CN107809265B - COFDM wireless broadband ad hoc network module suitable for complex environment - Google Patents

Abstract

The invention discloses a COFDM wireless broadband ad hoc network module suitable for complex environments, comprising a casing and an ad hoc network mainboard circuit; the ad hoc network mainboard circuit includes radio frequency reception, radio frequency interference detection, radio frequency transmission, broadband radio frequency transceiver unit, baseband The unit, the self-organized network protocol implementation unit, the user interface unit, and the low-ripple analog-digital isolated power supply system are composed of a system bandwidth of 24M‑60Mbps throughput rate, which can satisfy any 6‑10 hops, and the minimum bandwidth between any nodes is greater than 3Mbps throughput rate. The wireless signal baseband can be adjusted to 300M‑6G, supports FDD frequency hopping and TDD multiplexing connection, high wireless signal linearity, automatic radio frequency interference detection technology, strong anti-interference ability, good spurious suppression, high receiving sensitivity, and good filtering effect. The high noise ratio can meet the communication module of wireless broadband ad hoc network in complex environment. Using this module, it can be designed into any form of ad hoc network product, which can be applied to industrial customers or individual combat systems.

Description

COFDM wireless broadband ad hoc network module suitable for complex environments

technical field

The invention relates to the technical field of wireless ad hoc network communication, in particular to a COFDM wireless broadband ad hoc network module suitable for complex environments.

Background technique

In special industry applications such as public security, fire protection, electric power, petroleum and other fields, it is impossible to establish a fixed wireless communication network at the incident site in advance, and the application environment of these industries is very complex, such as in the narrow streets of high-rise buildings, multi-storey basement signal It is impossible to establish an effective emergency wireless communication network, and it is impossible to transmit the information on the scene of the accident to a safe place. At present, there are no good wireless products for ad hoc networks on the market.

The traditional public mobile network is a pre-established network, which must rely on infrastructure construction, and must have a wireless cellular coverage network built with base stations and wired optical fibers; at the same time, it is a point-to-multipoint star network, and mobile terminals do not have routing functions. Data transmission It can only be exchanged through the base station. If the base station is damaged, the communication will be interrupted. The damage resistance of the network is poor, and the maintenance and operation cost is high. This is why it cannot be applied to the emergency communication needs of industrial customers.

The existing products in the traditional industry are all point-to-point single communication networks, and large-scale networking applications cannot be realized. Ad-hoc network communication products on the market mainly include products based on Bluetooth and Zigbee in the field of IoT, and broadband communication products based on the 802.11 protocol family in short distances. The communication bandwidth of the former is very narrow, the nodes are only about ten kbs, and only low-speed data information can be transmitted. Large communication data and video data with high real-time requirements cannot be transmitted; ad-hoc network products based on the 802.11 protocol family are born for home and office. The fixed use design of the site has poor mobility. If the number of access nodes is greater than 4, the performance will drop sharply, and the node switching delay is high. The application has no use value in the field of emergency communication.

At present, the ad hoc network products applied to industrial customers on the market are basically various products based on the improvement of the MESH function of the 802.11 protocol. The switching time of several points is tens of seconds, and there are frequent network node switching and deadlock problems, and bandwidth jitter is large. High latency, short communication distance, and poor mobility; wireless signals have poor linearity of the receiving circuit, small dynamic range, and low signal-to-noise ratio, resulting in high bit error rate and poor anti-interference ability. Dispersed and secondary intermodulation signals interfere with the reception of adjacent nodes; these serious defects lead to this kind of products can only be demonstrated and cannot meet the real application requirements of industry customers.

Any ad hoc network communication must meet the characteristics of fast switching and high-speed mobility. It adopts distributed networking network technology, does not have the management of central base station control nodes, and does not rely on any wired and communication infrastructure. It is provided in special industries and under special conditions. A means of guaranteeing emergency network communications. When any ad hoc network module is turned on, it will automatically collect other ad hoc network communication modules or relay modules nearby, and dynamically establish a communication network.

