Power wireless local area network information security transmission method and related device

Abstract

The invention belongs to the field of wireless communication, and discloses a power wireless local area network information security transmission method and a related device, and the method comprises the steps: obtaining a current physical layer leader sequence and a physical layer header, and carrying out the processing of to-be-transmitted data on the basis of the current physical layer leader sequence and the physical layer header, thereby achieving the dynamic operation of the physical layer leader sequence and the physical layer header. Meanwhile, when data to be transmitted are modulated by adopting an orthogonal frequency division multiplexing technology, a positive value random quantity is introduced to modify a cyclic prefix selection area and length and modify subcarrier parameters, so that the randomness and unpredictability of signal transmission are further improved, and the hiding of physical layer waveform parameters is realized. By dynamically switching the waveform factors of the physical layer, an attacker is difficult to capture and identify the characteristic information of the wireless signal due to the dynamic change, so that the anti-reconnaissance and anti-interception capabilities of the system are greatly improved. A parameter dynamic change rule can be self-formulated for the power wireless local area network, so that the powerful supervision capability of the power industry on the wireless local area network technology can be realized.

Description

Technical Field

[0001] The invention belongs to the field of wireless communications and relates to a method for securely transmitting information in a power wireless local area network and a related device. Background Art

[0002] With the continuous evolution of the times and the rapid improvement of communication technology, the standards and performance of WLAN are being continuously optimized to meet users' higher pursuit of speed and stability. However, in the vast world of wireless communication, security challenges are always present, requiring the communications industry to shoulder the responsibility of protecting data security and ensure that information is safe at every step of transmission, carrying and processing. However, the open nature of wireless communication systems makes them vulnerable to attacks, interference and interception, and faces severe security risks. With the increasing sophistication of wireless interference and attack methods, technologies such as wireless reconnaissance, conventional wireless interference, and wireless penetration access attacks have been widely used in network electromagnetic space operations. These technologies can quietly sneak into the other party's wireless network and carry out effective attacks by utilizing signal waveform parameters such as communication protocols, signal frame structures, signal code types, and modulation methods.

[0003] As an advanced wireless high-speed communication technology, EUHT technology, with its full-duplex communication technology and flexible MAC mechanism, realizes multi-task and multi-user time-division scheduling, significantly improving communication efficiency. Compared with WAPI technology, the latter is based on the well-known WiFi as its underlying protocol, which is limited in customization and development, and is vulnerable to a variety of attacks against the WiFi protocol, and the attack cost is relatively low. Although the EUHT protocol is also open, its customizable nature requires attackers to invest a lot of time in research before they can carry out effective attacks.

[0004] The electric power wireless LAN EPWL is a wireless LAN technology that is deeply customized and developed based on technologies such as EUHT or WIA-FA to meet the needs of the power industry. At present, the security protection of wireless communication systems mainly focuses on the link layer and upper layers, while the security protection of the physical layer seems to be inadequate, and risks such as signal interception, interference and attack still exist. Attackers can easily eavesdrop through open wireless channels, or even lurk in the system waiting for an opportunity to launch an attack. Although technologies such as EUHT and WIA-FA have mature standards, and the physical layer and MAC layer protocols are public, this also provides attackers with a basis for designing attack methods. Therefore, these technologies have obvious shortcomings in the security protection of the physical layer, which makes EPWL still face the risk of attack and interference due to the exposure of the physical layer waveform. Summary of the invention

[0005] The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art and provide a method and related device for secure transmission of information in a power wireless local area network.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a method for secure transmission of information in a power wireless local area network, which is applied to a power wireless local area network transmitter, and includes: obtaining data to be transmitted and a current physical layer preamble sequence and a physical layer header; modulating the data to be transmitted using an orthogonal frequency division multiplexing technique to obtain a modulated signal; wherein, during the modulation process, a current positive random value is obtained, and a cyclic prefix selection area and length are modified according to the current positive random value, and a subcarrier parameter is modified according to the current positive random value; the current physical layer preamble sequence, the physical layer header and the modulated signal are combined into transmission information and sent to a power wireless local area network receiver; wherein the transmission information is used to trigger the power wireless local area network receiver to parse the transmission information according to the obtained current physical layer preamble sequence and the physical layer header to obtain a modulated signal, and demodulate the modulated signal using an orthogonal frequency division multiplexing technique to obtain the data to be transmitted; wherein, during the demodulation process, the power wireless local area network receiver obtains a current positive random value, and modifies the cyclic prefix selection area and length according to the current positive random value, and a subcarrier parameter is modified according to the current positive random value.

[0008] Optionally, it also includes: modifying the current physical layer preamble sequence and physical layer header according to the current area requirements; wherein the modification of the current physical layer preamble sequence and physical layer header includes one or more of the following: increasing or decreasing the number of short training sequence preamble code symbols of the current physical layer preamble sequence; increasing or decreasing the number of long training sequence preamble code symbols of the current physical layer preamble sequence; increasing or decreasing the number of signal field symbols of the current physical layer header; modifying the modulation mode field of the current physical layer header; configuring a private information field carrying coding information and / or modulation information in the signal field of the current physical layer header.

[0009] Optionally, the current positive random quantity is generated by a random sequence generator using a random number or time as a seed.

[0010] Optionally, modifying the cyclic prefix selection area and length according to the current positive random amount includes: the cyclic prefix selection area moves to the next symbol with the current positive random amount, and the cyclic prefix length changes by the previous cyclic prefix length plus the current positive random amount.

[0011] Optionally, modifying the subcarrier parameters according to the current positive random quantity includes: modifying the amplitude and number of subcarriers according to the current positive random quantity.

[0012] According to a second aspect of the present invention, a method for secure transmission of information in a power wireless local area network is provided, which is applied to a receiving end of the power wireless local area network, and includes: obtaining a current physical layer preamble sequence and a physical layer header, and receiving transmission information sent by a transmitting end of the power wireless local area network; wherein the transmission information is a modulated signal obtained by the transmitting end of the power wireless local area network by modulating the data to be transmitted by using an orthogonal frequency division multiplexing technology, and combining the current physical layer preamble sequence, the physical layer header and the modulated signal; wherein, during the modulation process, the transmitting end of the power wireless local area network obtains a current positive random quantity, and modifies a cyclic prefix selection area and length according to the current positive random quantity, and modifies a subcarrier parameter according to the current positive random quantity; parses the transmission information according to the current physical layer preamble sequence and the physical layer header to obtain a modulated signal; and demodulates the modulated signal by using an orthogonal frequency division multiplexing technology to obtain the data to be transmitted; wherein, during the demodulation process, the current positive random quantity is obtained, and the cyclic prefix selection area and length are modified according to the current positive random quantity, and the subcarrier parameter is modified according to the current positive random quantity.

