LoRa channel hopping method and device based on WiFi backoff guard band

Abstract

The invention provides a LoRa channel hopping method and device based on a WiFi backoff guard band, and the method comprises the steps: constructing a channel quality model and an interference set based on an SINR and RSSI sequence obtained from a specified channel of each channel group; on the basis of the constructed channel quality model, a specified channel in the optimal WiFi protected channel group is selected for detection; if the channel quality is lower than a preset threshold value, identifying a WiFi working channel by adopting a sib-channel-based detection algorithm, and reselecting an available protected channel group; selecting a hopping target channel according to an interference set based on the selected protected channel group, configuring a spreading factor in combination with a node geographic position, and realizing dynamic scheduling of node transmission based on a WiFi traffic model; based on the configured transmission parameters, synchronization with the sending node is carried out, the target channel is continuously monitored at the same time, and the available channel group is reselected when the channel performance is reduced, so that the potential interference can be converted into a protection opportunity while the WiFi performance is not reduced, and the LoRa communication reliability and the spectrum utilization rate are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of cognitive radio networks, and in particular relates to a LoRa channel hopping method and device based on a WiFi backoff protection band. Background Art

[0002] Due to the existence of wireless technologies such as WiFi, ZigBee, and Bluetooth, LoRa deployed in the same unlicensed 2.4 GHz band may be severely affected by cross-technology interference (CTI). This is mainly due to the power asymmetry between LoRa and other wireless technologies and the relatively long transmission time of LoRa. In an environment where WiFi and LoRa coexist, the highest packet damage rate of LoRa devices can reach 94%. Therefore, WiFi interference has become the main bottleneck affecting the performance of LoRa networks.

[0003] To effectively alleviate the cross-technology interference problem, researchers have proposed various anti-interference solutions at the physical layer (PHY layer) and media access control layer (MAC layer) of LoRa networks. Due to the accessibility of physical layer information, existing physical layer solutions mainly focus on recovering damaged symbols. However, these methods rely on dedicated hardware platforms to capture IQ signals, which limits their wide application in practical scenarios. Existing MAC layer solutions mainly include WiFi spectrum reservation and payload encoding mechanisms. The WiFi spectrum reservation scheme avoids interference by identifying and allocating specific frequency bands, but this method reduces the available bandwidth of WiFi, thereby affecting its communication performance. Payload encoding, on the other hand, improves the reliability of data transmission through redundant encoding, but this method is limited by the inherent reliability limitations of the encoding scheme and is incompatible with existing commercial devices, resulting in significant challenges in actual deployment.

[0004] Channel hopping is an important MAC layer method that can be implemented on existing commercial LoRa devices by switching between different available channels without modifying the device hardware. This method effectively avoids cross-technology interference (CTI), does not affect the communication performance of WiFi, and does not require changing the payload structure of LoRa, thus ensuring the coexistence of LoRa and WiFi networks. Summary of the Invention

[0005] In view of this, the present invention aims to overcome the defects in the prior art and proposes a LoRa channel hopping method and device based on a WiFi backoff protection band.

[0006] To achieve the above object, the technical solution of the present invention is realized as follows:

[0007] The embodiments of the present invention provide a LoRa channel hopping method and apparatus based on a WiFi backoff protection band. The method includes the following steps:

[0008] Based on the SINR and RSSI sequences obtained on the designated channels of each channel group, construct a channel quality model and an interference set;

[0009] Based on the constructed channel quality model, select the designated channel in the optimal WiFi protected channel group for detection;

[0010] If its channel quality is lower than a preset threshold, use the sibling channel detection algorithm to identify the WiFi working channel and reselect an available protected channel group;

[0011] Based on the selected protected channel group, select the hopping target channel according to the interference set, configure the spreading factor in combination with the node geographical location, and at the same time implement dynamic scheduling of node transmission based on the WiFi traffic model;

[0012] Based on the configured transmission parameters, synchronize with the sending node, continuously monitor the target channel, and reselect an available channel group when the channel performance degrades.

[0013] According to one aspect of the present invention, the backoff protection band includes a backoff band and a protection band; the LoRa channels within the backoff band are called backoff channels, and the LoRa channels within the protection band are called protection channels; the protection band is a spectrum isolation band set between WiFi channels to avoid inter-channel interference, so as to reduce signal leakage and interference; the bandwidth of the protection band is set to 3MHz in the 802.11b standard and 5MHz in the 802.11g / n standard; when the WiFi signal passes through the protection band, its power will be significantly attenuated, and it is usually regarded as an idle spectrum area; except for WiFi channel 1 and WiFi channel 13, there is a protection band on each side of each WiFi working channel. According to the CSMA protocol of WiFi, when a WiFi device transmits on a certain channel, other devices that are about to work on this channel or adjacent channels (there is a frequency band overlap area) will enter the backoff state; the backoff band is a non-overlapping spectrum area of adjacent WiFi channels that overlaps with the WiFi working channel but does not completely overlap with it. It is a frequency band with a bandwidth greater than 3MHz formed by discovering new idle frequency bands on the basis of the original protection band; note that the extended frequency band only considers the case where the current WiFi working channel remains unchanged, and according to the CSMA / CA protocol, there will be no new WiFi interference sources working in the frequency band; in particular, the left protection band of WiFi channel 2 is called the backoff band of WiFi channel 2, and the right protection band of WiFi channel 12 is called the backoff band of WiFi channel 12.

[0014] According to one aspect of the present invention, the steps of constructing a channel quality model and an interference set based on the SINR and RSSI sequences obtained from the designated channels in each channel group are as follows:

[0015] For each designated channel, sample the RSSI sequence of the channel within a preset time window, and perform WiFi beacon detection based on the RSSI sequence to obtain the WiFi interference source information of the channel, including the RSSI mean value of all interference sources in the channel and the total number of interference sources;

[0016] Among them, the designated channel is the middle channel of each LoRa channel group; according to the WiFi channel overlap pattern in the 2.4G frequency band, all LoRa channels are divided into 16 different channel groups, and each channel group has the same interference state;

[0017] For each designated channel, calculate the signal-to-interference-plus-noise ratio (SINR) of the channel by using the received signal strength of the data packets received on the channel and the RSSI sequence collected at the current moment;

[0018] Construct a channel quality model by using the SINR values of all designated channels;

[0019] Use the WiFi interference source information obtained by performing WiFi beacon detection on all designated channels, and adopt an initial interference detection algorithm to determine the WiFi operating channels in the environment and construct an interference set;

[0020] Among them, the specific steps of the WiFi beacon detection algorithm include:

[0021] Screen out the potential interference RSSI sequences greater than the noise threshold from the sampled RSSI sequence; use the fluctuation time interval threshold and signal strength difference threshold between consecutive beacon frames of the WiFi device to screen the RSSI value pairs of the same interference source on the potential interference RSSI sequence; in order to avoid continuously detecting the beacon frames of the same interference source, use the RSSI sampling time span and signal strength difference threshold corresponding to a single WiFi beacon frame to exclude the identified interference source RSSI value pairs; calculate the RSSI mean value and the total number of interference sources of each interference source according to the detected interference source RSSI value pairs.

