Diversity fusion scatter communication device and communication method

Abstract

The invention discloses a diversity fusion scatter communication device and a communication method, and relates to technologies of scatter communication channel fading resistance, system spectrum resource utilization rate improvement and the like in the technical field of communication. The antenna is composed of an antenna unit, an outdoor unit, an indoor unit and the like. According to the communication method, the adaptive diversity protocol is adopted to track the channel state in real time, rate adaptive adjustment and diversity mode selection can be automatically realized, the anti-fading and anti-interference capabilities of the system are improved by adjusting the diversity mode, the reliability and robustness of the system are improved, the receiving and transmitting rate range of the system is expanded, and the communication efficiency is improved. The application scenarios of the system are increased, and the system is especially suitable for medium / remote and large-capacity scatter communication.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a diversity fusion scattering communication device and a communication method. Background Art

[0002] Scattering communication uses the forward bend transmission effect of radio waves caused by inhomogeneities in the atmospheric medium to achieve beyond-line-of-sight wireless communication. It has the advantages of long single-hop span, wide available wireless frequency band, large communication capacity, natural and stable channel existence without payment, anti-destruction, anti-interference and anti-interception, etc., and has been widely used in the field of communication technology. However, due to the irregular scattering of radio waves by inhomogeneities in the atmospheric medium, several transmission paths are constructed, resulting in multipath effects, which leads to the fact that scattering communication is often accompanied by severe channel fading. In response to this phenomenon, a scattering communication solution that supports a certain diversity mode is usually used as a countermeasure to improve system performance and reliability.

[0003] However, the single diversity mode has the following shortcomings in actual use: when the channel fading phenomenon is serious, the system performance and reliability are low. When the channel fading phenomenon is not serious, the utilization rate of resources such as spectrum of the diversity system is low.

[0004] How to strike a balance between system performance, reliability and utilization of system resources such as spectrum is an issue that needs to be urgently addressed with existing technologies. Summary of the invention

[0005] The purpose of the present invention is to avoid the shortcomings of the above-mentioned background technology and provide a diversity-fused scattering communication device and communication method that simultaneously has spatial diversity, frequency diversity and time diversity capabilities. The introduction of the device and method can significantly improve the performance, reliability and resource utilization of scattering communication equipment in different application environments, and obtain better communication quality.

[0006] The technical solution adopted by the present invention is:

[0007] A diversity fusion scattering communication device comprises an antenna unit 1, an indoor unit 2 and an outdoor unit 3;

[0008] The antenna unit 1 includes a plurality of antennas, the outdoor unit 2 includes a plurality of transceiver channels including a power amplifier, a duplexer and a low noise amplifier; the outdoor unit 3 includes an A / D unit, a D / A unit, a modulator, a demodulator, a control unit and a plurality of transceiver channels including a frequency converter and an intermediate frequency amplifier;

[0009] The receiving process is:

[0010] The antenna receives the RF signal sent by the opposite end, and outputs it to the low-noise amplifier through the corresponding duplexer; the low-noise amplifier performs low-noise amplification on the RF signal and outputs it to the frequency converter; the frequency converter down-converts the low-noise amplified RF signal to the intermediate frequency according to the frequency control signal output by the control unit, and outputs the intermediate frequency signal to the intermediate frequency amplifier; the intermediate frequency amplifier adjusts the intermediate frequency signal to the set amplitude and outputs it to the A / D unit; the A / D unit down-converts and performs analog-to-digital conversion on the intermediate frequency signal after amplitude adjustment to form a digital baseband signal, and outputs the digital baseband signal to the demodulator; the demodulator demodulates the digital baseband signal according to the receive diversity mode and receive rate mode output by the control unit, obtains the received information and outputs it to the control unit, and at the same time performs analog-to-digital conversion on the digital baseband signal The frequency domain / time domain channel characteristics of the signal are extracted and output to the control unit, and the frequency domain / time domain channel characteristics include time domain signal power, frequency domain signal power, time domain expansion, signal-to-noise ratio and carrier frequency deviation; the control unit performs adaptive diversity protocol control processing on the received information to obtain adaptive control protocol information and service information, outputs the service information, and monitors the transmission channel according to the frequency domain / time domain channel characteristic extraction results. At the same time, the control unit receives Beidou timing information to complete synchronization with the transmitting end time, and then switches the receiving diversity mode and receiving rate mode according to the diversity mode and rate mode switching adjustment time contained in the adaptive control protocol information, outputs the frequency control signal to the frequency converter and power amplifier, and outputs the receiving diversity mode and receiving rate mode to the demodulator;

