Wireless local area network terminal time domain wake-up method, system and device and storage medium

Abstract

The invention discloses a wireless local area network terminal time domain wake-up method, system and device and a storage medium, and belongs to the technical field of wireless communication, and the method comprises the steps: distributing a unique cyclic prefix (CP) length for each wireless terminal at an access point (AP), and building a mapping table of the CP length and the wireless terminal; when a wake-up signal is sent, the AP adds CP with the corresponding length to the selected OFDM short training sequence according to the CP length of the target wireless terminal; when the wireless terminal is in a silent state, an air interface wireless time domain signal is acquired only through a front-end radio frequency part, window sliding calculation is performed on the acquired wireless time domain signal, and a symbol synchronization point is judged through a Schmidt algorithm; and the wireless terminal counts the number of continuous symbol synchronization points to obtain the CP length, the CP length is compared with the CP length allocated by the wireless terminal, and if the CP length is equal to the CP length allocated by the wireless terminal, the wireless terminal quits the silent state and is awakened. According to the invention, quick wakeup can be realized while low power consumption is maintained, and additional hardware is avoided.

Description

Technical Field

[0001] This invention belongs to the field of wireless communication technology, specifically relating to a method, system, device, and storage medium for time-domain wake-up of a wireless local area network terminal. Background Technology

[0002] In today's era, communication technology continues to develop rapidly, and users' demands for network experience are constantly increasing, making the pursuit of faster speeds and more stable performance an inevitable trend. Against this backdrop, Wireless Local Area Networks (WLANs), as a key technology to meet user needs, are continuously evolving and improving their standards and performance.

[0003] During the critical period of the power industry's transformation and upgrading from traditional systems to new power systems, the application of wireless LAN communication technology in power scenarios such as substations, converter stations, and transmission lines is becoming increasingly widespread. As the scale of terminals using wireless LAN transmission in power scenarios continues to expand, the types of sensors are also becoming increasingly diverse. Under normal circumstances, sensor data is reported periodically, while during non-transmission periods, terminal devices remain silent to reduce power consumption. However, in the silent state, terminal devices cannot respond promptly to service demands triggered by critical events. To balance the low-power requirements of data acquisition terminals with the real-time response to sudden service demands of critical events, a fast and effective real-time wake-up technology is urgently needed to resolve the conflict between the low-power requirements and high real-time requirements of acquisition terminals. Early wireless LANs typically lacked dedicated wake-up technology, mainly relying on terminals periodically listening to beacon frames at the physical layer to achieve wake-up. While new wireless LAN technologies (such as WiFi 6 and WiFi 7) use trigger frames to wake up terminals, and combine MAC-based wake-up technology with application-based wake-up technology (such as timed wake-up and message push triggering) to control terminal activation, these methods all require detection and frequency domain decoding of the air interface wireless signal, which increases terminal power consumption to some extent and affects the usage time of many low-power devices, failing to meet the strict requirements for low power consumption and real-time performance in power scenarios. Summary of the Invention

[0004] The purpose of this invention is to address the problems in the prior art by providing a method, system, device, and storage medium for time-domain wake-up of a wireless local area network terminal, avoiding additional hardware, simplifying protocol processing, and achieving fast wake-up while maintaining low power consumption.

[0005] To achieve the above objectives, the present invention provides the following technical solution: Firstly, a method for time-domain wake-up of a wireless local area network terminal includes: At the access point (AP), a unique cyclic prefix (CP) length is assigned to each wireless terminal, and a mapping table between the cyclic prefix CP length and the wireless terminal is established. Based on the mapping table between the cyclic prefix (CP) length and the wireless terminal, when a wake-up signal is sent, the access point (AP) adds a cyclic prefix (CP) of the corresponding length to the selected orthogonal frequency division multiplexing (OFDM) short training sequence according to the CP length of the target wireless terminal. Based on the short training sequence of Orthogonal Frequency Division Multiplexing (OFDM) with an added cyclic prefix (CP) of the corresponding length, when the wireless terminal is in a silent state, only the air interface wireless time domain signal is collected through the front-end radio frequency part. The collected wireless time domain signal is subjected to window sliding calculation, and the symbol synchronization point is determined by the Schmidl algorithm. The wireless terminal counts the number of consecutive symbol synchronization points to obtain the cyclic prefix (CP) length, and compares it with the cyclic prefix (CP) length allocated by the wireless terminal itself. If they are equal, the corresponding wireless terminal exits the silent state and is woken up.

[0006] As a preferred embodiment, in the step of allocating a unique cyclic prefix (CP) length to each wireless terminal at the access point (AP), each wireless terminal periodically reports service data to the access point (AP). After receiving the service data periodically reported by the wireless terminal, the access point (AP) allocates a unique cyclic prefix (CP) length to the corresponding wireless terminal according to the wireless terminal's identifier and the wake-up allocation scheme for the cyclic prefix (CP) length. When the access point (AP) sends a command to the wireless terminal specifying the length of the wake-up cyclic prefix (CP), the wireless terminal sets the symbol synchronization parameters after receiving the command. Before the next periodic reporting of service data by the wireless terminal, when the access point (AP) needs to perform temporary data collection, it sends a wake-up time-domain signal based on the cyclic prefix (CP). The wake-up time-domain signal based on the cyclic prefix (CP) contains only one short training sequence of orthogonal frequency division multiplexing (OFDM) data.

[0007] As a preferred embodiment, the selected Orthogonal Frequency Division Multiplexing (OFDM) short training sequence carries non-zero data on even-numbered subcarriers in the frequency domain, while carrying zero data on odd-numbered subcarriers. The inverse Fourier transform is performed on the short training sequence of Orthogonal Frequency Division Multiplexing (OFDM) to form an OFDM time-domain signal. The OFDM time-domain signal has the characteristic that the first half and the second half are symmetrical and equal. Based on the required cyclic prefix (CP) length of the target wireless terminal to be woken up, the corresponding cyclic prefix (CP) length is added to the OFDM time domain signal.