The nodes of the network can form a chain network or a star network according to their location. The data information in the network will choose the best path to communicate with the target node according to the status of each node. When a node in the network fails, other nodes can continue to communicate.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is that the ad hoc network products currently on the market applied to industrial customers are basically various products based on the improvement of the MESH function of the 802.11 protocol, the node switching time is tens of seconds, and there are frequent network node switching and Deadlock problem, large bandwidth jitter, high delay, short communication distance, and poor mobility; wireless signals have poor linearity of the receiving circuit, small dynamic range, and low signal-to-noise ratio, resulting in high bit error rate, poor anti-interference ability, and mutual distance between nodes The spurious and secondary intermodulation signals emitted by the recent transmission signal interfere with the reception of adjacent nodes; these serious defects lead to this kind of products can only be demonstrated and cannot meet the real application needs of industry customers. The purpose is to provide products suitable for complex environments. The COFDM wireless broadband ad hoc network module solves the above problems.

The present invention is achieved through the following technical solutions:

A COFDM wireless broadband ad hoc network module suitable for complex environments, including a chassis, an ad hoc network mainboard circuit; an ad hoc network mainboard circuit including a radio frequency receiving unit, a radio frequency interference detection unit, a radio frequency transmitting unit, a broadband radio frequency transceiver unit, and a baseband unit, self-organized network protocol implementation unit, user interface unit, and low-ripple analog-digital isolated power supply system; wherein, the radio frequency receiving unit includes two sets of symmetrical signal inputs, two sets of radio frequency receiving matching networks, two sets of receiving balance transformer networks, Two groups of first receiving two-phase filters; the radio frequency signal from space is processed and output by the radio frequency receiving and matching network and connected to the receiving balance transformer network, and the two outputs of the receiving balance transformer network are connected to the first receiving two-phase filter, and the first receiving two-phase filter is connected to the first receiving two-phase filter. The filter outputs the analog signal into the broadband radio frequency transceiver unit; the radio frequency interference detection unit includes a broadband interference detection matching network, an interference detection balance transformer network, and a second receiving two-phase filter, and the radio frequency signal from the wireless space is detected and matched by the broadband interference The output after network processing is connected to the interference detection balance transformer network into two outputs and enters the second receiving bi-phase filter, and the output analog signal enters the broadband radio frequency transceiver unit; Two sets of transmitting balance transformer networks and two sets of RF transmission matching networks; the dual-channel MIMO 2X2 radio frequency transceiver of the broadband RF transceiver unit sends two sets of analog signals into the transmission dual-phase filter, and the output of the transmission dual-phase filter enters the transmission balance transformer network output The single-channel analog signal enters the RF transmission matching network, the RF transmission matching network outputs TX, and the TX enters the transmitting antenna; the broadband RF transceiver unit includes a low-noise power supply, a dual-channel MIMO 2X2 RF transceiver, a multi-channel clock generator, VCO, RF-CLK; the dual-channel MIMO 2X2 RF transceiver receives the RX1 and RX2 dual-channel differential RF signals output by the first two sets of the first receiving bi-phase filter in the RF receiving unit, and the input is converted into digital RX DATA after internal processing, including 2 channels of RX Data information enters the baseband unit. The dual-channel MIMO 2X2 RF transceiver converts the baseband digital I/Q signal output from the baseband unit into dual-channel RF signal output through internal processing. The low-noise power output is connected to the dual-channel MIMO 2X2 RF transceiver. It provides low 4-channel high PSRR 80d power output, and the multi-channel clock generator and VCO form a multi-channel 0.1ppm clock source for the dual-channel MIMO 2X2 RF transceiver and baseband unit. Two digital signal inputs of the broadband radio frequency transceiver unit and one channel observation digital signal input from the broadband radio frequency transceiver unit are used to send the output two digital signals to the broadband radio frequency transceiver unit; the input and output interfaces of the control signal of the baseband unit are the same as The input and output interface of the control signal of the broadband radio frequency transceiver unit is connected; the baseband unit is connected with the 4xDSP+CPU chip data read channel, write channel and parameter configuration interface of the ad hoc network protocol implementation unit; The networking protocol implementation unit is used to realize that the core component of the unit is a 4xDSP+CPU chip, which is connected with the user unit, the baseband unit, the digital interface of the broadband RF transceiver unit, and the control interface, so as to realize the two-way data from the user unit to the user unit. After processing, it is sent to the baseband unit, the access switching of the node, the switching of the working mode, and the dual-channel MIMO 2X2 RF transceiver is set up through the control interface; the user interface unit includes the RJ45 network