[0011] The sending process is:

[0012] The control unit jointly judges the signal-to-noise ratio and signal power of the frequency domain / time domain channel characteristics to generate the transceiver rate mode to be switched, and jointly judges the time domain signal power, frequency domain signal power and time domain expansion to generate the transceiver diversity mode to be switched, and at the same time generates the transceiver rate mode to be switched and the estimated adjustment time of the transceiver diversity mode to be switched. The transceiver diversity mode, transceiver rate mode and diversity mode and switching adjustment time together constitute the adaptive control protocol information. The control unit simultaneously receives external business data, performs adaptive diversity protocol control processing on the business information and the adaptive control protocol information, converts them into transmission information and then outputs them to the modulator; at the same time, the control unit receives Beidou timing information to complete synchronization with the receiving end time, and then transmits the information according to the adaptive control protocol. The diversity mode and rate mode switching adjustment time contained in the proposal information is used to switch the transmission diversity mode and transmission rate mode, and the transmission diversity mode and transmission rate mode are output to the modulator; the modulator modulates the transmission information into a digital baseband signal according to the transmission diversity mode and transmission rate mode output by the control unit, and outputs the digital baseband signal to the D / A unit; the D / A unit performs digital-to-analog conversion and up-conversion on the digital baseband signal to form an intermediate frequency signal, and outputs the intermediate frequency signal to the frequency converter; the frequency converter up-converts the intermediate frequency signal into a radio frequency signal according to the frequency control signal output by the control unit, and outputs it to the power amplifier; the power amplifier amplifies the radio frequency signal according to the frequency control signal output by the control unit, and outputs it to the antenna through the duplexer, and the antenna sends the amplified radio frequency signal to the opposite end.

[0013] A scattering communication method based on diversity fusion implemented by the above scattering communication device comprises the following steps:

[0014] S1: Both ends of the communication use space, frequency and time diversity to complete the communication link establishment;

[0015] S2: Both ends of the communication use an adaptive control protocol to control the diversity mode selection and rate adaptive adjustment in real time according to communication requirements, and complete the diversity mode and rate switching through information exchange between the two sides;

[0016] S3: When the two ends of communication cannot exchange information for a certain period of time due to poor channel quality, the link is considered broken. After the channel quality is restored, they need to return to step S1 to establish the link and resume normal communication.

[0017] Furthermore, the specific process of S1 is:

[0018] At the transmitting end, the modulator will retransmit the digital baseband signal carrying the same transmission information in a certain time period, and will not retransmit after a fixed number of retransmissions. The multi-channel D / A unit sends the intermediate frequency signal carrying the same transmission information, and the multi-channel frequency converter performs frequency switching according to a given frequency sequence. At the receiving end, the multi-channel frequency converter receives the channel and switches the frequency modulator according to the frequency switching method of the transmitting channel. The multi-channel A / D unit performs maximum ratio combining processing on the received intermediate frequency signal carrying the same transmission information. The demodulator performs maximum ratio combining processing on the digital baseband signal carrying the same transmission information according to the retransmission period consistent with the modulator; and the receiving and transmitting rate mode is fixed to the system's minimum transmission rate.

[0019] Furthermore, the specific process of S2 is:

[0020] S21: Rate adaptive adjustment. During the communication process, the receiving control unit jointly judges the signal-to-noise ratio and signal power of the frequency domain / time domain channel characteristics. If the received signal-to-noise ratio and received signal power are better than the theoretical signal-to-noise ratio threshold and empirical signal power of the current receiving rate, it is determined that the receiving rate of the receiving end demodulator needs to be increased and the corresponding sending rate of the transmitting end modulator needs to be increased. Otherwise, the receiving rate of the receiving end demodulator needs to be reduced and the corresponding sending rate of the transmitting end modulator needs to be reduced. When the rate is adjusted to the upper or lower limit of the transmitting end modulator and the receiving end demodulator capacity, the rate is kept unchanged.