[0008] As a preferred approach, when the wireless terminal is in silent mode and only the air interface wireless time-domain signal is acquired through the front-end radio frequency section, a data segment with a length equal to the number of Fourier transform points is selected, starting from the initial point. The Schmidl algorithm calculates the M value of the initial point using the following expression:

[0009]

[0010]

[0011] In the formula, The autocorrelation value before and after receiving data, The conjugate data value of the received data. To calculate the position of the start point of the sequence in the received sequence, For count values, To receive data values, For the Fourier transform series, For the power spectral density of the received data; The M value represents the starting point for receiving data; The calculated M value is compared with the set threshold value. If the M value is greater than the threshold value, counting begins. Continue calculating the M value at the next moment. If the M value at the next moment is also greater than the set threshold, continue counting and continuously loop the process of calculating the M value and comparing it with the threshold until the M value is less than the threshold. The counting result is compared with the cyclic prefix (CP) length allocated by the wireless terminal itself. If the counting result is equal to the cyclic prefix (CP) length allocated by the wireless terminal itself, the wireless terminal exits the silent state and starts data reporting and transmission. If the counting result is not equal to the cyclic prefix (CP) length allocated by the wireless terminal itself, the wireless terminal continues to remain in the silent state until the time for the wireless terminal to periodically report service data to the access point (AP) arrives.

[0012] As a preferred embodiment, each set of mapping data in the mapping table between the cyclic prefix (CP) length and the wireless terminal includes a mapping start time; When an access point (AP) assigns a unique cyclic prefix (CP) length to each wireless terminal, it determines whether a CP length should be assigned to a newly connected wireless terminal. If no CP length is assigned, the mapping table is searched to find the first CP length position that has not been assigned to a wireless terminal, and then the position is assigned to the corresponding wireless terminal. If no CP length position is found, the longest CP length is incremented by 1, and the mapping table length is increased to serve as the new CP length position. For wireless terminals that have already been assigned a cyclic prefix (CP) length, update the mapping start time to the current time; Periodically check the difference between the current time and the start time of the wireless terminal in the mapping table. When the difference is greater than the specified time, delete the mapping relationship of the corresponding wireless terminal.

[0013] Secondly, a wireless local area network terminal time-domain wake-up system is provided, comprising: The Cyclic Prefix (CP) Length Allocation Module is used to allocate a unique cyclic prefix (CP) length to each wireless terminal at the access point (AP) and to establish a mapping table between the cyclic prefix (CP) length and the wireless terminal. The short training sequence cyclic prefix (CP) addition module is used to add a cyclic prefix (CP) of the corresponding length to the selected orthogonal frequency division multiplexing (OFDM) short training sequence based on the mapping table between the CP length and the wireless terminal when a wake-up signal is sent. The symbol synchronization point determination module is used to determine the symbol synchronization point based on the short training sequence of Orthogonal Frequency Division Multiplexing (OFDM) with an added cyclic prefix (CP) of the corresponding length. When the wireless terminal is in a silent state, it only collects the air interface wireless time domain signal through the front-end radio frequency part, performs window sliding calculation on the collected wireless time domain signal, and determines the symbol synchronization point through the Schmidl algorithm. The cyclic prefix (CP) length comparison wake-up module is used by the wireless terminal to count the number of consecutive symbol synchronization points, obtain the cyclic prefix (CP) length, and compare it with the cyclic prefix (CP) length allocated by the wireless terminal itself. If they are equal, the corresponding wireless terminal exits the silent state and is woken up.

[0014] As a preferred embodiment, when the access point (AP) allocates a unique cyclic prefix CP length to each wireless terminal, each wireless terminal periodically reports service data to the access point (AP). After receiving the service data periodically reported by the wireless terminal, the access point (AP) allocates a unique cyclic prefix CP length to the corresponding wireless terminal according to the wireless terminal's identifier and the wake-up allocation scheme for the cyclic prefix CP length. When the access point (AP) sends a command to the wireless terminal specifying the length of the wake-up cyclic prefix (CP), the wireless terminal sets the symbol synchronization parameters after receiving the command. Before the next periodic reporting of service data by the wireless terminal, when the access point (AP) needs to perform temporary data collection, it sends a wake-up time-domain signal based on the cyclic prefix (CP). The wake-up time-domain signal based on the cyclic prefix (CP) contains only one short training sequence of orthogonal frequency division multiplexing (OFDM) data.

[0015] As a preferred embodiment, when the short training sequence cyclic prefix (CP) adding module adds a cyclic prefix (CP) of the corresponding length to the selected orthogonal frequency division multiplexing (OFDM) short training sequence, the selected OFDM short training sequence carries non-zero data on even-numbered subcarriers in the frequency domain, and carries zero data on odd-numbered subcarriers. The short training sequence cyclic prefix (CP) addition module performs inverse Fourier transform on the orthogonal frequency division multiplexing (OFDM) short training sequence to form an orthogonal frequency division multiplexing (OFDM) time domain signal. The orthogonal frequency division multiplexing (OFDM) time domain signal has the characteristic that the first half and the second half are symmetrical and equal. Based on the required cyclic prefix (CP) length of the target wireless terminal to be woken up, the corresponding cyclic prefix (CP) length is added to the OFDM time domain signal.

[0016] As a preferred embodiment, when the wireless terminal is in a silent state and only acquires the air interface wireless time domain signal through the front-end radio frequency section, the symbol synchronization point determination module selects a data segment with a length equal to the number of Fourier transform points, starting from the initial point; the Schmidl algorithm calculates the M value of the initial point using the following expression:

[0017]

[0018]

[0019] In the formula, The autocorrelation value before and after receiving data, The conjugate data value of the received data. To calculate the position of the start point of the sequence in the received sequence, For count values, To receive data values, For the Fourier transform series, For the power spectral density of the received data; The M value represents the starting point for receiving data; The cyclic prefix CP length comparison wake-up module compares the calculated M value with the set threshold value. If the M value is greater than the threshold value, it starts counting. Continue calculating the M value at the next moment. If the M value at the next moment is also greater than the set threshold, continue counting and continuously loop the process of calculating the M value and comparing it with the threshold until the M value is less than the threshold. The counting result is compared with the cyclic prefix (CP) length allocated by the wireless terminal itself. If the counting result is equal to the cyclic prefix (CP) length allocated by the wireless terminal itself, the wireless terminal exits the silent state and starts data reporting and transmission. If the counting result is not equal to the cyclic prefix (CP) length allocated by the wireless terminal itself, the wireless terminal continues to remain in the silent state until the time for the wireless terminal to periodically report service data to the access point (AP) arrives.

