CN108449094B - Method for realizing ZigBee and Wifi interoperation based on GNU Radio - Google Patents

Abstract

The invention relates to a method for realizing the interoperation between ZigBee and Wifi based on GNU Radio, belonging to the technical field of wireless communication. The method comprises the following steps: setting parameters on a GNU Radio software Radio platform, connecting a clock recovery module for clock recovery after making a difference with a demodulated signal, and then outputting symbol data, realizing detection of a physical frame in a module Packet Sink module, and decoding the whole MAC protocol data unit with the help of a data Packet length field; completing the conversion from the ZigBee MAC frame to the WiFi MAC frame; and sending the encapsulated data frame to a WiFi PHY module for signal modulation, and then sending the data frame to a USRP for sending. The invention solves the problem of too low transmission speed of the ZigBee, improves the operability of the ZigBee, has longer transmission distance and higher speed, and is convenient to be interconnected with the user terminal.

Description

Method for realizing ZigBee and Wifi interoperation based on GNU Radio

Technical Field

The invention belongs to the technical field of wireless communication, and relates to a method for realizing the interoperation between ZigBee and Wifi based on GNU Radio.

Background

In recent years, the technology of the concerned wireless sensor network is developed rapidly, and meanwhile, the life of people is gradually influenced by vocabularies such as wireless control, wireless networking and wireless positioning, so that great convenience is brought to people. Wireless communication networks are gradually paid more attention to by people with the widespread use of modern internet technology and computer technology, and the unique advantages thereof also affect various aspects of social life. At present, Wireless sensors represented by a newly-developed ZigBee Wireless Sensor Network (WSN) develop rapidly, and become a new trend in the technical field of communication transmission. The system has the characteristics of low price, low power consumption, strong self-organization and the like, and is suitable for many occasions. The ZigBee nodes are distributed in a specific area, the information of various monitoring objects is sensed and collected by combining different types of sensors according to specific requirements, then the information is self-organized to form a network, and the information is transmitted to a user monitoring end through the formed network. The wireless sensor network is an effective extension of the human perception outside world, is a wireless communication path between a sensor and an observer, and greatly expands the detection range. However, the transmission speed of ZigBee has become a factor limiting the development thereof.

Meanwhile, various transmission networks develop rapidly, and a WiFi (Wireless Fidelity) network has better popularization and better development prospect due to the special performance of the WiFi network. WiFi is a network technology based on the IEEE802.11 protocol, which is essentially commercially certified. In daily life, terminal devices such as mobile phones and tablet computers are formally connected to the internet by means of a WiFi technology, and the wireless network access system has the advantages of being high in transmission rate, long in working distance, easy to establish and the like. WiFi is a bridge for seamless connection between a user terminal and the internet. Monitoring smart homes from the medical field and the environment, the smart homes permeate various aspects of social life.

In order to solve the problem that the ZigBee transmission speed is too low and improve the operability of the ZigBee, a ZigBee-WiFi network is provided and is mainly applied to intelligent home and coal mine safety monitoring systems. The ZigBee-WiFi network not only has the advantages of the ZigBee network, but also is added with the WiFi function on the basis of the ZigBee network, the transmission distance is longer, the speed is higher, and more importantly, the ZigBee-WiFi network is convenient to be interconnected with the user terminal. The most key problem of the ZigBee-WiFi network is how to realize the interoperation of the ZigBee and the Wi-Fi.

The GNU Radio can also be called as open source software Radio, and adopts a software Radio concept, almost all things which can be completed by software in an actual communication system are written into software codes, and tasks which must be completed by hardware are left to a universal hardware device (usually USRP) for completion, so that the combination of the GNU Radio and the USRP can complete various communication tasks, and services such as a transmitting path, a receiving path, channel interception and the like are provided for the communication system. At present, most of methods for realizing the interoperation between ZigBee and Wi-Fi are realized by hardware, the method has poor flexibility and is limited by hardware conditions, and any link can be flexibly changed according to actual needs through software realization. Therefore, the method for realizing the interoperation between the ZigBee and the Wi-Fi through software has certain research significance.

Disclosure of Invention

In view of this, the present invention provides a method for implementing ZigBee and Wifi interoperation based on GNU Radio, which can flexibly change any link according to actual needs, and overcomes the inflexibility of the existing hardware implementation method.

