Pulse frequency agile radar communication integrated signal generation device

Abstract

The present application relates to a kind of radar communication integration signal generation device based on pulse frequency agility, belong to radar communication integration technical field.The device includes spread spectrum modulation unit, pulse modulation unit, nonlinear unit, power amplifier unit;The spread spectrum modulation unit receives user data, through data grouping, selection mapping and phase shift mapping, data is loaded to pseudo-random sequence to realize spread spectrum modulation, and output to the pulse modulation unit;The pulse modulation unit completes pulse amplitude modulation, and after integration, output to the nonlinear unit;The nonlinear unit is based on cubic power nonlinear frequency modulation signal generation carrier frequency and phase pseudo-random variable radar communication integration signal, and output to the power amplifier unit;The power amplifier unit received signal is power amplified and output to antenna.The present application improves the anti-interference ability of radar communication integration modulated signal, information transmission capacity and power utilization rate.

Description

Technical Field

[0001] This invention relates to an integrated radar and communication signal generation device based on pulse frequency agility, belonging to the field of integrated radar and communication technology. Background Technology

[0002] Radar detection and wireless communication, as two of the most common and important applications of modern radio technology, are designed and developed independently according to different functions and frequency bands. Radar is mainly used for target detection and identification, while communication aims to achieve information transmission between devices. However, with the exponential increase in the number of wireless devices and the higher bandwidth requirements for high-speed data transmission, the electromagnetic spectrum has become overcrowded. In military applications, facing the increasing threats from weapon platforms and complex electromagnetic environments, the confrontation between individual electronic equipment can no longer meet the diverse needs of future battlefield operations. Radar-communication integration is an effective way to solve these problems.

[0003] Suppression jamming, repeater jamming, and deceptive jamming are typical jamming methods in radar electronic countermeasures. In the field of integrated radar and communication systems, improving the effectiveness of these systems while simultaneously enhancing their anti-electronic jamming capabilities is crucial, as it relates to important indicators such as the flexibility and reliability of target detection. With the development of radar electronic countermeasures technology, especially the rapid advancement of active jamming technology based on digital radio frequency memory, the adaptability of integrated radar and communication signals to complex electromagnetic environments presents a significant challenge to their design. Furthermore, existing research on how to improve the anti-jamming capabilities of integrated radar and communication signals is limited in the field of integrated radar and communication systems.

[0004] Therefore, improving the anti-interference capability of integrated radar and communication signals is a difficult problem that needs to be solved in the current design of integrated radar and communication signals. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a pulse frequency agile radar communication integrated signal generation device that can improve the anti-interference capability of radar communication integrated signals.

[0006] The present invention provides an integrated radar and communication signal generation device based on pulse frequency agility, comprising a spread spectrum modulation unit, a pulse modulation unit, a nonlinear unit, and a power amplifier unit.

[0007] The spread spectrum modulation unit receives user data, loads the data into a pseudo-random sequence through data grouping, selection mapping, and phase shift mapping to achieve spread spectrum modulation, and outputs it to the pulse modulation unit.

[0008] The pulse modulation unit performs pulse amplitude modulation, integrates the pulses, and outputs the result to the nonlinear unit.

[0009] The nonlinear unit generates a radar-communication integrated signal with pseudo-random variable carrier frequency and phase based on a cubic nonlinear frequency modulation signal, and outputs it to the power amplifier unit.

[0010] The power amplifier unit amplifies the received signal and outputs it to the antenna.

[0011] Furthermore, in the technical solution disclosed in this invention, the spread spectrum modulation unit includes a data packetization module, a pseudo-random sequence generation module, a selection mapping module, and a phase shift mapping module;

[0012] The data grouping module groups the received user data into groups, which include p-bit selection mapping groups and q-bit phase shift mapping groups. The p-bit selection mapping groups are output to the selection mapping module, and the q-bit phase shift mapping groups are output to the phase shift mapping module.