[0020] As a preferred embodiment, each set of mapping data in the mapping table between the cyclic prefix CP length and the wireless terminal established by the cyclic prefix CP length allocation module includes a mapping start time; When an access point (AP) assigns a unique cyclic prefix (CP) length to each wireless terminal, it determines whether a CP length should be assigned to a newly connected wireless terminal. If no CP length is assigned, the mapping table is searched to find the first CP length position that has not been assigned to a wireless terminal, and then the position is assigned to the corresponding wireless terminal. If no CP length position is found, the longest CP length is incremented by 1, and the mapping table length is increased to serve as the new CP length position. For wireless terminals that have already been assigned a cyclic prefix (CP) length, update the mapping start time to the current time; Periodically check the difference between the current time and the start time of the wireless terminal in the mapping table. When the difference is greater than the specified time, delete the mapping relationship of the corresponding wireless terminal.

[0021] Thirdly, an electronic device is provided, including a processor and a memory, the processor being configured to execute a computer program stored in the memory to implement the wireless local area network terminal time-domain wake-up method as described in the first aspect.

[0022] Fourthly, a computer-readable storage medium is provided, the computer-readable storage medium storing at least one instruction, which, when executed by a processor, implements the wireless local area network terminal time-domain wake-up method as described in the first aspect.

[0023] Compared with the prior art, the first aspect of the present invention has at least the following beneficial effects: Existing physical layer-based wake-up technologies require independent hardware detection devices, increasing hardware costs and integration complexity, and also present clock synchronization challenges with the main system. MAC layer-based wake-up technologies require the terminal to periodically listen to MAC layer signaling while in sleep mode, increasing protocol and computational overhead and resulting in high energy consumption. For IoT detection devices deployed in large numbers in power scenarios, both low power consumption and rapid response to sudden service demands are required, which existing technologies struggle to meet simultaneously. The root cause of these problems is that existing technologies either rely on additional hardware or complex protocols, failing to achieve rapid wake-up while maintaining low power consumption. The proposed wireless LAN terminal time-domain wake-up method utilizes the cyclic prefix (CP) characteristics of Orthogonal Frequency Division Multiplexing (OFDM) signals, encoding wake-up information by adjusting the CP length, eliminating the need for additional hardware. The wireless terminal only needs to activate the front-end RF section for simple symbol synchronization detection, without complex protocol processing, thus reducing power consumption. The CP length is mapped one-to-one with the wireless terminal, enabling precise wake-up of specific wireless terminals. Wake-up judgment based on physical layer signal characteristics results in fast response speed, meeting sudden service demands. Dynamically allocating and updating the cyclic prefix (CP) length mapping table adapts to network changes and improves flexibility. This approach avoids additional hardware, simplifies protocol processing, and achieves fast wake-up while maintaining low power consumption. The wake-up decision in this invention is performed only in the time domain and does not involve symbol demodulation, significantly reducing terminal power consumption in silent mode. During paging, the paging content does not include specific wireless terminal characteristics, thus improving security.

[0024] It is understood that the beneficial effects of the second to fourth aspects mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 Flowchart of the wireless local area network terminal time-domain wake-up method according to an embodiment of the present invention; Figure 2 A schematic diagram illustrating communication between a wireless terminal and an access point (AP) according to an embodiment of the present invention; Figure 3 Schematic diagram of wireless terminal cyclic prefix (CP) length allocation according to an embodiment of the present invention; Figure 4A schematic diagram of the time-domain wake-up system structure for a wireless local area network terminal according to an embodiment of the present invention. Detailed Implementation

[0027] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0028] Existing technology 1 A Wake-Up Receiver (WUR) is an ultra-low-power physical layer component that operates independently of traditional Wi-Fi transceivers. Its core functions are as follows: continuously listening for wake-up signals at a specific frequency; upon detecting a target signal, it triggers the main system to wake from sleep mode. During the main system's wake-up period, the WUR remains silent and does not participate in data transmission. Typically, the WUR uses a specific sequence (such as Manchester encoding) to transmit wireless signals. It utilizes a third-party hardware acquisition device (RF front-end) to receive wireless signals, employs an envelope detector to extract the signal envelope, and then uses a digital correlator to match it against a preset specific sequence. If the detection result exceeds a threshold, the wake-up circuit is triggered. Specific implementation methods include: frequency hopping wake-up, transmitting a wake-up signal on a specific frequency channel; and phase encoding, using signal phase changes to carry wake-up commands.

[0029] The WUR wake-up frame consists of the following parts: Preamble: 7-10 bytes, used for synchronization and detection.

[0030] Address field: 4~8 bytes, identifies the target device.

[0031] Control field: 2 bytes, indicating the wake-up type (such as normal wake-up, emergency wake-up).

[0032] CRC check: 2 bytes, ensuring frame integrity.

[0033] WUR's key technical indicators include the following components: Wake-up sensitivity: refers to the minimum detectable signal strength, typically <-70dBm.

[0034] Wake-up latency: The time from signal detection to wake-up from the main system, typically <1ms.

[0035] False wake-up rate: The probability of being woken up by a non-target signal, which should be <0.1%.

[0036] Missed wake-up rate: The probability that the target signal does not trigger a wake-up, which should be <0.01%.

[0037] Physical layer WUR technology, through dedicated hardware design, achieves ultra-fast wake-up under ultra-low power conditions, providing an ideal solution for long standby times and real-time responses of IoT devices. With advancements in process technology and increased integration, WUR will become a standard component in future wireless communications, driving profound changes in fields such as smart homes and healthcare.

[0038] However, existing technology 1 has some problems. Using existing technology 1 for terminal wake-up requires a separate hardware detection device, which increases hardware costs; if integrated with the main device, the integration complexity will increase significantly, and there is a problem of clock synchronization between WUR and the main system; because the wake-up frequency used is inconsistent with the main device frequency, the attenuation of air transmission is abnormal, so there may be problems such as failure to wake up when needed or the main device not working properly after wake-up.

[0039] Existing technology 2 The MAC (Medium Access Control Layer) is located at the data link layer and is responsible for coordinating the terminal's access to the wireless channel. The core objective of MAC layer wake-up technology is to achieve "on-demand wake-up" of the terminal through software protocol optimization without increasing hardware complexity, balancing power consumption, wake-up latency, and real-time requirements. Compared to physical layer WUR (Wake-up Receiver) technology, MAC layer solutions do not require dedicated hardware and have greater compatibility. However, because they rely on upper-layer protocol monitoring and require data demodulation and decoding, power consumption is typically higher.

[0040] In wireless local area networks (such as WiFi), access points (APs) periodically send beacon frames (typically every 100ms to 500ms). These frames contain network status, timing information, etc. Terminals listen for these beacon frames to determine if there is data to receive; if so, they wake up; otherwise, they remain asleep. This approach is advantageous due to its simplicity, strong compatibility, and suitability for scenarios with high real-time requirements (such as industrial control).

