A method and device for realizing coexistence of ZigBee signal and WiFi signal

Abstract

The present disclosure provides a method for achieving coexistence of ZigBee signals and WiFi signals, which includes: receiving a mixed signal, wherein the mixed signal is composed of a WiFi signal and a ZigBee signal, detecting an interference pattern of the mixed signal, wherein the interference pattern includes a WiFi signal with a complete preamble code, a ZigBee signal with a complete preamble code, and a signal without a complete preamble code, and separating the WiFi signal and the ZigBee signal from the mixed signal based on each interference pattern, thereby achieving harmonious coexistence of the ZigBee signal and the WiFi signal without making any changes to the terminal nodes of the ZigBee and WiFi networks.

Description

Technical Field

[0001] The present disclosure relates to the field of communication technology, and more specifically, to a method and device for achieving coexistence of ZigBee signals and WiFi signals. Background Art

[0002] In recent years, with the advancement of the "Smart City" plan, urban wireless sensor networks have become crucial. Urban wireless sensor networks complete environmental monitoring tasks through the connection of sensor nodes and efficient networks. In most urban wireless sensor networks, ZigBee networks and WiFi networks often coexist. However, due to the characteristics of WiFi signals, WiFi signals can easily interfere with the communication of ZigBee networks. At the same time, related studies have also confirmed that the communication of WiFi networks will also be interfered by ZigBee signals.

[0003] Existing network coexistence solutions generally set the channels of each network terminal node so that WiFi signals and ZigBee signals occupy different channels. However, for urban wireless sensor networks with a large number of terminal nodes, it is very difficult and costly to modify the software or hardware of the terminal nodes. Moreover, even if they are interfered by ZigBee signals, most individual owners of WiFi network terminal nodes are unwilling to make any changes. At the same time, people hope to minimize the performance degradation caused by the coexistence of WiFi signals and ZigBee signals.

[0004] Public Content

[0005] In view of this, the present disclosure provides a method for achieving coexistence of ZigBee signals and WiFi signals, which includes: receiving a mixed signal, wherein the mixed signal is composed of a WiFi signal and a ZigBee signal; detecting an interference pattern of the mixed signal, wherein the interference pattern includes a WiFi signal with a complete preamble, a ZigBee signal with a complete preamble, and no complete preamble; and separating the WiFi signal and the ZigBee signal from the mixed signal based on each of the interference patterns.

[0006] Optionally, separating the WiFi signal and the ZigBee signal from the mixed signal based on each interference pattern respectively includes: when the interference pattern is that the WiFi signal preamble is complete, generating the WiFi signal channel parameter based on the WiFi signal preamble, removing the WiFi signal from the mixed signal by using interference nulling technology, and generating an interference-free ZigBee signal;

[0007] The interference-free ZigBee signal is demodulated to obtain the ZigBee signal channel parameters, and the ZigBee signal is regenerated based on the ZigBee signal channel parameters to perform interference elimination to obtain the interference-free WiFi signal.

[0008] Optionally, the WiFi signal and the ZigBee signal are separated from the mixed signal based on each interference pattern, including: when the interference pattern is that the ZigBee preamble code is complete, generating channel parameters of the ZigBee signal based on the ZigBee signal preamble code, removing the ZigBee signal in the mixed signal by using interference nulling technology, and generating an interference-free WiFi signal; demodulating the interference-free WiFi signal to obtain the WiFi signal channel parameters, and regenerating the WiFi signal based on the WiFi signal channel parameters to eliminate interference and obtain an interference-free ZigBee signal.

[0009] Optionally, the WiFi signal and the ZigBee signal are separated from the mixed signal based on each of the interference patterns, including: when the interference pattern is the one without a complete preamble code, recovering the WiFi signal channel parameters according to the channel parameters of the uninterfered subcarriers in the WiFi signal, removing the WiFi signal from the mixed signal by using interference nulling technology, and obtaining an interference-free ZigBee signal; demodulating the interference-free ZigBee signal to obtain the ZigBee signal channel parameters, regenerating the ZigBee signal based on the ZigBee signal channel parameters, performing interference elimination, and obtaining an interference-free WiFi signal.

