Radar communication integrated device based on linear frequency modulation

Abstract

The invention discloses a radar communication integrated device based on linear frequency modulation, and the device comprises an uplink branch which mixes a communication modulation signal and a radar pulse signal to form a new modulation pulse; the antenna branch is used for carrying out wireless communication on the new modulation pulse by utilizing a beam sidelobe effect of a radar; and the downlink branch circuit performs primary amplification on the mixed radar echo signal and the communication downlink signal, performs downlink separation on the mixed radar echo signal and the communication downlink signal through a communication signal processing system and a radar signal processing system respectively, and outputs a radar signal and a communication signal after related processing of the branch circuit.

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic communication engineering, and in particular relates to a radar communication integrated device based on linear frequency modulation. Background Art

[0002] Radar and communications are two key components of the radio field. Radar is used to detect targets, and the results of these detections must be communicated and disseminated through communications. With the rapid development of radio technology and the proliferation of various electronic communications devices, frequency overlap and mutual interference between radar and antennas have led to an increasingly complex electromagnetic environment. Traditional radar stations often coexist with both radar and wireless communications. Radar interference with wireless communications can easily lead to errors and false alarms, while communications can affect radar observation targets. A typical phenomenon is that when radar and wireless communications operate simultaneously, a large number of interfering signals, such as dots and asynchronous pulse strips, appear on the radar display, impairing radar detection.

[0003] Radar has a greater impact on communications due to its high radio frequency power, and may even block the normal operation of wireless communications. Figure 1 Therefore, it is very important to integrate radar and communication into an integrated design, especially on limited space platforms such as ships and aircraft. Summary of the Invention

[0004] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a radar communication integrated device based on linear frequency modulation, which can simultaneously realize signal communication and radar transmission functions and solve the integration problem.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows: A radar communication integrated device based on linear frequency modulation, the device comprising: an uplink branch, wherein the uplink branch mixes the communication modulation signal and the radar pulse signal to form a new modulation pulse; An antenna branch, wherein the antenna branch transmits the new modulated pulse by utilizing a radar beam sidelobe effect for wireless communication; The downlink branch preliminarily amplifies the mixed radar echo signal and communication downlink signal, and then performs downlink separation by the communication and radar signal processing systems respectively, and outputs the radar transmission signal and the communication transmission signal after the relevant processing of the branch.

[0006] Furthermore, the uplink branch includes a modulator, a radar waveform generator, a mixer, a first up-conversion frequency (intermediate frequency), and a second up-conversion frequency (radio frequency) connected in sequence.

[0007] Furthermore, the downlink branch includes a power splitter, a communication signal receiving branch, and a radar signal receiving branch; wherein, The radar signal receiving branch includes an A / D conversion module, a filter, and an envelope detection module; The communication signal receiving branch includes a communication receiver and a signal processing circuit thereof.

[0008] Furthermore, the antenna branch includes an antenna beam main lobe and a beam side lobe, and the level of the beam side lobe is 10-13 dB lower than the level of the beam main lobe.

[0009] Furthermore, the communication signal is: , ; The radar sends the signal: , ; The synthetic transmit signal is: , , ; Where, Sending signals for communication, Sending a signal to the radar, is the synthetic signal, T is the period; f0 is the frequency modulation frequency, is the modulation phase of the communication modulation signal, is the frequency modulation slope, K1 and K2 are the coefficients of communication and radar signals respectively.

[0010] As a preferred implementation scheme of the present application, the communication modulation signal is an MPSK signal or a QPSK signal.

