Parallel transmission method from WiFi to LoRa, Bluetooth and ZigBee based on cross-protocol communication

Abstract

The invention discloses a parallel transmission method from WiFi to LoRa, Bluetooth and ZigBee based on cross-protocol communication, which comprises the following steps: uniformly up-sampling wireless heterogeneous signals to the same sampling rate through a CCK symbol synchronization mechanism; generating a compensation carrier based on the estimated frequency offset, completing frequency band migration of different wireless heterogeneous signals according to the compensation carrier so as to place different signals on different carrier frequencies, and directly adding the generated wireless heterogeneous signals with different carrier frequencies in a time domain to obtain a mixed signal; and performing reverse engineering simulation on the mixed signal to obtain a WiFi signal carrying information of a plurality of wireless devices, performing scrambling processing on the WiFi signal, converting a scrambled bit stream into a radio frequency signal through a CCK modulator, and transmitting the radio frequency signal through an antenna. According to the invention, direct communication from WiFi to a plurality of Internet of Things devices can be realized.

Description

Technical Field

[0001] The present invention relates to the technical field of Internet of Things communication, and particularly to a parallel transmission method from WiFi to LoRa, Bluetooth, and ZigBee based on cross-protocol communication. Background Art

[0002] WiFi and wireless communication devices such as ZigBee, BLE, and LoRa all share the 2.4Ghz ISM band, but they each have different characteristics. The bandwidth of WiFi is 11Mhz, while the bandwidths of ZigBee and Bluetooth are 2Mhz, and the bandwidth of LoRa at 2.4G is 1.625Mhz. Moreover, the signal bandwidth of 802.11b can cover the communication channels of most wireless devices.

[0003] Currently, there is no method that can simulate multiple wireless signals through 802.11b to achieve parallel communication between WiFi and Internet of Things devices. There are still technical defects such as low efficiency and complexity in the communication between heterogeneous Internet of Things devices. Summary of the Invention

[0004] The purpose of the present invention is to provide a parallel transmission method from WiFi to LoRa, Bluetooth, and ZigBee based on cross-protocol communication, aiming to achieve direct communication from WiFi to multiple Internet of Things devices. By combining multiple wireless signals in the WiFi signal and sending them together, the generated signal can be received and decoded by multiple commercial Internet of Things devices.

[0005] To achieve the above technical purpose, the technical solution adopted by the present invention is as follows:

[0006] The present invention discloses a parallel transmission method from WiFi to LoRa, Bluetooth, and ZigBee based on cross-protocol communication. The method combines multiple wireless heterogeneous signals in the WiFi signal and sends them together, and the generated signal is received and decoded by multiple commercial Internet of Things devices. The method includes the following steps:

[0007] Through the CCK symbol synchronization mechanism, uniformly upsample the wireless heterogeneous signals to the same sampling rate to make the wireless heterogeneous signals compatible with Wi-Fi constraints;

[0008] Generate a compensation carrier based on the estimated frequency offset, and perform frequency band migration on different wireless heterogeneous signals according to the compensation carrier to place different signals on different carrier frequencies. Directly add the wireless heterogeneous signals with different carrier frequencies in the time domain to obtain a mixed signal;

[0009] The mixed signal is processed through reverse engineering simulation to obtain a WiFi signal carrying information of multiple wireless devices. The WiFi signal is scrambled, and the scrambled bit stream is converted into a radio frequency signal through a CCK modulator and transmitted through an antenna.

[0010] Further, the process of uniformly upsampling wireless heterogeneous signals to the same sampling rate through the CCK symbol synchronization mechanism includes the following steps:

[0011] Find the least common multiple of different wireless heterogeneous signals according to the sampling rate of WiFi, and uniformly upsample them to the same sampling rate; pad with 0s to make the total length of all wireless heterogeneous signals an integer multiple of 32.

[0012] Further, the process of generating a compensation carrier based on the estimated frequency offset and completing frequency band migration for different wireless heterogeneous signals according to the compensation carrier includes the following steps:

[0013] Based on the estimated frequency offset f off Generate a compensation carrier And multiply it point by point with the received signal to complete frequency band migration:

[0014] s compensated (t) = s received (t) · c(t)

[0015] In the formula, where s received (t) is the initial wireless signal, s compensated (t) is the offset signal;

[0016] The selection basis of the carrier frequency is:

[0017]

[0018] Where are the center frequencies of two different carriers respectively, are the bandwidths of two signals respectively.

