A radar communication integrated device based on linear frequency modulation

Abstract

The invention discloses a radar communication integrated device based on linear frequency modulation, the device comprises: an uplink branch, the uplink branch mixes a communication modulation signal and a radar pulse signal to form a new modulation pulse; an antenna branch, the antenna branch uses the new modulation pulse to perform wireless communication by using the beam sidelobe effect of the radar; a downlink branch, the downlink branch performs downlink separation on the mixed radar echo signal and the communication downlink signal after preliminary amplification by the communication and radar signal processing systems respectively, and outputs the radar signal and the communication signal after the related processing of the branches.

Description

Technical Field

[0001] The 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 communication are two important components in the field of radio. Radar is used to detect targets, and the results of detection must be conveyed and published by communication. With the rapid development of radio technology and the continuous emergence of various electronic communication equipment, the frequency bands between radars and antennas are crossed and interfere with each other, making the electromagnetic environment more complex. In traditional radar stations, radar and wireless communication are often at the same site. Radar interference with wireless communication is prone to bit errors and false alarms, while communication may affect radar observation targets. A typical phenomenon is that when radar and wireless communication are working at the same time, a large number of point-shaped and asynchronous pulse strip interference signals will appear on the radar display, which has a certain impact on radar detection targets.

[0003] Radar has a greater impact on communications due to its high radio frequency power, and may even block the normal wireless communication. 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] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A radar communication integrated device based on linear frequency modulation, the device comprising:

[0007] An uplink branch, wherein the uplink branch mixes the communication modulation signal and the radar pulse signal to form a new modulation pulse;

[0008] An antenna branch, wherein the antenna branch uses the new modulated pulse to perform wireless communication by utilizing a radar beam sidelobe effect;

[0009] 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 transmission signal and the communication transmission signal after the relevant processing of the branch.

[0010] 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) which are connected in sequence.

[0011] Furthermore, the downlink branch includes a power splitter, a communication signal receiving branch, and a radar signal receiving branch; wherein,

[0012] The radar signal receiving branch includes an A / D conversion module, a filter, and an envelope detection module;

[0013] The communication signal receiving branch includes a communication receiver and a signal processing circuit thereof.

[0014] 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.

[0015] Furthermore, the communication sending signal is: , ;

[0016] The radar sends the signal: , ;

[0017] The synthetic transmit signal is: , , ;

[0018] In the formula, Sending signals for communication, Sending a signal to the radar, is the synthetic signal, T is the period;

[0019] 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.

[0020] As a preferred implementation scheme of the present application, the communication modulation signal is an MPSK signal or a QPSK signal.

[0021] Beneficial effects of the present invention:

[0022] The present invention utilizes the high-power transmitting device of the radar and the sidelobe effect of the transmitting beam to integrate radar communication, and solves the problem of mutual interference and improves the effective utilization rate of equipment within a certain spatial range. With the rapid development of wireless digital technology today, the technology to solve the integration problem is already very mature. The key to the integration of radar communication lies in the waveform design and the rational use of the radar beam, which generally includes frequency domain synthesis, time domain pulse combination, and spatial domain separation. Frequency domain synthesis is to mix the communication and radar pulse signals of different modulation modes (signal addition or multiplication), transform them into a new mixed signal and transmit them. After the received signal is initially amplified, the signal processing system of the communication and radar performs relevant processing according to their modulation modes, effectively separates the radar echo and communication signal, and completes the detection and communication tasks of radar communication. Time domain pulse combination is to compile radar and communication signals in the same cycle in time sequence, and the return signal is separated by different timing and modulation modes for communication and radar signals. Spatial domain separation refers to sending communication signals in a specific direction for wireless communication and radar detection in other directions. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of a wireless communication signal jammer radar;

[0024] Figure 2 It is a block diagram of the integrated communication components of linear frequency modulation radar;

[0025] Figure 3 This is a schematic diagram of the communication + LFM / MPSK modulation waveform;

[0026] Figure 4 This is a schematic diagram of the radar-LFM modulation waveform;

[0027] Figure 5 This is the radar echo signal separation processing block diagram. DETAILED DESCRIPTION

[0028] In order to facilitate the understanding of those skilled in the art, the present invention is further described below in conjunction with embodiments and drawings. The contents mentioned in the implementation modes are not intended to limit the present invention.