[0041] The Trigger frame wake-up technology used in WiFi 6 and later versions involves the AP actively sending a Trigger frame to explicitly instruct the target terminal to wake up and prepare to receive data, avoiding continuous listening by the terminal. This technology is further optimized in IEEE 802.11be (WiFi 7), supporting multi-user MIMO wake-up and improving efficiency. The specific process is as follows: The terminal enters a sleep state, with only some modules of the MAC layer operating at low power; when data needs to be sent to the terminal, a Trigger frame carrying the terminal identifier is sent; the terminal's MAC layer parses the Trigger frame and wakes up to establish a data connection.

[0042] Table 1 MAC Layer Wake-up Technical Parameters

[0043] Existing MAC layer wake-up technologies primarily utilize protocols for wake-up. During this process, even without data transmission, the terminal needs to periodically wake up to listen, leading to high power consumption. MAC layer wake-up technology typically requires the terminal to periodically listen for MAC layer signaling (such as Beacon frames, Trigger frames, etc.) while in sleep mode to detect the presence of wake-up commands. Although the listening cycle can be optimized, frequent channel detection and signaling parsing still consume power. Furthermore, air interface signaling processing adds extra power consumption. When there are many terminals in the network, the MAC layer needs to process more wake-up signaling, and the terminal needs to continuously parse this signaling to confirm whether it has been woken up. Moreover, multi-terminal contention can cause wake-up delays. When the MAC layer uses contention-based access methods (such as CSMA / CA, Carrier Sense Multiple Access / Collision Avoidance), multiple terminals simultaneously competing for channel resources may cause wake-up signaling transmission failures or delays. Additionally, the protocol implementation is complex. MAC layer wake-up technology needs to be deeply coupled with the MAC layer mechanisms of specific network protocols, such as WiFi, ZigBee, and LoRaWAN (Long Range Wide Area Network), and the wake-up logic varies significantly between different protocols.

[0044] This invention, based on the technical characteristics of independently controllable power WLANs, implements terminal wake-up at the physical layer according to a customized waveform. Simultaneously, it employs a dynamic mapping relationship between identifiers and terminals to achieve wake-up functionality within the WLAN terminal area. This solves the cost and other problems caused by the need to redeploy external hardware in existing physical layer wake-up technologies, as well as the additional protocol and computational overhead required for MAC layer terminal wake-up. It maintains the speed and effectiveness of physical layer wake-up technology while reducing the protocol customization and computational overhead required for MAC layer terminal wake-up technology.

[0045] Wireless LANs (WLANs) employ a burst access technology architecture, and wireless wake-up functionality is an essential feature of WLAN technology. In power industry scenarios, there are numerous IoT monitoring devices, and an increasing number of these devices use WLANs for data transmission. Typically, the collected data is reported to the system periodically by the terminal devices, such as every 15 minutes. When not transmitting data, the terminal devices are in a silent state, not emitting power signals to conserve power. When real-time data is required, the terminal needs to be woken up to transmit the data in real time.

[0046] As can be seen from the shortcomings of existing technology one, physical layer-based wake-up technology requires customized dedicated hardware equipment for wireless signal acquisition and analysis. The addition of these devices increases costs and maintenance complexity, and also raises the issue of coordination between the wake-up device and the service device.

[0047] As can be seen from the shortcomings of existing technology 2, MAC-based wake-up technology requires customized dedicated protocols for terminal wake-up. During implementation, wireless signals need to be collected, encoded, and decoded. These protocol processing and encoding / decoding processes increase computational complexity, place high demands on the power of IoT terminals, and significantly increase the complexity of the wake-up terminal protocol.

[0048] In power scenarios such as substations and converter stations, data acquisition devices, represented by IoT sensors, are increasingly deployed to achieve fine-grained data collection. These devices are characterized by their small size, low power consumption, strong environmental adaptability, and wide deployment. These characteristics enable the devices to minimize power consumption while meeting the requirements of business data acquisition, data storage, and data transmission. This requires the data acquisition devices to operate at full load during operation, collecting data and transmitting it back via wireless modules, resulting in significant power consumption. When the devices are not in operation, they enter a low-power or deep sleep state, significantly reducing power consumption during non-operational periods, thereby reducing the overall power consumption of the data acquisition device. While data acquisition devices can proactively report business information based on their own set conditions when in low-power or deep sleep mode, they cannot meet the business requirements for rapid response to critical events. To ensure both low system power consumption of the data acquisition terminal and the ability to respond to sudden business needs during critical events, wireless wake-up technology is typically used to enable the data acquisition device to transition from deep sleep mode to normal operation. Wireless wake-up technology keeps devices in deep sleep most of the time, only waking them up quickly when they receive a specific wireless signal, thus reducing overall energy consumption during long-term operation. As a core mechanism connecting sleep-time energy saving and instant response, the wireless wake-up function is a crucial indicator of the reliability of IoT data acquisition devices. It resolves the core contradiction in the IoT—the conflict between low power consumption and high real-time requirements—allowing large-scale devices to operate stably for extended periods while also responding in real time during critical moments.

[0049] This invention, based on applications in power scenarios, proposes a technical solution for waking up target terminals by using a transforming cyclic prefix method to determine the synchronization platform width of burst pulse symbols through an algorithm. This invention solves the problems of increased costs and maintenance complexity caused by the need for customized dedicated hardware in existing physical layer-based wake-up technologies, and also avoids the coordination issues between the wake-up device and service devices. Furthermore, this invention addresses the problem of needing customized dedicated protocols for terminal wake-up in existing MAC-based wake-up technologies, avoiding the need for wireless signal acquisition and encoding / decoding during implementation, thereby reducing computational complexity and lowering the power consumption requirements of IoT terminals in existing technologies.