interface, the USB user interface, and the status display module. The RJ45 network interface is the same as the 4xDSP. +CPU's MAC PHY interface is connected, the USB user interface is directly connected with the 4xDSP+CPU's USB2.0 interface, and the status display is connected with the 4xDSP+CPU UART. power supply. In order to solve the appeal problem, the RF receiving circuit includes 2 independent band RF inputs, 2 independent RF receiving matching networks, 2 receiving balance transformer networks, and 2 first receiving two-phase filters, among which the receiving balance transformer network adopts BD0310J50200AHF, BD0215J50200AHF, their outputs are sequentially connected to the AD9371 chip, the core component of the broadband RF transceiver unit, AD9371 completes ADC conversion after down-converting the received RF signal, and outputs a digital baseband signal after multi-stage digital filtering. The insertion loss of the entire input RF signal processing process is less than 3dBm, the suppression level 3 is greater than 60dB; the radio frequency interference detection unit passes through the radio frequency receiving matching network, and the output is connected with the interference detection balance transformer network BD0618J50200AHF, and the output after the connection of the second receiving two-phase filter enters the same broadband RF transceiver unit core chip AD9371, AD9371 completes ADC conversion after down-converting the received interference RF signal, and outputs digital baseband signal to the baseband unit after multi-stage digital filtering. One input channel of this chip is used for spatial interference detection, which is used as routing calculation, transmission optimal path confirmation, transmission bandwidth The implementation of guarantee and anti-interference measures provides a physical basis for decision-making; the 2-channel digital baseband signals from the baseband unit FPGA are sent to the AD9371, and after the multi-stage output digital deliberation of the AD9371, the DAC output passes through the transmitting bidirectional filter, and then enters the 300M in turn. -1000M B0322J5050AHF, 1200-1800M NCR2-183+ transmit balance transformer network, turn the differential signal into single-ended input to the RF transmit matching network to output two TX signals, the entire transmit RF ±100M out-of-band spurious suppression is greater than 70dbm, This greatly ensures the receiving performance in FDD mode; through the low-ripple analog-digital isolated power supply system, the PSRR reaches 80dB, and multiple MIC5524 are used to provide four sets of power outputs of 1.2V, 1.8V, 3.3V, and 3.3V. And each group of power supply is designed with a special filter circuit, and the output power supply is less than 2mv, which ensures the reliable operation of the core chip AD9371 of the dual-channel MIMO2X2 RF transceiver, and the demodulation sensitivity is guaranteed. One set of 3.3V is used to supply the clock circuit to ensure that the phase noise of the clock source is not deteriorated; the band unit is implemented by ALTERA FPGA to complete the modulation and demodulation algorithm, and the COFDM modulation and demodulation algorithm is creatively used to realize channel transmission. Compared with WIFI and other ad-hoc network modulation and demodulation OFDM protocols, it has the advantages of inherently faster moving speed, excellent anti-Doppler frequency shift effect, and high demodulation flexibility. 2-channel and dual-channel MIMO 2X2 RF transceiver receives digital baseband signal input. 1-channel interference detection array baseband signal input and demodulate to form original data stream for processing by 4XDSP+CPU chip, 2-channel 4XDSP+CPU chip sends data stream through COFDM modulation to form 2-channel independent digital baseband signal into dual-channel MIMO 2X2 RF transceiver Its COFDM modulation supports 4M/8M/10M/20M/40M spectrum bandwidth, and can automatically adapt to different spectrum bandwidth networking protocols according to channel conditions and communication load. The realization unit uses its core component 4xDSP+CPU chip to complete the docking with the FPGA chip , The DSP completes the implementation of the ad hoc network routing algorithm at the MAC layer and the realization of the networking protocol, which is different from the traditional implementation of routing and networking protocols at the IP layer, and improves the response speed of the entire system in networking and node access, especially when The multi-hop efficiency of the system chain network is improved by 15%, which realizes multi-hop relay transmission in complex mountainous areas and basements, and achieves a large data throughput rate for each node; its internal CPU completes human-computer data interaction, and the system is in this state. Display, and innovatively establish a manual pre-intervention node mechanism according to the characteristics of industry customers, which brings bandwidth sacrifice to reduce unnecessary node jumps and ensures that the jump delay of any node in the system is less than 5ms. Therefore, the current market is solved by the above technical means. The ad hoc network products used in the industry customers are basically various products based on the improvement of the MESH function of the 802.11 protocol. The switching time of several points is tens of seconds, and there are frequent network node switching and deadlock problems, and bandwidth jitter and large delay. High, short communication distance, poor mobility; there is poor linearity of the receiving circuit on the wireless signal, small dynamic range, low signal-to-noise ratio, high bit error rate, poor anti-interference ability, when the nodes are close to each other, the spurious, The secondary intermodulation signal interferes with the reception of adjacent nodes; these serious defects lead to the problem that such products can only be demonstrated and cannot meet the real application requirements of industry customers.