In order to achieve the purpose, the invention provides the following technical scheme:

a method for realizing ZigBee and Wifi interoperation based on GNU Radio comprises the following steps:

s1: on a GNU Radio software Radio platform, setting the Center frequency (Center Freq) of USRP Source to be 2.48GHz, the sampling rate (Sps) to be 4M, the Gain Type (Gain Type) to be Normalized and the output Type to be complete Float 32; after receiving the ZigBee signal according to the setting, the USRP firstly enters an rxin port of an IEEE 802.15.4PHY module, then a signal flow enters a queue Demod module for demodulation, then a Single policy IIR Filter is connected, the Filter data type is set to be Float, then a Clock Recovery module (Clock Recovery) is connected for Clock Recovery after the difference is made with the demodulated signal, then symbol data is output, the detection of a physical frame is realized in a module Packet Sink module, and the whole MAC Protocol Data Unit (MPDU) is decoded with the help of a data Packet length field; the synchronizer needs to detect the preamble 0x00 of 4 bytes, and a complete MAC Protocol Data Unit (MPDU) is found and it is added to a message queue; finally, the signal flows to an rxout port of an IEEE 802.15.4PHY module to complete demodulation in an OQPSK mode;

s2: after the signal is demodulated by OQPSK, the signal is sent to an IEEE 802.15.4MAC module to carry out de-encapsulation of a ZigBee MAC frame MPDU and temporarily store the data, and the module mainly removes a frame header MHR and a frame tail MFR and temporarily stores a data load MSDU;

s3: sending the temporarily stored data in the previous step into a WiFi MAC module, repacking the data according to the IEEE802.11 standard, and encapsulating the repacked data into a WiFi MAC frame, wherein S2-S3 complete the conversion from the ZigBee MAC frame to the WiFi MAC frame;

s4: sending the encapsulated data frame to a WiFi PHY module to modulate signals according to the IEEE802.11 standard;

s5: and sending the modulated WiFi signals into the USRP.

The invention has the beneficial effects that: the invention solves the problem of too low transmission speed of the ZigBee, improves the operability of the ZigBee, not only has the advantages of the ZigBee network, but also increases the WiFi function on the basis of the ZigBee network, has longer transmission distance and higher speed, and more importantly, is convenient to be interconnected with the user terminal.

Drawings

In order to make the object, technical scheme and beneficial effect of the invention more clear, the invention provides the following drawings for explanation:

FIG. 1 is a block diagram of a software implementation of GNU Radio on a software Radio platform according to the present invention;

FIG. 2 is a detailed view of an IEEE 802.15.4PHY module of the present invention;

FIG. 3 is a schematic diagram of ZigBee and WiFi networking;

FIG. 4 is a schematic diagram of an embodiment of the present invention.

Detailed Description

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

In order to achieve the above object, the present invention utilizes the great operability of software Radio GNU Radio to implement the interoperation between ZigBee and WiFi on the USRP platform, as shown in fig. 1, the implementation process includes the following steps:

step 1 the invention is completed on the GNU Radio software Radio platform, the Center frequency (Center Freq) of the USRP Source is set to 2.48GHz, the sampling rate (Sps) is 4M, the Gain Type (Gain Type) is Normalized, and the output Type is complete Float 32. After receiving the ZigBee signal according to the setting, the USRP firstly enters the rxin port of the IEEE 802.15.4PHY module (details of the IEEE 802.15.4PHY module are shown in fig. 2), then the signal stream enters the quadraturedmod module for demodulation, then a Single policy IIR Filter is connected, the Filter data type is set to Float, then a Clock Recovery module (Clock Recovery) is connected for Clock Recovery after the difference is made with the demodulated signal, then symbol data is output, physical frame detection is realized in the Packet Sink module, and the whole MAC Protocol Data Unit (MPDU) is decoded with the help of the Packet length field. The synchronizer needs to detect the preamble 0x00 of 4 bytes and a complete MAC Protocol Data Unit (MPDU) is found and it is added to a message queue. Finally, the signal flows to an rxout port of an IEEE 802.15.4PHY module to complete demodulation in an OQPSK mode; as shown in fig. 2.

Step 2, after the signal is demodulated by OQPSK, the signal is sent to an IEEE 802.15.4MAC module to unpack a ZigBee MAC frame MPDU and temporarily store the data, and the module mainly removes a frame header MHR and a frame tail MFR and temporarily stores a data load MSDU (the IEEE 802.15.4MAC frame is shown in the following table);

step 3, sending the temporarily stored data in the previous Step into a WiFi MAC module, repacking the data according to the IEEE802.11 standard, and packaging the data into a WiFi MAC frame, wherein the transition from the ZigBee MAC frame to the WiFi MAC frame is completed from Step 2 to Step 3 (the WiFi MAC frame is shown in the following table, and the ZigBee MAC frame and the WiFi MAC frame can be found to be different compared with the above table);

step 4, sending the encapsulated data frame to a WiFi PHY module to modulate signals according to the IEEE802.11 standard;

step 5, sending the modulated WiFi signal into a USRP for sending;

the ZigBee technology is used in occasions with low speed, short distance, low power consumption, strong self-organization and wide coverage range, and is suitable for acquiring small data at a site end; WiFi is a network technology with the characteristics of long distance and high speed, and is concerned by the characteristic of being able to conveniently access Internet network. The invention combines ZigBee and WiFi networks, and realizes the interoperation of ZigBee and WiFi through a software Radio platform GNU Radio, as shown in FIG. 3.