[0050] Please see Figure 1 The wireless local area network terminal time-domain wake-up method of this invention mainly includes the following steps: At the access point (AP), a unique cyclic prefix (CP) length is assigned to each wireless terminal, and a mapping table between the cyclic prefix CP length and the wireless terminal is established. Based on the mapping table between the cyclic prefix (CP) length and the wireless terminal, when a wake-up signal is sent, the access point (AP) adds a cyclic prefix (CP) of the corresponding length to the selected orthogonal frequency division multiplexing (OFDM) short training sequence according to the CP length of the target wireless terminal. Based on the short training sequence of Orthogonal Frequency Division Multiplexing (OFDM) with an added cyclic prefix (CP) of the corresponding length, when the wireless terminal is in a silent state, only the air interface wireless time domain signal is collected through the front-end radio frequency part. The collected wireless time domain signal is subjected to window sliding calculation, and the symbol synchronization point is determined by the Schmidl algorithm. The wireless terminal counts the number of consecutive symbol synchronization points to obtain the cyclic prefix (CP) length, and compares it with the cyclic prefix (CP) length allocated by the wireless terminal itself. If they are equal, the corresponding wireless terminal exits the silent state and is woken up.

[0051] Wireless local area networks (WLANs) employ Orthogonal Frequency Division Multiplexing (OFDM) modulation technology. To effectively address inter-symbol interference (ISI) and subcarrier interference (LCI), a cyclic prefix (CP) is typically used to suppress interference. The CP is used to reduce or eliminate ISI caused by multipath propagation. The length of the CP is related to the maximum coverage radius of the cell; a longer CP results in a larger coverage area. During design, the CP is positively correlated with the guard period (GP), thus determining the cell radius.

[0052] Orthogonal Frequency Division Multiplexing (OFDM) is a widely used modulation and demodulation technique in wireless communication. It divides a high-speed data stream into multiple low-speed data streams to reduce the impact of frequency-selective fading in multipath transmission and improve channel utilization. Specific modulation methods can employ digital modulation techniques such as Quadrature Amplitude Modulation (QAM) and Phase Shift Keying (PSK). Modulation symbols are mapped onto each subcarrier to generate OFDM symbols. The length of an OFDM symbol is typically a power of 2 to facilitate Fast Fourier Transform (FFT) calculations in both the time and frequency domains.

[0053] OFDM symbol synchronization is primarily determined by calculating the autocorrelation of the time-domain signal. Specifically, a signal of one OFDM symbol length is received in the time domain, exhibiting certain correlation characteristics, such as conjugate correlation, centrosymmetric correlation, and autocorrelation. These sequences can be generated by specific frequency-domain coding or composed of user-defined sequences. In the frequency-domain coding characteristics, even-numbered subcarriers carry the data, and after inverse Fourier transform, the time-domain signal exhibits conjugate symmetry.

[0054] The Schmidl algorithm is an OFDM symbol synchronization algorithm based on training sequences, proposed by Timothy Schmidl and Donald Cox. It is primarily used for timing synchronization and frequency offset estimation in OFDM systems. The training sequence typically consists of two OFDM symbols. The first symbol, in the time domain, comprises two identical parts, which can be used for symbol timing synchronization and estimation of fractional-fold frequency offset. The data modulated on even-fold subcarriers in the second training symbol has a differential relationship with the corresponding data in the first symbol, used for estimation of integer-fold frequency offset. This algorithm utilizes the correlation between the two parts of the first symbol in the training sequence for timing synchronization. Since the first and second halves of the first symbol are identical, the carrier frequency deviation only affects the phase shift. Taking the conjugate of the first half of the data and multiplying it by the corresponding (interval T / 2) data of the second half eliminates the channel influence, leaving only a phase difference of φ = πTΔf (where T is the symbol period and Δf is the carrier frequency deviation). At the beginning of the training symbol, each pair of corresponding data is multiplied, and this phase difference accumulates. The timing metric is obtained by calculating the correlation function. The Schmidl algorithm has a "flat-topped" region when determining symbol synchronization, the length of which is the same as the length of the cyclic prefix.

[0055] Please see Figure 2 In one possible implementation, in the step of allocating a unique cyclic prefix (CP) length to each wireless terminal at the access point (AP), each wireless terminal periodically reports service data to the access point (AP). like Figure 3 As shown, after receiving the service data periodically reported by the wireless terminal, the access point (AP) allocates a unique cyclic prefix (CP) length to the corresponding wireless terminal according to the wireless terminal's identifier and the wake-up allocation scheme for the cyclic prefix (CP) length. When the access point (AP) sends a command to the wireless terminal specifying the length of the wake-up cyclic prefix (CP), the wireless terminal sets the symbol synchronization parameters after receiving the command. Before the next periodic reporting of service data by the wireless terminal, when the access point (AP) needs to perform temporary data collection, it sends a wake-up time-domain signal based on the cyclic prefix (CP). The wake-up time-domain signal based on the cyclic prefix (CP) contains only one short training sequence of orthogonal frequency division multiplexing (OFDM) data.

[0056] In one possible implementation, the selected orthogonal frequency division multiplexing (OFDM) short training sequence carries non-zero data on even-numbered subcarriers in the frequency domain, while the odd-numbered subcarriers carry zero data. The short training sequence of Orthogonal Frequency Division Multiplexing (OFDM) is subjected to Inverse Fast Fourier Transform (IFFT) to form an OFDM time-domain signal. The OFDM time-domain signal has the characteristic that the first half and the second half are symmetrical and equal. Based on the required cyclic prefix (CP) length of the target wireless terminal to be woken up, the corresponding cyclic prefix (CP) length is added to the OFDM time domain signal.

[0057] In one possible implementation, when the wireless terminal is in a silent state and only the air interface wireless time domain signal is collected through the front-end radio frequency part, a data segment with a length equal to the number of Fourier transform points is selected, starting from the starting point. Schmidl's algorithm calculates the M value of the starting point using the following expression:

[0058]

[0059]

[0060] In the formula, The autocorrelation value before and after receiving data, The conjugate data value of the received data. To calculate the position of the start point of the sequence in the received sequence, For count values, To receive data values, For the Fourier transform series, For the power spectral density of the received data; The M value represents the starting point for receiving data; The calculated M value is compared with the set threshold value. If the M value is greater than the threshold value, counting begins. Continue calculating the M value at the next moment. If the M value at the next moment is also greater than the set threshold, continue counting and continuously loop the process of calculating the M value and comparing it with the threshold until the M value is less than the threshold. The counting result is compared with the cyclic prefix (CP) length allocated by the wireless terminal itself. If the counting result is equal to the cyclic prefix (CP) length allocated by the wireless terminal itself, the wireless terminal exits the silent state and starts data reporting and transmission. If the counting result is not equal to the cyclic prefix (CP) length allocated by the wireless terminal itself, the wireless terminal continues to remain in the silent state until the time for the wireless terminal to periodically report service data to the access point (AP) arrives.