[0013] The third aspect of the present invention provides a method for secure transmission of information in a power wireless local area network, which is applied to a power wireless local area network system including a power wireless local area network transmitter and a power wireless local area network receiver, and comprises: obtaining data to be transmitted and a current physical layer leading sequence and a physical layer header through the power wireless local area network transmitter, and modulating the data to be transmitted using an orthogonal frequency division multiplexing technology to obtain a modulated signal; wherein, during the modulation process, the current positive random quantity is obtained, and the cyclic prefix selection area and length are modified according to the current positive random quantity, and the subcarrier parameters are modified according to the current positive random quantity; the current physical layer leading sequence is modified through the power wireless local area network transmitter. The method comprises the following steps: combining the physical layer header and the modulation signal into transmission information and sending the transmission information to the electric power wireless LAN receiving end; obtaining the current physical layer leading sequence and the physical layer header through the electric power wireless LAN receiving end, and receiving the transmission information sent by the electric power wireless LAN sending end; and parsing the transmission information according to the current physical layer leading sequence and the physical layer header to obtain the modulation signal; and demodulating the modulation signal by using the orthogonal frequency division multiplexing technology through the electric power wireless LAN receiving end to obtain the data to be transmitted; wherein, in the demodulation process, the current positive random quantity is obtained, and the cyclic prefix selection area and length are modified according to the current positive random quantity, and the subcarrier parameter is modified according to the current positive random quantity.

[0014] In a fourth aspect, the present invention provides a power wireless local area network information security transmission system, which is applied to the power wireless local area network transmitting end, and includes: a data acquisition module, which is used to acquire the data to be transmitted and the current physical layer leading sequence and physical layer header; a data modulation module, which is used to modulate the data to be transmitted using orthogonal frequency division multiplexing technology to obtain a modulated signal; wherein, during the modulation process, the current positive random value is obtained, and the cyclic prefix selection area and length are modified according to the current positive random value, and the subcarrier parameter is modified according to the current positive random value; a data sending module, which is used to combine the current physical layer leading sequence and the physical layer header and the modulated signal into transmission information and send it to the power wireless local area network receiving end; wherein the transmission information is used to trigger the power wireless local area network receiving end to parse the transmission information according to the acquired current physical layer leading sequence and physical layer header to obtain the modulated signal, and demodulate the modulated signal using orthogonal frequency division multiplexing technology to obtain the data to be transmitted; wherein, during the demodulation process, the power wireless local area network receiving end obtains the current positive random value, and modifies the cyclic prefix selection area and length according to the current positive random value, and modifies the subcarrier parameter according to the current positive random value.

[0015] In a fifth aspect, the present invention provides a power wireless local area network information security transmission system, which is applied to the power wireless local area network receiving end, and includes: a data receiving module, which is used to obtain the current physical layer preamble sequence and physical layer header and receive the transmission information sent by the power wireless local area network sending end; wherein the transmission information is obtained by the power wireless local area network sending end by modulating the data to be transmitted by adopting orthogonal frequency division multiplexing technology to obtain a modulated signal, and combining the current physical layer preamble sequence and physical layer header and the modulated signal; wherein, during the modulation process, the power wireless local area network sending end obtains the current positive random value, and modifies the cyclic prefix selection area and length according to the current positive random value, and modifies the subcarrier parameter according to the current positive random value; a data parsing module, which is used to parse the transmission information according to the current physical layer preamble sequence and physical layer header to obtain the modulated signal; a data demodulation module, which is used to demodulate the modulated signal by adopting orthogonal frequency division multiplexing technology to obtain the data to be transmitted; wherein, during the demodulation process, the current positive random value is obtained, and the cyclic prefix selection area and length are modified according to the current positive random value, and the subcarrier parameter is modified according to the current positive random value.

[0016] In a sixth aspect of the present invention, a power wireless LAN information security transmission device is provided, which is applied to a power wireless LAN system including a power wireless LAN transmitting end and a power wireless LAN receiving end, including: a power wireless LAN information security transmission system as described above and applied to the power wireless LAN transmitting end, which is arranged at the power wireless LAN transmitting end; and a power wireless LAN information security transmission system as described above and applied to the power wireless LAN receiving end, which is arranged at the power wireless LAN receiving end.

[0017] In a seventh aspect of the present invention, a computer device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above-mentioned method for secure transmission of information in a power wireless local area network when executing the computer program.

[0018] An eighth aspect of the present invention is a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the above-mentioned method for secure transmission of information in a power wireless local area network are implemented.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The method for secure transmission of information in a power wireless local area network of the present invention obtains the current physical layer preamble sequence and physical layer header, and processes the data to be transmitted based on the obtained physical layer preamble sequence and physical layer header, thereby realizing the dynamic nature of the physical layer preamble sequence and physical layer header. At the same time, when the data to be transmitted is modulated using orthogonal frequency division multiplexing technology, the randomness and unpredictability of signal transmission are further increased by introducing positive random quantities to modify the cyclic prefix selection area and length and modify the subcarrier parameters, thereby realizing the hiding of the physical layer waveform parameters. By dynamically switching the physical layer waveform factor, this dynamic change makes it difficult for attackers to capture and identify the characteristic information of the wireless signal, thereby greatly improving the system's anti-reconnaissance and anti-interception capabilities. In addition, dynamic parameter change rules can be formulated for the power wireless local area network, thereby realizing the power industry's strong regulatory capabilities for wireless local area network technology and realizing the power industry's autonomous control over the field of wireless communications. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The present invention is a flowchart of a method for securely transmitting information in a power wireless local area network applied to a transmitting end of a power wireless local area network according to an embodiment of the present invention.

[0022] Figure 2 The figure is a schematic diagram of the existing cyclic prefix principle of an embodiment of the present invention.

[0023] Figure 3 The figure is a schematic diagram of the principle of randomized cyclic prefix according to an embodiment of the present invention.

[0024] Figure 4 Schematic diagram of a conventional OFDM system model according to an embodiment of the present invention.

[0025] Figure 5 Schematic diagram of the OFDM signal generation principle according to an embodiment of the present invention.

[0026] Figure 6 This is a random generation diagram of the EPWL physical layer waveform according to an embodiment of the present invention.

[0027] Figure 7 The present invention is a flowchart of a method for securely transmitting information in a power wireless local area network applied to a receiving end of a power wireless local area network according to an embodiment of the present invention.

[0028] Figure 8 The present invention is a flowchart of a method for securely transmitting power wireless local area network information applied to a power wireless local area network system according to an embodiment of the present invention.

[0029] Fig. 9 The present invention is a block diagram of a power wireless local area network information security transmission system applied to a power wireless local area network transmitter according to an embodiment of the present invention.

