Ad hoc network wireless communication implementation method based on narrowband spread frequency hopping

Abstract

The invention discloses an ad hoc network wireless communication implementation method based on narrowband spread frequency hopping, and relates to the technical field of ad hoc network wireless communication. The invention aims to realize long-distance wireless communication, ensure the success rate of communication and enhance the anti-interference capability. Comprising the following steps: performing communication by adopting a spread spectrum mode, increasing the bandwidth of a radio frequency signal, adding a spread spectrum factor into the bandwidth, and increasing the transmission distance; a frequency hopping mechanism is realized in a frequency division multiplexing mode, and the transmission speed is improved through frequency division multiplexing. The bandwidth of the radio frequency signal is increased, the spread spectrum factor is added, the error-tolerant rate is effectively increased, the transmission distance is increased, the problem of short communication distance is solved, channels are randomly monitored through a random number generation algorithm, optimal frequency channels are optimized, the network is maintained by a main node and is directly communicated with equipment, and the communication efficiency is improved. Therefore, the network structure complexity is effectively reduced, the management difficulty is reduced, and the communication timeliness is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless communication of a self-organizing network, and in particular to a method for realizing wireless communication of a self-organizing network based on narrowband spread frequency hopping. Background Art

[0002] The implementation of the Internet of Things and artificial intelligence technology applications has put forward higher requirements for the intelligent management of homes, hotels, and office buildings; the communication methods of smart devices are divided into two categories: wired communication and wireless communication. Wired communication has fast transmission speed, strong anti-interference ability, and high security. It is an ideal communication method, but it requires the installation of additional hardware equipment. Wireless communication communicates through radio waves transmitted in the air. This method is highly flexible, has a wide coverage range, and is easy to move and expand. However, wireless communication signals are easily interfered, have slow transmission speeds, and the transmission success rate is not as high as that of wired communication.

[0003] The most common and low-cost communication methods for smart devices on the market are basically zigbee, Bluetooth, WiFi and other communication methods. For home user scenarios, multiple gateways are required to cover the entire home scenario. Multiple gateways cause unstable communication, cumbersome debugging, difficult power supply and high cost. If it is an office building or a large family, it is necessary to add gateways or relays, or enable mesh and other functions, which will cause redundant connections, increase network complexity, and cause network congestion, packet loss and other problems.

[0004] Therefore, a method for realizing wireless communication in ad hoc networks based on narrowband spread spectrum frequency hopping is proposed. Summary of the invention

[0005] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a method for realizing wireless communication in an ad hoc network based on narrowband spread frequency hopping.

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

[0007] The method for realizing wireless communication of a self-organizing network based on narrowband spread frequency hopping includes the following steps:

[0008] S1: Use spread spectrum to communicate, increase the bandwidth of the RF signal, and add a spread factor to it to increase the transmission distance;

[0009] S2: frequency hopping mechanism is realized by frequency division multiplexing, which improves the transmission speed;

[0010] S3: It adopts a star network structure with one master and multiple slaves. The network is maintained by the master node and communicates directly with the devices, reducing the complexity of the network structure.

[0011] S4: Optimize the composition of the communication frame to realize the operation of the entire communication cycle.

[0012] Preferably: the theoretical basis of the spread spectrum communication in the spread spectrum mode in step S1 is based on:

[0013] Shannon's channel capacity formula, also known as Shannon's formula:

[0014] C = w × log2 (1 + S / N).

[0015] Further: the frequency hopping mechanism is implemented by frequency division multiplexing in the step S2, wherein the frequency hopping mechanism adopts frequency division multiplexing, through which the transmission speed is improved and the problem of mutual frequency interference is avoided, and the principle of frequency division multiplexing is based on frequency division multiplexing FDM.

[0016] Further: The protocol stack in the frequency division multiplexing has planned a total of 48 channels for communication. Before transmitting, the master node uses a random number generation algorithm to randomly monitor the channel and select the best frequency channel. In addition, each superframe will randomly select four channels for transformation, and splice multiple signals of different frequency bands into a broadband signal. It mainly includes three operation steps:

[0017] S11: upsampling;

[0018] S22: filtering;

[0019] S33: Accumulation.

[0020] As a preferred solution of the present invention: in the one-master-multiple-slave star network structure in step S3, the network is maintained by the master node and communicates directly with the device.

[0021] As a further solution of the present invention: the master node automatically assigns a logical address to a subnode according to the subnode reported at random time, the number of subnodes managed by the group node is 255, the master node binds the physical address and logical address of the subnode, and regenerates a random timetable.