[0019] Further, the process of directly adding wireless heterogeneous signals with different generated carrier frequencies in the time domain to obtain a mixed signal includes the following steps:

[0020] Segment the generated carrier waveform according to cck symbols so that each symbol is independently modulated, and pad 0s at the end of the signal with fewer symbols to make the lengths consistent;

[0021] Directly add the generated wireless heterogeneous signals with different carrier frequencies in the time domain, and use the superposition principle of linear systems to mix the wireless heterogeneous signals to obtain a mixed signal containing the superposition of multiple wireless device signals. The total power after superposition approaches the sum of the powers of each wireless heterogeneous signal.

[0022] Further, the process of obtaining a Wi-Fi signal carrying information of multiple wireless devices through reverse engineering simulation of the mixed signal includes the following steps:

[0023] Perform reverse engineering on the mixed signal. For the pseudo-random code (PN sequence) interference of Wi-Fi, perform correlation operations through a known PN sequence template, and reverse the scrambling operation to restore the original modulation symbols; according to the codeword mapping rule of CCK modulation in the IEEE 802.11b standard (such as the mapping table from 4-bit symbols to 8-bit codewords), construct an inverse lookup table to restore the received symbols to the original data bits of the Internet of Things devices.

[0024] The durations of CCK codewords and symbols such as ZigBee, BLE, and Lora are different. For 802.11b with a bandwidth of 11 MHz, each CCK codeword consists of 8 chips and has a duration of 1 / 11 μs. The symbol codewords of Internet of Things devices require a longer time, so more CCK codewords are needed to establish a mapping table between the signal and the CCK cluster to achieve the simulation of the phase sequence. We set multiple consecutive chips to the same phase and change the frequency of the output waveform by reducing the rate of phase change; specifically, control the phase change slope through the following formula:

[0025]

[0026] where φ(n) is the phase value of the nth chip, φ0 is the initial phase, n is the current chip serial number, k is the repetition coefficient, and T symbol is the target symbol duration.

[0027] Further, the process of scrambling the Wi-Fi signal and converting the scrambled bit stream into a radio frequency signal through a CCK modulator includes the following steps:

[0028] Scramble the original data bits of the Wi-Fi signal to eliminate long consecutive 0 sequences or 1 sequences in the data;

[0029] The scrambled bit stream is converted into a radio frequency signal through a CCK modulator; specifically, each CCK symbol corresponds to 8 original data bits, and these data bits are divided into two groups, corresponding to the selection of two complementary codes respectively. The finally obtained modulation symbol is determined by the linear combination of the two complementary codes, forming four phase states corresponding to the constellation diagram. Each phase state corresponds to a baseband waveform, and the final composite signal is generated through I / Q modulation.

[0030] Further, perform spread spectrum processing on the modulation symbols to expand the spectrum of each modulation symbol to a wider bandwidth; specifically, generate a pseudo-noise sequence through the following formula:

[0031]

[0032] where s n is the spreading sequence at the nth moment, s n-1 is the spreading chip of the previous moment, s n-10 is the spreading chip of the 10th previous moment;

[0033] Multiply each modulation symbol element-by-element with the pseudo-noise sequence to generate a spreading symbol sequence of length 11. Finally, process the spreading symbol sequence through the baseband module and convert it into a radio frequency signal for transmission through the antenna.

[0034] Furthermore, the demodulation process of the radio frequency signal includes:

[0035] Decompose the received radio frequency signal into the frequency domain, filter out the components higher than the target signal bandwidth through a low-pass filter to retain the spectral components within the target frequency band, and then convert the retained spectral components back to the time domain to demodulate and obtain the corresponding data information.