The main reason why ZigBee can be widely used is its strong networking capability. Currently, ZigBee communication includes three communication modes, namely broadcast, multicast, and unicast. Each node has a specific assigned address, and the router node and the terminal node can transmit the address of a sending object to a designated coordinator by setting the address of the sending object. Broadcast is when the terminal node sends data to the surroundings, all node devices in the network can receive the data, but this way causes congestion in the network and should limit the use. The multicast is to group the nodes in the network and communicate the devices with the same group number, and the grouping mode is beneficial to the management of the network and is suitable for complex large-scale networks. The unicast communication method is also called on-demand, and is limited to the communication among specific devices in the network. A communication connection is established between the two points and data cannot be received by the other node.

In the embodiment, a broadcast communication mode is adopted, and the ZigBee node CC2530 of the Shimadaga Gongben electronic technology Co., Ltd is used for cooperating with the USRP N210 and the daughter board UBX-40 thereof to complete the interoperation between the ZigBee and the WiFi, as shown in FIG. 4.

The ZigBee node CC2530 sends data frames to USRP1 and a computer PC1(personal computer), the USRP1 sends the frequency-converted signals to a software Radio platform GNU Radio of the PC1, and the modules are configured as follows: the Center frequency (Center Freq) of the USRP Source is set to 2.48GHz, the sampling rate (Sps) is 4M, the Gain Type (Gain Type) is Normalized, and the output Type is complete Float 32; then the signal flow enters a Quadrature Demod module for demodulation, then a Single poll IIR Filter is connected, the data type of a Filter is set as Float, then a clock recovery module (clock recovery) is connected for clock recovery after the difference is made with the demodulated signal, then symbol data is output, the detection of a physical frame is realized in a module Packet Sink module, and the whole MAC Protocol Data Unit (MPDU) is decoded under the help of a data Packet length field; after the signal is demodulated by OQPSK, the signal is sent to an IEEE 802.15.4MAC module to carry out the decapsulation of a ZigBee MAC frame MPDU and temporarily store the data, and in the module, a frame header MHR and a frame tail MFR are mainly removed and a data load MSDU is temporarily stored. And then, adding a WiFi frame header and a WiFi frame header into the temporarily stored data again according to the IEEE802.11 standard, then, physically modulating the repackaged and packaged data in a WiFi PHY module, and then sending the data to a USRP2 and a PC2 through a USRP1, wherein the USRP2 and the PC2 are equivalent to a WiFi receiving end and are responsible for demodulating and decapsulating signals sent by the USRP 1. The interoperation between ZigBee and WiFi is completed.

Finally, it is noted that the above-mentioned preferred embodiments illustrate rather than limit the invention, and that, although the invention has been described in detail with reference to the above-mentioned preferred embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the scope of the invention as defined by the appended claims.

Claims (1)

1. A method for realizing ZigBee and Wifi interoperation based on GNU Radio is characterized in that: the method comprises the following steps:

s1: using open Source software Radio GNU Radio, setting the Center frequency of a universal software Radio peripheral USRP Source (Universal software Radio protocol) Freq to be 2.48GHz, the sampling rate Sps to be 4M, the Gain Type to be Normalized, and the output Type to be complete Float 32; after receiving the ZigBee signal according to the setting, the USRP firstly enters an rxin port of an IEEE 802.15.4PHY module, then a signal flow enters a queue Demod module for demodulation, then a Single poll IIR Filter is connected, the type of Filter data is set to be Float, then a Clock Recovery module is connected for Clock Recovery after the difference is made with the demodulated signal, then symbol data is output, the detection of a physical frame is realized in a module Packet Sink module, and the whole MAC protocol data unit MPDU is decoded with the help of a data Packet length field; the synchronizer needs to detect the preamble 0x00 of 4 bytes, and a complete MAC protocol data unit MPDU is found and added to a message queue; finally, the signal flows to an rxout port of an IEEE 802.15.4PHY module to complete demodulation in an OQPSK mode;

s2: after the signal is demodulated by OQPSK, the signal is sent to an IEEE 802.15.4MAC module to carry out de-encapsulation of a ZigBee MAC frame MPDU and temporarily store the data, and the module mainly removes a frame header MHR and a frame tail MFR and temporarily stores a data load MSDU;

the IEEE 802.15.4MAC frame is as follows:

s3: sending the temporarily stored data in the previous step into a WiFi MAC module, repacking the data according to the IEEE802.11 standard, and encapsulating the repacked data into a WiFi MAC frame, wherein S2-S3 complete the conversion from the ZigBee MAC frame to the WiFi MAC frame;

the WiFi MAC frame is as follows:

s4: sending the encapsulated data frame to a WiFi PHY module to modulate signals according to the IEEE802.11 standard;

s5: and sending the modulated WiFi signals into the USRP.

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