[0010] Optionally, detecting the interference mode of the mixed signal includes: performing a fast Fourier transform on the sampled value of the mixed signal to obtain the carrier energy of the mixed signal, and when the energy of the subcarrier is greater than a preset threshold, it is a valid subcarrier; detecting whether the valid subcarrier contains the ZigBee signal or the WiFi signal; and obtaining different interference modes according to the detection results of detecting the complete preamble of the WiFi signal and the complete preamble of the ZigBee signal. Wherein, when the mixed signal contains the WiFi signal preamble, the interference mode is that the WiFi signal preamble is complete; when the mixed signal contains the ZigBee signal preamble, the interference mode is that the ZigBee preamble is complete; when the mixed signal does not contain the ZigBee signal preamble and the WiFi signal preamble, the interference mode is that there is no complete preamble.

[0011] Optionally, after detecting whether the effective subcarrier includes a preamble code of a ZigBee signal or a WiFi signal, it also includes: determining the starting positions of the ZigBee signal and the WiFi signal in the mixed signal; wherein, for the WiFi signal, the starting position of the WiFi signal in the mixed signal is detected by autocorrelation, and after frequency offset estimation and compensation are performed on the WIFI signal, the starting position of the WiFi signal in the mixed signal is cross-correlated with a long training sequence to determine the precise starting position of the WiFi signal; for the ZigBee signal, the starting position of the ZigBee signal in the mixed signal is detected by autocorrelation, and after frequency offset estimation and compensation are performed on the ZigBee signal, the starting position of the ZigBee signal in the mixed signal is cross-correlated with a frame start symbol to determine the precise starting position of the ZigBee signal.

[0012] Optionally, after detecting the interference pattern of the mixed signal, the method further includes: performing spectrum shifting and merging of the WiFi signal and the ZigBee signal based on center frequency deviations of the WiFi signal and the ZigBee signal.

[0013] Optionally, after separating the WiFi signal and the ZigBee signal from the mixed signal based on each of the interference patterns, the method further includes: demodulating the WiFi signal, wherein the demodulating the WiFi signal includes accurately estimating and compensating for the WiFi signal's frequency offset, and demodulating the ZigBee signal, wherein the demodulating the ZigBee signal includes performing frequency offset estimation and compensation, phase recovery, sampling error recovery, and OQPSK demodulation on the ZigBee signal.

[0014] On the other hand, the present disclosure further provides a device for realizing coexistence of ZigBee signals and WiFi signals, which includes: a receiving module, used to receive and sample a mixed signal, wherein the mixed signal is composed of a WiFi signal and a ZigBee signal; an interference pattern detection module, used to detect the interference pattern of the mixed signal, wherein the interference pattern includes a WiFi signal with a complete preamble code, a ZigBee signal with a complete preamble code, and a device without a complete preamble code; and a separation module, used to demodulate the WiFi signal and the ZigBee signal respectively based on each interference pattern.

[0015] The present disclosure provides a method for realizing coexistence of ZigBee signals and WiFi signals, wherein the demodulation module further comprises: a first interference mode separation unit, which is used to generate the WiFi signal channel parameters based on the WiFi signal preamble code when the interference mode is that the WiFi signal preamble code is complete, and to remove the WiFi signal in the mixed signal by using the interference nulling technology to generate an interference-free ZigBee signal; demodulate the interference-free ZigBee signal to obtain the ZigBee signal channel parameters, regenerate the ZigBee signal based on the ZigBee signal channel parameters and perform interference elimination to obtain an interference-free WiFi signal; and a second interference mode separation unit, which is used to generate the ZigBee signal channel parameters based on the ZigBee signal preamble code when the interference mode is that the WiFi signal preamble code is complete, and to remove the WiFi signal in the mixed signal by using the interference nulling technology to generate an interference-free WiFi signal; The ZigBee signal in the mixed signal is removed by using a nulling technology to generate an interference-free WiFi signal; the WiFi signal without interference is demodulated to obtain the WiFi signal channel parameters, the WiFi signal is regenerated based on the WiFi signal channel parameters and interference elimination is performed to obtain an interference-free ZigBee signal; a third interference mode separation unit is used to restore the WiFi signal channel parameters according to the channel parameters of the non-interfered subcarriers in the WiFi signal when the interference mode is the one without a complete preamble code, and the WiFi signal in the mixed signal is removed by using an interference nulling technology to obtain an interference-free ZigBee signal; the ZigBee signal without interference is demodulated to obtain the ZigBee signal channel parameters, the ZigBee signal is regenerated based on the ZigBee signal channel parameters to perform interference elimination and obtain an interference-free WiFi signal.

