A diversity fusion scattering communication device

Abstract

The present invention discloses a diversity-integrated scatter communication device and method, which relates to technologies for scatter communication to combat channel fading and improve system spectrum resource utilization. The device comprises an antenna unit, an outdoor unit, and an indoor unit. The communication method utilizes an adaptive diversity protocol to track channel status in real time, automatically implementing adaptive rate adjustment and diversity mode selection. Adjusting the diversity mode enhances the system's fading and anti-interference capabilities, improves system reliability and robustness, expands the system's transmit and receive rate range, and broadens the system's application scenarios. The method is particularly suitable for medium- and long-range, high-capacity scatter communications.

Description

Technical Field

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

[0002] Scattering communication exploits the forward bend effect of atmospheric inhomogeneities on radio waves to achieve beyond-line-of-sight wireless communication. It boasts advantages such as long single-hop distance, wide available wireless frequency bands, high communication capacity, naturally stable channels requiring no fees, and robustness against destruction, interference, and interception. Consequently, it has been widely used in communications technology. However, because atmospheric inhomogeneities scatter radio waves irregularly, creating multiple transmission paths and generating multipath effects, scattering communication is often accompanied by severe channel fading. To address this, scattering communication solutions that support some form of diversity are often employed to improve system performance and reliability.

[0003] However, a single diversity approach has the following drawbacks in actual use: when channel fading is severe, system performance and reliability are low; when channel fading is not severe, resource utilization of the diversity system, such as spectrum, is low.

[0004] How to strike a balance between system performance, reliability, and utilization of resources such as system spectrum is an urgent problem that needs to be solved by existing technologies. Summary of the Invention

[0005] The present invention aims to overcome the shortcomings of the aforementioned background technologies and provide a scatter communication device that integrates spatial, frequency, and time diversity. This device significantly improves the performance, reliability, and resource utilization of scatter communication equipment in various application environments, resulting in superior communication quality.

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

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

[0008] The antenna unit 1 includes multiple antennas, the outdoor unit 2 includes multiple transceiver channels including a power amplifier, a duplexer, and a low-noise amplifier; the indoor unit 3 includes an A / D unit, a D / A unit, a modulator, a demodulator, a control unit, and multiple 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 analog-to-digital converts 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. 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 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, rate mode and 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 makes a joint judgment on 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 makes a joint judgment on 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 expected adjustment time of the transceiver rate mode to be switched and 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 receives business data from the outside at the same time, performs adaptive diversity protocol control processing on the business information and 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 performs adaptive control protocol control 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] The implementation method of the device comprises the following steps:

[0014] S1: Both ends of the communication use space, frequency, and time diversity to establish a communication link.

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

[0016] S3: If the two ends of a communication are unable to exchange information for a certain period of time due to poor channel quality, the link is considered broken. After the channel quality recovers, they need to return to step S1 to reestablish the link and resume normal communication.

[0017] Among them, the specific process of S2 is:

[0018] S21: Rate adaptive adjustment. During the communication process, the receiving control unit jointly determines the signal-to-noise ratio (SNR) and signal power of the frequency / time domain channel characteristics. If the received SNR and received signal power are better than the theoretical SNR threshold and empirical signal power of the current receiving rate, it is determined that the receiving rate of the receiving demodulator and the corresponding transmitting modulator need to be increased. Otherwise, the receiving rate of the receiving demodulator and the corresponding transmitting modulator need to be reduced. When the rate is adjusted to the upper or lower limit of the transmitting modulator and receiving demodulator capabilities, the rate remains unchanged.

[0019] S22: Diversity mode selection. During the communication process, the receiving end control unit jointly judges 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 over 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 over time, the number of retransmissions is reduced until no retransmission occurs, otherwise the number of retransmissions is increased and stopped when the upper limit of the number of retransmissions is reached;

[0020] Furthermore, the specific process of S1 is:

[0021] At the transmitting end, the modulator will retransmit the digital baseband signal carrying the same transmission information according to a certain time period, and will not retransmit it 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 switches the frequency modulator in the receiving channel 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. The transmission and reception rate mode is fixed to the system's minimum transmission rate.

[0022] Furthermore, the specific process of S2 also includes:

[0023] S23: When the channel quality meets the set requirements, the three types of space, frequency, and time diversity are stopped. That is, each D / A channel 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;

[0024] 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 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.