[0061] In one possible implementation, each set of mapping data in the mapping table between the cyclic prefix CP length and the wireless terminal includes a mapping start time; When an access point (AP) assigns a unique cyclic prefix (CP) length to each wireless terminal, it determines whether a CP length should be assigned to a newly connected wireless terminal. If no CP length is assigned, the mapping table is searched to find the first CP length position that has not been assigned to a wireless terminal, and then the position is assigned to the corresponding wireless terminal. If no CP length position is found, the longest CP length is incremented by 1, and the mapping table length is increased to serve as the new CP length position. For wireless terminals that have already been assigned a cyclic prefix (CP) length, update the mapping start time to the current time; Periodically check the difference between the current time and the start time of the wireless terminal in the mapping table. When the difference is greater than the specified time, delete the mapping relationship of the corresponding wireless terminal.

[0062] This invention presents a time-domain wake-up method for wireless local area network (WLAN) terminals based on power WLAN terminal wake-up technology with a changing cyclic prefix, fully utilizing the modulation characteristics of orthogonal frequency division multiplexing (OFDM) signals. The method leverages the synchronization characteristics of OFDM symbols, adjusting the length of the cyclic prefix to cause a change in the OFDM synchronization symbol platform width, thereby achieving terminal wake-up. This method enables rapid wake-up, effectively improving detection efficiency, reducing detection costs, and lowering the power consumption of terminal devices, providing a solid technical foundation for terminal wake-up in power WLANs with autonomous and controllable characteristics.

[0063] This invention's method can be applied to power wireless LAN communication systems, and can also be integrated into power wireless LAN communication chips based on physical layer waveform editable technology. It can be used to design power-specific wireless LAN communication products, providing strong support for enhancing product functionality. After the technology is widely adopted, it can enable the construction of an autonomous and controllable power wireless LAN communication system for fixed locations such as substations and converter stations. It can effectively solve the problem of autonomous controllability of wake-up technology in power industry wireless LAN communication technology, replacing various wake-up technologies used in the 802.11 series of similar products. This effectively improves the controllability of power wireless LAN technology and enhances the application level of wireless LANs in substations, converter stations, and other scenarios.

[0064] Please see Figure 4 Another embodiment of the present invention also proposes a wireless local area network terminal time-domain wake-up system, comprising: The Cyclic Prefix (CP) Length Allocation Module is used to allocate a unique cyclic prefix (CP) length to each wireless terminal at the access point (AP) and to establish a mapping table between the cyclic prefix (CP) length and the wireless terminal. The short training sequence cyclic prefix (CP) addition module is used to add a cyclic prefix (CP) of the corresponding length to the selected orthogonal frequency division multiplexing (OFDM) short training sequence based on the mapping table between the CP length and the wireless terminal when a wake-up signal is sent. The symbol synchronization point determination module is used to determine the symbol synchronization point based on the short training sequence of Orthogonal Frequency Division Multiplexing (OFDM) with an added cyclic prefix (CP) of the corresponding length. When the wireless terminal is in a silent state, it only collects the air interface wireless time domain signal through the front-end radio frequency part, performs window sliding calculation on the collected wireless time domain signal, and determines the symbol synchronization point through the Schmidl algorithm. The cyclic prefix (CP) length comparison wake-up module is used by the wireless terminal to count the number of consecutive symbol synchronization points, obtain the cyclic prefix (CP) length, and compare it with the cyclic prefix (CP) length allocated by the wireless terminal itself. If they are equal, the corresponding wireless terminal exits the silent state and is woken up.

[0065] In one possible implementation, when the access point (AP) allocates a unique cyclic prefix CP length to each wireless terminal, each wireless terminal periodically reports service data to the access point (AP). After receiving the service data periodically reported by the wireless terminal, the access point (AP) allocates a unique cyclic prefix CP length to the corresponding wireless terminal according to the wireless terminal's identifier and the wake-up allocation scheme for the cyclic prefix CP length. When the access point (AP) sends a command to the wireless terminal specifying the length of the wake-up cyclic prefix (CP), the wireless terminal sets the symbol synchronization parameters after receiving the command. Before the next periodic reporting of service data by the wireless terminal, when the access point (AP) needs to perform temporary data collection, it sends a wake-up time-domain signal based on the cyclic prefix (CP). The wake-up time-domain signal based on the cyclic prefix (CP) contains only one short training sequence of orthogonal frequency division multiplexing (OFDM) data.

[0066] In one possible implementation, when the short training sequence cyclic prefix (CP) adding module adds a cyclic prefix (CP) of a corresponding length to a selected orthogonal frequency division multiplexing (OFDM) short training sequence, the selected OFDM short training sequence carries non-zero data on even-numbered subcarriers in the frequency domain, and carries zero data on odd-numbered subcarriers. The short training sequence cyclic prefix (CP) addition module performs inverse Fourier transform on the orthogonal frequency division multiplexing (OFDM) short training sequence to form an orthogonal frequency division multiplexing (OFDM) time domain signal. The orthogonal frequency division multiplexing (OFDM) time domain signal has the characteristic that the first half and the second half are symmetrical and equal. Based on the required cyclic prefix (CP) length of the target wireless terminal to be woken up, the corresponding cyclic prefix (CP) length is added to the OFDM time domain signal.

[0067] In one possible implementation, when the wireless terminal is in a silent state and only acquires the air interface wireless time domain signal through the front-end radio frequency section, the symbol synchronization point determination module selects a data segment with a length equal to the number of Fourier transform points, starting from the initial point; the Schmidl algorithm calculates the M value of the initial point using the following expression:

[0068]

[0069]

[0070] In the formula, The autocorrelation value before and after receiving data, The conjugate data value of the received data. To calculate the position of the start point of the sequence in the received sequence, For count values, To receive data values, For the Fourier transform series, For the power spectral density of the received data; The M value represents the starting point for receiving data; The cyclic prefix CP length comparison wake-up module compares the calculated M value with the set threshold value. If the M value is greater than the threshold value, it starts counting. Continue calculating the M value at the next moment. If the M value at the next moment is also greater than the set threshold, continue counting and continuously loop the process of calculating the M value and comparing it with the threshold until the M value is less than the threshold. The counting result is compared with the cyclic prefix (CP) length allocated by the wireless terminal itself. If the counting result is equal to the cyclic prefix (CP) length allocated by the wireless terminal itself, the wireless terminal exits the silent state and starts data reporting and transmission. If the counting result is not equal to the cyclic prefix (CP) length allocated by the wireless terminal itself, the wireless terminal continues to remain in the silent state until the time for the wireless terminal to periodically report service data to the access point (AP) arrives.

