio frequency (RF) interface, etc.

[0049] Device 300 can perform one or more processes described herein. Device 300 can perform operations based on processor 320, and processor executes computer-readable instructions and / or codes that can be stored by non-transitory computer-readable media (such as memory 330 and / or storage component 340). Computer-readable media can refer to non-transitory memory devices. Memory devices can include memory space within a single physical storage device and / or memory space distributed between multiple physical storage devices. Some embodiments may involve systems, methods, and / or computer-readable media at any possible level of integrated technical details. In addition, one or more of the components described herein can be implemented as instructions that are stored on a computer-readable medium and are executable by at least one processor (and / or can include at least one processor). Computer-readable media can include (multiple) computer-readable non-transitory storage media, which (multiple) computer-readable non-transitory storage media have computer-readable program instructions for causing the processor to perform operations.

[0050] Computer readable storage medium can be a tangible device, which can retain and store instructions for use by instruction execution devices. Computer readable storage medium can be, for example, but not limited to, electronic storage device, magnetic storage device, optical storage device, electromagnetic storage device, semiconductor storage device, or any suitable combination of the above. A non-exhaustive list of more specific examples of computer readable storage medium includes: portable computer floppy disk, hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable compact disc read-only memory (CD-ROM), digital versatile disk (DVD), memory stick, floppy disk, mechanical encoding device (such as a convex structure in a punch card or groove) with instructions recorded thereon, and any suitable combination of the above. Computer readable storage medium as used herein itself should not be interpreted as transient signal, such as radio wave or other free propagating electromagnetic wave, electromagnetic wave propagated by waveguide or other transmission medium (for example, light pulse passing through optical fiber cable) or electrical signal sent by wire.

[0051] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to a corresponding computing / processing device via a network (e.g., the Internet, a local area network, a wide area network, and / or a wireless network), or downloaded to an external computer or external storage device. The network can include copper transmission cables, optical transmission fibers, wireless transmissions, routers, firewalls, switches, gateway computers, and / or edge servers. The network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network, and forwards the computer-readable program instructions to be stored in a computer-readable storage medium in the corresponding computing / processing device.

[0052] The computer readable program code / instruction for performing the operation can be an assembly instruction, an instruction set architecture (ISA) instruction, a machine instruction, a machine-related instruction, a microcode, a firmware instruction, a state setting data, a configuration data of an integrated circuit system, or a source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​(such as Smalltalk, C++, etc.) and process programming languages ​​(such as "C" programming languages ​​or similar programming languages). The computer readable program instruction can be executed completely on the user's computer, partially on the user's computer, executed as an independent software package, partially on the user's computer and partially on a remote computer, or completely on a remote computer or server. In the latter case, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection to an external computer can be executed (for example, using an Internet service provider through the Internet). In some embodiments, an electronic circuit system (including, for example, a programmable logic circuit system, a field programmable gate array (FPGA) or a programmable logic array (PLA)) can execute computer readable program instructions by using the state information of the computer readable program instruction to personalize the electronic circuit system, thereby performing various aspects or operations.

[0053] These computer-readable program instructions may be provided to a processor 320 of a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine, such that the instructions executed via the processor 320 of the computer or other programmable data processing device create components for implementing the functions / actions specified in the flowchart and / or block diagram blocks. These computer-readable program instructions may also be stored in a computer-readable storage medium (such as a memory 330), which may direct a computer, a programmable data processing device, and / or other device to operate in a particular manner, such that the computer-readable storage medium having the instructions stored therein includes an article of manufacture, which includes instructions for implementing various aspects of the functions / actions specified in the flowchart and / or block diagram blocks.

[0054] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operating steps to be performed on the computer, other programmable apparatus, or other device, thereby producing a computer-implemented process, so that the instructions executed on the computer, other programmable apparatus, or other device implement the functions / actions specified in the flowchart and / or block diagram blocks.

[0055] The computer-readable instructions and / or code may be read into the memory 330 and / or storage component 340 from another computer-readable medium or from another device via the communication interface 370. The computer-readable instructions and / or code stored in the memory 330 and / or storage component 340, if or when executed by the processor 320, may cause the device 300 to perform one or more processes described herein.

[0056] Alternatively or additionally, hardwired circuitry may be used in place of or in combination with software instructions to perform one or more processes described herein.Thus, the embodiments described herein are not limited to any specific combination of hardware circuitry and software.