[0030] Fig.10 The present invention is a block diagram of a system for securely transmitting information in a power wireless local area network applied to a receiving end of a power wireless local area network according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0032] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0033] First, the English full names and Chinese definitions of the abbreviations appearing in the present invention are introduced: WLAN: Wireless Local Area Network; EPWL: Electric Power WLAN; Wi-Fi: Wireless Fidelity; WAPI: Wireless LAN Authentication and Privacy Infrastructure; ETSI: European Telecommunication Standard Institute; CSMA / CA: Carrier Sense Multiple Access Collision Avoidance; RTS / CTS: Request To Send / Clear To Send; STA: Station; AP: Access point; WEP: Wired Equivalent Privacy; WPA: Wi-Fi Protected Access WiFi; PHY: Physical; MAC: Media access control layer; OFDM: Orthogonal Frequency Division Multiplexing, orthogonal frequency division multiplexing; TDMA: Time division multiple access, time division multiple access; EUHT: Enhanced Ultra-High Throughput, enhanced ultra-high throughput wireless communication system; WIA-FA: Wireless Networks for Industrial Automation, industrial automation wireless network; CP: Cyclic Prefix, cyclic prefix; GP: Guard period, guard period; PCM: Pulse Code Modulation, pulse code modulation; QAM: Quadrature Amplitude Modulation, orthogonal amplitude modulation; PSK: Phase Shift Keying, phase shift keying; IFFT: Inverse Fast Fourier Transform, fast Fourier transform; FFT: Fast Fourier Transform, fast Fourier transform.

[0034] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0035] With the advancement of the times and the development of communication technology, in order to meet the needs of users for faster and more stable use, the standards and performance of WLAN are constantly improving and improving. So far, the IEEE 802.11 standards (including those being formulated and those already released) have reached more than 20, including spectrum planning, quality assurance, architecture enhancement, service networking, security and encryption, network management and convergence, and the technical standard system of WLAN has taken shape. Among them, the physical layer standards that IEEE 802.11 has released include 802.11a, 802.11b, 802.11g and 802.11n, and the physical layer standards that are being formulated are 802.11ac and 802.11ad. After years of development, the data transmission capacity of WLAN has increased from 11Mbit / s in the 802.11b period to 600Mbit / s in 802.11n. In the near future, the transmission rate of 802.11ac and 802.11ad will reach 1G / s at the highest.

[0036] In fact, in addition to the 802.11 standard, there are several other wireless LAN standards, such as the HiperLan / HiperLan2 standard developed by the European Telecommunications Standards Institute (ETSI), the HomeRF standard developed by the HomeRF Working Group, and the Bluetooth technical specifications developed by the Bluetooth Special Interest Group (BSIG). However, among the many WLAN standards, the international mainstream WLAN technology is still the Wi-Fi technology promoted by the Wi-Fi Alliance, and the standards it supports are the 802.11 series of standards.

[0037] However, WiFi technology has several shortcomings. In terms of autonomy and controllability, based on the IEEE 802.11 standard, the technology, chips and mainstream standards are controlled by the developers and do not have autonomy and controllability; in terms of reliability, the use of the CSMA / CA competition mechanism will cause air interface resource competition with other industries' WiFi, which will cause serious interference to the network in dense scenarios, thus affecting the normal operation of the business; in terms of security, management frames and control frames cannot be encrypted, and there may be many types of attacks, such as RTS / CTS flooding attacks, forged frame attacks such as large Duration, and the physical layer is open and transparent, which makes it easy for attackers to obtain relevant information and launch network attacks; in terms of access authentication, WEP and WPA authentication methods are mostly used. WEP encryption uses static shared keys, which has low security; WPA also has security attack risks.

[0038] As a security standard for wireless LAN, WAPI proposes a three-way peer authentication architecture based on the underlying WiFi communication protocol to authenticate the identity of STA and AP. With the continuous improvement of the security requirements for wireless LAN, the WAPI industry has also ushered in new development opportunities, and the pace of construction in industries such as energy and transportation has continued to accelerate. There are still several problems in the application of WAPI technology to power business. In terms of autonomous controllability, the underlying communication protocol is based on WiFi technology, and the mainstream chips are controlled by R&D and are not autonomously controllable; in terms of security, WAPI is different from IEEE802.11 in terms of authentication and encryption. Its underlying PHY and MAC layers both use the IEEE 802.11 standard, and its management frames and control frames cannot be encrypted. There may be various types of attacks, such as RTS / CTS flooding attacks, forged frame attacks such as large Duration, and there are still physical layer security issues; in terms of reliability, the WAPI underlying protocol is based on IEEE 802.11, which will cause air interface resource competition with WiFi in other industries, and will cause serious interference to the WAPI network in dense scenarios, thereby affecting the normal operation of the business.

[0039] WIA-PA has become an official IEC international standard, making it one of the three major international standards in the field of wireless industrial process automation. It has made breakthroughs in technologies such as high-precision time synchronization, OFDM-based frequency domain polling, dynamic TDMA access based on channel cognition, and multi-mode reliable retransmission, solving the challenges faced by industrial applications of wireless technology, such as high concurrency, anti-interference, and hard real-time.

[0040] EUHT technology is a new generation of wireless communication technology. Starting from the basic principles of wireless communication, EUHT technology has carried out innovative design of the frame structure, pilot, precoding, channel estimation, channel prediction, physical layer, MAC layer, protocol layer, synchronization, control and scheduling involved in wireless communication. The underlying communication protocol of EUHT and WIA-FA technology is autonomous and controllable. The power wireless LAN EPWL can be customized and developed based on this technology according to the needs of power business, and can be superior to WAPI technology in terms of security and reliability. Compared with WAPI technology, the underlying protocol of EUHT technology is based on WiFi, and the underlying protocol is controlled. It is difficult to customize and develop according to user needs. Because the protocol is publicly known to the public, there are many ways to attack the WiFi protocol. Attackers only need a very simple and cheap way to attack WiFi or WAPI networks. Although the EUHT protocol is also open, it can be customized and modified, and attackers need to spend a lot of time to study if they want to attack the EUHT network. The physical layer frame structure of EUHT is as follows: short preamble sequence, long preamble sequence, system information channel, transmission control channel, downlink transmission channel, downlink probing channel, downlink protection interval, uplink probing channel, uplink scheduling request channel, uplink transmission channel, uplink random access channel and uplink protection interval. The definition of each subchannel in the physical layer frame structure of EUHT is shown in Table 1.

[0041] Table 1

[0042]

[0043]

[0044] The physical layer of EUHT technology adopts orthogonal frequency division multiplexing OFDM technology, and provides the basic parameters of OFDM. It supports 20MHz, 40MHz and 80MHz bands, 20MHz is the basic bandwidth of the system, and the following table 2 is the basic parameters of 20MHz OFDM.

[0045] Table 2

[0046]

[0047]

[0048] It can be seen that in this standard, the physical layer frame format setting and modulation mode of EUHT are public, and the frame format and modulation mode are also set. It can be seen that EUHT technology does not protect the physical layer, so the information transmitted by EUHT technology can be easily intercepted, interfered, and attacked.