[0022] According to one aspect of the present invention, the specific steps of the initial interference detection algorithm include:

[0023] By successively detecting all specified channels, execute the WiFi beacon detection algorithm based on the collected RSSI sequence to obtain interference source information, and perform the following operations in a polling manner according to the obtained WiFi interference source information: For each specified channel, if there is WiFi interference on this channel and it belongs to the edge channel group, directly determine the working channel of the interference source and store the RSSI mean value of the corresponding interference source; otherwise, if there is WiFi interference on this channel and at least one specified channel in the adjacent channel group is also affected by WiFi interference, calculate the minimum absolute RSSI mean difference between each interference source on this channel and the interference sources on the adjacent specified channels in a polling manner, and identify the working channel of the interference source interfering with the current channel according to the sign relationship and magnitude thereof, and at the same time store the RSSI mean value of the corresponding interference source.

[0024] According to one aspect of the present invention, the specific steps of the algorithm based on sibling channel detection include:

[0025] Based on the channel carrier frequency, determine the channel group to which the current LoRa channel belongs, and select the corresponding channel detection algorithm; for the backoff channel, perform binary search detection; for the protection channel, perform adjacent guard band detection.

[0026] Use the RSSI sequence collected on the current LoRa channel to perform WiFi beacon detection to obtain interference source information.

[0027] Based on the binary search detection, calculate the WiFi channel range to which the current LoRa channel belongs, i.e., the detection range; detect the adjacent LoRa channel groups within the backoff band of the intermediate WiFi channel to obtain their interference status, and halve the detection range according to the interference status, and repeat the above steps until the detection range is reduced to 1 to determine the WiFi working channel.

[0028] Based on the adjacent guard band detection, detect the adjacent LoRa channel groups to obtain their interference status; if only one channel group in the adjacent channel group has WiFi interference, directly determine the WiFi working channel according to the difference in WiFi overlapping channels corresponding to different LoRa channel groups; otherwise, compare with the RSSI mean values of the interference sources in the adjacent channel group, determine the adjacent channel group with the smallest absolute mean difference, and determine the working channel of the interference source according to the absolute value magnitude and sign relationship of the minimum difference.

[0029] According to one aspect of the present invention, for the selected protected channel group, select the hopping target channel according to the interference set, configure the spreading factor in combination with the node geographical location, and at the same time realize the dynamic scheduling of node transmission based on the WiFi traffic model. The specific steps include:

[0030] After determining the available LoRa protected channel groups, utilize the WiFi channel occupancy information maintained by the interference set to select the LoRa channel with the largest center frequency interval from the WiFi operating channel as the hopping target channel;

[0031] Nodes are randomly distributed within the coverage area of a single base station, and spreading factors are assigned according to the geographical locations of the nodes;

[0032] Based on the channel quality of the hopping target channel and the length of the WiFi busy period, specify nodes with different spreading factors to perform data transmission;

[0033] According to one aspect of the present invention, the transmission parameters based on configuration are synchronized with the sending node, while continuously monitoring the target channel and reselecting available channel groups when the channel performance deteriorates. The specific steps include:

[0034] After determining the wireless link transmission parameters, use a LoRa channel that does not overlap with the WiFi channel as the broadcast channel to send control data packets;

[0035] After receiving the control data packet, the node modifies its transmission parameters and continues data transmission;

[0036] Before synchronizing the transmission parameters, the base station probes the hopping target channel. When receiving a data packet sent by a node on the target channel, use the received signal strength of the received data packet and the RSSI sequence collected at the current moment to calculate the SINR of the channel; if the SINR value is lower than the preset threshold, execute the step of identifying the WiFi operating channel using the sibling channel detection algorithm and reselecting available protected channel groups if its channel quality is lower than the preset threshold;

[0037] During data transmission, the receiving end continuously monitors the performance of the hopping channel using the packet reception rate (PRR). If the PRR is lower than the preset threshold, execute the step of identifying the WiFi operating channel using the sibling channel detection algorithm and reselecting available protected channel groups if its channel quality is lower than the preset threshold; if the PRR is greater than or equal to the preset threshold, continue to communicate with the sending node using this channel;

[0038] Over time, the interference set may exhibit obvious time-varying characteristics, resulting in the invalidation of the established database or the inability to find available protected channel groups; after the channel quality of multiple hops is lower than the specified threshold, re-evaluate the interference environment and re-establish the interference set.

[0039] In a second aspect, an embodiment of the present invention provides a LoRa channel hopping device based on the WiFi backoff protection band, which is applied to the receiving end. The device includes:

[0040] A channel state database establishment module, configured to construct a channel quality model and an interference set based on SINR and RSSI sequences obtained on designated channels of each channel group;

[0041] An initial channel group selection module, configured to select a designated channel in the optimal WiFi protected channel group for detection based on the constructed channel quality model;

[0042] A channel group re-evaluation module, configured to, when the channel quality is lower than a preset threshold, identify the WiFi working channels by using a sibling channel detection algorithm and re-select an available protected channel group;

[0043] A transmission parameter configuration module, configured to select a hopping target channel based on the selected protected channel group according to the interference set, configure a spreading factor in combination with the node geographical location, and simultaneously implement dynamic scheduling of node transmissions based on a WiFi traffic model;

[0044] A channel coordination module, configured to synchronize with a sending node based on the configured transmission parameters, continuously monitor the target channel, and re-select an available channel group when the channel performance degrades.

[0045] According to an aspect of the present invention, the wireless communication device includes a memory, a communication interface, a processor, and a communication bus;

[0046] The memory is configured to store a computer program and provide data storage support;

[0047] The communication interface is configured to perform data interaction with external devices and support two-way communication;

[0048] The processor is configured to execute the computer program stored on the memory to implement the steps of any one of the above-mentioned LoRa channel hopping methods based on a WiFi backoff protection band;

[0049] The communication bus is configured to connect the processor, the communication interface, and the memory to implement data transmission and signal interaction between components.

[0050] In a third aspect, an embodiment of the present invention provides a computer-readable storage medium, in which a computer program is stored, and when executed by at least one processor, the steps of any one of the above-mentioned LoRa channel hopping methods based on a WiFi backoff protection band can be implemented.