[0036] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0037] The parallel transmission method from WiFi to LoRa, Bluetooth, and ZigBee based on cross-protocol communication of the present invention can send multiple wireless signals by integrating them into the WiFi signal, and the generated signal can be received and decoded by multiple commercial Internet of Things devices, thereby enabling direct communication from WiFi to multiple Internet of Things devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 is a schematic diagram of the principle of the parallel transmission method from WiFi to LoRa, Bluetooth, and ZigBee based on cross-protocol communication of the present invention;

[0039] Figure 2 is a schematic diagram of the reverse engineering design principle;

[0040] Figure 3 is a schematic diagram of decoding at the Internet of Things device end. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0041] The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0042] The present invention discloses a parallel transmission method from WiFi to LoRa, Bluetooth, and ZigBee based on cross-protocol communication. The method integrates multiple wireless heterogeneous signals into the WiFi signal for transmission, and the generated signal is received and decoded by multiple commercial Internet of Things devices; the method includes the following steps:

[0043] Through the CCK symbol synchronization mechanism, the wireless heterogeneous signals are uniformly upsampled to the same sampling rate, making the wireless heterogeneous signals compatible with Wi-Fi constraints;

[0044] A compensation carrier is generated based on the estimated frequency offset, and different wireless heterogeneous signals are subjected to frequency band migration according to the compensation carrier, so as to place different signals on different carrier frequencies. The wireless heterogeneous signals with different carrier frequencies are directly added in the time domain to obtain a mixed signal;

[0045] The mixed signal is subjected to reverse engineering simulation to obtain a Wi-Fi signal carrying information of multiple wireless devices. The Wi-Fi signal is scrambled, and the scrambled bit stream is converted into a radio frequency signal through a CCK modulator and sent through an antenna.

[0046] This embodiment adopts the CCK modulation technology in the 802.11b standard, and the core is to encode data through complementary codewords. Each CCK codeword consists of 32 complex chips and is generated through 4 phase parameters and satisfies:

[0047]

[0048] In the standard CCK codebook, The value of is restricted by the differential coding rule. Each codeword carries 8 bits of information. The 8-bit data is mapped to a complementary code sequence with a 11 MHz bandwidth. The anti-noise performance is enhanced through the spread spectrum technology (DSSS) - each CCK symbol consists of 11 chips, which are multiplied element by element with a pseudo-noise (PN) sequence, and the spectrum width is extended to 11 MHz to achieve a rate of 11 Mbps.

[0049] LoRa is designed specifically for ultra-low power wide area networks and adopts the CSS technology. The bandwidth is extended through a "chip" signal with linearly changing frequency to improve the anti-interference ability. Its core parameters include BW, SF, and symbol rate. In the modulation process, the baseband data is converted into a chip signal with a linearly increasing frequency over time, and then the spectrum characteristics are improved through a Gaussian filter. During demodulation, the receiving end uses the fast Fourier transform (FFT) to capture the instantaneous frequency of the chip signal, extracts the symbol information through a matched filter, and finally restores the original data through a decoder.

[0050] Zigbee is based on the IEEE 802.15.4 standard and features low power consumption and self-organizing networking. Its modulation technology focuses on frequency-shift keying (FSK) and phase-shift keying (PSK): in the 2.4GHz band, FSK is used at a data rate of 250kbps, and 0 / 1 is represented by the frequency offset (+15kHz or -15kHz); in the Sub-1GHz band, PSK is used, and modulation is achieved through phase changes (180° or 0°). During demodulation, the receiving end extracts the modulated signal through mixing and filtering, and then restores the original bit stream through phase comparison or frequency counting.

[0051] The modulation technology of BLE is mainly Gaussian frequency-shift keying (GFSK). The modulation process includes: adding a preamble and a check field after data grouping, generating a baseband signal through IQ modulation, and then up-converting it to the 2.4GHz band. During demodulation, the receiving end uses a phase-locked loop (PLL) to track the carrier frequency, restores the symbols through coherent demodulation, and corrects transmission errors through forward error correction (FEC). BLE supports two modes: broadcast and connection. In the experiment, the broadcast channel is used for reception to avoid the problem of frequency hopping.

[0052] See Figure 1 , this embodiment proposes a parallel communication based on multi-carrier symbol design, aiming to achieve direct communication from WiFi to various Internet of Things devices. By combining multiple wireless signals in the WiFi signal and sending them together, the generated signal can be received and decoded by multiple commercial Internet of Things devices. WIOT uses the CCK symbol synchronization mechanism to unify the sampling rate of heterogeneous signals to 44MHz, ensuring compatibility with Wi-Fi constraints, and migrating the different wireless signals to different frequency bands according to the compensated carrier to obtain a mixed signal. Then, the mixed signal is reverse-engineered and simulated to obtain a WiFi signal carrying the information of multiple wireless devices.