[0049] EPWL research is based on EUHT or WIA-FA and other autonomous and controllable technologies, and further customized and developed at the physical layer and MAC layer to form a wireless LAN technology dedicated to power. It can be seen that EPWL still has the possibility of being attacked and interfered due to the exposure of the physical layer waveform. Therefore, in order to improve the physical layer security of the EPWL communication system, physical layer means such as antennas and modulation are used to achieve information security transmission, reduce the enemy's receiving bandwidth and power, increase system noise, and solve the problem of secure communication of information in the open signal space, so that the enemy's signal reconnaissance means are completely ineffective and data recovery is impossible.

[0050] In addition, EPWL application scenarios are basically fixed business terminals, and the end-to-end transmission distance and transmission path are also fixed. Therefore, the wireless LAN modulation and demodulation method remains unchanged during the transmission process. Compared with mobile scenarios, the modulation and demodulation method needs to be adaptively adjusted as the distance changes. Taking advantage of the fixed nature of the business terminals in the power industry, EPWL can adopt a modulation and demodulation method to change the waveform signal characteristics of EPWL by changing the subcarrier parameters and cyclic prefix.

[0051] Physical layer security technology refers to the use of physical layer means such as antennas and modulation to achieve secure information transmission in wireless communication systems, reduce the enemy's receiving bandwidth and power, increase system noise, solve the problem of secure communication of information in the open signal space, and make the enemy's signal reconnaissance means completely ineffective and unable to recover data. Physical layer security generally includes two categories: physical layer signal security protection and physical layer channel feature security utilization: (1) Physical layer signal security protection technology mainly performs security designs such as encryption, scrambling and anti-interference on open air interface signals to achieve signal feature hiding and secure signal transmission, mainly including complex signal design, spatial polarization, artificial noise signal design, etc.; (2) Physical layer channel feature security utilization mainly refers to the use of the rich and personalized "fingerprint" features presented by wireless signals for key distribution, authentication enhancement, etc., to enhance the security design of the upper layer security protection system, mainly including wireless channel fingerprint generation, wireless channel key distribution, physical layer identity authentication, etc.

[0052] Designing random disturbances on physical layer transmission signals is an effective way to protect physical layer signal security. It can remove the inherent characteristics of the waveform, increase the randomness of the waveform, and achieve transmission parameter concealment.

[0053] The underlying protocol of EPWL technology can be customized and optimized based on technologies such as EUHT. In order to further improve the security of the EPWL system, on the one hand, the preamble sequence length of the frame structure can be dynamically switched to make the synchronization information of the useful signal received by the receiver uncontrollable, so that the preamble sequences of EPWL in fixed places such as different substations and converter stations are different; on the other hand, a wireless security transmission scheme can be designed based on the OFDM waveform architecture. On the basis of traditional signal processing, two physical security transmission functions, cyclic prefix disturbance and carrier jitter controlled by random sequences, are introduced to achieve waveform parameter hiding and the physical layer waveforms of different substations, converter stations and other scenarios are randomly generated, thereby improving the system's anti-reconnaissance and anti-interception capabilities.

[0054] The preamble sequence in wireless communication is an important signal used to achieve synchronization and signal detection in wireless communication systems. The preamble sequence usually consists of three parts: cyclic prefix (CP), preamble sequence (ZC sequence) and guard time slot (GP or GT). The selection and design of these components depends on specific communication requirements and system parameters, such as cell coverage radius, propagation delay and Doppler motion.

[0055] Cyclic prefix (CP): used to reduce or eliminate inter-symbol interference caused by multipath propagation. The length of CP is related to the maximum coverage radius of the cell. The longer the CP, the larger the coverage area of ​​the cell. In design, CP is positively correlated with the guard slot (GP), so CP determines the size of the cell radius. Preamble sequence (ZC sequence): generated based on Zadoff-Chu (ZC) sequence. These sequences have excellent autocorrelation, which helps to accurately detect and synchronize signals at the receiving end. The length and type of ZC sequence are selected according to specific communication standards and system requirements. For example, the length of ZC sequence of formats 0 to 3 is fixed to 839, which is suitable for most cell radii; while the length of ZC sequence of format 4 is fixed to 139, which is suitable for ultra-short cell radii. Guard slot (GP or GT): located after the preamble sequence, used to prevent inter-symbol interference. The time length of GP determines the maximum coverage radius of the cell. The longer the GP time, the larger the coverage area of ​​the cell.

[0056] In addition, the preamble format includes long format preamble and short format preamble. Long format preamble is suitable for scenarios that require a larger coverage radius, such as low-frequency and macro cell sites; while short format preamble is suitable for situations with a smaller coverage radius, such as micro cell sites and medium and high frequency cells. This flexibility enables wireless communication systems to select the most appropriate preamble format according to different application scenarios, thereby optimizing communication performance.

[0057] Modulation technology is a process of converting the signal generated by the source into a form suitable for wireless transmission. It samples and quantizes the analog signal, modulates the optical carrier on and off with the binary digital signal "1" or "0", and performs pulse coding (PCM). The advantage of digital modulation is that it has strong anti-interference ability, and the influence of noise and dispersion does not accumulate during relaying, so long-distance transmission can be achieved. Its disadvantage is that it requires a wider frequency band and the equipment is also complex. The baseband signal is the original electrical signal, generally refers to the basic signal waveform, and in digital communication it refers to the corresponding electrical pulse. In wireless telemetry and remote control systems and radio technology, modulation is to use the baseband signal to control the parameters (amplitude, frequency and phase) of the high-frequency carrier so that these parameters change with the baseband signal. The baseband signal used to control the parameters of the high-frequency carrier is called the modulation signal. The unmodulated high-frequency electrical oscillation is called the carrier (it can be a sine wave or a non-sinusoidal wave, such as a square wave, a pulse sequence, etc.).

[0058] High-frequency electrical oscillations modulated by modulated signals are called modulated waves or modulated signals. The modulated signal is transmitted to the receiving end through the channel, and is restored to the original baseband signal after demodulation at the receiving end. Demodulation is the inverse transformation of modulation, which is the process of extracting the modulated signal from the modulated wave. Dual modulation is often used in radio communication. The first step is to modulate the first carrier (called subcarrier) with a digital signal or an analog signal. Or in multi-channel communication, modulation technology is used to achieve multiplexing (frequency division multiplexing and time division multiplexing). The second step is to modulate a common carrier with the modulated subcarrier or multiplexed signal for radio transmission. The second step of modulation is called secondary modulation. Modulating a high-frequency carrier with a baseband signal can reduce the size of the antenna in radio transmission and facilitate long-distance transmission. The application of modulation technology can also improve the signal's anti-interference ability.

[0059] High-frequency electrical oscillations modulated by modulated signals are called modulated waves or modulated signals. The modulated signal is transmitted to the receiving end through the channel, and is restored to the original baseband signal after demodulation at the receiving end. Demodulation is the inverse transformation of modulation, which is the process of extracting the modulated signal from the modulated wave. Dual modulation is often used in radio communication. The first step is to modulate the first carrier (called subcarrier) with a digital signal or an analog signal. Or in multi-channel communication, modulation technology is used to achieve multiplexing (frequency division multiplexing and time division multiplexing). The second step is to modulate a common carrier with the modulated subcarrier or multiplexed signal for radio transmission. The second step of modulation is called secondary modulation. Modulating a high-frequency carrier with a baseband signal can reduce the size of the antenna in radio transmission and facilitate long-distance transmission. The application of modulation technology can also improve the signal's anti-interference ability.