[0057] Figure 3 The number and arrangement of components shown are provided as examples. Figure 3 There may be more components, fewer components, different components, or differently arranged components than shown. Figure 3 Two or more components shown may be implemented in a single component, or Figure 3 The single component shown may be implemented as multiple distributed components. Additionally or alternatively, Figure 3 The illustrated set (one or more) of components may perform the operations described as being performed by Figure 3 Another group of components shown performs one or more functions.

[0058] Figure 4 4 is a diagram illustrating an example of a wireless communication system according to various embodiments of the present disclosure. The wireless communication system 400 (which may also be referred to as a wireless wide area network (WWAN)) may include one or more user equipments (UEs) 410, one or more base stations 420, at least one transmission network 430, and at least one core network 440. Device 300 ( Figure 3 ) can be incorporated in UE 410 or base station 420.

[0059] One or more UEs 410 may access at least one core network 440 and / or IP services 450 via a connection to one or more base stations 420 through the RAN domain 424 and through at least one transport network 430. Examples of UE 410 may include a cellular phone, a smart phone, a Session Initiation Protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a global positioning system (GPS), a multimedia device, a video device, a digital audio player (e.g., an MP3 player), a camera, a game console, a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, large or small kitchen appliances, a healthcare device, an implant, a sensor / actuator, a display, or any other similarly functional device. Some of the one or more UEs 410 may be referred to as Internet of Things (IoT) devices (e.g., a parking meter, a gas pump, a toaster, a vehicle, a heart monitor, etc.). One or more UEs 410 may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communication device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile agent, a client or some other suitable terminology.

[0060] The one or more base stations 420 may wirelessly communicate with the one or more UEs 410 via the RAN domain 424. Each of the one or more base stations 420 may provide communication coverage to one or more UEs 410 located within the geographic coverage area of ​​the base station 420. Figure 4 As shown, the base station 420 may transmit one or more beamformed signals in one or more transmit directions to the one or more UEs 410. The one or more UEs 410 may receive the beamformed signals in one or more receive directions from the base station 420. Alternatively or additionally, the one or more UEs 410 may transmit the beamformed signals in one or more transmit directions to the base station 420. The base station 420 may receive the beamformed signals in one or more receive directions from the one or more UEs 410.

[0061] One or more base stations 420 may include a macro cell (e.g., a high-power cellular base station) and / or a small cell (e.g., a low-power cellular base station. Small cells may include femto cells, pico cells, and micro cells. Base station 420 (whether a macro cell or a large cell) may include and / or be referred to as an access point (AP), an evolved (or evolved universal terrestrial radio access network (E-UTRAN)) Node B (eNB), a next-generation Node B (gNB), or any other type of base station known to those of ordinary skill in the art.

[0062] The one or more base stations 420 may be configured to interface (e.g., establish a connection, transmit data, etc.) with at least one core network 440 via at least one transport network 430. In addition to other functions, the one or more base stations 420 may also perform one or more of the following functions: transmit data (e.g., uplink data) received from one or more UEs 410 to at least one core network 440 via at least one transport network 430, and transmit data (e.g., downlink data) received from at least one core network 440 via at least one transport network 430 to one or more UEs 410.

[0063] The transport network 430 may transmit data (e.g., uplink data, downlink data) and / or signaling between the RAN domain 424 and the CN domain 444. For example, the transport network 430 may provide one or more backhaul links between one or more base stations 420 and at least one core network 440. The backhaul link may be wired or wireless.

[0064] The core network 440 may be configured to provide one or more services (e.g., enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC), and massive machine type communication (mMTC), etc.) to one or more UEs 410 connected to the RAN domain 424 via the TN domain 434. Alternatively or additionally, the core network 440 may be used as an entry point for IP services 450. The IP services 450 may include the Internet, an intranet, an IP multimedia subsystem (IMS), streaming services (e.g., video, audio, games, etc.), and / or other IP services.