[0021] S22: Diversity mode selection, during the communication process, the receiving end control unit makes a joint judgment on the time domain signal power, frequency domain signal power and time domain expansion; spatial diversity, if the frequency domain signal power and time domain expansion correlation coefficient received by each A / D are greater than a preset value, the D / A unit no longer sends the intermediate frequency signal carrying the same transmission information, and the A / D unit performs branching processing on the received intermediate frequency signal carrying the same transmission information, otherwise the D / A unit continues to send the intermediate frequency signal carrying the same transmission information; frequency diversity, if the frequency domain signal power and time domain expansion correlation coefficient of each frequency extracted by the demodulator increase in time, the frequency switching period is increased to the maximum switching period, otherwise the frequency switching period is reduced to the minimum switching period; time diversity, if the time domain signal power changes more slowly in time, the number of retransmissions is reduced until no retransmission is performed, otherwise the number of retransmissions is increased to the upper limit of the number of retransmissions and stops;

[0022] S23: When the channel quality reaches the set requirements, stop using the three types of diversity, namely, space, frequency and time. That is, each D / A sends an intermediate frequency signal carrying different transmission information, the frequency of each channel is consistent and does not switch, and the transmission information is not retransmitted in time. At the same time, the modulator and demodulator use code division multiplexing technology to distinguish the transmission information of each channel.

[0023] S24: During the communication process, when the receiving rate mode and diversity mode need to be switched, the switching result and the switching time are framed into transmission information and sent to the other end. After receiving the transmission information, the other end switches the sending rate mode and diversity mode at the switching time.

[0024] Compared with the background technology, the present invention has the following advantages:

[0025] 1. The present invention adopts an adaptive diversity protocol, which is used to track the channel status in real time. By adjusting the diversity mode, the anti-fading and anti-interference capabilities of the system are increased, thereby improving the reliability and robustness of the system.

[0026] 2. The present invention adopts an adaptive diversity protocol, which is used to jointly perform rate adaptive adjustment and diversity mode selection, thereby improving the range of the system's transceiver rate and increasing the application scenarios of the system.

[0027] 3. The data transmission process of the present invention utilizes multiple transmit and receive paths, provides the possibility of space division multiplexing, reduces mutual interference between communication links and performs data transmission through code division multiplexing technology, and further improves the throughput of the system.

[0028] 4. The present invention follows the principle of on-demand allocation and can selectively shut down some antennas and amplifiers to use one or several transceiver channels for data transmission, making the application of the device more flexible. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is an electrical principle block diagram of a diversity fusion scattering communication device of the present invention.

[0030] Figure 2 It is a flow chart of a diversity fusion scattering communication method of the present invention. DETAILED DESCRIPTION

[0031] The present invention is further described in detail below with reference to the accompanying drawings.

[0032] Reference Figure 1In an embodiment of the present invention, a diversity fusion scattering communication device includes an antenna unit 1, an outdoor unit 2 and an indoor unit 3; the antenna unit 1 includes a plurality of antennas, which are set to be three in this embodiment: antenna 1-1, antenna 1-2 and antenna 1-3; the outdoor unit 2 includes a plurality of transceiver channels including power amplifiers, duplexers and low noise amplifiers, which include power amplifiers 2-1-1, power amplifiers 2-1-2, power amplifiers 2-1-3, duplexers 2-2-1, duplexers 2-2-2, duplexers 2-2-3, low noise amplifiers 2-3-1, low noise amplifiers 2-3-2, low noise amplifiers 2-3-3, low noise amplifiers 2-3-4, low noise amplifiers 2-3-5, low noise amplifiers 2-3-6, low noise amplifiers 2-3-7, low noise amplifiers 2-3-8, low noise amplifiers 2-3-9, low noise amplifiers 2-4-10, low noise amplifiers 2-4-11, low noise amplifiers 2-4-20, low noise amplifiers 2-4-3, low noise amplifiers 2-4-12, low noise amplifiers 2-4-21, low noise amplifiers 2-4-3, low noise amplifiers 2-4-13, low noise amplifiers 2-4-23, low noise amplifiers 2-4-3, low noise amplifiers 2-4-14, low noise amplifiers 2-4-25, low noise amplifiers 2-4-3, low noise amplifiers 2-4-15, low noise amplifiers 2-4-26, low noise amplifiers 2-4-3, low noise amplifiers 2-4-16, low noise amplifiers 2-4-27, low noise amplifiers 2-4-3, low noise amplifiers 2-4-17, low noise amplifiers 2-4-28, Acoustic amplifier 2-3-2 and low noise amplifier 2-3-3; indoor unit 3 includes A / D unit, D / A unit, modulator, demodulator, control unit and multiple transceiver channels including frequency converter and intermediate frequency amplifier. This embodiment includes frequency converter 3-1-1, frequency converter 3-1-2, frequency converter 3-1-3, intermediate frequency amplifier 3-2-1, intermediate frequency amplifier 3-2-2, intermediate frequency amplifier 3-2-3, A / D unit 3-3, D / A unit 3-4, modulator 3-5, demodulator 3-6 and control unit 3-7; Figure 1 This is a schematic diagram of the electrical principle of a diversity fusion scattering communication device of the present invention. Figure 1 Connect the line.