[0051] Compared with the prior art, the present invention has the following advantages:

[0052] 1. Regarding the cross - technology interference problem between WiFi and LoRa, the present invention proposes a LoRa channel hopping method and device based on the WiFi back - off protection band, ensuring reliable LoRa communication in an environment where WiFi coexists. Based on the inherent characteristics of the WiFi CSMA mechanism, it identifies and utilizes the back - off protection band of the working WiFi channel to achieve reliable LoRa transmission, effectively converting potential interference into protection opportunities. While not degrading the performance of WiFi, it improves the reliability of LoRa transmission;

[0053] 2. To maximize network throughput, the present invention proposes dynamic transmission parameter optimization based on the WiFi traffic model, specifying the transmission of different SF nodes according to the channel quality and the length of the WiFi busy period, ensuring the transmission of LoRa data packets under the constraint of the WiFi interference time window and achieving efficient spectrum utilization.

[0054] 3. To quickly and accurately identify the working WiFi channels, the present invention proposes a dual - strategy method based on channel classification, namely binary search detection of the back - off channels and adjacent protection band detection of the protection channels.

[0055] The back - off protection band described in the present invention can achieve reliable LoRa transmission in a high - interference WiFi environment, further improving the spectrum utilization rate without degrading the performance of WiFi, which has important popularization significance for solving the cross - technology interference problem between IoT platforms and can provide similar interference management strategies for other IoT technologies (such as ZigBee). Brief Description of the Drawings

[0056] Figure 1 It is a schematic flow chart of the LoRa channel hopping method based on the WiFi back - off protection band according to the embodiment of the present invention;

[0057] Figure 2 It is a schematic diagram of the channel layout of WiFi and LoRa in the 2.4GHz ISM band according to the embodiment of the present invention;

[0058] Figure 3 It is a schematic diagram of the back - off protection band of WiFi channel 2 according to the embodiment of the present invention;

[0059] Figure 4 It is a schematic diagram of the WiFi channel grouping in the 2.4GHz band based on the CSMA back - off principle according to the embodiment of the present invention;

[0060] Figure 5 It is a schematic diagram of LoRa channel classification based on WiFi channel overlap according to the embodiment of the present invention;

[0061] Figure 6Schematic diagram of the LoRa channel hopping method based on the WiFi backoff protection band according to the embodiment of the present invention;

[0062] Figure 7 Schematic diagram of the RSSI sequence collected on the LoRa channel under WiFi interference according to the embodiment of the present invention;

[0063] Figure 8 Schematic diagram of performing binary search detection when there is WiFi interference in the backoff channel according to the embodiment of the present invention;

[0064] Figure 9 Schematic diagram of performing adjacent protection band detection when there is WiFi interference in the protection channel according to the embodiment of the present invention;

[0065] Figure 10 Schematic diagram of the SF allocation of the LoRa device according to the embodiment of the present invention;

[0066] Figure 11 Schematic diagram of the structure of the LoRa channel hopping device based on the WiFi backoff protection band according to the embodiment of the present invention;

[0067] Figure 12 Schematic diagram of the structure of a wireless communication device according to the embodiment of the present invention. Detailed implementation manners

[0068] The technical solution of the present invention will be further described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0069] Refer to Figure 1 , Figure 1 which is a flowchart of the LoRa channel hopping method based on the WiFi backoff protection band according to the embodiment of the present invention, applied to the LoRa receiver, and includes the following steps:

[0070] S101. Based on the SINR and RSSI sequences obtained on the designated channels of each channel group, construct a channel quality model and an interference set.

[0071] Among them, the designated channel is the middle channel of each LoRa channel group; as Figure 5 shown, in this embodiment, the LoRa channels in the 2.4G frequency band are divided into 16 different channel groups according to the WiFi channel overlap pattern, and each channel group has the same interference state.

[0072] Since the LoRa channel qualities within the same channel group are similar, in order to reduce the detection overhead and storage overhead, the channel quality model only stores the channel quality of the designated channel and uses the signal-to-interference-plus-noise ratio (SINR) as a quantization index to represent the channel quality, and its calculation formula is:

[0073] SINR = Psignal (dBm) - P interfere (dBm) (1)

[0074] where P signal is the received signal strength of the data packet, and P interfere is the received signal strength of the collected interference signal; please note that in the absence of LoRa transmission, the node can directly access the register readings to measure the ambient noise and interference signal strength, or obtain the LoRa signal strength by decoding the data packet.

[0075] The primary prerequisite for avoiding cross - technology interference is to accurately identify the WiFi interference sources in the current environment; in addition to bursty WiFi traffic, WiFi APs broadcast beacon frames at a fixed interval of 100 milliseconds; this embodiment utilizes this temporal regularity of WiFi beacons to identify WiFi interference by analyzing the RSSI sequence containing these periodic beacon frames; this embodiment does not describe the WiFi beacon detection algorithm here, and the detailed steps will be described in the subsequent Algorithm A section.

[0076] For each specified channel, sample the RSSI sequence of the channel within a preset time window, and perform WiFi beacon detection based on the RSSI sequence to obtain the WiFi interference source information of the channel, including the RSSI mean value of all interference sources in the channel and the total number of interference sources.

[0077] RSSI is an important indicator for evaluating signal strength and potential interference. In this embodiment, the preset time window is 400 ms for sampling the RSSI sequence; due to hardware device limitations, the sampling rate is 500 Hz.

[0078] For each specified channel, calculate the SINR of the channel using the received signal strength of the data packet received on the channel and the RSSI sequence collected at the current moment.

[0079] In this embodiment, the RSSI sequence collected at the current moment is composed of RSSI values sampled multiple times by the corresponding channel within the preset time window, and the RSSI sequence includes ambient noise, data packet signal strength, and interference signal strength.

[0080] The calculation of the signal - to - interference - plus - noise ratio (SINR) is based on the interference source information obtained by performing WiFi beacon detection on the sampled RSSI sequence. If a periodic WiFi beacon is detected, the interference signal strength is the RSSI mean value of the interference sources in the channel; if no WiFi beacon is detected, the interference signal strength is the mean value of the RSSI sampled values in the collected RSSI sequence that are higher than the noise threshold.

[0081] Among them, the noise threshold is used to distinguish interference signals from ambient noise; in this embodiment, the set threshold is -89 dBm.

[0082] To characterize the interference state of the channel in the current environment, based on the WiFi interference source information obtained from cross-channel detection, determine the current WiFi operating channel, and construct a channel state database containing an interference set and a channel quality model.

[0083] Use the SINR values of all specified channels to construct a channel quality model.

[0084] Use the WiFi interference source information obtained by performing WiFi beacon detection on all specified channels, and adopt an initial interference detection algorithm to determine the WiFi operating channels in the environment and construct an interference set.

[0085] This embodiment does not describe the initial interference detection algorithm in detail here. The specific steps of this algorithm will be further elaborated in subsequent Algorithm B.