[0029] Reference Figures 1 to 5 As shown, a radar communication integrated device based on linear frequency modulation, the device comprising:

[0030] An uplink branch, wherein the uplink branch mixes the communication modulation signal and the radar pulse signal to form a new modulation pulse;

[0031] An antenna branch, wherein the antenna branch uses the new modulated pulse to perform wireless communication by utilizing a radar beam sidelobe effect;

[0032] 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 transmission signal and the communication transmission signal after the relevant processing of the branch.

[0033] 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) which are connected in sequence.

[0034] Furthermore, the downlink branch includes a power splitter, a communication signal receiving branch, and a radar signal receiving branch; wherein,

[0035] The radar signal receiving branch includes an A / D conversion module, a filter, and an envelope detection module;

[0036] The communication signal receiving branch includes a communication receiver and a signal processing circuit thereof.

[0037] 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.

[0038] The present invention uses the same modulation pulse of frequency domain synthesis, that is, the same frequency linear frequency modulation method is used to mix the MPSK communication modulation signal and the radar pulse signal to form a new modulation pulse to radiate into the air. After the mixed radar echo signal and 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 uses the radar beam sidelobe effect for wireless communication, which is better at medium and short distances. The focus of the present invention is on waveform setting and downlink signal separation technology. The system composition is as follows Figure 2 shown.

[0039] The basic waveform of the present invention is a linear frequency modulation system, the communication signal is MPSK (QPSK can also be used) modulation + 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:

[0040] The communication signal is: , ;

[0041] The radar sends the signal: , ;

[0042] The synthetic transmit signal is: , , ;

[0043] In the formula, Sending signals for communication, Sending a signal to the radar, is the synthetic signal, T is the period;

[0044] 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.

[0045] The schematic diagram of the communication signal waveform is as follows: Figure 3 , radar sends the signal waveform diagram as shown Figure 4 ,The receiving end signal uses the coherent detection method for communication, separation and discrimination of radar signals.

[0046] The communication signal in the received signal is:

[0047] , ;

[0048] Where: : Communication receiving signal; : Gaussian white noise.

[0049] Due to the initial frequency f0 and the slope are all known, if the received signal Multiply it with the carrier signal and integrate the multiplication result 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 exact communication signal can be obtained by comparing it with the phase of the transmitted signal.

[0050] Coherent detection technology is relatively mature, and the real communication signal can be easily detected using existing technology modules.

[0051] After the radar echo signal is initially amplified and split by the receiving branch, it is screened 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 requirement. The principle block diagram is as follows Figure 5 shown.

[0052] The advantage of the integrated communication and radar settings is that it effectively eliminates mutual interference and simultaneously completes the functions of two pieces of equipment in one set, greatly improving equipment utilization.

[0053] The present invention utilizes the high-power transmitting device of the radar and the sidelobe effect of the transmitting beam to integrate radar communication, and solves the problem of mutual interference and improves the effective utilization rate of equipment within a certain spatial range. With the rapid development of wireless digital technology today, the technology to solve the integration problem is already very mature. The key to the integration of radar communication lies in the waveform design and the rational use of the radar beam, which generally includes frequency domain synthesis, time domain pulse combination, and spatial domain separation. Frequency domain synthesis is to mix the communication and radar pulse signals of different modulation modes (signal addition or multiplication), transform them into a new mixed signal and transmit them. After the received signal is initially amplified, the signal processing system of the communication and radar performs relevant processing according to their modulation modes, effectively separates the radar echo and communication signal, and completes the detection and communication tasks of radar communication. Time domain pulse combination is to compile radar and communication signals in the same cycle in time sequence, and the return signal is separated by different timing and modulation modes for communication and radar signals. Spatial domain separation refers to sending communication signals in a specific direction for wireless communication and radar detection in other directions.

[0054] 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 principle of the present invention. These improvements should also be regarded as the protection scope 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; Downlink branch, the downlink branch performs downlink separation on the mixed radar echo signal and communication downlink signal after preliminary amplification by the communication and radar signal processing systems respectively, and outputs the radar signal and the communication signal after relevant processing by the branch; 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; 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.

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 communication modulation signal is an MPSK signal or a QPSK signal.

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