[0033] The following takes one of the paths as an example for detailed description:

[0034] The receiving process is:

[0035] The antenna receives the RF signal sent by the opposite end, and outputs it to the low-noise amplifier through the corresponding duplexer; the low-noise amplifier performs low-noise amplification on the RF signal and outputs it to the frequency converter; the frequency converter down-converts the low-noise amplified RF signal to the intermediate frequency according to the frequency control signal output by the control unit, and outputs the intermediate frequency signal to the intermediate frequency amplifier; the intermediate frequency amplifier adjusts the intermediate frequency signal to the set amplitude and outputs it to the A / D unit; the A / D unit down-converts and performs analog-to-digital conversion on the intermediate frequency signal after amplitude adjustment to form a digital baseband signal, and outputs the digital baseband signal to the demodulator; the demodulator demodulates the digital baseband signal according to the receive diversity mode and receive rate mode output by the control unit, obtains the received information and outputs it to the control unit, and at the same time performs analog-to-digital conversion on the digital baseband signal The frequency domain / time domain channel characteristics of the signal are extracted and output to the control unit, and the frequency domain / time domain channel characteristics include time domain signal power, frequency domain signal power, time domain expansion, signal-to-noise ratio and carrier frequency deviation; the control unit performs adaptive diversity protocol control processing on the received information to obtain adaptive control protocol information and service information, outputs the service information, and monitors the transmission channel according to the frequency domain / time domain channel characteristic extraction results. At the same time, the control unit receives Beidou timing information to complete synchronization with the transmitting end time, and then switches the receiving diversity mode and receiving rate mode according to the diversity mode and rate mode switching adjustment time contained in the adaptive control protocol information, outputs the frequency control signal to the frequency converter and power amplifier, and outputs the receiving diversity mode and receiving rate mode to the demodulator;

[0036] The sending process is:

[0037] The control unit jointly judges the signal-to-noise ratio and signal power of the frequency domain / time domain channel characteristics to generate the transceiver rate mode to be switched, and jointly judges the time domain signal power, frequency domain signal power and time domain expansion to generate the transceiver diversity mode to be switched, and at the same time generates the transceiver rate mode to be switched and the estimated adjustment time of the transceiver diversity mode to be switched. The transceiver diversity mode, transceiver rate mode and diversity mode and switching adjustment time together constitute the adaptive control protocol information. The control unit simultaneously receives external business data, performs adaptive diversity protocol control processing on the business information and the adaptive control protocol information, converts them into transmission information and then outputs them to the modulator; at the same time, the control unit receives Beidou timing information to complete synchronization with the receiving end time, and then transmits the information according to the adaptive control protocol. The diversity mode and rate mode switching adjustment time contained in the proposal information is used to switch the transmission diversity mode and transmission rate mode, and the transmission diversity mode and transmission rate mode are output to the modulator; the modulator modulates the transmission information into a digital baseband signal according to the transmission diversity mode and transmission rate mode output by the control unit, and outputs the digital baseband signal to the D / A unit; the D / A unit performs digital-to-analog conversion and up-conversion on the digital baseband signal to form an intermediate frequency signal, and outputs the intermediate frequency signal to the frequency converter; the frequency converter up-converts the intermediate frequency signal into a radio frequency signal according to the frequency control signal output by the control unit, and outputs it to the power amplifier; the power amplifier amplifies the radio frequency signal according to the frequency control signal output by the control unit, and outputs it to the antenna through the duplexer, and the antenna sends the amplified radio frequency signal to the opposite end.