Further, the three-way wireless signals are independently received and connected to the radio frequency receiving matching network.

Further, when the two wireless signals are independently transmitted, the radio frequency transmission matching network is connected to the antenna.

Further, the output of the low-ripple analog-digital isolated power supply system is connected to the dual-channel MIMO 2X2 RF transceiver core chip AD9371; the output of the low-ripple analog-digital isolated power supply system is connected to the clock generator chip AD9528. Ensure low power supply noise and ripple, ensure that noise and ripple are not brought into the DAC and ADC circuits, and are not brought into the RF transceiver circuit. The RF noise floor of the entire system is designed to be lower than -95dbm.

Further, the algorithm of the baseband modulation and demodulation of the ad hoc network adopts COFDM. Using COFDM, making full use of its "non-line-of-sight" and "diffraction" transmission advantages, it can stably transmit high data streams in urban areas, mountains, inside and outside buildings and other invisible and obstructed environments.

Further, using 2 channels to transmit and receive can work in FDD mode or TDD mode. The access switching speed and transmission bandwidth of the system are guaranteed.

Compared with the prior art, the present invention has the following advantages and beneficial effects:

1. The present invention is suitable for COFDM wireless broadband ad hoc network modules in complex environments, providing a system bandwidth of 24M-60Mbps throughput rate, satisfying any 6-10 hops, the minimum bandwidth between any nodes is greater than 3Mbps throughput rate, and the wireless signal baseband meets 300M -6G adjustable, support FDD frequency hopping and TDD multiplexing connection, high linearity of wireless signal, strong anti-interference ability of radio frequency interference automatic detection technology, good spurious suppression, high receiving sensitivity, good filtering effect, high signal-to-noise ratio can satisfy The communication module of wireless broadband ad hoc network in complex environment, using this module, it can be designed into any form of ad hoc network product, which can be applied to industry customers or individual combat systems;

2. The present invention is suitable for COFDM wireless broadband ad hoc network modules in complex environments. By adopting COFDM, the advantages of "non-line-of-sight" and "diffraction" transmission are fully utilized, which cannot be used in urban areas, mountains, and inside and outside buildings. It can stably transmit a high data stream in a viewing and obstructed environment;

3. The present invention is suitable for COFDM wireless broadband ad hoc network modules in complex environments. By using a low-ripple analog-digital isolated power supply system, it ensures low power supply noise and ripple, and ensures that noise and ripple are not brought into DAC and ADC circuits. , without the RF transceiver circuit, the RF noise floor is lower than -95dbm when the whole system is designed to work.