[0060] OFDM technology is a modulation and demodulation technology widely used in wireless communications. 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. The specific modulation method can use digital modulation technologies such as QAM and PSK. The modulation symbol will be mapped to each subcarrier to generate an OFDM symbol. The length of the OFDM symbol is usually a power of 2 to facilitate FFT calculations in the time domain and frequency domain.

[0061] See also Figure 1 In one embodiment of the present invention, a method for securely transmitting information in a power wireless local area network is provided, which is applied to a transmitting end of the power wireless local area network and includes the following steps:

[0062] S11: Obtain the data to be transmitted and the current physical layer preamble sequence and physical layer header.

[0063] S12: Modulate the data to be transmitted using orthogonal frequency division multiplexing technology to obtain a modulated signal; wherein, during the modulation process, the current positive random value is obtained, and the cyclic prefix selection area and length are modified according to the current positive random value, and the subcarrier parameters are modified according to the current positive random value.

[0064] S13: Combine the current physical layer preamble sequence, physical layer header and modulation signal into transmission information and send it to the electric power wireless LAN receiving end; wherein the transmission information is used to trigger the electric power wireless LAN receiving end to parse the transmission information according to the acquired current physical layer preamble sequence and physical layer header to obtain the modulation signal, and demodulate the modulation signal using orthogonal frequency division multiplexing technology to obtain the data to be transmitted; wherein, during the demodulation process, the electric power wireless LAN receiving end obtains the current positive random quantity, and modifies the cyclic prefix selection area and length according to the current positive random quantity, and modifies the subcarrier parameter according to the current positive random quantity.

[0065] The method for secure transmission of information in a power wireless local area network of the present invention obtains the current physical layer preamble sequence and physical layer header, and processes the data to be transmitted based on the obtained physical layer preamble sequence and physical layer header, thereby realizing the dynamic nature of the physical layer preamble sequence and physical layer header. At the same time, when the data to be transmitted is modulated using orthogonal frequency division multiplexing technology, the randomness and unpredictability of signal transmission are further increased by introducing positive random quantities to modify the cyclic prefix selection area and length and modify the subcarrier parameters, thereby realizing the hiding of the physical layer waveform parameters. By dynamically switching the physical layer waveform factor, this dynamic change makes it difficult for attackers to capture and identify the characteristic information of the wireless signal, thereby greatly improving the system's anti-reconnaissance and anti-interception capabilities. In addition, dynamic parameter change rules can be formulated for the power wireless local area network, thereby realizing the power industry's strong regulatory capabilities for wireless local area network technology and realizing the power industry's autonomous control over the field of wireless communications.

[0066] In a possible implementation manner, the power wireless local area network information security transmission method further includes: modifying the current physical layer preamble sequence and physical layer header according to current regional requirements.

[0067] Among them, the modification of the current physical layer preamble sequence and physical layer header includes one or more of the following: increasing or decreasing the number of short training sequence preamble code symbols of the current physical layer preamble sequence; increasing or decreasing the number of long training sequence preamble code symbols of the current physical layer preamble sequence; increasing or decreasing the number of signal field symbols of the current physical layer header; modifying the modulation mode field of the current physical layer header; and configuring a private information field carrying coding information and / or modulation information in the signal field of the current physical layer header.

[0068] Specifically, the physical layer preamble sequence of EPWL is a series of signals sent before sending a useful signal. After the physical layer preamble sequence is sent, the valid signal is sent immediately. The role of the physical layer preamble sequence is to remind the receiving chip that the signal to be sent is a valid signal, so pay attention to receiving it to avoid losing the useful signal. By changing the physical layer preamble sequence, the synchronization information of receiving the valid signal can be changed. It is difficult for attackers to obtain the synchronization information of the valid signal, and it is difficult to capture the useful information of the transmission.

[0069] The data transmitted by the wireless LAN is encapsulated as a MAC Server Data Unit (MSDU) on the logical link control (LLC) layer of the data link layer, and then encapsulated as a MAC Protocol Data Unit (MPDU) through the MAC layer. The work of the data link layer is completed, and then the MPDU is transmitted to the physical layer, the upper sublayer of the physical layer, the physical layer convergence protocol (PLCP) layer, called the PLCP Service Data Unit (PSDU). PSDU is the data to be transmitted, and a preamble sequence and PHY Header are added to it to create a PLCP Protocol Data Unit (PPDU). The PPDU data format consists of a PLCP preamble sequence, PHY Header and PSDU. The physical layer dedicated frame structure of the wireless LAN for power applications is defined as STF, LTF, SIG and PSDU set in sequence. Among them, STF, LTF, SIG and PSDU are the same concepts as those in the 802.11 protocol, wherein STF is a general term for short training sequence preambles of different PPDU frame formats; LTF is a general term for long training sequence preambles of different PPDU frame formats; and SIG is a general term for SIGs of different PPDU frame formats.

[0070] The implementation of PLCP Preample and PLCP Header is different from the general 802.11 protocol, ensuring that normal general WLAN devices cannot identify or track the wireless signal of the current frame. When the RF front-end parses the frame preamble sequence and does not comply, it will be directly discarded without reporting to the upper layer. In order to meet the physical layer security requirements of wireless LANs for power applications, configurable and appropriate modifications are made to PLCP Preample and PLCP Header. Specifically, the number of short training sequence preamble symbols of the current physical layer preamble sequence can be increased or decreased, the number of long training sequence preamble symbols of the current physical layer preamble sequence can be increased or decreased, the number of signal field symbols of the current physical layer header can be increased or decreased, the modulation mode field of the current physical layer header can be modified, and a private information field carrying coding information and / or modulation information can be configured in the signal field of the current physical layer header.

[0071] In a possible implementation, the current positive random variable is generated by a random sequence generator using a random number or time as a seed.

[0072] Specifically, by customizing the random sequence generator of EPWL physical layer waveform parameters dedicated to the power industry, formulating dynamic parameter change rules and applying them to the OFDM physical layer waveform customization process, configuring a random sequence generator for the EPWL communication system, and customizing physical layer waveforms for EPWL in fixed places such as substations, converter stations and unmanned distribution rooms, the power industry will establish a strong regulatory capability for wireless LAN technology, and achieve independent control of the power industry in the field of wireless communications.

[0073] Among them, the random sequence generator can be set up independently, and then establish communication with the power wireless LAN transmitter and the power wireless LAN receiver respectively. It can also be set inside the power wireless LAN transmitter or the power wireless LAN receiver, and based on the secure communication between the power wireless LAN transmitter and the power wireless LAN receiver, the interaction of positive random quantities between the two is realized.