[0053] The principle of the parallel transmission method in this embodiment will be elaborated in detail below.

[0054] In this embodiment, the hardware used includes: the general software radio USRP B210, the CC2650 equipped with Zigbee and BLE modules, and the commercial Lora device equipped with SX1280. In this embodiment, multiple Internet of Things signals are simulated through the CCK physical layer to obtain the corresponding mixed signal, and the USRP B210 is used to select the 802.11b mode for transmission, and parameters such as the center frequency and transmission power are adjusted. In this embodiment, Lora and Zigbee are used for reception at the same time, and the simulation and performance are verified.

[0055] I. Multi-carrier symbol design

[0056] Before the WiFi simulation, prepare the signals to be simulated. The multi-carrier symbol design is part of the reverse engineering work, and this process is mainly divided into two parts. The first step is to adjust their sampling rates and align the symbols. Since different wireless devices use different bandwidths, their sampling rates are also different. Before performing reverse engineering, it is necessary to unify their sampling rates. Therefore, find the least common multiple according to the sampling rate of WiFi and upsample them to 44Mhz uniformly to ensure that the starting waveform is aligned with the subsequent alignment process. In the symbol alignment part, pad with zeros to make the total length an integer multiple of 32 to ensure that it can be divided into complete CCK symbols. The second step is carrier compensation. Based on the estimated frequency offset f off Generate the compensation carrier And multiply it point by point with the received signal to complete the frequency band migration:

[0057] s compensated (t) = s received (t)·c(t)

[0058] To ensure real-time performance, the compensation process uses the Overlap-Add (OLA) technique to avoid signal reconstruction delay. Place different signals on different carrier frequencies, and there needs to be isolation between the carriers, otherwise interference will occur between different signals. The selection basis of the carrier frequency is:

[0059]

[0060] Segment the generated carrier waveform according to the cck symbols to ensure that each symbol is independently modulated. Since the number of symbols between different wireless signals may be different, pad zeros at the end of the signal with fewer symbols to make their lengths the same. Padding zeros only extends the time-domain waveform and does not change its frequency-domain characteristics. The receiving end can ignore these invalid signals through the protocol identifier. Directly add the wireless signals with different carrier frequencies in the time domain and use the superposition principle of linear systems to achieve signal mixing. Since the spectra of the two signals are separated, the total power after superposition is close to the sum of the powers of each signal. In this way, a signal containing the superposition of signals from multiple wireless devices can be obtained.

[0061] II. Reverse Engineering Design

[0062] During wireless communication, various communication devices usually adopt different modulation schemes due to different communication protocols. However, in order to enable simulation of communication between WiFi and Internet of Things (IoT) devices, the constraints of both aspects must be considered. First is the limitation of CCK modulation. When WiFi transmits simulated IoT signals, the frequency range and duration between them must match the receiving end. For CCK modulation in the 11Mbps mode, WiFi must simulate a single continuous waveform with the maximum time length. The duration of CCK codewords is different from that of symbols such as ZigBee, BLE, and Lora. Specifically, for 802.11b with a bandwidth of 11MHz, each CCK codeword consists of 8 chips and has a duration of 1 / 11 μs. The symbol words of IoT devices require a longer time, so more CCK codewords are needed to establish a mapping table between the signal and the CCK cluster to achieve simulation of the phase sequence. Assuming that arbitrary valid QPSK chips can be generated, then an appropriate chip sequence can be selected to change the frequency of the output waveform by reducing the rate of phase change. Briefly, by setting multiple consecutive chips to the same phase, the phase change slope can be controlled through the formula:

[0063]

[0064] where k is the repetition coefficient, and T symbol is the target symbol duration. Based on this research, CCK modulation can be used to generate 11MHz IoT signals. The core of WIOT is to find the optimal WiFi payload through reverse engineering technology. Assume that the signal received by the wireless device is a standard and known signal. Protocols such as 802.11b that adopt CCK modulation require some signal processing to recover the original data bits of the WiFi transmitter. The purpose of this embodiment is to perform reverse engineering on the target signal, obtain the data bits of the IoT device after WiFi decoding through a series of operations such as descrambling and demapping, and then perform forward modulation and transmission based on the data bits. Through such a process, the transmitted WiFi signal will have similar characteristics to the signal waveform of the wireless device. Figure 2 Schematic diagram of the reverse engineering design principle.