Description of drawings

The accompanying drawings described herein are used to provide further understanding of the embodiments of the present invention, and constitute a part of the present application, and do not constitute limitations to the embodiments of the present invention. In the attached image:

Fig. 1 is a schematic block diagram of the circuit principle of an ad hoc network mainboard of the present invention;

2 is a schematic diagram of the implementation of a radio frequency receiving matching network circuit of the present invention;

Fig. 3 is the implementation principle diagram of the network circuit of the receiving balance transformer of the present invention;

4 is a schematic diagram of the implementation of the receiving bi-phase filter circuit of the present invention;

5 is a schematic diagram of the implementation of the transmitting bi-phase filter circuit of the present invention;

6 is a schematic diagram of the implementation of a transmitter balanced transformer network and a radio frequency transmitter matching circuit of the present invention;

FIG. 7 is a block diagram of the design principle of the low-noise power supply of the present invention.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and the accompanying drawings. as a limitation of the present invention.

Example

As shown in FIG. 1 , the present invention is applicable to a COFDM wireless broadband ad hoc network module in a complex environment, including a chassis and an ad hoc network mainboard circuit; the ad hoc network mainboard circuit includes a radio frequency receiving unit, a radio frequency interference detection unit, and a radio frequency transmitting unit , a broadband radio frequency transceiver unit, a baseband unit, an ad hoc network protocol implementation unit, a user interface unit, and a low-ripple analog-digital isolated power supply system; wherein, the radio frequency receiving unit includes two symmetrical sets of signal inputs, two sets of radio frequency receiving matching networks, Two sets of receiving balance transformer networks and two sets of first receiving two-phase filters; the radio frequency signal from space is processed and output by the radio frequency receiving matching network and then connected to the receiving balance transformer network, and the two outputs of the receiving balance transformer network are connected to the first receiving two-phase filter The first receiving bi-phase filter outputs the analog signal into the broadband radio frequency transceiver unit; the radio frequency interference detection unit includes a broadband interference detection matching network, an interference detection balance transformer network, and a second receiving bi-phase filter, from the wireless space After the RF signal is processed by the broadband interference detection and matching network, the output is connected to the interference detection balance transformer network and becomes two outputs into the second receiving dual-phase filter. The output analog signal enters the broadband RF transceiver unit; the RF transmitter unit includes two symmetrical groups. Transmitting group bi-phase filters, two groups of transmitting balanced transformer networks, two groups of RF transmission matching networks; the dual-channel MIMO 2X2 RF transceiver of the broadband RF transceiver unit sends out two groups of analog signals into the transmitting bi-phase filter, and the transmitting bi-phase filter The output enters the transmitting balance transformer network and the single-channel analog signal enters the RF transmission matching network. The RF transmission matching network outputs TX, and the TX enters the transmitting antenna; the broadband RF transceiver unit includes a low-noise power supply, a dual-channel MIMO 2X2 RF transceiver, multiple Channel clock generator, VCO, RF-CLK; dual-channel MIMO 2X2 RF transceiver receives the two sets of first receiving bi-phase filters in the RF receiving unit The RX1 and RX2 dual-channel differential RF signal input is converted into digital after internal processing RX DATA, including 2 channels of RX data information, enters the baseband unit, and the dual-channel MIMO2X2 RF transceiver converts the baseband digital I/Q signal output from the baseband unit into dual-channel RF signal output through internal processing, and the low-noise power output is the same as the dual-channel output. The MIMO 2X2 RF transceiver connection provides it with 4 channels of low PSRR 80d power output, and the multi-channel clock generator and VCO form a multi-channel 0.1ppm clock source for the dual-channel MIMO 2X2 RF transceiver and baseband unit. Provide clock source; baseband The unit is used to receive two digital signal inputs from the broadband radio frequency transceiver unit and one channel observation digital signal