[0086] S102, Based on the constructed channel quality model, select the specified channels in the optimal WiFi protected channel group for detection.

[0087] Based on the constructed channel quality model, the channel quality of the specified channels in 16 LoRa channel groups can be obtained.

[0088] In this embodiment, preferentially select the channel group to which the specified channel with the maximum signal-to-interference-plus-noise ratio (SINR) belongs as the optimal WiFi protected channel group.

[0089] The dynamic characteristics of WiFi interference may cause the existing channel state information to become outdated, thus affecting the selection of the optimal WiFi protected channel group based on the information stored in the database. Therefore, it is particularly important to re-detect the available WiFi protected channel groups.

[0090] As Figure 2 shown, this embodiment selects the LoRa channel located in the non-overlapping frequency band of the WiFi channel as the broadcast channel; the LoRa channel to the left of WiFi channel 1 always remains interference-free and is thus used as the broadcast channel.

[0091] The base station transmits control data packets through the broadcast channel. The control data packet contains the carrier frequency information of the target channel. After receiving the control data packet, the node modifies its corresponding transmission parameters and continues data transmission.

[0092] The specified channels in the available protected channel group are the target channels for communicating with the node. When receiving the data packet sent by the node on the target channel, use the received signal strength of the received data packet and the RSSI sequence collected at the current moment to calculate the SINR of the target channel.

[0093] S103, if its channel quality is lower than a preset threshold, the WiFi operating channel is identified using a sibling channel detection algorithm and an available protected channel group is reselected.

[0094] Among them, the channel quality is characterized by the signal-to-interference-plus-noise ratio (SINR) or the packet reception ratio (PRR).

[0095] To prevent interference between channels, WiFi channels are separated by guard bands. WiFi standards 802.11b and 802.11g / n specify guard bands of 3 MHz and 5 MHz respectively; in fact, with modern WiFi radio technology effectively suppressing signal leakage, the width of these guard bands is larger than the frequency band range required for most practical applications. Research shows that a WiFi signal with a maximum power of 20 dBm will experience a significant power attenuation of 38.5 dB within the guard band, and the guard band can be used to achieve reliable transmission of ZigBee; this characteristic of the guard band also provides an opportunity for reliable transmission of LoRa.

[0096] The potential of WiFi to protect wireless communication technologies operating on overlapping frequency bands of its guard bands stems from the CSMA protocol implemented at the MAC layer. In addition to the aforementioned guard bands, the present invention uses the CSMA / CA protocol to discover additional idle spectrum regions, bringing more potential transmission opportunities. This untapped potential is generally applicable to all WiFi standards in the 2.4G band. Specifically, when a WiFi device transmits on WiFi channel 2, other devices that are about to operate on the overlapping frequency bands (WiFi channels 1 to WiFi channels 6) will perform a backoff operation; as Figure 3 shown, there is basically no interference in the left frequency band of WiFi channel 2; in this embodiment, the idle frequency band on the left side of WiFi channel 2 is called the backoff band, and it is collectively called the backoff guard band with the traditional guard band on the right side. The backoff guard band is associated with the WiFi operating channel.

[0097] As Figure 5 shown, in this embodiment, according to the interference pattern of WiFi channels, the LoRa channels in the 2.4G band are divided into three categories, namely backoff channels, protected channels, and unavailable channels; the LoRa channels within the backoff band are called backoff channels, and the LoRa channels within the guard band are called protected channels; in addition, in order to more accurately analyze the WiFi channel overlapping pattern, we divide these channels into 16 different channel groups, and the channels in each group have the same interference characteristics.

[0098] In WiFi communication, the Carrier Sense Multiple Access (CSMA) protocol is adopted for collision avoidance. When multiple Access Points (APs) are within the same coverage area, different frequency bands must be allocated to each access point to prevent interference caused by sharing the channel. According to the IEEE 802.11 standard, a WiFi network supports concurrent transmission on up to three non-overlapping channels, such as WiFi channels 1, 6, and 11.

[0099] As Figure 4 shown, the WiFi channels within the 2.4 GHz frequency band are divided into 5 groups. Regardless of how the grouping is done, the backoff protection band (including the backoff band and the protection band) always occupies a rather large portion of the spectrum. Based on this, the present invention utilizes these underutilized frequency bands to enhance the reliability of LoRa transmission.

[0100] An important prerequisite for utilizing these neglected frequency bands is to accurately identify the WiFi working channels. As Figure 4 shown, once the WiFi working channels are accurately identified, it becomes simple to select a suitable LoRa channel for transmission.

[0101] To quickly and accurately identify the WiFi working channels, the detection order of LoRa channels must be carefully designed; due to channel asymmetry, a LoRa node can only detect one channel at a time. Detecting channels sequentially during WiFi transmission may lead to inaccurate detection results. To address this limitation, the present invention introduces a dual-strategy method based on channel classification, that is, based on the sibling channel detection algorithm, a binary search detection is performed on the backoff channels, and an adjacent protection band detection is performed on the protection channels.

[0102] This embodiment does not describe the sibling channel detection algorithm in detail here, and the specific steps will be further elaborated later.

[0103] After successfully identifying the WiFi working channels, the available LoRa channel groups are directly determined according to the established LoRa channel group allocation information. As Figure 9 shown, if the detected interference source working channel is WiFi channel 9, then LoRa channel groups 8 and 13 are the available protected channel groups.

[0104] In this embodiment, first, the most likely channel groups are selected and detected based on the channel state database. When the measured SINR exceeds a predetermined threshold, then that LoRa channel group is selected as the available protected channel group; otherwise, it is necessary to re-evaluate the environment and identify the WiFi working channels, and select the LoRa channel group within its backoff protection band as the available protected channel group.

[0105] Over time, the interference set may exhibit significant time-varying characteristics, resulting in the invalidation of the established database or the inability to find an available protected channel group; in this embodiment, after the channel quality of multiple hops is lower than the specified threshold, the interference environment is re-evaluated and the interference set is re-established.

[0106] S104, Based on the selected protected channel group, select the hopping target channel according to the interference set, configure the spreading factor in combination with the node geographical location, and at the same time implement dynamic scheduling of node transmission based on the WiFi traffic model.

[0107] The backoff protection band of each WiFi channel contains multiple LoRa channels, and complex channel selection is required. Only the channel with the largest SINR is selected as the hopping target channel. In a large-scale LoRa network, this method may prove to be sub-optimal because the competition of concurrent nodes for the optimal channel will seriously affect network performance.

[0108] After determining the available LoRa protected channel group, use the WiFi channel occupancy information maintained by the interference set to select the LoRa channel with the largest frequency interval from the center frequency of the WiFi working channel as the hopping target channel.

[0109] Within the coverage area of a single base station, a node random distribution model is adopted, and the spreading factor is allocated according to the geographical location of the nodes.