[0065] Figure 5 A flow chart of a method 500 for generating a wake-up signal according to an embodiment is shown. Specifically, the method includes an operation 510, in which a wake-up signal generator receives a plurality of input samples. In operation 520, a subcarrier mapping of the received plurality of input samples maps the plurality of input samples to a set of subcarriers, which results in a subcarrier mapper output. In operation 530, a first OFDM signal is generated by mapping at least a portion of the subcarrier mapper output (generated in operation 520) to a first frequency band, wherein the first frequency band corresponds to a first wake-up signal symbol. In operation 540, a second OFDM signal is generated by mapping at least a portion of the subcarrier mapper output (generated in operation 520) to a second frequency band, wherein the second frequency band corresponds to a second wake-up signal symbol. Finally, in operation 550, a wake-up signal is generated, the wake-up signal comprising at least a portion of the first OFDM signal (generated in operation 530) for representing the first wake-up signal symbol and at least a portion of the second OFDM signal (generated in operation 540) for representing the second wake-up signal symbol.

[0066] The flowchart and block diagram in the figure illustrate the possible implementation architecture, function and operation of the system, method and computer-readable medium according to various embodiments. In this regard, each block in the flowchart or block diagram can represent (multiple) microservices, modules, segments or parts of instructions, which include one or more executable instructions for implementing (multiple) specified logical functions. Compared with what is shown in the figure, the method, computer system and computer-readable medium may include more blocks, fewer blocks, different blocks or blocks arranged differently. In some alternative implementations, the functions described in the block may not appear in the order shown in the figure. For example, in fact, the two blocks shown in succession can be executed simultaneously or substantially simultaneously, or these blocks can sometimes be executed in the opposite order, depending on the functions involved. It will also be noted that each block illustrated in the block diagram and / or flowchart and the combination of blocks in the block diagram and / or flowchart can be implemented by a system based on special hardware, which performs a specified function or action or performs a combination of special hardware and computer instructions.

Claims

1. A method for generating a wake-up signal, the method being executed by at least one processor and comprising: receiving a plurality of input samples; performing subcarrier mapping on the plurality of input samples to a set of subcarriers, thereby generating a subcarrier mapper output; generating a first orthogonal frequency division multiplexing (OFDM) signal by mapping at least a portion of the subcarrier mapper output to a first frequency band, wherein the first frequency band corresponds to a first wake-up signal symbol; generating a second OFDM signal by mapping at least a portion of the subcarrier mapper output to a second frequency band, wherein the second frequency band corresponds to a second wake-up signal symbol; as well as A wake-up signal is generated, the wake-up signal including at least a portion of the first OFDM signal representing the first wake-up symbol and at least a portion of a second OFDM signal representing the second wake-up symbol.

2. The method of claim 1 , wherein mapping at least a portion of the subcarrier mapper output to the first frequency band comprises: A first inverse discrete Fourier transform (IDFT) is performed on the subcarrier mapper output, and mapping at least a portion of the subcarrier mapper output to the second frequency band includes performing a second IDFT on the subcarrier mapper output.

3. The method of claim 2, wherein generating the first OFDM signal further comprises: At least one of a cyclic prefix (CP) and a guard interval is prepended to an output of the first IDFT, and generating the second OFDM signal further comprises: prepending at least one of a cyclic prefix (CP) and a guard interval to an output of the second IDFT.

4. The method according to claim 3, further comprising: Modulating the wake-up signal to a carrier frequency; Processing the wake-up signal using a digital-to-analog converter; as well as Sends a modulated analog wake-up signal.

5. The method of claim 1, wherein the plurality of input samples comprises at least one of: binary phase shift keying (BPSK) modulated symbols, and quadrature phase shift keying (QPSK) modulated symbols.

6. The method according to claim 1, further comprising: Prior to performing subcarrier mapping, the plurality of input samples are processed using a frequency domain window.

7. The method according to claim 6, further comprising: Before performing subcarrier mapping, a phase transformation operation is performed on the plurality of input samples.

8. A wake-up signal waveform generator, comprising: at least one memory configured to store computer program code; as well as At least one processor is configured to access the at least one memory and operate according to the instructions of the computer program code, wherein the computer program code comprises: receiving code configured to cause the at least one processor to: receive a plurality of input samples; executing code configured to cause the at least one processor to: perform subcarrier mapping on the plurality of input samples to a set of subcarriers, thereby generating a subcarrier mapper output; first generating code configured to cause the at least one processor to: generate a first orthogonal frequency division multiplexing (OFDM) signal by mapping at least a portion of the subcarrier mapper output to a first frequency band, wherein the first frequency band corresponds to a first wake-up signal symbol; A second generating code configured to cause the at least one processor to: generate a second OFDM signal by mapping at least a portion of the subcarrier mapper output to a second frequency band, wherein the second frequency band corresponds to a second wake-up signal symbol; and The third generating code is configured to cause the at least one processor to: generate a wake-up signal, wherein the wake-up signal includes: at least a portion of the first OFDM signal for representing the first wake-up symbol, and at least a portion of the second OFDM signal for representing the second wake-up signal.