[0016] The spatial light omnidirectional receiving method and device provided by the present disclosure have at least the following advantages:

[0017] (1) By designing a device that enables the coexistence of ZigBee signals and WiFi signals, WiFi signals and ZigBee signals can coexist harmoniously without making any changes to the terminal nodes of the ZigBee and WiFi networks.

[0018] (2) By separating ZigBee signals from WiFi signals, the mutual interference problem between ZigBee signals and WiFi signals is solved. At the same time, by judging different interference modes, the signal separation steps can be simplified and the network throughput can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of a device application scenario in which ZigBee signals and WiFi signals coexist according to an embodiment of the present disclosure is schematically shown;

[0020] Figure 2 A method for coexistence of ZigBee signals and WiFi signals according to an embodiment of the present disclosure is schematically shown;

[0021] Figure 3 A schematic diagram of a device module for coexistence of ZigBee signals and WiFi signals according to an embodiment of the present disclosure is shown;

[0022] Figure 4 Schematically shows a schematic diagram of a separation module according to an embodiment of the present disclosure;

[0023] Figure 5 Schematically shows a mixed signal spectrum diagram according to an embodiment of the present disclosure;

[0024] Fig. 6A Schematically showing the detection result when frequency offset compensation is not performed according to an embodiment of the present disclosure;

[0025] Figure 6B The detection result after frequency offset compensation according to the embodiment of the present disclosure is schematically shown;

[0026] Fig. 7A The amplitude of the channel parameter of a WiFi signal interfered by a ZigBee signal according to an embodiment of the present disclosure is schematically shown;

[0027] Figure 7B The phase of the channel parameter of a WiFi signal interfered by a ZigBee signal according to an embodiment of the present disclosure is schematically shown;

[0028] Fig. 8A The WiFi signal channel parameter recovery result according to the embodiment of the present disclosure is schematically shown;

[0029] Figure 8B The result of accurately estimating the frequency deviation of a WiFi signal according to an embodiment of the present disclosure is schematically shown. DETAILED DESCRIPTION

[0030] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present disclosure. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0031] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise", "include", etc. used herein indicate the existence of features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0032] Figure 1 A schematic diagram of a device application scenario in which ZigBee signals and WiFi signals coexist according to an embodiment of the present disclosure is schematically shown.

[0033] The ZigBee terminal node 101 is used to receive ZigBee signals, and the WiFi terminal node 102 is used to receive WiFi signals. Since there is mutual interference between ZigBee signals and WiFi signals, the signals received by the ZigBee terminal node 101 and the WiFi terminal node 102 are mixed signals after interference.

[0034] In order to eliminate interference in the signal, a device 100 for realizing coexistence of ZigBee signals and WiFi signals is now designed, which is used to receive signals from ZigBee terminal nodes 101 and WiFi terminal nodes 102. The device 100 for realizing coexistence of ZigBee signals and WiFi signals processes the above mixed signals to separate ZigBee signals and WiFi signals, remove mutual interference between the two signals, and realize harmonious coexistence of ZigBee signals and WiFi signals.