[0110] The selection of the spreading factor presents an inherent trade-off. Higher values will increase the receiving sensitivity and transmission distance, but at the same time the transmission time becomes longer; therefore, this embodiment adopts a location-based spreading factor allocation strategy; as Figure 10 shown, use the orthogonality of different spreading factors to minimize the collision probability between nodes.

[0111] Based on the channel quality of the hopping target channel and the length of the WiFi busy period, nodes with different spreading factors are specified to perform data transmission.

[0112] In a densely deployed LoRa network, WiFi interference has a high degree of time dynamics; based on this, this embodiment proposes a dynamic spreading factor determination method based on the WiFi traffic model, specifying the transmission of nodes with different spreading factors according to the channel quality and the duration of the WiFi busy period, ensuring the completion of LoRa packet transmission under the constraint of the WiFi interference time window and reducing cross-technology interference.

[0113] S105, Based on the configured transmission parameters, synchronize with the sending node, continuously monitor the target channel at the same time, and re-select the available channel group when the channel performance degrades.

[0114] After determining the wireless link transmission parameters, transmission parameter synchronization is required; a LoRa channel that does not overlap with the WiFi channel is used as the broadcast channel to send control data packets.

[0115] After the node receives the control data packet, it modifies its transmission parameters and continues data transmission.

[0116] After selecting the hopping channel, to ensure the reliability of transmission, before transmission parameter synchronization, the base station needs to detect the channel to verify its availability.

[0117] When receiving a data packet sent by the node on the target channel, use the received signal strength of the received data packet and the RSSI sequence collected at the current moment to calculate the SINR of the channel; if the SINR value is lower than the preset threshold, execute step S103.

[0118] During data transmission, due to the time-varying nature of WiFi interference and the complex coexistence environment, it is necessary to continuously monitor the channel quality; to avoid interference caused by sudden WiFi traffic, in this embodiment, PRR is used as a quantitative indicator to evaluate the long-term performance of the channel.

[0119] This embodiment adopts a hierarchical quality assessment mechanism, using SINR for physical layer quality assessment during the channel switching phase, and using PRR for link layer performance verification during the data transmission phase.

[0120] During data transmission, evaluate PRR by calculating the proportion of correctly received data packets; if PRR is lower than the preset threshold, execute step S103; if PRR is greater than or equal to the preset threshold, continue to communicate with the node using this channel.

[0121] In this embodiment, the preset threshold of PRR is 90%, and if PRR is higher than this threshold, it indicates that the channel quality is good and reliable transmission can be achieved.

[0122] In the embodiment of the present invention, two algorithms are involved in S101, and the specific steps are as follows:

[0123] Algorithm A: WiFi beacon detection, and the specific steps of this algorithm include A1 to A4.

[0124] Step A1: Compare the values in the RSSI sequence with the noise threshold to screen out valid data, and store the corresponding time index values and RSSI values. The RSSI values with signal strength higher than the noise threshold are regarded as potential interference signals.

[0125] The sampled RSSI sequence includes environmental noise, interference signals, and the signal strength of data packets. In this embodiment, the RSSI sequence after screening to remove environmental noise is called the potential interference sequence.

[0126] Step A2: For each value in the potential interference sequence, verify whether the RSSI value is from a WiFi beacon frame; assume that the current RSSI value is the RSSI value of the first WiFi beacon frame sampled from a certain interference source, record its position in the sequence, and add it to the beacon frame set; subsequently, within the fluctuation time interval threshold between consecutive beacon frames, search for the RSSI value of the subsequent WiFi beacon frame whose RSSI value difference does not exceed the preset threshold; if the condition is met, it is considered to belong to the same interference source, and it is added to the current beacon frame set, and continue to search for the RSSI value of the next beacon frame that may belong to the same interference source starting from the newly found RSSI value; if the time interval or RSSI difference exceeds the preset threshold, backtrack and reselect the RSSI value of the previous beacon frame, and at the same time clear its record in the beacon frame set; it should be noted that if the number of RSSI values recorded in the current beacon frame set is 0, no backtracking operation is performed.

[0127] Due to the regularity of the WiFi AP, the number of beacon frames of the same interference source within a fixed time window is fixed. If the number of RSSI values in the beacon frame set reaches the preset number, it is considered that periodic beacon frames are found, that is, a new WiFi interference source; otherwise, point the index position to the next RSSI value of the recorded sequence position, and repeat the above operations until the time index of the newly pointed RSSI value is greater than 100 ms.

[0128] Step A3: After identifying the periodic WiFi beacon frames, store the corresponding RSSI value pairs, and continue to search for the RSSI value pairs of other interference sources; in order to avoid continuously retrieving the RSSI values of the same interference source, use the RSSI sampling time span corresponding to a single WiFi beacon frame and the volatility threshold of the RSSI value to exclude the RSSI values of the identified interference sources. Specifically, in this embodiment, by setting an appropriate time window and signal strength difference threshold, continuous detection of beacon frames of the same interference source is avoided.

[0129] Utilize the regularity of the WiFi AP to poll and retrieve the RSSI values within 100 ms of the time series as the RSSI values of the first WiFi beacon frames sampled from different interference sources, so as to identify all interference sources and their RSSI value pairs on this channel.

[0130] Step A4: Calculate the RSSI mean value of each interference source according to the detected RSSI value pairs of each interference source, and calculate the total number of interference sources.

[0131] Figure 7 Shows an RSSI sequence sampled in a certain LoRa channel containing WiFi interference. The sequence contains interference signals caused by two WiFi interference sources, and each interference source is composed of its corresponding beacon frame and data packet.

[0132] Algorithm B: Initial interference detection. The specific steps of this algorithm include B1 to B2.

[0133] Step B1: Initialize the interference set I = zeros(16, 4, n).

[0134] Where n is the maximum number of interference sources existing in a single WiFi channel.

[0135] As Figure 5 shown, there are a total of 16 LoRa channel groups, and each LoRa channel group overlaps with at most 4 WiFi channels.

[0136] Step B2: According to the WiFi interference source information of the middle channels of the obtained 16 LoRa channel groups ( and ), if polling is performed for the following operations.

[0137] If the channel group i to which the obtained WiFi interference source information belongs is 1 or 16, the working channel of the interference source can be directly determined, and the corresponding If it is other channel groups and there is at least one channel group with WiFi interference in the adjacent channel groups, for the RSSI means of the interference sources of this channel group are polled for the following calculations, that is, is calculated with for each RSSI mean in, and the smallest absolute difference is respectively selected; if , then Otherwise, If |d| > D th , then Otherwise, l rel = j > i? 3:2, and is stored in I[i][l rel .