[0038] like Figure 2 As shown, a diversity fusion scattering communication method includes the following steps:

[0039] S1: Both ends of the communication use space, frequency and time diversity to complete the communication link establishment.

[0040] At the beginning of link establishment, both ends of communication need to know the longitude and latitude information of the other end and the local end, and use the Beidou positioning and directional signals to complete the antenna alignment of the six antennas at both ends of communication to achieve the purpose of optimal signal reception.

[0041] During the link establishment process, three diversity modes, namely space, frequency and time, are used simultaneously; in space diversity, the three receiving and transmitting channels of the D / A unit and the A / D unit contain the same transmission information, that is, the transmission information carried by the radio frequency signals received and transmitted by the three antennas at the same time is completely consistent, so as to achieve the maximum triple space diversity effect; in frequency diversity, the three frequency converters perform frequency switching according to a given frequency sequence, so as to achieve the best frequency hopping diversity effect. This process relies on Beidou timing information to complete the time alignment of the receiving and transmitting ends, so as to achieve the function of simultaneous corresponding switching of the receiving and transmitting frequencies; in time diversity, the transmission information is retransmitted according to a certain time period, and the number of retransmissions is the upper limit of the number of retransmissions, so as to achieve the maximum time diversity effect; in rate mode, the receiving and transmitting rate mode is fixed to the minimum transmission rate of the system; under the above configuration, the two communicating ends perform adaptive control protocol information transmission in the most reliable mode in the device of the present invention, and do not perform other information transmission such as business.

[0042] When both ends of the communication complete the adaptive control protocol information exchange, the communication link is established.

[0043] S2: Both ends of the communication use an adaptive control protocol to control the diversity mode selection and rate adaptive adjustment in real time according to communication requirements, and complete the diversity mode and rate switching through information exchange between the two sides;

[0044] The adaptive diversity protocol in step S2 is specifically:

[0045] S21: Rate adaptive adjustment. During the communication process, the receiving control unit jointly judges the signal-to-noise ratio and signal power of the frequency domain / time domain channel characteristics. If the received signal-to-noise ratio and received signal power are better than the theoretical signal-to-noise ratio threshold and empirical signal power of the current receiving rate, it is determined that the receiving rate of the receiving end demodulator needs to be increased and the corresponding sending rate of the transmitting end modulator needs to be increased. Otherwise, the receiving rate of the receiving end demodulator needs to be reduced and the corresponding sending rate of the transmitting end modulator needs to be reduced. When the rate is adjusted to the upper or lower limit of the transmitting end modulator and the receiving end demodulator capacity, the rate is kept unchanged.

[0046] When the rate is adaptively adjusted, the adaptive control protocol will send the local reception rate adjustment result and the estimated adjustment time to the other end. After receiving the adaptive control protocol information, the other end will adjust the sending rate according to the estimated adjustment time to complete the rate adaptive switching.

[0047] S22: Diversity mode selection, during the communication process, the receiving end control unit makes a joint judgment on the time domain signal power, frequency domain signal power and time domain expansion; spatial diversity, if the frequency domain signal power and time domain expansion correlation coefficient received by each A / D are greater than a preset value, the D / A unit no longer sends the intermediate frequency signal carrying the same transmission information, and the A / D unit performs branching processing on the received intermediate frequency signal carrying the same transmission information, otherwise the D / A unit continues to send the intermediate frequency signal carrying the same transmission information; frequency diversity, if the frequency domain signal power and time domain expansion correlation coefficient of each frequency extracted by the demodulator increase in time, the frequency switching period is increased to the maximum switching period, otherwise the frequency switching period is reduced to the minimum switching period; time diversity, if the time domain signal power changes more slowly in time, the number of retransmissions is reduced until no retransmission is performed, otherwise the number of retransmissions is increased to the upper limit of the number of retransmissions and stops;

[0048] When the diversity mode is adjusted, the adaptive control protocol will send the local diversity mode adjustment result and the estimated adjustment time to the other end. After receiving the adaptive control protocol information, the other end will adjust the diversity mode according to the estimated adjustment time to complete the diversity mode switching.