[0011] Beneficial effects of the present invention: This invention utilizes the sidelobe effects of radar's high-power transmitter and transmit beam to achieve integrated radar and communication integration, eliminating mutual interference and improving equipment utilization within a specific spatial range. With the rapid development of wireless digital technology, the technology to address this integration challenge has matured. The key to radar and communication integration lies in waveform design and the rational use of the radar beam. Common methods include frequency domain synthesis, time domain pulse combining, and spatial splitting. Frequency domain synthesis combines communication and radar pulse signals with different modulation schemes (by adding or multiplying them), transforming them into a new mixed signal for transmission. After initial amplification, the received signal is processed by the communication and radar signal processing systems based on their modulation schemes, effectively separating the radar echo and communication signal, thus completing the radar communication detection and interconnection tasks. Time domain pulse combining compiles radar and communication signals in chronological order within the same cycle. The return signal separates the communication and radar signals based on timing and modulation scheme. Spatial splitting involves transmitting communication signals in a specific direction for wireless communication and radar detection in other directions. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 Schematic diagram of wireless communication signal jamming radar; Figure 2 This is a block diagram of the integrated communication components of the linear frequency modulation radar; Figure 3 This is a schematic diagram of the communication + LFM / MPSK modulation waveform; Figure 4 This is a schematic diagram of the radar-LFM modulation waveform; Figure 5 This is the radar echo signal separation and processing block diagram. DETAILED DESCRIPTION

[0013] In order to facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments and drawings. The contents mentioned in the embodiments are not intended to limit the present invention.

[0014] Reference Figures 1 to 5 As shown, a radar communication integrated device based on linear frequency modulation, the device comprising: an uplink branch, wherein the uplink branch mixes the communication modulation signal and the radar pulse signal to form a new modulation pulse; An antenna branch, wherein the antenna branch transmits the new modulated pulse by utilizing a radar beam sidelobe effect for wireless communication; The downlink branch preliminarily amplifies the mixed radar echo signal and communication downlink signal, and then performs downlink separation by the communication and radar signal processing systems respectively, and outputs the radar transmission signal and the communication transmission signal after the relevant processing of the branch.

[0015] Furthermore, the uplink branch includes a modulator, a radar waveform generator, a mixer, a first up-conversion frequency (intermediate frequency), and a second up-conversion frequency (radio frequency) connected in sequence.

[0016] Furthermore, the downlink branch includes a power splitter, a communication signal receiving branch, and a radar signal receiving branch; wherein, The radar signal receiving branch includes an A / D conversion module, a filter, and an envelope detection module; The communication signal receiving branch includes a communication receiver and a signal processing circuit thereof.

[0017] Furthermore, the antenna branch includes an antenna beam main lobe and a beam side lobe, and the level of the beam side lobe is 10-13 dB lower than the level of the beam main lobe.

[0018] The present invention is a same modulated pulse synthesized in the frequency domain, that is, the same frequency linear frequency modulation method is adopted to mix the MPSK communication modulation signal and the radar pulse signal to form a new modulation pulse to be radiated into the air. After the mixed radar echo signal and the communication downlink signal are initially amplified, they are sorted and processed by the communication and radar signal processing systems respectively to complete their respective transmission tasks. The antenna branch of the present invention utilizes the beam sidelobe effect of the radar for wireless communication, which is better at medium and short distances. The focus of the present invention is on the waveform setting and downlink signal separation technology. The system composition is as follows Figure 2 shown.

[0019] The basic waveform of the present invention is a linear frequency modulation system. The communication signal is MPSK (QPSK can also be used) modulated with positive slope linear frequency modulation, and the radar pulse signal is a negative slope linear frequency modulation signal. The expressions of the two transmission signals are as follows: The communication signal is: , ; The radar sends the signal: , ; The synthetic transmit signal is: , , ; Where, Sending signals for communication, Sending a signal to the radar, is the synthetic signal, T is the period; f0 is the frequency modulation frequency, is the modulation phase of the communication modulation signal, MPSK modulation phase, if QPSK modulation signal is used, for , , , ; is the frequency modulation slope, K1 and K2 are the coefficients of communication and radar signals respectively.

[0020] The waveform diagram of the communication signal is as follows: Figure 3 , radar sends signal waveform diagram as shown Figure 4 ,The receiving end signal uses coherent detection method for communication, separation and discrimination of radar signals.

[0021] The communication signal in the received signal is: , ; Where: : Communication receiving signal; : Gaussian white noise.