[0035] The present disclosure does not require any changes to the terminal nodes of the ZigBee and WiFi networks. It only requires designing a device 100 that enables the coexistence of ZigBee signals and WiFi signals, so as to achieve harmonious coexistence of WiFi signals and ZigBee signals.

[0036] Figure 2 A method for coexistence of ZigBee signals and WiFi signals according to an embodiment of the present disclosure is schematically shown. The method includes S201 to S203.

[0037] Operation S201: receiving a mixed signal, where the mixed signal consists of a WiFi signal and a ZigBee signal.

[0038] According to the embodiment of the present disclosure The data of WiFi signal, is the data of the ZigBee signal at time t. The mixed signal received at time t can be expressed as:

[0039] (1)

[0040] Among them, H W is the WiFi channel parameter, HZ is the ZigBee channel parameter, is the center frequency deviation of WiFi and ZigBee signals, n(t) is the noise, and j is the imaginary unit. , is the ratio of pi, which is 3.14…, and e is a mathematical constant, which is the base of the natural logarithm function, 2.71…. The mixed signal spectrum is shown in Figure 3 shown.

[0041] Operation S202: detecting an interference pattern of a mixed signal, wherein the interference pattern includes a WiFi signal with a complete preamble, a ZigBee signal with a complete preamble, and a signal with no complete preamble.

[0042] When a mixed signal is received, it is first necessary to identify which interference mode the mixed signal belongs to. The sampled values ​​of the mixed signal are subjected to a fast Fourier transform to obtain the energy of each subcarrier of the mixed signal. When the subcarrier energy is greater than a preset threshold, it is a valid subcarrier. For example, every 80 sampled values ​​are grouped together, and after removing the cyclic redundancy of the WiFi signal, a 64-point fast Fourier transform is performed, and then the energy on each subcarrier is detected. If the energy of the subcarrier is 5dB higher than the noise, it is considered that there is a signal on this subcarrier, and this subcarrier is a valid subcarrier.

[0043] Detect whether the effective subcarrier contains ZigBee signal or WiFi signal. Different interference modes are obtained according to the relevant detection results of WiFi signal preamble and ZigBee signal preamble. Among them, when the mixed signal contains WiFi signal preamble, the interference mode is that the WiFi signal preamble is complete; when the mixed signal contains ZigBee signal preamble, the interference mode is that the ZigBee preamble is complete; when the mixed signal does not contain ZigBee signal preamble and WiFi signal preamble, the interference mode is that there is no complete preamble.

[0044] At the same time, it is also necessary to determine the starting positions of the ZigBee signal and the WiFi signal in the mixed signal. Accurate signal boundary detection helps the subsequent signal separation work.

[0045] Because the preambles of WiFi and ZigBee signals have the characteristic of repetition, the signal boundary detection can be completed by autocorrelation. However, autocorrelation can only be used to detect the preambles that are not interfered with. When WiFi and ZigBee signals interfere with each other, the preamble of the signal that arrives later is interfered with, so the signal starting position cannot be detected by the autocorrelation method.

[0046] For WiFi signals, the starting position of the WiFi signal in the mixed signal is detected by autocorrelation. After the frequency offset of the WiFi signal is estimated and compensated, the starting position of the WiFi signal in the mixed signal is cross-correlated with the long training sequence to determine the precise starting position of the mixed signal.

[0047] For ZigBee signals, the starting position of the ZigBee signal in the mixed signal is detected by autocorrelation. After the frequency offset of the ZigBee signal is estimated and compensated, the starting position of the ZigBee signal in the mixed signal is cross-correlated with the frame start symbol to determine the precise starting position of the mixed signal.

[0048] According to the embodiment of the present disclosure, after performing autocorrelation detection on the mixed signal, the approximate starting position of the frame is detected, and it is not affected by the frequency deviation. In order to detect the precise starting position. The method of cross-correlating the received signal with the known sequence is used to realize signal boundary detection. In order to reduce the influence of frequency deviation on cross-correlation, it is necessary to estimate and compensate the frequency deviation of the signal first, and then perform the cross-correlation operation. Fig. 6A and Figure 6B The effect of frequency offset compensation on the detection of the starting position is compared. It can be seen from the figure that frequency offset compensation can significantly improve the robustness of the detection of the starting position.