[0022] As a further solution of the present invention: the composition of the communication frame in step S4 is optimized to realize the operation of the entire communication cycle, and the composition of the communication frame is based on a superframe, and one superframe is one communication cycle.

[0023] Based on the above scheme: the communication cycle consists of 4 parts:

[0024] 1 beacon period

[0025] In the first stage, the master node (gateway) sends a beacon frame. The channel information used in this cycle and the next cycle is obtained from the channel management module (using frequency division multiplexing). The channel of this cycle is randomly generated by the previous cycle, and the channel of the next cycle is randomly generated by this cycle. The channel information is placed in the superframe, and then the number of slots in the non-contention period and the contention period is specified according to whether the gateway has control information, and placed in the beacon frame, switching to the channel used in this cycle, and sending a beacon frame. After a period interval, it immediately enters the non-contention period;

[0026] 2Non-competition period

[0027] The non-contention period is only used for the master node to send data and the slave node to receive information. In the home and building environment, the main purpose is control, so the design cycle exists to prioritize the data delivery. When the master node has application data to be delivered, the protocol stack will first cache the message to the queue. At the beginning of the superframe, it will determine whether there is data to be delivered, and then increase the number of slots in the non-contention period. Each slot sends a packet of data frames. The child node is in the receiving state. After receiving the data frame, it determines whether the frame target is itself. If so, it returns ACK and processes the data.

[0028] 3. Competition Period

[0029] The contention period is used for the child nodes to report data and the master node to receive information. At the beginning of the slot, the child node that sends data will perform a random delay and detect whether the channel is busy during the delay. If the channel is still idle at the end of the delay, the data frame will be sent and wait for ACK within the slot period. If the channel is detected to be busy during the delay, it means that other child nodes have sent data frames in this slot, and the child node will wait for the next slot to repeat the process.

[0030] 4 Broadcast period

[0031] Period is mainly used for devices that have not joined the network to quickly join the network. Period has two channels, one at each end of the protocol stack communication channel. Before a child node joins the network, when it needs to enter the network, it randomly enters a channel for monitoring and switches channels periodically. The master node enters the broadcast channel during period and sends the channel used by the next superframe. If the child node receives information, it immediately switches channels and enters the receiving state, waiting for the arrival of the beacon frame and joining the network.

[0032] Based on the above scheme: the protocol frame of the communication cycle is encrypted with AES128. When the master node and the sub-node are networked, they exchange and save UUID and a random number with each other. When unicasting, the radio frequency data is sent after being encrypted with AES using the UUID and random number of the device. When broadcasting, the radio frequency data is sent after being encrypted with AES using the UUID of the gateway.

[0033] The beneficial effects of the present invention are:

[0034] 1. A method for realizing wireless communication in a self-organizing network based on narrowband spread frequency hopping, which effectively improves the fault tolerance rate and transmission distance by increasing the bandwidth of the radio frequency signal and adding a spread spectrum factor to it, thus solving the problem of short communication distance.

[0035] 2. A method for realizing wireless communication in a self-organizing network based on narrowband spread frequency hopping, which uses a random number generation algorithm to randomly monitor channels and select the best frequency channel.

[0036] 3. A method for implementing wireless communication in a self-organizing network based on narrowband spread frequency hopping, in which the network is maintained by a master node and communicates directly with the device, thereby effectively reducing the complexity of the network structure, reducing the difficulty of management, and improving the timeliness of communication.

[0037] 4. A method for realizing wireless communication in a self-organizing network based on narrowband spread frequency hopping, which manages the active reporting mechanism of sub-nodes through a timetable, continuously optimizes the time of each communication, avoids conflicts, saves communication time, and ensures timeliness. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a flow chart of a method for realizing wireless communication in a self-organizing network based on narrowband spread frequency hopping proposed by the present invention;

[0039] Figure 2 It is a frequency division multiplexing FDM process diagram of a method for realizing wireless communication of a self-organizing network based on narrowband spread frequency hopping proposed by the present invention;

[0040] Figure 3 It is a frequency division multiplexing schematic diagram of a method for realizing wireless communication of a self-organizing network based on narrowband spread frequency hopping proposed by the present invention;

[0041] Figure 4 It is a waveform diagram after upsampling of the method for realizing wireless communication of a self-organizing network based on narrowband spread frequency hopping proposed by the present invention;

[0042] Figure 5 It is a filtered waveform diagram of the method for realizing wireless communication of a self-organizing network based on narrowband spread frequency hopping proposed by the present invention;

[0043] Figure 6 It is a modulation y(n) simulation diagram of the method for realizing wireless communication of a self-organizing network based on narrowband spread frequency hopping proposed by the present invention.