[0074] In a possible implementation, modifying the cyclic prefix selection area and length according to the current positive random value includes: the cyclic prefix selection area moves to the next symbol with the current positive random value, and the cyclic prefix length changes by the previous cyclic prefix length plus the current positive random value.

[0075] Specifically, OFDM is a special multi-carrier transmission scheme, which can be regarded as a modulation technology or a multiplexing technology. In short, it uses multiple mutually orthogonal sub-carriers to carry information for transmission. The basic idea of ​​OFDM is to divide a given channel into many sub-channels in the frequency domain, and keep the sub-channels orthogonal to each other. High-speed data streams are allocated to multiple orthogonal sub-channels for transmission, so that the symbol rate on the sub-channel is greatly reduced, and the duration of a single data symbol is greatly prolonged, so it has a strong ability to resist delay spread and reduces the influence of inter-symbol interference (ISI) easily caused by high-speed transmission. Usually, a guard interval is added before the OFDM symbol is sent to the channel. As long as the guard interval is greater than the maximum delay spread of the channel, the influence of ISI can be completely eliminated in theory. The usual practice is to add a cyclic prefix (CP), and in some systems, a cyclic suffix (CS) is also added. This is a more distinctive processing technology of the OFDM system. Orthogonal frequency division multiplexing (OFDM) is a type of multi-carrier modulation (MCM) technology.

[0076] The OFDM signal CP is used to eliminate multipath interference in wireless channels, but it also causes the system to have obvious second-order cyclic correlation characteristics, which threatens the security of the system. By utilizing the randomness of the transmitted information itself, the CP selection area and length randomization are proposed, and the security of the system is further enhanced. The principle is as follows Figure 2 and 3 shown.

[0077] Unlike the traditional CP selection process of directly copying the sample value of the last time domain symbol, the CP selection area in the new method moves to the next symbol by a positive random amount, and the CP length also changes by this positive random amount. For example, under the EUHT standard, the CP selection area moves to the next symbol by a positive random amount, and the CP length changes by the original CP length plus the positive random amount.

[0078] In a possible implementation, modifying the subcarrier parameters according to the current positive random value includes: modifying the amplitude and number of subcarriers according to the current positive random value.

[0079] For details, see Figure 4 For the OFDM system model, at the transmitting end, the serial data stream is sent to the operation unit for IFFT transformation after encoding, modulation and serial / parallel conversion, and then a guard interval needs to be added, and then it is converted into an analog signal through D / A and sent to the channel for transmission; at the receiving end, the analog OFDM signal received by the channel is converted into a serial digital signal through A / D conversion, and then the guard interval is removed, and then it is sent to the operation unit for FFT operation, and finally the original source signal can be restored after parallel-to-serial conversion and decoding.

[0080] The OFDM transmitter maps the information bit stream into a PSK or QAM symbol sequence, and then converts the symbol sequence into N parallel symbol streams. Each of the N serial / parallel converted symbols is modulated by a different subcarrier. The signal generation block diagram is shown in the figure. Figure 5 As shown, the frequency domain signal X[k] modulates the subcarriers of frequency, where the number of carriers is N = 0, 1, 2, ..., n-1. At the receiver, these signals can be demodulated using the orthogonality of the subcarriers. The frequency domain symbol of each subcarrier is inverse fast Fourier transformed to obtain the time domain symbol x[n], where n represents a discrete time point in the time domain (from 0 to N-1). Then the time domain expression of the OFDM signal can be expressed as:

[0081]

[0082] From the above expressions, it can be seen that the OFDM signal can be determined based on the amplitude X[k] and the number of subcarriers N. These two parameters can still change dynamically through positive random quantities, making the OFDM physical layer waveform of EPWL distinctive and dynamically switchable.

[0083] From the above cyclic prefix scrambling and subcarrier jitter, the physical layer security of EPWL can be improved. Based on the OFDM waveform architecture design, the present invention introduces two physical layer security transmission functions, cyclic prefix scrambling and carrier jitter controlled by random sequences on the basis of traditional signal processing, to achieve waveform parameter hiding and improve the anti-reconnaissance and anti-interception capabilities of the EPWL system. The random sequence is generated by a random sequence generator with a random number or time as a seed. Figure 6 As shown in the figure, the processing flow at the transmitting end is similar to that of the traditional OFDM system. After the data bit stream is encoded, it is mapped into symbols according to a certain modulation method, such as phase shift keying, orthogonal amplitude modulation, spread spectrum, etc., and then constellation mapping is performed. When the complex signal undergoes OFDM modulation fast Fourier inverse transform, the subcarrier jitter function is introduced, and then the CP is jittered to remove the phase characteristics and form OFDM symbols. In this way, through the physical layer scrambling control based on random sequences, the physical layer waveform of EPWL is different in different application scenarios, which can not only ensure the security of the EPWL communication system, but also control the use of the EPWL system in the power industry through the EPWL administrator, realizing the autonomous control of the wireless LAN by the power industry.

[0084] The power wireless LAN information security transmission method of the present invention can be applied to the power wireless LAN communication system, or based on the physical layer waveform editable technical solution, the power wireless LAN communication chip tape-out can be carried out to design a wireless LAN communication product dedicated to power. After the results are promoted and applied, a highly reliable, autonomous and controllable power wireless LAN communication system can be established for fixed places such as substations and converter stations, which can effectively solve the problems of wireless LAN communication technology in the power industry and realize import substitution of similar products such as WiFi and WAPI. The results can effectively alleviate the monitoring pressure of safety supervisors, and it is expected to save on-site personnel configuration, and further strengthen the safety management and control level of substations, converter stations and other scenes.

[0085] See also Figure 7 In another embodiment of the present invention, a method for securely transmitting information in a power wireless local area network is provided, which is applied to a receiving end of the power wireless local area network and includes the following steps:

[0086] S21: Obtain the current physical layer preamble sequence and physical layer header, and receive the transmission information sent by the power wireless LAN transmitter; wherein the transmission information is obtained by the power wireless LAN transmitter by modulating the data to be transmitted using orthogonal frequency division multiplexing technology to obtain a modulated signal, and combining the current physical layer preamble sequence, physical layer header and modulated signal; wherein, during the modulation process, the power wireless LAN transmitter obtains the current positive random quantity, and modifies the cyclic prefix selection area and length according to the current positive random quantity, and modifies the subcarrier parameters according to the current positive random quantity.

[0087] S22: parse the transmission information according to the current physical layer preamble sequence and the physical layer header to obtain a modulated signal.

[0088] S23: demodulate the modulated signal using orthogonal frequency division multiplexing technology to obtain data to be transmitted; wherein, during the demodulation process, the current positive random value is obtained, and the cyclic prefix selection area and length are modified according to the current positive random value, and the subcarrier parameters are modified according to the current positive random value.