[0013] The pseudo-random sequence generation module is used to generate N pairwise or quasi-orthogonal pseudo-random sequences, each with a bit length of M, and output them to the selection mapping module.

[0014] The selection mapping module maps each data combination of the p-bit selection mapping group to the i-th pseudo-random sequence selected from the N pseudo-random sequences according to a one-to-one mapping relationship, and outputs it to the phase shift mapping module. Each data combination of the p-bit selection mapping group can only be mapped to one pseudo-random sequence, and the pseudo-random sequences mapped to any two data combinations are different.

[0015] The phase shift mapping module maps each data combination of the q-bit phase shift mapping group to the cyclic shift state of the i-th pseudo-random sequence according to a one-to-one mapping relationship, and outputs it to the pulse modulation unit. Each data combination of the q-bit phase shift mapping group can only be mapped to one cyclic shift state of the i-th pseudo-random sequence, and the cyclic shift states of the pseudo-random sequences mapped by any two data combinations are different.

[0016] Furthermore, in the technical solution disclosed in this invention, the pulse modulation unit includes a pulse waveform generation module, a pulse amplitude modulation module, and an integration module;

[0017] The pulse waveform generation module is used to generate a pulse waveform γ(t) and output it to the pulse amplitude modulation module;

[0018] The pulse amplitude modulation module is connected to the phase shift mapping module. It uses pulse amplitude modulation to load each bit of the cyclic shift state of the i-th pseudo-random sequence onto the pulse waveform γ(t) and outputs it to the integration module.

[0019] The integration module integrates the received signal and outputs it to the nonlinear unit.

[0020] Furthermore, in the technical solution disclosed in this invention, the nonlinear unit includes a carrier frequency control module, a phase control module, and a nonlinear modulation module;

[0021] The carrier frequency control module is used to generate a pseudo-random carrier frequency signal f. c And output to the nonlinear modulation module;

[0022] The phase control module is used to generate pseudo-random phase signals. And output to the nonlinear modulation module;

[0023] The nonlinear modulation module is connected to the integration module and uses the received integrated signal as an additional phase of the cubic nonlinear frequency modulated signal; the nonlinear modulation module modulates the signal according to the pseudo-random carrier frequency signal f. c and the pseudo-random phase signal A radar-communication integrated signal is generated and output to the power amplifier unit. The radar-communication integrated signal is:

[0024]

[0025] Among them, f c Let B be the carrier frequency of the integrated radar-communication signal, B be the signal bandwidth factor, and T be the signal time factor. The j-th bit data is the k-th cyclic shift state of the i-th pseudo-random sequence participating in modulation, where k is a positive integer, k = 0, 1, 2, ..., M-1, and j is a positive integer, j = 1, 2, ..., M.

[0026] Furthermore, in the technical solution disclosed in this invention, the pseudo-random phase signal generated by the phase control module... It is a uniformly distributed random number with a value range of [-π, π], and each data point in the cyclic shift state of the i-th pseudo-random sequence is statistically independent.

[0027] Furthermore, in the technical solution disclosed in this invention, the pseudo-random carrier frequency signal f generated by the carrier frequency control module... c It is from the frequency hopping sequence [f1,f2,…,f M The data is pseudo-randomly selected from the i-th pseudo-random sequence, and each data point in the cyclic shift state of the i-th pseudo-random sequence is statistically independent.

[0028] Furthermore, in the technical solution disclosed in this invention, the cyclic shift is a cyclic left shift or a cyclic right shift, with 1 bit of data shifted in each cycle.

[0029] Furthermore, in the technical solution disclosed in this invention, the number of bits p in the selection mapping group and the number N of the pseudo-random sequence satisfy the following relationship: symbol This indicates rounding down to the nearest integer.

[0030] Furthermore, in the technical solution disclosed in this invention, the number of bits q in the phase shift mapping group and the number of bits M in the pseudo-random sequence satisfy the following relationship: symbol This indicates rounding down to the nearest integer.