[0065] III. IEEE 802.11b Transmission

[0066] Starting from the acquisition of data bits through reverse engineering, the 802.11b then performs a series of operations on the original data bits and sends them. These data bits are first processed by a scrambler to eliminate the DC bias and spectral non-uniformity caused by long consecutive 0 or 1 sequences in the data. The scrambled bit stream is converted into a radio frequency signal through a CCK modulator. CCK is the modulation method used by IEEE 802.11b, which achieves high-speed transmission by mapping data to the phase states of complementary code sequences. Each CCK symbol corresponds to 8 original data bits, and these data bits are divided into two groups, corresponding to the selection of two complementary codes respectively. The final modulation symbol is determined by the linear combination of the two complementary codes, forming four phase states corresponding to the constellation diagram. Each phase state corresponds to a specific baseband waveform, and the final composite signal is generated through I / Q modulation. The modulated symbols need to be further enhanced in anti-jamming ability through CCK spread spectrum. The spread spectrum expands the spectrum of each symbol to a wider bandwidth. During the spread spectrum process, a pseudo-noise sequence is generated, and its generation method is as follows:

[0067]

[0068] Each CCK symbol is multiplied element by element with the PN sequence to generate a spread spectrum symbol sequence with a length of 11. Finally, it is processed by the baseband module and converted into a radio frequency signal, and finally sent through the antenna.

[0069] IV. Decoding Preprocessing of IoT Devices

[0070] The first step in signal demodulation is to preprocess the received signal to eliminate the influence of noise interference and channel distortion. Low-pass filtering is the core step of preprocessing: Since IoT devices operate in the 2.4G ISM band, WiFi signals and other radio frequency interferences will seriously submerge narrowband IoT signals. Therefore, the device needs to pass through a low-pass filter before demodulation to filter out components higher than the target signal bandwidth. For example, for LoRa nodes, the cut-off frequency of the filter can be set to 1.625 MHz + Δ (Δ is the guard band width, usually taken as 5 - 10 kHz), so that the corresponding LoRa signal can be extracted from the simulated mixed signal. This process can be achieved through frequency domain filtering of the fast Fourier transform (FFT) and inverse FFT (IFFT): After decomposing the received signal into the frequency domain, the spectral components within the target frequency band are retained and then converted back to the time domain. After preprocessing the signal, the desired data information is obtained through the normal demodulation process. Figure 3 Schematic diagram of decoding for IoT device side.

[0071] Although the preferred embodiments of the present application have been described, additional changes and modifications can be made to these embodiments by those skilled in the art once they learn of the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications that fall within the scope of the present application.

[0072] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these modifications and variations.

Claims

1. A parallel transmission method from WiFi to LoRa, Bluetooth and ZigBee based on cross-protocol communication, characterized in that: The method combines multiple wireless heterogeneous signals into a WiFi signal and sends them together, and the generated signal is received and decoded by multiple commercial IoT devices; the method includes the following steps: Through the CCK symbol synchronization mechanism, wireless heterogeneous signals are uniformly upsampled to the same sampling rate, making wireless heterogeneous signals compatible with Wi-Fi constraints; A compensation carrier is generated based on the estimated frequency offset, and different wireless heterogeneous signals are frequency-band migrated according to the compensation carrier, so that different signals are placed on different carrier frequencies. The wireless heterogeneous signals generated with different carrier frequencies are directly added in the time domain to obtain a mixed signal. The mixed signal is simulated through reverse engineering to obtain a WiFi signal carrying information of multiple wireless devices. The WiFi signal is scrambled, and the scrambled bit stream is converted into a radio frequency signal through a CCK modulator and sent through an antenna.

2. The parallel transmission method from WiFi to LoRa, Bluetooth and ZigBee based on cross-protocol communication according to claim 1, characterized in that: The process of uniformly upsampling wireless heterogeneous signals to the same sampling rate through the CCK symbol synchronization mechanism includes the following steps: According to the sampling rate of WiFi, the common multiples of different wireless heterogeneous signals are calculated and they are uniformly upsampled to the same sampling rate. By padding with 0, the total length of all wireless heterogeneous signals becomes an integer multiple of 32.