input from the broadband radio frequency transceiver unit, and is used to send the output two digital signals to the broadband radio frequency transceiver unit; the control of the baseband unit The input and output interface of the signal is connected with the input and output interface of the control signal of the broadband radio frequency transceiver unit; the baseband unit is connected with the 4xDSP+CPU chip data read channel, write channel and parameter configuration of the ad hoc network protocol realization unit Interface connection; Ad-hoc network protocol implementation unit, used to realize the core component of the unit is a 4xDSP+CPU chip, docking with the user unit, baseband unit, broadband radio frequency transceiver unit digital interface docking, control interface docking, in order to realize the future and users The bidirectional data of the unit is processed and sent to the baseband unit; the access switching of the node, the switching of the working mode, the dual-channel MIMO 2X2 radio frequency transceiver is set through the control interface; the user interface unit, including the RJ45 network interface, the USB user interface, the status display module, RJ45 The network interface is connected with the MAC PHY interface of the 4xDSP+CPU, the USB user interface is directly connected with the USB2.0 interface of the 4xDSP+CPU, and the status display is connected with the UART of the 4xDSP+CPU; the low-ripple analog-digital isolated power supply system is used for the whole system Provides interference-free power. The three-way wireless signal is independently received and connected to the radio frequency receiving matching network. When the two wireless signals are transmitted independently, the radio frequency transmission matching network is connected with the antenna. The output of the low-ripple analog-digital isolated power supply system is connected with the core chip AD9371 of the dual-channel MIMO 2X2 radio frequency transceiver; the output of the low-ripple analog-digital isolated power supply system is connected with the clock generator chip AD9528. The algorithm of the self-organized network baseband modulation and demodulation of the self-organized network protocol realization unit adopts COFDM. Using 2 channels to send and receive can work in FDD mode or TDD mode. The dual-channel MIMO 2X2 RF transceiver design features ADI's high-performance, highly-integrated wideband RF transceivers that provide dual-channel transmitters and receivers, integrated frequency synthesizers, and test and digital signal processing capabilities. Can support 300M-6G range of RF output and input, support 200M bandwidth receiving and transmitting 100M bandwidth ad hoc network RF performance requirements, can achieve multi-channel signal transmission and reception at the same time, can work in different frequency FDD transceiver mode, can also work in the same frequency TDD mode Transceiver, provides a strong physical guarantee for realizing high bandwidth, high throughput, ms-level node switching, and access deletion of ad hoc networks. At the same time, it uses multiple digital filters integrated in it to achieve high steepness filtering performance to ensure the output signal shoulder band and signal-to-noise ratio. This is the guarantee that he can transmit a long distance in a complex environment; the ad hoc network protocol implementation unit uses its core component 4xDSP+CPU chip to complete the connection with the FPGA chip, and the DSP completes the ad hoc network routing algorithm at the MAC layer. The implementation of the protocol, which is different from the traditional implementation of routing and networking protocols at the IP layer, improves the response speed of the entire system in networking and node access, especially when the system is chained with multiple hops. Mountainous areas and basements realize multi-hop relay transmission to achieve a large data throughput rate for each node; its internal CPU completes human-machine data interaction, the state of the system is displayed, and an innovative manual pre-intervention node mechanism is established according to the characteristics of industry customers. , in order to reduce the bandwidth sacrifice caused by unnecessary node jumps, and ensure that the jump delay of any node in the system is less than 5ms.

As shown in Figure 2, the RF receiving matching network is actually a typical π filter, which achieves a dual-band bandwidth of 100Mhz, RX1 center frequency 1.4G, RX2 center frequency 840M, and each network suppresses more than 40db. When interference enters, ensure that the input impedance is 50 ohms. In other frequency bands, it is necessary to adjust the matching parameters of its capacitance, resistance and inductance, so that the dual-band design further improves the wireless anti-interference ability.