[0071] In one possible implementation, each set of mapping data in the mapping table between the cyclic prefix CP length and the wireless terminal established by the cyclic prefix CP length allocation module contains a mapping start time. When an access point (AP) assigns a unique cyclic prefix (CP) length to each wireless terminal, it determines whether a CP length should be assigned to a newly connected wireless terminal. If no CP length is assigned, the mapping table is searched to find the first CP length position that has not been assigned to a wireless terminal, and then the position is assigned to the corresponding wireless terminal. If no CP length position is found, the longest CP length is incremented by 1, and the mapping table length is increased to serve as the new CP length position. For wireless terminals that have already been assigned a cyclic prefix (CP) length, update the mapping start time to the current time; Periodically check the difference between the current time and the start time of the wireless terminal in the mapping table. When the difference is greater than the specified time, delete the mapping relationship of the corresponding wireless terminal.

[0072] Another embodiment of the present invention provides an electronic device including a processor and a memory, the processor being used to execute a computer program stored in the memory to implement the wireless local area network terminal time-domain wake-up method.

[0073] Another embodiment of the present invention provides a computer-readable storage medium storing at least one instruction that, when executed by a processor, implements the wireless local area network terminal time-domain wake-up method.

[0074] The computer program includes computer program code, which can be in the form of source code, object code, executable file, or some intermediate form. The computer-readable storage medium can include any entity or device capable of carrying the computer program code, a medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory, a random access memory, an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc. It should be noted that the content included in the computer-readable medium can be appropriately added or removed according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium does not include electrical carrier signals and telecommunication signals. For ease of explanation, the above content only shows the parts related to the embodiments of the present invention; for specific technical details not disclosed, please refer to the method section of the embodiments of the present invention. This computer-readable storage medium is non-transitory and can be stored in storage devices formed by various electronic devices, enabling the execution process described in the method of the embodiments of the present invention.

[0075] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0076] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0077] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0078] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for time-domain wake-up of a wireless local area network terminal, characterized in that, include: At the access point (AP), a unique cyclic prefix (CP) length is assigned to each wireless terminal, and a mapping table between the cyclic prefix CP length and the wireless terminal is established. Based on the mapping table between the cyclic prefix (CP) length and the wireless terminal, when a wake-up signal is sent, the access point (AP) adds a cyclic prefix (CP) of the corresponding length to the selected orthogonal frequency division multiplexing (OFDM) short training sequence according to the CP length of the target wireless terminal. Based on the short training sequence of Orthogonal Frequency Division Multiplexing (OFDM) with an added cyclic prefix (CP) of the corresponding length, when the wireless terminal is in a silent state, only the air interface wireless time domain signal is collected through the front-end radio frequency part. The collected wireless time domain signal is subjected to window sliding calculation, and the symbol synchronization point is determined by the Schmidl algorithm. The wireless terminal counts the number of consecutive symbol synchronization points to obtain the cyclic prefix (CP) length, and compares it with the cyclic prefix (CP) length allocated by the wireless terminal itself. If they are equal, the corresponding wireless terminal exits the silent state and is woken up.

2. The wireless local area network terminal time-domain wake-up method according to claim 1, characterized in that, In the step of allocating a unique cyclic prefix (CP) length to each wireless terminal at the access point (AP), each wireless terminal periodically reports service data to the access point (AP). After receiving the service data periodically reported by the wireless terminal, the access point (AP) allocates a unique cyclic prefix (CP) length to the corresponding wireless terminal according to the wireless terminal's identifier and the wake-up allocation scheme for the cyclic prefix (CP) length. When the access point (AP) sends a command to the wireless terminal specifying the length of the wake-up cyclic prefix (CP), the wireless terminal sets the symbol synchronization parameters after receiving the command. Before the next periodic reporting of service data by the wireless terminal, when the access point (AP) needs to perform temporary data collection, it sends a wake-up time-domain signal based on the cyclic prefix (CP). The wake-up time-domain signal based on the cyclic prefix (CP) contains only one short training sequence of orthogonal frequency division multiplexing (OFDM) data.

3. The wireless local area network terminal time-domain wake-up method according to claim 1, characterized in that, The selected orthogonal frequency division multiplexing (OFDM) short training sequence carries non-zero data on even-numbered subcarriers in the frequency domain, while carrying zero data on odd-numbered subcarriers. The inverse Fourier transform is performed on the short training sequence of Orthogonal Frequency Division Multiplexing (OFDM) to form an OFDM time-domain signal. The OFDM time-domain signal has the characteristic that the first half and the second half are symmetrical and equal. Based on the required cyclic prefix (CP) length of the target wireless terminal to be woken up, the corresponding cyclic prefix (CP) length is added to the OFDM time domain signal.

4. The wireless local area network terminal time-domain wake-up method according to claim 3, characterized in that, When the wireless terminal is in silent mode, and only the over-the-air wireless time-domain signal is acquired through the front-end radio frequency section, a data segment with a length equal to the number of Fourier transform points is selected, starting from the initial point. The Schmidl algorithm uses the following expression to calculate the M value of the initial point: In the formula, The autocorrelation value before and after receiving data, The conjugate data value of the received data. To calculate the position of the start point of the sequence in the received sequence, For count values, To receive data values, For the Fourier transform series, For the power spectral density of the received data; The M value represents the starting point for receiving data; The calculated M value is compared with the set threshold value. If the M value is greater than the threshold value, counting begins. Continue calculating the M value at the next moment. If the M value at the next moment is also greater than the set threshold, continue counting and continuously loop the process of calculating the M value and comparing it with the threshold until the M value is less than the threshold. The counting result is compared with the cyclic prefix (CP) length allocated by the wireless terminal itself. If the counting result is equal to the cyclic prefix (CP) length allocated by the wireless terminal itself, the wireless terminal exits the silent state and starts data reporting and transmission. If the counting result is not equal to the cyclic prefix (CP) length allocated by the wireless terminal itself, the wireless terminal continues to remain in the silent state until the time for the wireless terminal to periodically report service data to the access point (AP) arrives.