3. The parallel transmission method from WiFi to LoRa, Bluetooth and ZigBee based on cross-protocol communication according to claim 1, characterized in that: The process of generating a compensation carrier based on the estimated frequency offset and completing frequency band migration of different wireless heterogeneous signals according to the compensation carrier includes the following steps: Based on the estimated frequency offset f off Generate Compensation Carrier And multiply it point by point with the received signal to complete the frequency band migration: s compensated (t)=s received (t)·c(t) In the formula, s received (t) is the initial wireless signal, s compensated (t) is the signal after shifting; The carrier frequency is selected based on: in are the center frequencies of two different carriers, are the bandwidths of the two signals respectively.

4. The parallel transmission method from WiFi to LoRa, Bluetooth and ZigBee based on cross-protocol communication according to claim 1, characterized in that: The process of directly adding wireless heterogeneous signals generated with different carrier frequencies in the time domain to obtain a mixed signal includes the following steps: The generated carrier waveform is segmented according to the CCK symbol so that each symbol is modulated independently, and zeros are added to the end of the signal with fewer symbols to make the length consistent; The generated wireless heterogeneous signals with different carrier frequencies are directly added in the time domain, and the wireless heterogeneous signals are mixed using the superposition principle of linear systems to obtain a mixed signal containing the superposition of multiple wireless device signals. The total power after superposition approaches the sum of the powers of each wireless heterogeneous signal.

5. The parallel transmission method from WiFi to LoRa, Bluetooth and ZigBee based on cross-protocol communication according to claim 1, characterized in that: The process of reverse engineering a mixed signal to obtain a WiFi signal carrying information of multiple wireless devices includes the following steps: Reverse engineering is used on the mixed signal to perform correlation operations on the pseudo-random code interference of Wi-Fi through a known pseudo-random code template, and the scrambling operation is reversed to restore the original modulation symbol. According to the codeword mapping rules of CCK modulation in the IEEE 802.11b standard, a reverse lookup table is constructed to restore the received symbols to the original data bits of the IoT device, where each CCK codeword consists of multiple chips. Multiple consecutive chips are set to the same phase, and the frequency of the output waveform is changed by reducing the rate of phase change, so as to establish a mapping table between the signal and the CCK cluster based on the CCK codeword to simulate the phase sequence; specifically, the phase change slope is controlled by the following formula: Where φ(n) is the nth chip phase value, φ0 is the initial phase, n is the current chip number, k is the repetition coefficient, T symbol is the target symbol duration.

6. The parallel transmission method from WiFi to LoRa, Bluetooth and ZigBee based on cross-protocol communication according to claim 1, characterized in that: The process of scrambling the WiFi signal and converting the scrambled bit stream into a radio frequency signal through a CCK modulator includes the following steps: Scramble the original data bits of the WiFi signal to eliminate long continuous sequences of 0 or 1 in the data; The scrambled bit stream is converted into a radio frequency signal through a CCK modulator; specifically, each CCK symbol corresponds to 8 original data bits, which are divided into two groups, corresponding to the selection of two complementary codes. The final modulation symbol is determined by the linear combination of the two complementary codes, forming four phase states of the corresponding constellation diagram. Each phase state corresponds to a baseband waveform, and the final composite signal is generated through I / Q modulation.

7. The parallel transmission method from WiFi to LoRa, Bluetooth and ZigBee based on cross-protocol communication according to claim 6, characterized in that: The modulation symbols are spread spectrum processed so that the spectrum of each modulation symbol is expanded to a wider bandwidth; specifically, the pseudo noise sequence is generated by the following formula: s n =s n-1 ⊕s n-10 Where s n is the spreading sequence at time n, s n-1 is the spreading code chip at the previous moment, s n-10 It is the spread spectrum code chip at the 10th moment before. Each modulation symbol is multiplied element by element with the pseudo noise sequence to generate a spread spectrum symbol sequence with a length of 11. Finally, the spread spectrum symbol sequence is processed by the baseband module and converted into a radio frequency signal, which is sent through the antenna.

8. The parallel transmission method from WiFi to LoRa, Bluetooth and ZigBee based on cross-protocol communication according to claim 1, characterized in that: The demodulation process of the radio frequency signal includes: The received RF signal is decomposed into the frequency domain, and the components higher than the target signal bandwidth are filtered out through a low-pass filter to retain the spectral components within the target frequency band. The retained spectral components are then converted back to the time domain and demodulated to obtain the corresponding data information.

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