As shown in Figure 3, the purpose of the receiving balance transformer network is to turn the input single-port network into a differential network, and isolate other out-of-band spurs from entering the post-stage network. The BD0215J50200AH, F adopts a bi-phase filter network with good isolation and less than 1.5dB insertion loss, and its output differential signal enters the receiver.

As shown in Figure 4, the receiving bi-phase filter circuit performs band-pass filtering on the signal output from the receiving balance transformer network, the circuit form is exactly the same, and different receiving bands (RX1, RX2, SNRX) are debugged with different parameters, which can achieve 200M bandwidth, The insertion loss is less than 2.5Db, the suppression is greater than 30dB technical parameters, and the signals that do not belong to the band are further filtered out. The interference detection balance transformer network adopts the 600-1800M balance transformer BD0618J50200AHF, and its circuit form is completely the same as Figure 3. It can detect all interference signals and working signals in this band, and use it as a decision for the post-stage frequency modulation scheme. TDD mode allocation ensures fast switching of nodes , bandwidth allocation, physical guarantee to avoid interference.

As shown in Figure 5, the transmit bi-phase filter filters the RF output from the dual-channel MIMO 2X2 RF transceiver to ensure that out-of-band spurs are not carried into the wireless space and do not interfere with the RX signal in FDD mode of operation. 2 transmit bi-phase filters work on the center frequency 840M and 1.4G band, the bandwidth is 100M, the impedance is 50 ohms, and the suppression is greater than 40dB. AVDD_1V8 and low noise power output 1.8V connection, TX+, TX- and MIMO 2X2 RF transceiver RF Output TX1+, TX1- (the other group is connected with TX2+, TX2-), and output BAL_TX+ and BAL_TX- after network filtering and enter the transmitting output balance transformer network.

As shown in Figure 6, the two groups of transmitting and output balanced transformer networks use B0322J5050AHF of 300M-1000M and NCR2-183+ of 1200-1800M respectively. The input signal is converted into a single-port signal output, and after entering the transmission matching network for processing, it is convenient for the upper antenna to be transmitted or the external PA to transmit.

As shown in Figure 7, the broadband RF transceiver unit is specially designed to optimize the low-noise power supply. It uses a PSRR of 80dB, and uses multiple MIC5524 to provide four sets of power outputs of 1.2V, 1.8V, 3.3V, and 3.3V, and each power supply A special filter circuit is designed, and the output power is less than 2mv, which ensures the reliable operation of the dual-channel MIMO 2X2 RF transceiver, and the demodulation sensitivity is guaranteed. One set of 3.3V is used to supply the clock circuit to ensure that the phase noise of the clock source is not deteriorated.

The specific embodiments described above further describe the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention, and are not intended to limit the scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (4)