[0025] Compared with the background technology, the present invention has the following advantages:

[0026] 1. The present invention adopts an adaptive diversity protocol to track the channel status in real time. By adjusting the diversity mode, the system's anti-fading and anti-interference capabilities are increased, thereby improving the system's reliability and robustness.

[0027] 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 system's application scenarios.

[0028] 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 system throughput.

[0029] 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

[0030] Figure 1 This is a block diagram of the electrical principle of a diversity-fusion scattering communication device of the present invention.

[0031] Figure 2 It is a flow chart of a diversity fusion scattering communication method of the present invention. DETAILED DESCRIPTION

[0032] The present invention will be further described in detail below with reference to the accompanying drawings.

[0033] 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 multiple antennas, which are set to three in this embodiment: antenna 1-1, antenna 1-2, and antenna 1-3; the outdoor unit 2 includes multiple transmit and receive 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, and low-noise amplifiers. Acoustic amplifier 2-3-2 and low-noise amplifier 2-3-3; indoor unit 3 includes an A / D unit, a D / A unit, a modulator, a demodulator, a control unit, and multiple transceiver channels including frequency converters and intermediate frequency amplifiers. In this embodiment, it 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.

[0034] The following takes one of the routes as an example for detailed description:

[0035] The receiving process is:

[0036] 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 analog-to-digital converts 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. 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 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, rate mode and 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;

[0037] The sending process is:

[0038] The control unit makes a joint judgment on 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 makes a joint judgment on 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 expected adjustment time of the transceiver rate mode to be switched and 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 receives business data from the outside at the same time, performs adaptive diversity protocol control processing on the business information and 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 performs adaptive control protocol control 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.

[0039] like Figure 2 As shown, a diversity fusion scattering communication method includes the following steps:

[0040] S1: Both ends of the communication use space, frequency, and time diversity to establish a communication link.

[0041] At the beginning of link establishment, both ends of the 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 the communication to achieve the purpose of optimal signal reception.

[0042] During the link establishment process, three diversity modes, space, frequency and time, are used simultaneously; in space diversity, the three transceiver 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 transmitted and received 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 to achieve the best frequency hopping diversity effect. This process relies on Beidou timing information to complete the time alignment of the transmitting and receiving ends to achieve the function of simultaneous switching of the transmitting and receiving 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 transceiver rate mode is fixed to the system's minimum transmission rate; under the above configuration, the communicating ends transmit adaptive control protocol information in the most reliable mode in the device of the present invention, and do not transmit other information such as business.

[0043] When both ends of the communication complete the adaptive control protocol information exchange, the communication link is established.

[0044] S2: Each end of the communication uses an adaptive control protocol to control diversity mode selection and rate adaptive adjustment in real time according to communication requirements, and completes diversity mode and rate switching through information exchange between the two sides;

[0045] The adaptive diversity protocol in step S2 is specifically:

[0046] S21: Rate adaptive adjustment. During the communication process, the receiving control unit jointly determines the signal-to-noise ratio (SNR) and signal power of the frequency / time domain channel characteristics. If the received SNR and received signal power are better than the theoretical SNR threshold and empirical signal power of the current receiving rate, it is determined that the receiving rate of the receiving demodulator and the corresponding transmitting modulator need to be increased. Otherwise, the receiving rate of the receiving demodulator and the corresponding transmitting modulator need to be reduced. When the rate is adjusted to the upper or lower limit of the transmitting modulator and receiving demodulator capabilities, the rate remains unchanged.

[0047] During rate adaptive adjustment, the adaptive control protocol sends the local end's receive rate adjustment result and the estimated adjustment time to the peer end. After receiving the adaptive control protocol information, the peer end adjusts the send rate based on the estimated adjustment time, completing rate adaptive switching.

[0048] S22: Diversity mode selection. During the communication process, the receiving end control unit jointly judges 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 over 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 over time, the number of retransmissions is reduced until no retransmission occurs, otherwise the number of retransmissions is increased and stopped when the upper limit of the number of retransmissions is reached;

[0049] When the diversity mode is adjusted, the adaptive control protocol sends the local diversity mode adjustment result and the estimated adjustment time to the peer end. After receiving the adaptive control protocol information, the peer end adjusts the diversity mode according to the estimated adjustment time to complete the diversity mode switch.