[0044] Figure 7 It is a network structure diagram of the method for realizing wireless communication of a self-organizing network based on narrowband spread frequency hopping proposed by the present invention.

[0045] Figure 8 The present invention is a logical operation diagram of a method for realizing wireless communication in a self-organizing network based on narrowband spread frequency hopping.

[0046] Fig. 9 It is a schematic diagram of a master node of a method for realizing wireless communication in a self-organizing network based on narrowband spread frequency hopping proposed by the present invention;

[0047] Fig.10 It is a schematic diagram of sub-nodes of the method for realizing wireless communication of a self-organizing network based on narrowband spread frequency hopping proposed by the present invention. DETAILED DESCRIPTION

[0048] The technical solution of this patent is further described in detail below in conjunction with specific implementation methods.

[0049] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0050] Embodiment 1:

[0051] A method for implementing wireless communication in a self-organizing network based on narrowband spread frequency hopping, such as Figure 1 As shown, the following steps are included:

[0052] S1: Use spread spectrum to communicate, increase the bandwidth of the RF signal, and add a spread factor to it to increase the transmission distance;

[0053] S2: frequency hopping mechanism is realized by frequency division multiplexing, which improves the transmission speed;

[0054] S3: It adopts a star network structure with one master and multiple slaves. The network is maintained by the master node and communicates directly with the devices, reducing the complexity of the network structure.

[0055] S4: Optimize the composition of the communication frame to realize the operation of the entire communication cycle.

[0056] Embodiment 2:

[0057] A method for implementing wireless communication in a self-organizing network based on narrowband spread frequency hopping, such as Figure 1 As shown, the following steps are included:

[0058] S1: Use spread spectrum to communicate, increase the bandwidth of the RF signal, and add a spread factor to it to increase the transmission distance;

[0059] S2: frequency hopping mechanism is realized by frequency division multiplexing, which improves the transmission speed;

[0060] S3: It adopts a star network structure with one master and multiple slaves. The network is maintained by the master node and communicates directly with the devices, reducing the complexity of the network structure.

[0061] S4: Optimize the composition of the communication frame to realize the operation of the entire communication cycle;

[0062] The theoretical basis of the spread spectrum communication in the spread spectrum mode in the S1 step is based on:

[0063] Shannon's channel capacity formula, also known as Shannon's formula:

[0064] C = w × log2 (1 + S / N)

[0065] In this formula: C is the information transmission rate; S is the useful signal power; W is the bandwidth; N is the noise power.

[0066] The above formula shows that when the signal transmission rate C is constant, the signal bandwidth W and the signal-to-noise ratio (S / N) are interchangeable, that is, increasing the signal bandwidth can reduce the requirement for the signal-to-noise ratio. When the bandwidth increases to a certain extent, the signal-to-noise ratio is allowed to be further reduced, and the useful signal power can be close to the noise power.

[0067] By increasing the bandwidth of the RF signal and adding a spread spectrum factor to it, the fault tolerance rate can be effectively improved, the transmission distance can be increased, and the problem of short communication distance can be solved.

[0068] The frequency hopping mechanism is implemented by frequency division multiplexing in step S2, wherein the frequency hopping mechanism adopts frequency division multiplexing, through which the transmission speed is improved and the problems of mutual interference of frequencies are avoided. The principle of frequency division multiplexing is based on frequency division multiplexing FDM, and its operation process is as follows: Figure 2 As shown;

[0069] Usually x1..4(t) can be the serial-to-parallel conversion of the same sequence, or different sequences. The frequency division multiplexing diagram is as follows Figure 3 As shown;

[0070] The protocol stack has planned a total of 48 channels for communication. Before transmitting, the master node uses a random number generation algorithm to randomly monitor channels and select the best frequency channel. In addition, four channels are randomly selected for transformation in each superframe, and signals of multiple different frequency bands are spliced ​​into a broadband signal. It mainly includes three operation steps:

[0071] S11: upsampling;

[0072] S22: filtering;

[0073] S33: Accumulation.