[0049] S23: When the channel quality reaches the set requirements, stop using the three types of diversity, namely, space, frequency and time. That is, each D / A sends an intermediate frequency signal carrying different transmission information, the frequency of each channel is consistent and does not switch, and the transmission information is not retransmitted in time. At the same time, the modulator and demodulator use code division multiplexing technology to distinguish the transmission information of each channel.

[0050] S24: During the communication process, when the receiving rate mode and diversity mode need to be switched, the switching result and switching time are framed into the transmission information and sent to the other end. After receiving the transmission information, the other end switches the sending rate mode and diversity mode at the switching time. S3: When the two ends of the communication cannot exchange information for a certain period of time due to poor channel quality, it is judged as a broken link. After the channel quality is restored, it is necessary to return to step S1 to establish the link to restore normal communication.

[0051] S3: When the two ends of communication cannot exchange information for a certain period of time due to poor channel quality, the link is considered broken. After the channel quality is restored, they need to return to step S1 to establish the link and resume normal communication.

Claims

1. A diversity fusion scattering communication device, characterized in that: It comprises an antenna unit (1), an indoor unit (2) and an outdoor unit (3); The antenna unit (1) includes a plurality of antennas, the outdoor unit (2) includes a plurality of transceiver channels including a power amplifier, a duplexer and a low noise amplifier; the outdoor unit (3) includes an A / D unit, a D / A unit, a modulator, a demodulator, a control unit and a plurality of transceiver channels including a frequency converter and an intermediate frequency amplifier; The receiving process is: The antenna receives the RF signal sent by the other end and outputs it to the low-noise amplifier through the corresponding duplexer; The low noise amplifier performs low noise amplification on the RF signal and outputs it to the frequency converter; the frequency converter down-converts the low noise amplified RF signal to an intermediate frequency according to the frequency control signal output by the control unit, and outputs the intermediate frequency signal to the intermediate frequency amplifier; the intermediate frequency amplifier adjusts the intermediate frequency signal to a set amplitude and outputs it to the A / D unit; the A / D unit performs down-conversion and analog-to-digital conversion on the intermediate frequency signal after amplitude adjustment to form a digital baseband signal, and outputs the digital baseband signal to the demodulator; The demodulator demodulates the digital baseband signal according to the receiving diversity mode and receiving rate mode output by the control unit, obtains the receiving information and outputs it to the control unit, and extracts the frequency domain / time domain channel characteristics of the digital baseband signal and outputs them to the control unit. The frequency domain / time domain channel characteristics include time domain signal power, frequency domain signal power, time domain extension, signal-to-noise ratio and carrier frequency deviation; the control unit performs adaptive diversity protocol control processing on the receiving information to obtain adaptive control protocol information and service information, outputs the service information, and monitors the transmission channel according to the frequency domain / time domain channel feature extraction results. At the same time, the control unit receives Beidou timing information to complete synchronization with the transmitting end time, and then switches the receiving diversity mode and receiving rate mode according to the diversity mode and rate mode switching adjustment time contained in the adaptive control protocol information, outputs the frequency control signal to the frequency converter and the power amplifier, and outputs the receiving diversity mode and the receiving rate mode to the demodulator; The sending process is: The control unit jointly judges the signal-to-noise ratio and signal power of the frequency domain / time domain channel characteristics to generate a transceiver rate mode to be switched, and jointly judges the time domain signal power, the frequency domain signal power and the time domain expansion to generate a transceiver diversity mode to be switched, and at the same time generates a transceiver rate mode to be switched and an estimated adjustment time of the transceiver diversity mode to be switched. The transceiver diversity mode, the transceiver rate mode, the diversity mode and the switching adjustment time together constitute the adaptive control protocol information. The control unit simultaneously receives external service data, performs adaptive diversity protocol control processing on the service information and the adaptive control protocol information, converts them into transmission information and outputs them to the modulator; at the same time, the control unit receives Beidou timing information to complete synchronization with the receiving end time, and then switches the transmission diversity mode and the transmission rate mode according to the diversity mode and rate mode switching adjustment time contained in the adaptive control protocol information, and outputs the transmission diversity mode and the transmission rate mode to the modulator; The modulator performs digital baseband signal modulation on the transmission information according to the transmission diversity mode and transmission rate mode output by the control unit, and outputs the digital baseband signal to the D / A unit; the D / A unit performs digital-to-analog conversion and up-conversion on the digital baseband signal to form an intermediate frequency signal, and outputs the intermediate frequency signal to the frequency converter; the frequency converter up-converts the intermediate frequency signal into a radio frequency signal according to the frequency control signal output by the control unit, and outputs it to the power amplifier; the power amplifier amplifies the radio frequency signal according to the frequency control signal output by the control unit, and outputs it to the antenna through the duplexer, and the antenna sends the amplified radio frequency signal to the opposite end.