[0050] S23: When the channel quality reaches the set requirements, the three types of space, frequency and time diversity are stopped. 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.

[0051] S24: During communication, if the receive rate mode and diversity mode need to be switched, the switch result and switch time are framed into a transmission message and sent to the peer end. After receiving the transmission message, the peer end switches the transmit rate mode and diversity mode at the switch time. S3: If the two communicating ends are unable to exchange information for a specified period of time due to poor channel quality, the link is considered broken. Normal communication can only be restored by returning to step S1 and reestablishing the link after channel quality recovers.

[0052] S3: If the two ends of a communication are unable to exchange information for a certain period of time due to poor channel quality, the link is considered broken. After the channel quality recovers, they need to return to step S1 to reestablish the link and resume normal communication.

Claims

1. A diversity fusion scattering communication device, characterized in that: It includes an antenna unit (1), an outdoor unit (2) and an indoor unit (3); The antenna unit (1) includes a plurality of antennas, and the outdoor unit (2) includes a plurality of transceiver channels including a power amplifier, a duplexer, and a low noise amplifier; The indoor unit (3) includes an A / D unit, a D / A unit, a modulator, a demodulator, a control unit, and multiple 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 down-converts and performs analog-to-digital conversion on the amplitude-adjusted intermediate frequency signal 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, rate mode and 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; 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, frequency domain signal power and time domain extension to generate a transceiver diversity mode to be switched, and simultaneously generates an estimated adjustment time for the transceiver rate mode to be switched and the transceiver diversity mode to be switched. The transceiver diversity mode, transceiver rate mode, diversity mode and switching adjustment time together constitute adaptive control protocol information. The control unit simultaneously receives service data from the outside, performs adaptive diversity protocol control processing on the service information and 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 time synchronization with the receiving end, and then switches the transmitting diversity mode and transmitting rate mode according to the diversity mode and rate mode switching adjustment time contained in the adaptive control protocol information, and outputs the transmitting diversity mode and transmitting rate mode to the modulator; The modulator modulates the transmission information into a digital baseband signal according to the transmit diversity mode and transmit 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-converts 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 an RF signal according to the frequency control signal output by the control unit, and outputs it to the power amplifier; the power amplifier amplifies the RF signal according to the frequency control signal output by the control unit, and outputs it to the antenna through the duplexer, and the antenna transmits the amplified RF signal to the other end; The implementation method of the device comprises the following steps: S1: Both ends of the communication use space, frequency, and time diversity to establish a communication link. S2: Each end of the communication uses an adaptive control protocol to control diversity mode selection and rate adaptive adjustment in real time according to communication requirements, and completes diversity mode and rate switching through information exchange between the two sides; S3: If the two ends of a communication are unable to exchange information for a certain period of time due to poor channel quality, the link is considered broken. After the channel quality recovers, the link must be established again in step S1 to resume normal communication. Among them, the specific process of S2 is: S21: Rate adaptive adjustment. During the communication process, the receiving control unit jointly determines the signal-to-noise ratio (SNR) and signal power of the frequency / time domain channel characteristics. If the received SNR and received signal power are better than the theoretical SNR threshold and empirical signal power of the current receiving rate, it is determined that the receiving rate of the receiving demodulator and the corresponding transmitting modulator need to be increased. Otherwise, the receiving rate of the receiving demodulator and the corresponding transmitting modulator need to be reduced. When the rate is adjusted to the upper or lower limit of the transmitting modulator and receiving demodulator capabilities, the rate remains unchanged. S22: Diversity mode selection. During the communication process, the receiving end control unit jointly judges 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 branches 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 there is no retransmission, otherwise the number of retransmissions is increased and stopped when the upper limit of the number of retransmissions is reached.

2. The diversity fusion scattering communication device according to claim 1, 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 according to a certain time period, and will not retransmit it 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 switches the frequency modulator in the receiving channel 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. The transmission and reception rate mode is fixed to the system's minimum transmission rate.

3. The diversity fusion scattering communication device according to claim 1, characterized in that: The specific process of S2 further includes: S23: When the channel quality meets the set requirements, the three types of space, frequency, and time diversity are stopped. That is, each D / A channel 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 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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