[0049] According to the embodiment of the present disclosure, spectrum shifting and merging are also required, because a wideband RF front end is used to simultaneously receive a mixed signal consisting of WiFi signals and ZigBee signals, and it is necessary to perform spectrum shifting and merging of WiFi signals and ZigBee signals based on the center frequency deviation of WiFi and ZigBee signals, and move the WiFi and ZigBee signals to the corresponding center frequencies respectively, and then perform corresponding processing.

[0050] In operation S203 , the WiFi signal and the ZigBee signal are respectively separated from the mixed signal based on the interference patterns.

[0051] According to the embodiments of the present disclosure, different separation means may be used to separate WiFi signals and ZigBee signals according to various interference patterns.

[0052] When the interference mode is that the WiFi signal preamble is complete, the WiFi signal channel parameters are generated based on the WiFi signal preamble, and the WiFi signal in the mixed signal is removed by interference nulling technology to generate an interference-free ZigBee signal. The interference-free ZigBee signal is demodulated to obtain the ZigBee signal channel parameters, and the ZigBee signal is regenerated based on the ZigBee signal channel parameters to perform interference elimination and obtain an interference-free WiFi signal.

[0053] When the interference mode is that the ZigBee preamble is complete, the channel parameters of the ZigBee signal are generated based on the ZigBee signal preamble, and the ZigBee signal in the mixed signal is removed by using the interference nulling technology to generate an interference-free WiFi signal; the interference-free WiFi signal is demodulated to obtain the WiFi signal channel parameters, and the WiFi signal is regenerated based on the WiFi signal channel parameters to perform interference elimination to obtain an interference-free ZigBee signal.

[0054] When the interference mode is without a complete preamble, the WiFi signal channel parameters are restored according to the channel parameters of the non-interfered subcarriers in the WiFi signal, and the WiFi signal in the mixed signal is removed by using the interference nulling technology to obtain an interference-free ZigBee signal; the interference-free ZigBee signal is demodulated to obtain the ZigBee signal channel parameters, and the ZigBee signal is regenerated based on the ZigBee signal channel parameters to perform interference elimination to obtain an interference-free WiFi signal.

[0055] Now, taking the complete preamble signal separation process in a mixed signal as an example, the separation method provided by the present disclosure is specifically described.

[0056] When the interference mode is without a complete preamble, it is necessary to first restore the WiFi signal channel parameters based on the channel parameters of the uninterrupted subcarriers in the WiFi signal, and use the interference nulling technology to remove the WiFi signal from the mixed signal. In order to better eliminate the WiFi signal, the WiFi data is used to accurately estimate the frequency deviation of the WiFi signal, thereby obtaining a better interference elimination effect. Figure 8B It can be seen that the phase of the WiFi signal after frequency offset compensation still changes linearly. Therefore, we use linear approximation to reduce the impact of noise to improve the accuracy of frequency offset estimation. At the same time, for WiFi and ZigBee signals using heterogeneous technology systems, due to the differences in the time, space and frequency characteristics of WiFi and ZigBee signals, the WiFi signal may be completely interfered in time, while only some subcarriers are interfered in frequency. From the frequency domain, WiFi signals and ZigBee signals overlap only in some frequencies, such as Fig. 7A and Figure 7B As shown in Figure 1. Since ZigBee is a narrowband signal and WiFi is a broadband signal, the WiFi channel parameters of the interfered subcarriers can be estimated by the WiFi channel parameters of the non-interfered subcarriers. The channel parameters of the interfered subcarriers are interpolated by a quartic polynomial. The interpolation result is shown in Figure 1. Fig. 8A As shown. Fig. 8A It can be seen that the interference from the ZigBee signal has been weakened and the WiFi channel parameters have been restored.