2. A scattering communication method based on diversity fusion implemented by the scattering communication device according to claim 1, characterized in that: The following steps are involved: S1: Both ends of the communication use space, frequency and time diversity to complete the communication link establishment; S2: Both ends of the communication use an adaptive control protocol to control the diversity mode selection and rate adaptive adjustment in real time according to communication requirements, and complete the diversity mode and rate switching through information exchange between the two sides; S3: When the two ends of communication cannot exchange information for a certain period of time due to poor channel quality, the link is considered broken. After the channel quality is restored, they need to return to step S1 to establish the link and resume normal communication.

3. The diversity fusion scattering communication method according to claim 2, characterized in that: The specific process of S1 is as follows: At the transmitting end, the modulator will retransmit the digital baseband signal carrying the same transmission information in a certain time period, and will not retransmit after a fixed number of retransmissions. The multi-channel D / A unit sends the intermediate frequency signal carrying the same transmission information, and the multi-channel frequency converter performs frequency switching according to a given frequency sequence. At the receiving end, the multi-channel frequency converter receives the channel and switches the frequency modulator according to the frequency switching method of the transmitting channel. The multi-channel A / D unit performs maximum ratio combining processing on the received intermediate frequency signal carrying the same transmission information. The demodulator performs maximum ratio combining processing on the digital baseband signal carrying the same transmission information according to the retransmission period consistent with the modulator; and the receiving and transmitting rate mode is fixed to the system's minimum transmission rate.

4. The diversity fusion scattering communication method according to claim 3, characterized in that: The specific process of S2 is: S21: Rate adaptive adjustment. During the communication process, the receiving control unit jointly judges the signal-to-noise ratio and signal power of the frequency domain / time domain channel characteristics. If the received signal-to-noise ratio and received signal power are better than the theoretical signal-to-noise ratio threshold and empirical signal power of the current receiving rate, it is determined that the receiving rate of the receiving end demodulator needs to be increased and the corresponding sending rate of the transmitting end modulator needs to be increased. Otherwise, the receiving rate of the receiving end demodulator needs to be reduced and the corresponding sending rate of the transmitting end modulator needs to be reduced. When the rate is adjusted to the upper or lower limit of the transmitting end modulator and the receiving end demodulator capacity, the rate is kept unchanged. S22: Diversity mode selection, during the communication process, the receiving end control unit makes a joint judgment on the time domain signal power, frequency domain signal power and time domain expansion; spatial diversity, if the frequency domain signal power and time domain expansion correlation coefficient received by each A / D are greater than a preset value, the D / A unit no longer sends the intermediate frequency signal carrying the same transmission information, and the A / D unit performs branching processing on the received intermediate frequency signal carrying the same transmission information, otherwise the D / A unit continues to send the intermediate frequency signal carrying the same transmission information; frequency diversity, if the frequency domain signal power and time domain expansion correlation coefficient of each frequency extracted by the demodulator increase in time, the frequency switching period is increased to the maximum switching period, otherwise the frequency switching period is reduced to the minimum switching period; time diversity, if the time domain signal power changes more slowly in time, the number of retransmissions is reduced until no retransmission is performed, otherwise the number of retransmissions is increased to the upper limit of the number of retransmissions and stops; S23: When the channel quality reaches the set requirements, stop using the three types of diversity, namely, space, frequency and time. That is, each D / A sends an intermediate frequency signal carrying different transmission information, the frequency of each channel is consistent and does not switch, and the transmission information is not retransmitted in time. At the same time, the modulator and demodulator use code division multiplexing technology to distinguish the transmission information of each channel. S24: During the communication process, when the receiving rate mode and diversity mode need to be switched, the switching result and the switching time are framed into transmission information and sent to the other end. After receiving the transmission information, the other end switches the sending rate mode and diversity mode at the switching time.

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