1. A COFDM wireless broadband ad hoc network module suitable for complex environments, characterized in that it includes a chassis, an ad hoc network motherboard circuit; the ad hoc network motherboard circuit includes a radio frequency receiving unit, a radio frequency interference detection unit, a radio frequency transmitting unit, a broadband A radio frequency transceiver unit, a baseband unit, an ad hoc network protocol implementation unit, a user interface unit, and a low-ripple analog-digital isolated power supply system; wherein, The radio frequency receiving unit includes two sets of symmetrical signal inputs, two sets of radio frequency receiving and matching networks, two sets of receiving balance transformer networks, and two sets of first receiving two-phase filters; the radio frequency signals from the space are processed by the radio frequency receiving and matching network, and the output is connected and received. Balance transformer network, the two outputs of the receiving balance transformer network are connected to the first receiving bi-phase filter, and the first receiving bi-phase filter outputs the analog signal and enters the broadband radio frequency transceiver unit; The radio frequency interference detection unit includes a broadband interference detection matching network, an interference detection balance transformer network, and a second receiving two-phase filter. The output of the radio frequency signal from the wireless space after being processed by the broadband interference detection matching network is connected to the interference detection balance transformer The network becomes two-way output and enters the second receiving bi-phase filter, and the output analog signal enters the broadband radio frequency transceiver unit; The radio frequency transmitting unit includes two sets of symmetrical two-phase transmission filters, two sets of transmitting balance transformer networks, and two sets of radio frequency transmission matching networks; the dual-channel MIMO 2X2 radio frequency transceiver of the broadband radio frequency transceiver unit sends two sets of analog signals into the transmitting dual Phase filter, the output of the transmitting bi-phase filter enters the transmitting balance transformer network, and the single-channel analog signal enters the RF transmission matching network, and the RF transmission matching network outputs the TX signal, and the TX signal enters the transmitting antenna; Broadband RF transceiver unit, including a low-noise power supply, a dual-channel MIMO 2X2 RF transceiver, a multi-channel clock generator, VCO, RF-CLK; the dual-channel MIMO 2X2 RF transceiver receives two sets of first receivers in the RF receiving unit The RX1 and RX2 dual-channel differential RF signal inputs output by the bi-phase filter are internally processed into digital RX DATA signals, including 2-channel RX data information, and the dual-channel MIMO 2X2 RF transceiver converts the baseband digital I/Q output from the baseband unit. The signal is internally processed into dual-channel RF signal output. The low-noise power output is connected to the dual-channel MIMO 2X2 RF transceiver to provide it with 4-channel low-PSRR 80d power output. The multi-channel clock generator and VCO form a multi-channel 0.1ppm The clock sources of the two channels provide clock sources for the dual-channel MIMO 2X2 RF transceiver and baseband unit respectively; The baseband unit is used to receive two channels of digital RX DATA signal input from the broadband radio frequency transceiver unit and one channel observation digital signal input from the broadband radio frequency transceiver unit, and to send the output two channels of digital RX DATA signals to the broadband radio frequency transceiver unit The input and output interface of the control signal of the baseband unit is connected with the input and output interface of the control signal of the broadband radio frequency transceiver unit; the baseband unit is connected with the 4xDSP+CPU chip data read channel, write channel and parameter configuration interface of the ad hoc network protocol realization unit; The core component of the ad hoc network protocol implementation unit is a 4xDSP+CPU chip. The 4xDSP+CPU chip is connected with the user interface unit, the baseband unit, the digital interface of the broadband radio frequency transceiver unit, and the control interface. , in order to realize that the bidirectional data from the user interface unit is processed and sent to the baseband unit; the access switching and working mode switching of the node of the dual-channel MIMO 2X2 radio frequency transceiver are set through the control interface; User interface unit, including RJ45 network interface, USB user interface, and status display module. The RJ45 network interface is connected to the MAC PHY interface of the 4xDSP+CPU chip, and the USB user interface is directly connected to the USB2.0 interface of the 4xDSP+CPU chip. The status display module Connect with UART of 4xDSP+CPU chip; A low-ripple analog-to-digital isolated power supply system is used to provide interference-free power to the entire system. 2. The COFDM wireless broadband ad hoc network module suitable for a complex environment according to claim 1, wherein the output of the low-ripple analog-digital isolation power supply system is the same as the dual-channel MIMO 2X2 radio frequency transceiver core chip AD9371 connection; the output of the low-ripple analog-digital isolated power supply system is connected to the clock generator chip AD9528. 3 . The COFDM wireless broadband ad hoc network module suitable for complex environments according to claim 1 , wherein the algorithm of the ad hoc network baseband modulation and demodulation of the ad hoc network protocol implementation unit adopts COFDM. 4 . 4 . The COFDM wireless broadband ad hoc network module suitable for complex environments according to claim 1 , characterized in that it can operate in FDD mode or TDD mode by using 2 channels for transceiving. 5 .

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