[0057] The above method can not only obtain the complete WiFi signal channel parameters, but also obtain the interference-free ZigBee signal from the mixed signal by setting the WiFi signal interference to zero.

[0058] The mixed signal is shown in equation (1). By demodulating the interference-free ZigBee signal, the ZigBee signal channel parameters can be obtained. The ZigBee signal can be regenerated based on the ZigBee signal channel parameters as shown in the following equation:

[0059] (2)

[0060] It is possible to remove the ZigBee signal from the mixed signal and obtain the WiFi signal:

[0061] (3)

[0062] According to the embodiment of the present disclosure, it is also necessary to demodulate the WiFi signal and the ZigBee signal respectively.

[0063] The demodulation of WiFi signals includes accurate frequency offset estimation and compensation of WiFi signals.

[0064] The demodulation of ZigBee signals includes frequency offset estimation and compensation, phase recovery, sampling error recovery and OQPSK demodulation of ZigBee signals.

[0065] Since the frequency deviation of ZigBee nodes can reach up to 200KHz, it is necessary to estimate and compensate for the frequency deviation of ZigBee signals.

[0066] The OQPSK modulation used by ZigBee signals is expressed as:

[0067] (4)

[0068] in, is the modulation sequence number, is the frequency deviation, is the phase deviation, n is the code element number, A n is the amplitude of the nth code element, j is the imaginary unit, that is, , is the ratio of pi, which is 3.14…, and e is a mathematical constant, which is the base of the natural logarithm function, 2.71…. According to the above formula, the received signal is affected by modulation, frequency deviation and phase deviation. In order to remove the influence of modulation, we will raise the received signal to the fourth power, that is:

[0069] (5)

[0070] Then, the modulation-independent signal is subjected to fast Fourier transform to obtain a 4-fold frequency deviation.

[0071] Compensate the signal using the above estimation:

[0072] (6)

[0073] According to the embodiment of the present disclosure, the sampling frequency f s =2MHz, the number of fast Fourier transform points is 2048. The minimum frequency deviation that can be estimated is 244.14 Hz, and the maximum frequency deviation is 250 kHz.

[0074] After the frequency offset compensation of the ZigBee signal, the ZigBee signal needs to be phase recovered and sampled back based on a phase-locked loop before it can be demodulated using OQPSK to obtain the ZigBee signal.

[0075] According to the embodiment of the present disclosure, a phase-locked loop (PLL) is used to recover the sampling deviation of the received signal. The sampling recovery module gives an output value for every two input values, and the output value is the signal after sampling recovery.

[0076] Based on the digital oscillator control submodule, an interpolation position is selected, and the sampling error detection submodule is controlled to detect the sampling error, and the interpolation position selected by the digital oscillator control submodule is updated based on the sampling error. Among them, the digital control oscillator control submodule updates the output of the interpolation filter. The sampling error is detected by the oversampling error detector. The sampling error is input to the digital control oscillator control submodule after passing through an adjustable proportional integral loop filter. The loop bandwidth and loop damping factor of the loop filter are both adjustable. According to the embodiment of the present disclosure, the loop bandwidth and the loop damping factor are set to 0.07 and 2 respectively to achieve fast locking and reduce sampling error.

[0077] Figure 3 A device for realizing coexistence of ZigBee signals and WiFi signals according to an embodiment of the present disclosure is schematically shown. The device comprises: a receiving module (310), an interference pattern detection module (320), a separation module (330) and a demodulation module (340).

[0078] A receiving module (310), used for receiving and sampling a mixed signal, wherein the mixed signal is composed of a WiFi signal and a ZigBee signal;

[0079] An interference pattern detection module (320) is used to detect the interference pattern of the mixed signal, wherein the interference pattern includes a WiFi signal with a complete preamble, a ZigBee signal with a complete preamble, and a signal with no complete preamble;

[0080] The separation module (330) is used to demodulate the WiFi signal and the ZigBee signal respectively based on each interference pattern.