9. The wake-up signal waveform generator according to claim 8, The first generated code further includes: code configured to cause the at least one processor to perform a first inverse discrete Fourier transform (IDFT) on at least a portion of the subcarrier mapper output, and The second generating code further comprises: code configured to cause the at least one processor to perform a second IDFT on at least a portion of the subcarrier mapper output.

10. The wake-up signal waveform generator according to claim 9, The first generated code further includes: code configured to cause the at least one processor to prepend at least one of a cyclic prefix (CP) and a guard interval to an output of the first IDFT, and The second generating code further includes: a code configured to cause the at least one processor to prepend at least one of a cyclic prefix (CP) and a guard interval to an output of the second IDFT.

11. The wake-up signal waveform generator of claim 10, further comprising a transmitter, wherein the computer program code further comprises: a modulation code configured to cause the at least one processor to modulate the wake-up signal to a carrier frequency; a conversion code configured to cause the at least one processor to convert the wake-up signal from a digital signal to an analog signal; as well as Transmitting code configured to cause the at least one processor to transmit a modulated analog wake-up signal by the transmitter. 12 . The wake-up signal waveform generator of claim 8 , wherein the plurality of input samples include at least one of: binary phase shift keying (BPSK) modulated symbols, and quadrature phase shift keying (QPSK) modulated symbols.

13. The wake-up signal waveform generator of claim 8, wherein the computer program code further comprises processing code configured to cause the at least one processor to: process the plurality of input samples using a frequency domain window before performing subcarrier mapping.

14. The wake-up signal waveform generator according to claim 13, wherein the computer program code further comprises a phase change code, wherein the phase change code is configured to cause the at least one processor to: perform a phase change operation on the plurality of input samples before performing subcarrier mapping.

15. A non-transitory computer readable medium having stored therein instructions, which, when executed by a processor in a wake-up signal waveform generator, cause the processor to perform a method comprising: receiving a plurality of input samples; performing subcarrier mapping on the plurality of input samples to a set of subcarriers, thereby generating a subcarrier mapper output; generating a first orthogonal frequency division multiplexing (OFDM) signal by mapping at least a portion of the subcarrier mapper output to a first frequency band, wherein the first frequency band corresponds to a first wake-up signal symbol; generating a second OFDM signal by mapping at least a portion of the subcarrier mapper output to a second frequency band, wherein the second frequency band corresponds to a second wake-up signal symbol; as well as A wake-up signal is generated, the wake-up signal including at least a portion of the first OFDM signal representing the first wake-up symbol and at least a portion of a second OFDM signal representing the second wake-up signal.

16. The non-transitory computer readable medium of claim 15, wherein mapping at least a portion of the subcarrier mapper output to the first frequency band comprises: A first inverse discrete Fourier transform (IDFT) is performed on the subcarrier mapper output, and mapping at least a portion of the subcarrier mapper output to the second frequency band includes performing a second IDFT on the subcarrier mapper output.

17. The non-transitory computer readable medium of claim 16, wherein generating the first OFDM signal further comprises: At least one of a cyclic prefix (CP) and a guard interval is prepended to an output of the first IDFT, and generating the second OFDM signal further comprises: prepending at least one of a cyclic prefix (CP) and a guard interval to an output of the second IDFT.

18. The non-transitory computer readable medium of claim 17, wherein the method further comprises: Modulating the wake-up signal to a carrier frequency; Processing the wake-up signal using a digital-to-analog converter; as well as Sends a modulated analog wake-up signal.

19. The non-transitory computer readable medium of claim 15, wherein the plurality of input samples comprises at least one of: binary phase shift keying (BPSK) modulated symbols, and quadrature phase shift keying (QPSK) modulated symbols.

20. The non-transitory computer readable medium of claim 15, wherein the method further comprises: Prior to performing subcarrier mapping, processing the plurality of input samples using a frequency domain window; as well as Before performing subcarrier mapping, a phase transformation operation is performed on the plurality of input samples.

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