[0138] Where i is the number of the current LoRa channel group, j is the number of the adjacent LoRa channel group with the smallest absolute RSSI mean difference, and are the RSSI mean and the number of interference sources obtained by performing WiFi beacon detection on the specified channel of the LoRa channel group i, is the RSSI mean of the kth interference source detected in the LoRa channel group i, and D th is the preset RSSI difference threshold for adjacent channel groups, is the minimum absolute RSSI mean difference between the k-th interfering source in LoRa channel group i and all interfering sources in LoRa channel group i-1, l rel is an array index. The LoRa channel group overlaps with at most 4 WiFi channels. According to the working channel of the interfering source, the RSSI mean of the corresponding interfering source is stored in the corresponding position.

[0139] Due to the uneven power spectral density of WiFi, the RSSI values of adjacent channel groups affected by the same WiFi interfering source are highly correlated. In this embodiment, the minimum absolute RSSI mean difference from the adjacent channel group is calculated, and the current WiFi working channel is identified based on its sign relationship and magnitude.

[0140] In the embodiment of the present invention, the specific implementation steps of S103 include the following steps C1 to C4.

[0141] Step C1: Determine the LoRa channel group i to which the current channel belongs according to the carrier frequency f of the current channel. If i < 5 or i > 12, perform binary search detection; otherwise, perform adjacent guard band detection.

[0142] Step C2: Perform WiFi beacon detection based on the RSSI sequence sampled from the current channel to obtain the interfering source information of the current channel and

[0143] where and are the RSSI mean of the interfering source and the number of interfering sources obtained by performing WiFi beacon detection on the specified channel in LoRa channel group i.

[0144] Step C3: For binary search detection, detect the interference status of LoRa channel group mid according to the following expression.

[0145]

[0146] Perform WiFi beacon detection on the specified channel in LoRa channel group mid to obtain the interfering source information and and update the channel detection range according to If then If then i = mid; repeat the above operations, continuously adjust the detection range until the detection range is 1 (i.e., edge = i); according to the final channel group number i, calculate the WiFi interfering source working channel l = (i < 5)? i : (i - 3).

[0147] Among them, edge is the boundary channel group. Initially, when i < 5, edge = 1, which is the starting boundary channel group; if i < 12, edge = 16, which is the ending boundary channel group.

[0148] Step C4: For adjacent guard band detection, sequentially perform WiFi beacon detection on adjacent channel groups, namely LoRa channel groups i - 1 and i + 1 within the adjacent guard band; if then the interference source operates on WiFi channel i; if then the interference source operates on WiFi channel i - 3; if WiFi interference is detected in both adjacent channel groups, by calculating and the minimum absolute RSSI mean difference of the adjacent channel groups to identify the WiFi operating channel. If there exists an RSSI mean in with the minimum absolute mean difference |d| from the RSSI mean in th , then j = i - 1, otherwise j = i + 1; if |d| > D then the operating channel of the WiFi interference source is

[0149] Otherwise, the operating channel of the WiFi interference source is l = Max(i, j) - 2. th where D

[0150] is the preset RSSI difference threshold for adjacent channel groups, j is the number of the detected LoRa channel group, and l is the identified operating channel of the WiFi interference source; since the interference state of the WiFi operating channel is exactly opposite to that of its guard band, therefore, in this embodiment, the operating channel of the WiFi is determined by detecting the interference state of the LoRa channels within the guard band of the WiFi channel. Figure 8 As shown in

[0151] For the guard channel, its corresponding LoRa channel group overlaps with 4 WiFi channels, and there is only one difference between the adjacent WiFi channels with overlapping guard bands; therefore, if the interference state of a channel group is different from that of the channel group within its adjacent guard band, the operating channel of the interference source can be directly determined.

[0152] In this embodiment, for the adjacent guard band detection of the protected channel, as Figure 9 shown, when operating in LoRa channel group 9, probe the adjacent channel groups to characterize the interference environment; if no WiFi beacon is detected in LoRa channel group 8, but a WiFi beacon is detected in LoRa channel group 10, the interference source is operating on WiFi channel 9; conversely, the interference source is operating on WiFi channel 6.

[0153] Each protected channel has two adjacent LoRa channel groups, but the LoRa device can only probe one channel at a time, so it is not possible to simultaneously probe the specified channels of two channel groups; when sequentially probing LoRa channels during WiFi transmission, the probing results may not be accurate; therefore, this embodiment uses the historical interference data stored in the interference set to predict the interference source;

[0154] Based on the above embodiment, now taking Figure 6 as an example for specific illustration, specifically:

[0155] In Figure 6Among them, the virtual arrow represents the data flow, the thin arrow represents the workflow, and the thick arrow represents the channel switching. The reception mainly includes three steps, namely, channel state acquisition, protected channel determination, and channel coordination. Among them, the channel state acquisition is based on the SINR and RSSI sequences obtained on the designated channels of each channel group to construct a channel quality model and an interference set; the protected channel determination step mainly selects an available protected channel group; based on the constructed channel quality model, the designated channel in the optimal WiFi protected channel group is selected for detection; if the SINR value obtained by detecting the designated channel of the optimal channel group is not lower than the preset threshold, then this channel group is an available protected channel group for channel coordination; if its SINR value is lower than the preset threshold, the WiFi working channel is identified using the sibling channel detection algorithm and an available protected channel group is reselected; the channel coordination step mainly performs transmission parameter determination, transmission coordination, and channel monitoring; based on the selected protected channel group, the hopping target channel is selected according to the interference set, and the spreading factor is configured in combination with the node geographical location, and at the same time, the dynamic scheduling of node transmission is realized based on the WiFi traffic model; the base station selects the hopping target channel to communicate with the node. When receiving the data packet sent by the node on the hopping target channel, the SINR of the channel is calculated using the received signal strength of the received data packet and the RSSI sequence collected at the current moment; if the SINR value is lower than the preset threshold, the protected channel determination module is re-executed; if the SINR value is not lower than the preset threshold, based on the configured transmission parameters, the transmission parameters are synchronized with the node; during the data transmission process, the base station continuously monitors the hopping channel to determine whether the PRR of the channel is higher than the preset threshold; if the PRR is greater than or equal to the preset threshold, continue to use this channel to communicate with the sending node; if the PRR is lower than the preset threshold, the protected channel determination module is re-executed.

[0156] Corresponding to the above LoRa channel hopping method based on the WiFi backoff protection band, an embodiment of the present invention provides a LoRa channel hopping device based on the WiFi backoff protection band.

[0157] As Figure 11 shown, an embodiment of the present invention provides a structural schematic diagram of a LoRa channel hopping device based on the WiFi backoff protection band, which is applied to the LoRa receiving end. The device includes:

[0158] A channel state database establishment module 201, configured to construct a channel quality model and an interference set based on the SINR and RSSI sequences obtained on the designated channels of each channel group.