[0089] See also Figure 8 In another embodiment of the present invention, a method for secure transmission of information in a power wireless local area network is provided, which is applied to a power wireless local area network system including a power wireless local area network transmitter and a power wireless local area network receiver, and includes the following steps:

[0090] S31: obtaining the data to be transmitted and the current physical layer preamble sequence and physical layer header through the power wireless local area network transmitter, and modulating the data to be transmitted using orthogonal frequency division multiplexing technology to obtain a modulated signal; wherein, in the modulation process, the current positive random value is obtained, and the cyclic prefix selection area and length are modified according to the current positive random value, and the subcarrier parameter is modified according to the current positive random value;

[0091] S32: combining the current physical layer preamble sequence, the physical layer header and the modulation signal into transmission information through the power wireless local area network transmitting end and sending the information to the power wireless local area network receiving end;

[0092] S33: obtaining the current physical layer preamble sequence and the physical layer header through the power wireless local area network receiving end and receiving the transmission information sent by the power wireless local area network transmitting end; and parsing the transmission information according to the current physical layer preamble sequence and the physical layer header to obtain a modulated signal;

[0093] S34: The modulated signal is demodulated by the receiving end of the electric power wireless local area network using orthogonal frequency division multiplexing technology to obtain the data to be transmitted; wherein, during the demodulation process, the current positive random quantity is obtained, and the cyclic prefix selection area and length are modified according to the current positive random quantity, and the subcarrier parameters are modified according to the current positive random quantity.

[0094] The following are device embodiments of the present invention, which can be used to implement the method embodiments of the present invention. For details not disclosed in the device embodiments, please refer to the method embodiments of the present invention.

[0095] See also Fig. 9In another embodiment of the present invention, a power wireless LAN information security transmission system is provided, which is applied to the power wireless LAN sending end and can be used to implement the above-mentioned power wireless LAN information security transmission method applied to the power wireless LAN sending end. Specifically, the power wireless LAN information security transmission system includes a data acquisition module, a data modulation module and a data sending module.

[0096] Among them, the data acquisition module is used to obtain the data to be transmitted and the current physical layer leading sequence and physical layer header; the data modulation module is used to modulate the data to be transmitted using orthogonal frequency division multiplexing technology to obtain a modulated signal; wherein, during the modulation process, the current positive random value is obtained, and the cyclic prefix selection area and length are modified according to the current positive random value, and the subcarrier parameter is modified according to the current positive random value; the data sending module is used to combine the current physical layer leading sequence, the physical layer header and the modulated signal into transmission information and send it to the power wireless LAN receiving end; wherein the transmission information is used to trigger the power wireless LAN receiving end to parse the transmission information according to the acquired current physical layer leading sequence and physical layer header to obtain the modulated signal, and demodulate the modulated signal using orthogonal frequency division multiplexing technology to obtain the data to be transmitted; wherein, during the demodulation process, the power wireless LAN receiving end obtains the current positive random value, and modifies the cyclic prefix selection area and length according to the current positive random value, and modifies the subcarrier parameter according to the current positive random value.

[0097] See also Fig.10 In another embodiment of the present invention, a power wireless LAN information security transmission system is provided, which is applied to the power wireless LAN receiving end and can be used to implement the above-mentioned power wireless LAN information security transmission method applied to the power wireless LAN receiving end. Specifically, the power wireless LAN information security transmission system includes a data receiving module, a data parsing module and a data demodulation module.

[0098] Among them, the data receiving module is used to obtain the current physical layer preamble sequence and physical layer header and receive the transmission information sent by the power wireless local area network transmitter; wherein the transmission information is the power wireless local area network transmitter modulating the data to be transmitted by adopting orthogonal frequency division multiplexing technology to obtain a modulated signal, and combining the current physical layer preamble sequence and physical layer header and the modulated signal; wherein, during the modulation process, the power wireless local area network transmitter obtains the current positive random quantity, and modifies the cyclic prefix selection area and length according to the current positive random quantity, and modifies the subcarrier parameter according to the current positive random quantity; the data parsing module is used to parse the transmission information according to the current physical layer preamble sequence and physical layer header to obtain the modulated signal; the data demodulation module is used to demodulate the modulated signal by adopting orthogonal frequency division multiplexing technology to obtain the data to be transmitted; wherein, during the demodulation process, the current positive random quantity is obtained, and the cyclic prefix selection area and length are modified according to the current positive random quantity, and the subcarrier parameter is modified according to the current positive random quantity.

[0099] All relevant contents of each step involved in the embodiment of the aforementioned power wireless LAN information security transmission method can be referred to the functional description of the functional modules corresponding to the power wireless LAN information security transmission system in the embodiment of the present invention, and will not be repeated here.

[0100] In another embodiment of the present invention, a power wireless LAN information security transmission device is provided, which is applied to a power wireless LAN system including a power wireless LAN transmitting end and a power wireless LAN receiving end, including: a power wireless LAN information security transmission system as described above and applied to the power wireless LAN transmitting end, which is arranged at the power wireless LAN transmitting end; and a power wireless LAN information security transmission system as described above and applied to the power wireless LAN receiving end, which is arranged at the power wireless LAN receiving end.

[0101] The division of modules in the embodiments of the present invention is schematic and is only a logical function division. There may be other division methods in actual implementation. In addition, each functional module in each embodiment of the present invention may be integrated into one processor, or may exist physically separately, or two or more modules may be integrated into one module. The above-mentioned integrated modules may be implemented in the form of hardware or in the form of software functional modules.

[0102] In another embodiment of the present invention, a computer device is provided, the computer device including a processor and a memory, the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc., which are the computing core and control core of the terminal, which are suitable for implementing one or more instructions, and are specifically suitable for loading and executing one or more instructions in a computer storage medium to implement the corresponding method flow or corresponding function; the processor described in the embodiment of the present invention can be used for the operation of the power wireless local area network information security transmission method.

[0103] In another embodiment of the present invention, the present invention further provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device for storing programs and data. It is understandable that the computer-readable storage medium here can include both built-in storage media in a computer device and, of course, extended storage media supported by the computer device. The computer-readable storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by a processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the corresponding steps of the method for secure transmission of information in a power wireless local area network in the above embodiment.

[0104] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented 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.

[0105] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0106] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0107] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does 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 secure transmission of information in a power wireless local area network, characterized in that: Applied to the transmitter of power wireless LAN, including: Obtain the data to be transmitted and the current physical layer preamble sequence and physical layer header; The data to be transmitted is modulated by orthogonal frequency division multiplexing technology to obtain a modulated signal; wherein, during the modulation process, a current positive random value is obtained, and a cyclic prefix selection area and length are modified according to the current positive random value, and a subcarrier parameter is modified according to the current positive random value; The current physical layer preamble sequence, physical layer header and modulation signal are combined into transmission information and sent to the power wireless local area network receiving end; wherein the transmission information is used to trigger the power wireless local area network receiving end to parse the transmission information according to the acquired current physical layer preamble sequence and physical layer header to obtain the modulation signal, and demodulate the modulation signal using orthogonal frequency division multiplexing technology to obtain the data to be transmitted; wherein, during the demodulation process, the power wireless local area network receiving end obtains the current positive random quantity, and modifies the cyclic prefix selection area and length according to the current positive random quantity, and modifies the subcarrier parameter according to the current positive random quantity.