[0081] According to the embodiment of the present disclosure, Figure 4 As shown, the separation module (330) also includes a first interference mode separation unit (331), a second interference mode separation unit (332) and a third interference mode separation unit (333). The first interference mode separation unit (331) is used to generate the WiFi signal channel parameters based on the WiFi signal preamble when the interference mode is that the WiFi signal preamble is complete, and to remove the WiFi signal in the mixed signal by using the interference nulling technology to generate the ZigBee signal; the second interference mode separation unit (332) is used to generate the ZigBee signal channel parameters based on the ZigBee signal preamble when the interference mode is that the ZigBee preamble is complete, and to remove the ZigBee signal in the mixed signal by using the interference nulling technology to generate the WiFi signal; the third interference mode separation unit (333) is used to restore the WiFi signal channel parameters according to the channel parameters of the uninterfered subcarriers in the WiFi signal when the interference mode is that there is no complete preamble, and to eliminate the WiFi signal in the mixed signal by using the interference nulling technology to obtain the interference-free ZigBee signal. The interference-free ZigBee signal is demodulated, and interference elimination is performed according to the obtained ZigBee signal channel parameters to obtain an interference-free WiFi signal.

[0082] The demodulation module (340) is used to demodulate the WiFi signal and the ZigBee signal respectively.

[0083] Through a device that realizes the coexistence of ZigBee signals and WiFi signals, the coexistence of ZigBee signals and WiFi signals can be realized. Without making any changes to the terminal nodes of the ZigBee and WiFi networks, the harmonious coexistence of WiFi signals and ZigBee signals can be achieved.

[0084] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present disclosure in detail. It should be understood that the above are only specific embodiments of the present disclosure and are not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. A method for achieving coexistence of ZigBee signals and WiFi signals, wherein: include: Receiving a mixed signal, wherein the mixed signal consists of a WiFi signal and a ZigBee signal; Detecting an interference pattern of the mixed signal, wherein the interference pattern includes a WiFi signal preamble complete, a ZigBee preamble complete, and no complete preamble; when the mixed signal includes a WiFi signal preamble, the interference pattern is a WiFi signal preamble complete; when the mixed signal includes a ZigBee signal preamble, the interference pattern is a ZigBee preamble complete; when the mixed signal does not include a ZigBee signal preamble and a WiFi signal preamble, the interference pattern is no complete preamble; Separating the WiFi signal and the ZigBee signal from the mixed signal based on each of the interference patterns; The separating the WiFi signal and the ZigBee signal from the mixed signal based on each interference pattern respectively includes: When the interference pattern is that the WiFi signal preamble is complete, generating WiFi signal channel parameters based on the WiFi signal preamble, removing the WiFi signal from the mixed signal by using interference nulling technology, and generating an interference-free ZigBee signal; Demodulate the interference-free ZigBee signal to obtain ZigBee signal channel parameters, regenerate the ZigBee signal based on the ZigBee signal channel parameters, perform interference elimination, and obtain an interference-free WiFi signal; When the interference mode is that the ZigBee preamble is complete, generate ZigBee signal channel parameters based on the ZigBee signal preamble, remove the ZigBee signal from the mixed signal using interference nulling technology, and generate an interference-free WiFi signal; Demodulating the interference-free WiFi signal to obtain WiFi signal channel parameters, regenerating the WiFi signal based on the WiFi signal channel parameters, performing interference elimination, and obtaining an interference-free ZigBee signal; When the interference mode is the one without a complete preamble, the WiFi signal channel parameters are restored according to the channel parameters of the non-interfered subcarriers in the WiFi signal, and the WiFi signal in the mixed signal is removed by using the interference nulling technology to obtain an interference-free ZigBee signal; The interference-free ZigBee signal is demodulated to obtain the ZigBee signal channel parameters, the ZigBee signal is regenerated based on the ZigBee signal channel parameters, interference is eliminated, and a WiFi signal without interference is obtained.