[0074] The up-sampling in step S11 is as follows: Figure 4 As shown;

[0075] In the filtering of step S22, the waveform after sampling needs to filter the marked part, using the prototype filter. The waveform after filtering is as follows Figure 5 As shown;

[0076] The accumulation in step S33 is performed after filtering to obtain the simulation diagram of the modulated y(n) as shown in FIG. Figure 6 shown.

[0077] In the one-master-multiple-slave star network structure in step S3, the network is maintained by the master node and communicates directly with the device, thereby effectively reducing the complexity of the network structure, reducing the difficulty of management, and improving the timeliness of communication. The network structure diagram is as follows Figure 7 As shown;

[0078] The master node automatically assigns logical addresses to child nodes according to the child nodes reported at random time. The number of child nodes managed by the group node is 255. The master node binds the physical address and logical address of the child node, regenerates the random schedule, and manages the active reporting mechanism of the child node through the schedule. Each communication continuously optimizes the time, avoids conflicts, saves communication time, and ensures timeliness. The logical operation diagram is shown as follows: Figure 8 As shown;

[0079] The composition of the communication frame in step S4 is optimized to realize the operation of the entire communication cycle. The composition of the communication frame is based on a superframe. A superframe is a communication cycle, which consists of four parts:

[0080] 1 beacon period

[0081] In this stage, the master node (gateway) sends out a beacon frame. This cycle will obtain the channel information used in this cycle and the next cycle from the channel management module (using frequency division multiplexing). The channel of this cycle is randomly generated by the previous cycle, and the channel of the next cycle is randomly generated by this cycle. The channel information is placed in the superframe, and then the number of slots in the non-competitive period and the competitive period is specified according to whether the gateway has control information, and placed in the beacon frame. Switch to the channel used in this cycle, and send a beacon frame. After a period of time, it immediately enters the non-competitive period.

[0082] 2Non-competition period

[0083] It is stipulated that the non-contention period is only used for the master node to send data and the slave node to receive information. In environments such as homes and buildings, the main purpose is control, so this period is designed to give priority to ensuring the sending of data. When the master node has application data to send, the protocol stack will first cache the message to the queue. At the beginning of the superframe, it will determine whether there is data to be sent, and then increase the number of slots in the non-contention period. Each slot sends a packet of data frames. The child node is in the receiving state. After receiving the data frame, it determines whether the frame target is itself. If so, it returns ACK and processes the data.

[0084] 3. Competition Period

[0085] The specified contention period is used for the child nodes to report data and the master node to receive information. At the beginning of the slot, the child node that sends data will perform a random delay and detect whether the channel is busy during the delay. If the channel is still idle at the end of the delay, the data frame will be sent and wait for ACK within the slot cycle. If the channel is detected to be busy during the delay, it means that other child nodes have sent data frames in this slot, and the child node will wait for the next slot to repeat the process.

[0086] 4 Broadcast period

[0087] This period is mainly used for devices that have not joined the network to quickly join the network. There are two channels available during this period, one at each end of the protocol stack communication channel. Before the child node joins the network, when it needs to enter the network, it randomly enters a channel for monitoring and switches channels periodically. The master node will enter the broadcast channel during this period and send the channel used by the next superframe. If the child node receives information, it will immediately switch channels, enter the receiving state, wait for the arrival of the beacon frame, and join the network.

[0088] The protocol frame of the communication cycle is encrypted with AES128. When the master node and the sub-node are networked, they exchange and save the UUID and a random number. In unicast, the RF data is sent after being encrypted with AES using the UUID and random number of the device. In broadcast, the RF data is sent after being encrypted with AES using the UUID of the gateway.

[0089] The above is a preferred specific implementation manner of the present invention, and the protection scope of the present invention is not limited thereto. Any modification, equivalent substitution and improvement made by any technician familiar with the field within the technical scope disclosed by the present invention in combination with the prior art or public common sense, within the spirit and principle of the present invention, shall be covered by the protection scope of the present invention.

Claims

1. A method for realizing wireless communication in a self-organizing network based on narrowband spread frequency hopping. It is characterized in that The following steps are involved: S1: Use spread spectrum to communicate, increase the bandwidth of the RF signal, and add a spread factor to it to increase the transmission distance; S2: frequency hopping mechanism is realized by frequency division multiplexing, which improves the transmission speed; S3: It adopts a star network structure with one master and multiple slaves. The network is maintained by the master node and communicates directly with the devices, reducing the complexity of the network structure. S4: Optimize the composition of the communication frame to realize the operation of the entire communication cycle.