[0159] An initial channel group selection module 202, configured to select the designated channel in the optimal WiFi protected channel group for detection based on the constructed channel quality model.

[0160] The channel group re-evaluation module 203 is configured to identify the WiFi working channel using a sibling channel detection algorithm and re-select an available protected channel group when its channel quality is lower than a preset threshold.

[0161] The transmission parameter configuration module 204 is configured to select a hopping target channel based on the selected protected channel group according to an interference set, configure a spreading factor in combination with the node geographical location, and implement dynamic scheduling of node transmission based on a WiFi traffic model.

[0162] The channel coordination module 205 is configured to synchronize with a sending node based on the configured transmission parameters, continuously monitor the target channel, and re-select an available channel group when the channel performance degrades.

[0163] An embodiment of the present invention further provides a wireless communication device, as Figure 12 shown Figure 12 is a device structure diagram of an embodiment of the present invention, including a memory 301, a communication interface 302, a processor 303, and a communication bus 304.

[0164] The memory 301 is configured to store a computer program and provide data storage support.

[0165] The communication interface 302 is configured to perform data interaction with an external device and support two-way communication.

[0166] The processor 303 is configured to execute the computer program stored on the memory 303 to implement the steps of any one of the above-mentioned LoRa channel hopping methods based on a WiFi backoff protection band.

[0167] The communication bus 304 is configured to connect the memory 301, the communication interface 302, and the processor 303 to implement data transmission and signal interaction between components.

[0168] The processor of the wireless communication device may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; or a digital signal processor (DSP), an application specific integrated circuit (ASIC), or a programmable logic device such as a field-programmable gate array (FPGA). The specific selection of the processor is determined according to the actual application scenario and requirements.

[0169] The memory of the wireless communication device may include a Random Access Memory (RAM) and a non-volatile memory (NVM), such as a hard disk memory, a Solid State Drive (SSD), etc., or a storage device remote from the processor; specifically, the configuration of the memory can be optimized according to system requirements to support efficient data access and persistent storage, so as to meet the requirements of real-time performance and data integrity in the wireless communication system; the programs stored in the memory include an instruction set for the LoRa channel hopping method based on the WiFi backoff guard band, which supports the device to dynamically select available channels in an interference environment.

[0170] The communication bus of the wireless communication device can be a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, etc. According to specific application requirements, the communication bus can be dynamically configured as an address bus, a data bus, a control bus, etc. For the sake of simplicity in illustration, Figure 12 the communication bus shown in the figure is represented by a single thick line, and the actual architecture may include multiple buses or multiple bus types.

[0171] The communication interface of the wireless communication device is used to implement signal communication and data exchange between the device and other devices, ensuring the stability and reliability during the communication process.

[0172] An embodiment of the present invention provides a computer-readable storage medium, including but not limited to a Solid State Drive (SSD), a Flash Memory, or an optical disc memory, on which a computer-executable program is stored; when the program is executed by a processor configured with a LoRa communication module, the steps of any of the above LoRa channel hopping methods based on the WiFi backoff guard band are implemented.

[0173] The above embodiments can be implemented by hardware, software, or a combination thereof. The choice of the specific implementation method depends on the specific application scenario and design constraints of the technical solution. When implemented in software form, it can be partially or fully implemented in the form of a computer program product; the computer program product refers to a set of program codes that can run independently and complete specific functions, and is usually stored in a computer-readable storage medium, such as a hard disk, a memory card, or a flash memory, etc. These program code segments can be fully or partially implemented according to the processes or functions described in the embodiments of the present invention, and are stored in a computer-readable storage medium, and are read and executed by a computer system when needed.

[0174] In this specification, the writing focus of each embodiment lies in the description of the differences from other embodiments. Especially when it comes to the embodiments of the device, it is usually simplified based on the method embodiments. For the specific content, reference can be made to the description in the method part for a detailed understanding.

[0175] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. The LoRa channel hopping method based on WiFi backoff protection band is characterized by , applied to the receiving end, the method comprises the following steps: Based on the SINR and RSSI sequences obtained on the designated channels of each channel group, a channel quality model and an interference set are constructed; Based on the constructed channel quality model, select the designated channel in the optimal WiFi protected channel group for detection; If the channel quality is lower than the preset threshold, a sibling channel detection algorithm is used to identify the WiFi working channel and reselect an available protected channel group; Based on the selected protected channel group, the target channel for hopping is selected according to the interference set, and the spreading factor is configured in combination with the node's geographical location. At the same time, dynamic scheduling of node transmission is achieved based on the WiFi traffic model. Based on the configured transmission parameters, it synchronizes with the sending node, continuously monitors the target channel, and reselects the available channel group when the channel performance degrades.

2. The LoRa channel hopping method based on the WiFi backoff protection band according to claim 1, characterized in that, The retreat protection belt comprises a retreat belt and a protection belt; The LoRa channel in the backoff band is called the backoff channel, and the LoRa channel in the guard band is called the protection channel; the guard band is a spectrum isolation band set between WiFi channels to avoid inter-channel interference, so as to reduce signal leakage and interference; the bandwidth of the guard band is set to 3MHz in the 802.11b standard and 5MHz in the 802.11g / n standard; when the WiFi signal passes through the guard band, its power will be significantly attenuated, and it is usually regarded as an idle spectrum area; except for WiFi channel 1 and WiFi channel 13, each WiFi working channel has a guard band on the left and right sides; according to the WiFi CSMA protocol, when a WiFi device is transmitting on a certain channel, other devices that are about to work on this channel or adjacent channels (there is a frequency band overlap area) will enter the backoff state; the backoff band is a non-overlapping spectrum area of ​​adjacent WiFi channels that overlaps with the working WiFi channel but does not completely overlap with it. It is a frequency band with a bandwidth greater than 3MHz formed by discovering new idle frequency bands on the basis of the original guard band; please note that the extended frequency band only considers the case where the current WiFi working channel remains unchanged, and according to the CSMA / CA protocol, there will be no new; the frequency band where the WiFi interference source works.