2. The method for coexistence of ZigBee signals and WiFi signals according to claim 1, wherein: According to the detection results of the complete preamble of the WiFi signal and the complete preamble of the ZigBee signal, different interference modes are obtained, which also include: Determine the starting positions of the ZigBee signal and the WiFi signal in the mixed signal; wherein, For the WiFi signal, autocorrelation is used to detect the starting position of the WiFi signal in the mixed signal, and after frequency offset estimation and compensation are performed on the WiFi signal, cross-correlation is performed between the starting position of the WiFi signal in the mixed signal and the long training sequence to determine the precise starting position of the WiFi signal; For the ZigBee signal, the starting position of the ZigBee signal in the mixed signal is detected by autocorrelation. After frequency offset estimation and compensation of the ZigBee signal, the starting position of the ZigBee signal in the mixed signal is cross-correlated with the frame start symbol to determine the precise starting position of the ZigBee signal.

3. The method for coexistence of ZigBee signals and WiFi signals according to claim 1, wherein: After detecting the interference pattern of the mixed signal, the method further includes: Based on the center frequency deviation of the WiFi signal and the ZigBee signal, the WiFi signal and the ZigBee signal are spectrum shifted and combined.

4. The method for coexistence of ZigBee signals and WiFi signals according to claim 1, wherein: After separating the WiFi signal and the ZigBee signal from the mixed signal based on each interference pattern, the method further includes: Demodulating the WiFi signal, including accurately estimating and compensating for the WiFi signal's frequency offset; Demodulating the ZigBee signal includes performing frequency offset estimation and compensation, phase recovery and sampling error recovery, and OQPSK demodulation on the ZigBee signal.

5. A device for realizing coexistence of ZigBee signals and WiFi signals, wherein: include: A receiving module, used for receiving a mixed signal, wherein the mixed signal is composed of a WiFi signal and a ZigBee signal; An interference mode detection module is used to detect the interference mode of the mixed signal, wherein the interference mode includes a WiFi signal preamble code that is complete, a ZigBee preamble code that is complete, and no complete preamble code; when the mixed signal includes a WiFi signal preamble code, the interference mode is a WiFi signal preamble code that is complete; when the mixed signal includes a ZigBee signal preamble code, the interference mode is a ZigBee preamble code that is complete; when the mixed signal does not include a ZigBee signal preamble code and a WiFi signal preamble code, the interference mode is no complete preamble code; A separation module, configured to separate the WiFi signal and the ZigBee signal from the mixed signal based on each interference pattern; A first interference pattern separation unit is configured to generate a WiFi signal channel parameter based on the WiFi signal preamble code when the interference pattern is that the WiFi signal preamble code is complete, remove the WiFi signal from the mixed signal by using an interference nulling technique, and generate an interference-free ZigBee signal; demodulate the interference-free ZigBee signal to obtain the ZigBee signal channel parameter, regenerate the ZigBee signal based on the ZigBee signal channel parameter, perform interference elimination, and obtain an interference-free WiFi signal; A second interference pattern separation unit is configured to generate the ZigBee signal channel parameters based on the ZigBee signal preamble when the interference pattern is that the ZigBee preamble is complete, remove the ZigBee signal from the mixed signal by using interference nulling technology, and generate an interference-free WiFi signal; demodulate the interference-free WiFi signal to obtain the WiFi signal channel parameters, regenerate the WiFi signal based on the WiFi signal channel parameters, perform interference elimination, and obtain an interference-free ZigBee signal; The third interference mode separation unit is used for, when the interference mode is the one without a complete preamble code, restoring the WiFi signal channel parameters according to the channel parameters of the non-interfered subcarriers in the WiFi signal, removing the WiFi signal from the mixed signal by using the interference nulling technology, and obtaining an interference-free ZigBee signal; demodulating the interference-free ZigBee signal to obtain the ZigBee signal channel parameters, regenerating the ZigBee signal based on the ZigBee signal channel parameters, performing interference elimination, and obtaining an interference-free WiFi signal.

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