5. The wireless local area network terminal time-domain wake-up method according to claim 1, characterized in that, Each set of mapping data in the mapping table between the cyclic prefix CP length and the wireless terminal contains a mapping start time; When an access point (AP) assigns a unique cyclic prefix (CP) length to each wireless terminal, it determines whether a CP length should be assigned to a newly connected wireless terminal. If no CP length is assigned, the mapping table is searched to find the first CP length position that has not been assigned to a wireless terminal, and then the position is assigned to the corresponding wireless terminal. If no CP length position is found, the longest CP length is incremented by 1, and the mapping table length is increased to serve as the new CP length position. For wireless terminals that have already been assigned a cyclic prefix (CP) length, update the mapping start time to the current time; Periodically check the difference between the current time and the start time of the wireless terminal in the mapping table. When the difference is greater than the specified time, delete the mapping relationship of the corresponding wireless terminal.

6. A wireless local area network terminal time-domain wake-up system, characterized in that, include: The Cyclic Prefix (CP) Length Allocation Module is used to allocate a unique cyclic prefix (CP) length to each wireless terminal at the access point (AP) and to establish a mapping table between the cyclic prefix (CP) length and the wireless terminal. The short training sequence cyclic prefix (CP) addition module is used to add a cyclic prefix (CP) of the corresponding length to the selected orthogonal frequency division multiplexing (OFDM) short training sequence based on the mapping table between the CP length and the wireless terminal when a wake-up signal is sent. The symbol synchronization point determination module is used to determine the symbol synchronization point based on the short training sequence of Orthogonal Frequency Division Multiplexing (OFDM) with an added cyclic prefix (CP) of the corresponding length. When the wireless terminal is in a silent state, it only collects the air interface wireless time domain signal through the front-end radio frequency part, performs window sliding calculation on the collected wireless time domain signal, and determines the symbol synchronization point through the Schmidl algorithm. The cyclic prefix (CP) length comparison wake-up module is used by the wireless terminal to count the number of consecutive symbol synchronization points, obtain the cyclic prefix (CP) length, and compare it with the cyclic prefix (CP) length allocated by the wireless terminal itself. If they are equal, the corresponding wireless terminal exits the silent state and is woken up.

7. The wireless local area network terminal time-domain wake-up system according to claim 6, characterized in that, When the access point (AP) allocates a unique cyclic prefix CP length to each wireless terminal, each wireless terminal periodically reports service data to the access point (AP). After receiving the service data periodically reported by the wireless terminal, the access point (AP) allocates a unique cyclic prefix CP length to the corresponding wireless terminal according to the wireless terminal's identifier and the wake-up allocation scheme for the cyclic prefix CP length. When the access point (AP) sends a command to the wireless terminal specifying the length of the wake-up cyclic prefix (CP), the wireless terminal sets the symbol synchronization parameters after receiving the command. Before the next periodic reporting of service data by the wireless terminal, when the access point (AP) needs to perform temporary data collection, it sends a wake-up time-domain signal based on the cyclic prefix (CP). The wake-up time-domain signal based on the cyclic prefix (CP) contains only one short training sequence of orthogonal frequency division multiplexing (OFDM) data.

8. The wireless local area network terminal time-domain wake-up system according to claim 6, characterized in that, When the short training sequence cyclic prefix (CP) adding module adds a cyclic prefix (CP) of the corresponding length to the selected orthogonal frequency division multiplexing (OFDM) short training sequence, the selected OFDM short training sequence carries non-zero data on even-numbered subcarriers in the frequency domain, and carries zero data on odd-numbered subcarriers. The short training sequence cyclic prefix (CP) addition module performs inverse Fourier transform on the orthogonal frequency division multiplexing (OFDM) short training sequence to form an orthogonal frequency division multiplexing (OFDM) time domain signal. The orthogonal frequency division multiplexing (OFDM) time domain signal has the characteristic that the first half and the second half are symmetrical and equal. Based on the required cyclic prefix (CP) length of the target wireless terminal to be woken up, the corresponding cyclic prefix (CP) length is added to the OFDM time domain signal.

9. The wireless local area network terminal time-domain wake-up system according to claim 8, characterized in that, When the wireless terminal is in a silent state and only acquires the air interface wireless time domain signal through the front-end radio frequency section, the symbol synchronization point determination module selects a data segment with a length equal to the number of Fourier transform points, starting from the initial point. The Schmidl algorithm uses the following expression to calculate the M value of the initial point: In the formula, The autocorrelation value before and after receiving data, The conjugate data value of the received data. To calculate the position of the start point of the sequence in the received sequence, For count values, To receive data values, For the Fourier transform series, For the power spectral density of the received data; The M value represents the starting point for receiving data; The cyclic prefix CP length comparison wake-up module compares the calculated M value with the set threshold value. If the M value is greater than the threshold value, it starts counting. Continue calculating the M value at the next moment. If the M value at the next moment is also greater than the set threshold, continue counting and continuously loop the process of calculating the M value and comparing it with the threshold until the M value is less than the threshold. The counting result is compared with the cyclic prefix (CP) length allocated by the wireless terminal itself. If the counting result is equal to the cyclic prefix (CP) length allocated by the wireless terminal itself, the wireless terminal exits the silent state and starts data reporting and transmission. If the counting result is not equal to the cyclic prefix (CP) length allocated by the wireless terminal itself, the wireless terminal continues to remain in the silent state until the time for the wireless terminal to periodically report service data to the access point (AP) arrives.

10. The wireless local area network terminal time-domain wake-up system according to claim 6, characterized in that, The mapping table between the cyclic prefix CP length and the wireless terminal established by the cyclic prefix CP length allocation module contains a mapping start time for each group of mapping data. When an access point (AP) assigns a unique cyclic prefix (CP) length to each wireless terminal, it determines whether a CP length should be assigned to a newly connected wireless terminal. If no CP length is assigned, the mapping table is searched to find the first CP length position that has not been assigned to a wireless terminal, and then the position is assigned to the corresponding wireless terminal. If no CP length position is found, the longest CP length is incremented by 1, and the mapping table length is increased to serve as the new CP length position. For wireless terminals that have already been assigned a cyclic prefix (CP) length, update the mapping start time to the current time; Periodically check the difference between the current time and the start time of the wireless terminal in the mapping table. When the difference is greater than the specified time, delete the mapping relationship of the corresponding wireless terminal.

11. An electronic device, characterized in that, It includes a processor and a memory, the processor being configured to execute a computer program stored in the memory to implement the wireless local area network terminal time-domain wake-up method as described in any one of claims 1 to 5.

12. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores at least one instruction, which, when executed by a processor, implements the wireless local area network terminal time-domain wake-up method as described in any one of claims 1 to 5.

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