2. The method for realizing wireless communication in a self-organizing network based on narrowband spread frequency hopping according to claim 1, It is characterized in that The theoretical basis of the spread spectrum communication in the spread spectrum mode in the S1 step is based on: Shannon's channel capacity formula, also known as Shannon's formula: C = w × log2 (1 + S / N).

3. The method for realizing wireless communication in a self-organizing network based on narrowband spread frequency hopping according to claim 2, It is characterized in that The frequency hopping mechanism is implemented by frequency division multiplexing in step S2, wherein the frequency hopping mechanism adopts frequency division multiplexing to improve the transmission speed and avoid the problem of mutual frequency interference. The principle of frequency division multiplexing is based on frequency division multiplexing FDM.

4. The method for realizing wireless communication in a self-organizing network based on narrowband spread frequency hopping according to claim 3, It is characterized in that The protocol stack in the frequency division multiplexing has planned a total of 48 channels for communication. Before transmitting, the master node uses a random number generation algorithm to randomly monitor channels and select the best frequency channel. In addition, four channels are randomly selected for transformation in each superframe, and signals of multiple different frequency bands are spliced ​​into a broadband signal. It mainly includes three operation steps: S11: upsampling; S22: filtering; S33: Accumulation.

5. The method for realizing wireless communication in a self-organizing network based on narrowband spread frequency hopping according to claim 4, It is characterized in that In the one-master-multiple-slave star network structure in step S3, the network is maintained by the master node and communicates directly with the devices.

6. The method for realizing wireless communication in a self-organizing network based on narrowband spread frequency hopping according to claim 5, It is characterized in that The master node automatically assigns a logical address to the child node based on the child node reported at random time. The number of child nodes managed by the group node is 255. The master node binds the physical address and logical address of the child node and regenerates the random timetable.

7. The method for realizing wireless communication in a self-organizing network based on narrowband spread frequency hopping according to claim 6, It is characterized in that The composition of the communication frame in step S4 is optimized to realize the operation of the entire communication cycle. The composition of the communication frame is based on a superframe, and one superframe is one communication cycle.

8. The method for realizing wireless communication in a self-organizing network based on narrowband spread frequency hopping according to claim 7, It is characterized in that The communication cycle consists of 4 parts: 1 beacon period In the first stage, the master node (gateway) sends a beacon frame. The channel information used in this cycle and the next cycle is obtained from the channel management module (using frequency division multiplexing). The channel of this cycle is randomly generated by the previous cycle, and the channel of the next cycle is randomly generated by this cycle. The channel information is placed in the superframe, and then the number of slots in the non-contention period and the contention period is specified according to whether the gateway has control information, and placed in the beacon frame, switching to the channel used in this cycle, and sending a beacon frame. After a period interval, it immediately enters the non-contention period; 2Non-competition period The non-contention period is only used for the master node to send data and the slave node to receive information. In the home and building environment, the main purpose is control, so the design cycle exists to prioritize the data delivery. When the master node has application data to be delivered, the protocol stack will first cache the message to the queue. At the beginning of the superframe, it will determine whether there is data to be delivered, and then increase the number of slots in the non-contention period. Each slot sends a packet of data frames. The child node is in the receiving state. After receiving the data frame, it determines whether the frame target is itself. If so, it returns ACK and processes the data.

3. Competition Period The contention period is used for the child nodes to report data and the master node to receive information. At the beginning of the slot, the child node that sends data will perform a random delay and detect whether the channel is busy during the delay. If the channel is still idle at the end of the delay, the data frame will be sent and wait for ACK within the slot period. If the channel is detected to be busy during the delay, it means that other child nodes have sent data frames in this slot, and the child node will wait for the next slot to repeat the process. 4 Broadcast period Period is mainly used for devices that have not joined the network to quickly join the network. Period has two channels, one at each end of the protocol stack communication channel. Before a child node joins the network, when it needs to enter the network, it randomly enters a channel for monitoring and switches channels periodically. The master node enters the broadcast channel during period and sends the channel used by the next superframe. If the child node receives information, it immediately switches channels and enters the receiving state, waiting for the arrival of the beacon frame and joining the network.

9. The method for realizing wireless communication in a self-organizing network based on narrowband spread frequency hopping according to claim 8, It is characterized in that The protocol frame of the communication cycle is encrypted with AES128. When the master node and the sub-node are networked, they exchange and save the UUID and a random number. In unicast, the RF data is sent after being encrypted with AES using the UUID and random number of the device. In broadcast, the RF data is sent after being encrypted with AES using the UUID of the gateway.

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