[0022] Due to the initial frequency f0 and the slope are all known, if the received signal The frequency is multiplied by the carrier signal and the result is integrated within the cycle. If the frequency remains stable within the same cycle, the integration result is close to 0 for the FM signal, and the interference signal can be eliminated. Finally, the phase of the transmitted signal is compared to obtain the correct communication signal.

[0023] Coherent detection technology is relatively mature, and the real communication signal can be detected relatively easily using existing technology modules.

[0024] After the radar echo signal is initially amplified and split by the receiving branch, it is screened and identified in the signal processor to remove interference signals such as fixed echoes. After calculation in the DSP, it is output to the terminal recording device according to the constant false alarm requirements. The principle block diagram is as follows Figure 5 shown.

[0025] The advantage of the integrated communication and radar setting is that it effectively eliminates mutual interference and simultaneously completes the functions of two equipment in one set of equipment, greatly improving equipment utilization.

[0026] This invention utilizes the sidelobe effects of radar's high-power transmitter and transmit beam to achieve integrated radar and communication integration, eliminating mutual interference and improving equipment utilization within a specific spatial range. With the rapid development of wireless digital technology, the technology to address this integration challenge has matured. The key to radar and communication integration lies in waveform design and the rational use of the radar beam. Common methods include frequency domain synthesis, time domain pulse combining, and spatial splitting. Frequency domain synthesis combines communication and radar pulse signals with different modulation schemes (by adding or multiplying them), transforming them into a new mixed signal for transmission. After initial amplification, the received signal is processed by the communication and radar signal processing systems based on their modulation schemes, effectively separating the radar echo and communication signal, thus completing the radar communication detection and interconnection tasks. Time domain pulse combining compiles radar and communication signals in chronological order within the same cycle. The return signal separates the communication and radar signals based on timing and modulation scheme. Spatial splitting involves transmitting communication signals in a specific direction for wireless communication and radar detection in other directions.

[0027] The present invention has many specific application paths. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements can be made without departing from the principles of the present invention. These improvements should also be considered as the scope of protection of the present invention.

Claims

1. A radar communication integrated device based on linear frequency modulation, characterized in that: The device comprises: An uplink branch, wherein the uplink branch mixes the communication modulation signal and the radar pulse signal to form a new modulation pulse; An antenna branch, wherein the antenna branch uses the new modulated pulse to perform wireless communication by utilizing a radar beam sidelobe effect; The downlink branch initially amplifies the mixed radar echo signal and communication downlink signal, and then performs downlink separation by the communication and radar signal processing systems respectively, and outputs the radar signal and the communication signal after the related processing of the branch.

2. The radar communication integrated device based on linear frequency modulation according to claim 1, characterized in that: The uplink branch includes a modulator, a radar waveform generator, a mixer, a first up-conversion frequency, and a second up-conversion frequency which are connected in sequence.

3. The radar communication integrated device based on linear frequency modulation according to claim 1, characterized in that: The downlink branch includes a power splitter, a communication signal receiving branch, and a radar signal receiving branch; wherein, The radar signal receiving branch includes an A / D conversion module, a filter, and an envelope detection module; The communication signal receiving branch includes a communication receiver and a signal processing circuit thereof.

4. The radar communication integrated device based on linear frequency modulation according to claim 1, characterized in that: The antenna branch includes an antenna beam main lobe and a beam side lobe, and the level of the beam side lobe is 10-13dB lower than the level of the beam main lobe.

5. The radar communication integrated device based on linear frequency modulation according to claim 1, characterized in that: The communication signal is: , ; The radar sends the signal: , ; The synthetic transmit signal is: , ， ； In the formula, Sending signals for communication, Sending a signal to the radar, is the synthetic signal, T is the period; f0 is the frequency modulation frequency, is the modulation phase of the communication modulation signal, is the frequency modulation slope, K1 and K2 are the coefficients of communication and radar signals respectively.

6. The radar communication integrated device based on linear frequency modulation according to claim 1, characterized in that: The communication modulation signal is an MPSK signal or a QPSK signal.

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