2. The method for secure transmission of information in a power wireless local area network according to claim 1, characterized in that: Also includes: Modify the current physical layer preamble sequence and physical layer header according to the current regional requirements; The modifying of the current physical layer preamble sequence and physical layer header includes one or more of the following: Increase or decrease the number of short training sequence preamble symbols of the current physical layer preamble sequence; Increase or decrease the number of long training sequence preamble symbols of the current physical layer preamble sequence; Increase or decrease the number of signal field symbols in the current physical layer header; Modify the modulation mode field of the current physical layer header; A private information field carrying coding information and / or modulation information is configured in a signal field of a current physical layer header.

3. The method for secure transmission of information in a power wireless local area network according to claim 1, characterized in that: The current positive random quantity is generated by a random sequence generator using a random number or time as a seed.

4. The method for secure transmission of information in a power wireless local area network according to claim 1, characterized in that: Modifying the cyclic prefix selection area and length according to the current positive random amount includes: The cyclic prefix selection area moves to the next symbol by the current positive random amount, and the cyclic prefix length changes by the previous cyclic prefix length plus the current positive random amount.

5. The method for secure transmission of information in a power wireless local area network according to claim 1, characterized in that: Modifying the subcarrier parameter according to the current positive random value includes: Modifies the amplitude and number of subcarriers according to the current positive random amount.

6. A method for secure transmission of information in a power wireless local area network, characterized in that: Applied to the receiving end of power wireless LAN, including: Obtain the current physical layer preamble sequence and physical layer header and receive the transmission information sent by the power wireless local area network transmitter; wherein the transmission information is obtained by the power wireless local area network transmitter by modulating the data to be transmitted using orthogonal frequency division multiplexing technology to obtain a modulated signal, and combining the current physical layer preamble sequence and physical layer header and the modulated signal; wherein, during the modulation process, the power wireless local area network transmitter obtains the current positive random quantity, and modifies the cyclic prefix selection area and length according to the current positive random quantity, and modifies the subcarrier parameter according to the current positive random quantity; Parsing transmission information according to the current physical layer preamble sequence and physical layer header to obtain a modulated signal; The modulated signal is demodulated by orthogonal frequency division multiplexing technology to obtain the data to be transmitted; wherein, during the demodulation process, the current positive random quantity is obtained, and the cyclic prefix selection area and length are modified according to the current positive random quantity, and the subcarrier parameter is modified according to the current positive random quantity.

7. A method for secure transmission of information in a power wireless local area network, characterized in that: The power wireless LAN system applied to the power wireless LAN transmitting end and the power wireless LAN receiving end includes: The data to be transmitted and the current physical layer preamble sequence and physical layer header are obtained through the power wireless local area network transmitter, and the data to be transmitted is modulated by using orthogonal frequency division multiplexing technology to obtain a modulated signal; wherein, during the modulation process, the current positive random quantity is obtained, and the cyclic prefix selection area and length are modified according to the current positive random quantity, and the subcarrier parameter is modified according to the current positive random quantity; The current physical layer preamble sequence, the physical layer header and the modulated signal are combined into transmission information by the power wireless local area network transmitting end and sent to the power wireless local area network receiving end; Obtaining the current physical layer preamble sequence and physical layer header through the power wireless local area network receiving end and receiving the transmission information sent by the power wireless local area network transmitting end; and parsing the transmission information according to the current physical layer preamble sequence and physical layer header to obtain a modulated signal; The modulated signal is demodulated by the orthogonal frequency division multiplexing technology at the receiving end of the power wireless local area network to obtain the data to be transmitted; wherein, during the demodulation process, the current positive random quantity is obtained, and the cyclic prefix selection area and length are modified according to the current positive random quantity, and the subcarrier parameter is modified according to the current positive random quantity.

8. A power wireless local area network information security transmission system, characterized in that: Applied to the transmitter of power wireless LAN, including: A data acquisition module, used to acquire the data to be transmitted and the current physical layer leading sequence and physical layer header; A data modulation module, used for modulating the data to be transmitted by using orthogonal frequency division multiplexing technology to obtain a modulated signal; wherein, during the modulation process, the current positive random value is obtained, and the cyclic prefix selection area and length are modified according to the current positive random value, and the subcarrier parameter is modified according to the current positive random value; A data sending module is used to combine the current physical layer preamble sequence, physical layer header and modulation signal into transmission information and send it to the power wireless local area network receiving end; wherein the transmission information is used to trigger the power wireless local area network receiving end to parse the transmission information according to the acquired current physical layer preamble sequence and physical layer header to obtain the modulation signal, and demodulate the modulation signal using orthogonal frequency division multiplexing technology to obtain the data to be transmitted; wherein, during the demodulation process, the power wireless local area network receiving end obtains the current positive random quantity, and modifies the cyclic prefix selection area and length according to the current positive random quantity, and modifies the subcarrier parameter according to the current positive random quantity.

9. A power wireless local area network information security transmission system, characterized in that: Applied to the receiving end of power wireless LAN, including: A data receiving module, used to obtain the current physical layer preamble sequence and physical layer header and receive the transmission information sent by the power wireless local area network transmitter; wherein the transmission information is obtained by the power wireless local area network transmitter by modulating the data to be transmitted using orthogonal frequency division multiplexing technology to obtain a modulated signal, and combining the current physical layer preamble sequence and physical layer header and the modulated signal; wherein, during the modulation process, the power wireless local area network transmitter obtains the current positive random value, and modifies the cyclic prefix selection area and length according to the current positive random value, and modifies the subcarrier parameter according to the current positive random value; A data parsing module, used to parse the transmission information according to the current physical layer preamble sequence and the physical layer header to obtain a modulated signal; The data demodulation module is used to demodulate the modulated signal using orthogonal frequency division multiplexing technology to obtain the data to be transmitted; wherein, during the demodulation process, the current positive random quantity is obtained, and the cyclic prefix selection area and length are modified according to the current positive random quantity, and the subcarrier parameter is modified according to the current positive random quantity.

10. A power wireless local area network information security transmission device, characterized in that: The power wireless LAN system applied to the power wireless LAN transmitting end and the power wireless LAN receiving end includes: The power wireless local area network information security transmission system as claimed in claim 8, which is arranged at the transmitting end of the power wireless local area network; The power wireless local area network information security transmission system as claimed in claim 9 is arranged at the receiving end of the power wireless local area network.

11. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method for secure transmission of information in a power wireless local area network as claimed in any one of claims 1 to 7 are implemented.

12. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method for secure transmission of information in a power wireless local area network as claimed in any one of claims 1 to 7 are implemented.

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