[0031] Preferably, in the technical solution disclosed in this invention, the pulse waveform γ(t) is a 0th-order long spherical wave function.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] (1) Improved the ability to resist suppression interference.

[0034] In the technical solution disclosed in this invention, the carrier frequency control module of the nonlinear unit starts from the frequency hopping sequence [f1,f2,…,f M The pseudo-randomly generated carrier frequency signal f c Furthermore, each data point in the cyclic shift state of the i-th pseudo-random sequence is statistically independent, enabling agile pulse frequency changes in the integrated radar-communication signal. This makes it difficult for suppressive jamming signals to track the frequency changes of the integrated radar-communication signal in the frequency domain, thus preventing effective jamming. In existing technologies, the carrier frequency of the integrated radar-communication signal is usually fixed, making it difficult to resist suppressive jamming. Therefore, compared to existing technologies, this invention improves the anti-suppression jamming capability of the integrated radar-communication signal.

[0035] (2) Improved resistance to deceptive interference

[0036] In the technical solution disclosed in this invention, the spread spectrum unit loads the user data to be transmitted onto a pseudo-random sequence by selecting the mapping module and the phase shift mapping module, thereby achieving spectrum spread, reducing the power spectral density of the radar-communication integrated modulation signal, improving concealment, making it difficult for the jammer to grasp the parameters of the radar-communication integrated signal, and thus making it difficult for the jammer to carry out deceptive jamming.

[0037] (3) Improved resistance to forwarding interference.

[0038] In the technical solution disclosed in this invention, the phase control module of the nonlinear unit adopts a random initial phase method, so that the radar communication integrated signal avoids coherent accumulation with the repeater interference in the time domain; furthermore, since the pseudo-random sequences mapped by different data packets are different, the receiving system can use their orthogonality or quasi-orthogonality to convert the interference signals carrying different pseudo-random sequences into low power spectral noise signals, thereby effectively suppressing the repeater interference and improving the anti-interference capability.

[0039] (4) Improved the signal-to-interference ratio of integrated radar and communication signals.

[0040] In existing technologies, linear frequency modulated (LFM) signals are typically used to design integrated radar and communication signals. These signals have large sidelobes, and when sidelobes are suppressed using filters, severe waveform distortion occurs in the radar signal, thus reducing its anti-interference capability during channel transmission. The technical solution disclosed in this invention employs a cubic power to construct nonlinear frequency domain characteristics, thereby reducing the amplitude of radar signal sidelobes, minimizing signal distortion during sidelobe suppression, improving the signal-to-interference ratio (SIR) of the radar signal, and ultimately enhancing the reliability of integrated radar and communication signal transmission.

[0041] (5) Improved system power utilization

[0042] In the technical solution disclosed in this invention, the pulse waveform generated by the pulse modulation unit after data loading is output to the nonlinear unit in an integral form as an additional phase of the cubic nonlinear frequency modulated signal, thereby realizing an integrated waveform design for radar and communication, resulting in a unified modulation signal with constant envelope characteristics. Therefore, compared with the prior art, it can effectively improve the power utilization of the radar system and enhance the target detection range. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the integrated radar and communication signal generation device based on pulse frequency agility according to the present invention. Detailed Implementation

[0044] The present invention will now be described in further detail with reference to the embodiments and accompanying drawings, so that those skilled in the art can implement it based on the description.

[0045] In existing technologies, designing radar-communication integrated waveforms based on OFDM is a research hotspot in the field of radar-communication integration. However, the inherent peak-to-average power ratio (PAPR) characteristic of OFDM significantly reduces the system's power utilization, decreases the anti-interference capability of the radar-communication integrated signal, and reduces the target detection range, thus severely affecting the radar system's performance.