3. The LoRa channel hopping method based on WiFi backoff protection band according to claim 1, characterized in that, The channel quality model and the interference set are constructed based on the signal to interference noise ratio and RSSI sequence obtained in the designated channel of each channel group, and the specific steps include: For each designated channel, the RSSI sequence of the channel is sampled within a preset time window, and WiFi beacon detection is performed based on the RSSI sequence to obtain the WiFi interference source information of the channel, including the RSSI mean value of all interference sources of the channel and the total number of interference sources; Among them, the designated channel is the middle channel of each LoRa channel group; according to the WiFi channel overlapping mode on the 2.4G frequency band, all LoRa channels are divided into 16 different channel groups, and each channel group has the same interference state; For each designated channel, the signal to interference noise ratio of the channel is calculated using the received signal strength of the data packets received on the channel and the RSSI sequence collected at the current moment; Generate a channel quality model using the signal to interference and noise ratio values ​​of all designated channels; Using the WiFi interference source information obtained by WiFi beacon detection on all designated channels, an initial interference detection algorithm is used to determine the WiFi working channels in the environment and construct an interference set. The specific steps of the WiFi beacon detection algorithm include: The potential interference RSSI sequence greater than the interference threshold is screened out from the sampled RSSI sequence; the RSSI value pairs of the same interference source are screened out using the fluctuation time interval threshold and signal strength difference threshold between consecutive beacon frames of the WiFi device on the potential interference RSSI sequence; in order to avoid continuous detection of beacon frames of the same interference source, the RSSI sampling time span and signal strength difference threshold corresponding to a single WiFi beacon frame are used to exclude the RSSI value pairs of the identified interference source; the RSSI mean value of each interference source and the total number of interference sources are calculated based on the interference source RSSI value pairs detected.

4. The LoRa channel hopping method based on the WiFi backoff protection band according to claim 3, characterized in that: The initial interference detection algorithm specifically comprises the following steps: By detecting all designated channels in turn, the WiFi beacon detection algorithm is executed based on the collected RSSI sequence to obtain the interference source information, and the following operations are performed according to the obtained WiFi interference source information polling: for each designated channel, if the channel has WiFi interference and belongs to the edge channel group, the working channel of the interference source is directly determined, and the working channel of the corresponding interference source and its RSSI mean are stored; otherwise, if the channel has WiFi interference and the designated channel of the adjacent channel group also has WiFi interference, the RSSI value correlation of different channels under the same WiFi interference source is used to calculate the minimum RSSI mean absolute difference and its sign relationship with the adjacent designated channels to identify the interference source working channel that interferes with the current channel, and store the interference source working channel and its corresponding RSSI mean.

5. The LoRa channel hopping method based on WiFi backoff protection band according to claim 1, characterized in that ,The specific steps of the sibling channel detection algorithm include: Based on the channel carrier frequency, determine the channel group to which the current LoRa channel belongs, and select the corresponding channel detection algorithm; for the backoff channel, perform binary search detection; for the protection channel, perform adjacent protection band detection; Use the RSSI sequence collected on the current LoRa channel to detect WiFi beacons and obtain interference source information; Based on binary search detection, calculate the WiFi channel range to which the current LoRa channel belongs, that is, the detection range; detect the LoRa channel group in the backoff band of the middle WiFi channel to obtain its interference status, and halve the detection range according to the interference status. Repeat the above steps until the detection range is reduced to 1, and determine the WiFi working channel; Based on adjacent guard band detection, the adjacent LoRa channel groups are detected to obtain their interference status; if there is WiFi interference in the adjacent channel group and only one channel group has WiFi interference, the WiFi working channel is directly determined according to the difference in WiFi overlapping channels corresponding to different LoRa channel groups; otherwise, the RSSI mean of the interference source of the adjacent channel group is compared to determine the adjacent channel group with the smallest mean difference, and the working channel of the interference source is determined by combining the absolute value and sign relationship of the difference.

6. The LoRa channel hopping method based on WiFi backoff protection band according to claim 1, characterized in that, The method of selecting a hopping target channel based on the selected protected channel group according to the interference set, configuring a spreading factor in combination with the node's geographical location, and implementing dynamic scheduling of node transmission based on a WiFi traffic model specifically includes the following steps: After determining the available LoRa protected channel group, the WiFi channel occupancy information maintained by the interference set is used to select the LoRa channel with the largest frequency interval with the WiFi working channel as the hopping target channel; The nodes are randomly distributed in the coverage area of ​​a single base station, and the spreading factor is assigned according to the geographical location of the nodes; Based on the channel quality of the hopping target channel and the length of the WiFi busy period, nodes with different spreading factors are designated for data transmission.

7. The LoRa channel hopping method based on WiFi backoff protection band according to claim 1, characterized in that: The transmission parameters based on the configuration are synchronized with the sending node, the target channel is continuously monitored, and the available channel group is reselected when the channel performance decreases. The specific steps include: After determining the wireless link transmission parameters, use the LoRa channel that does not overlap with the WiFi channel as the broadcast channel to send control data packets; After receiving the control data packet, the node modifies its transmission parameters and continues data transmission; Before synchronizing the transmission parameters, the base station detects the target channel to be jumped. When receiving a data packet sent by a node on the target channel, the base station calculates the signal-to-interference-and-noise ratio of the channel using the received signal strength of the received data packet and the RSSI sequence collected at the current moment; if the signal-to-interference-and-noise ratio is lower than a preset threshold, the base station performs the steps of identifying the WiFi working channel based on a sibling channel detection algorithm and reselecting an available protected channel group if the channel quality is lower than the preset threshold; During the data transmission process, the receiving end uses the packet reception rate (PRR) to continuously monitor the hopping channel performance. If the PRR is lower than the preset threshold, it returns to execute the step of identifying the WiFi working channel based on the sibling channel detection algorithm and reselecting the available protected channel group if the channel quality is lower than the preset threshold; if the PRR is greater than or equal to the preset threshold, it continues to use the channel to communicate with the sending node; As time goes by, the interference set may show obvious time-varying characteristics, causing the established database to become invalid or unable to find available protected channel groups; after the channel quality of multiple hops is lower than the specified threshold, the interference environment is re-evaluated and the interference set is rebuilt.

8. A LoRa channel hopping device based on WiFi backoff protection band, characterized in that , applied to a receiving end, the device comprises: A channel state database building module, used to build a channel quality model and an interference set based on the signal to interference noise ratio and RSSI sequence obtained in the designated channel of each channel group; The initial channel group selection module selects the designated channel in the optimal WiFi protected channel group for detection based on the constructed channel quality model; A channel group re-evaluation module, used to identify the WiFi working channel and reselect an available protected channel group using a sibling channel detection algorithm when the channel quality is lower than a preset threshold; The transmission parameter configuration module is used to select the target channel for hopping based on the selected protected channel group and the interference set, and configure the spreading factor in combination with the node's geographical location, while realizing dynamic scheduling of node transmission based on the WiFi traffic model; The channel coordination module is used to synchronize with the sending node based on the configured transmission parameters, while continuously monitoring the target channel and reselecting the available channel group when the channel performance degrades.

9. A wireless communication device, characterized in that: including a memory, a communication interface, a processor and a communication bus; The memory is used to store computer programs and provide data storage support; The communication interface is used to exchange data with external devices and supports two-way communication; The processor is used to execute the computer program stored in the memory to implement the steps of the channel hopping method according to any one of claims 1 to 7; The communication bus is used to connect the processor, the communication interface and the memory to achieve data transmission and signal interaction between the components.

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