[0046] In existing technologies, to overcome the drawbacks of OFDM, linear frequency modulation (LFM) signals are used to design integrated radar-communication signals, giving them constant envelope characteristics, ensuring system power efficiency, and providing a wide spectral bandwidth to improve resolution when detecting targets. However, LFM signals have large spectral sidelobes. Suppressing these sidelobes through filtering leads to severe waveform distortion in the modulated signal, resulting in a decrease in the signal-to-noise ratio (SNR), reducing its ability to counter electronic interference and limiting its application environment. With the development of radar electronic countermeasures technology, especially the rapid advancement of active jamming technology based on digital radio frequency memory, the adaptability of integrated radar-communication signals in complex electromagnetic environments has become a serious challenge, necessitating improvements in the anti-jamming capabilities of integrated radar-communication signals.

[0047] To address this problem and improve the anti-interference capability of integrated radar and communication signals, this invention discloses an integrated radar and communication signal generation device based on pulse frequency agility. For example... Figure 1 As shown, the device includes a spread spectrum modulation unit, a pulse modulation unit, a nonlinear unit, and a power amplifier unit. The spread spectrum modulation unit receives user data, loads the data into a pseudo-random sequence through data grouping, selection mapping, and phase shift mapping to achieve spread spectrum modulation, and outputs it to the pulse modulation unit. The pulse modulation unit performs pulse amplitude modulation, integrates it, and outputs it to the nonlinear unit. The nonlinear unit generates a radar-communication integrated signal with pseudo-random variable carrier frequency and phase based on a cubic nonlinear frequency modulation signal and outputs it to the power amplifier unit. The power amplifier unit amplifies the received signal and outputs it to the antenna.

[0048] Furthermore, such as Figure 1 As shown, in the technical solution disclosed in the embodiments of the present invention, the spread spectrum modulation unit includes a data packetization module, a pseudo-random sequence generation module, a selection mapping module, and a phase shift mapping module;

[0049] The data grouping module groups the received user data into groups, which include p-bit selection mapping groups and q-bit phase shift mapping groups. The p-bit selection mapping groups are output to the selection mapping module, and the q-bit phase shift mapping groups are output to the phase shift mapping module.

[0050] The pseudo-random sequence generation module is used to generate N pairwise or quasi-orthogonal pseudo-random sequences, each with a bit length of M, and output them to the selection mapping module.

[0051] The selection mapping module maps each data combination of the p-bit selection mapping group to the selection of the i-th pseudo-random sequence from the N pseudo-random sequences according to a one-to-one mapping relationship and outputs it to the phase shift mapping module. Each data combination of the p-bit selection mapping group can only be mapped to one pseudo-random sequence, and the pseudo-random sequences mapped to any two data combinations are different.

[0052] The phase shift mapping module maps each data combination of the q-bit phase shift mapping group to the cyclic shift state of the i-th pseudo-random sequence according to a one-to-one mapping relationship, and outputs it to the pulse modulation unit. Each data combination of the q-bit phase shift mapping group can only be mapped to one cyclic shift state of the i-th pseudo-random sequence, and the cyclic shift states of the pseudo-random sequences mapped by any two data combinations are different.

[0053] In the technical solution disclosed in the embodiments of the present invention, the user's data to be transmitted is grouped, and the data to be transmitted is mapped to a pseudo-random sequence c by means of selection mapping and phase shift mapping. i In a certain cyclic shift state of (t), the pseudo-random sequence c i The number of bits M in (t) is greater than the number of bits in the data group, i.e., the pseudo-random sequence c i The chip duration in (t) is less than the data duration in the data group. Based on the relationship between duration and spectrum transformation, after mapping, spectrum broadening is achieved, resulting in a spread spectrum effect. This reduces the power spectral density of the signal, improves its concealment, and makes it difficult for reconnaissance equipment to obtain the waveform parameters of the integrated radar-communication signal. Deceptive jamming involves intercepting the jammed signal with listening equipment, analyzing its signal characteristics, obtaining signal parameters, and then releasing a deceptive jamming signal with similar parameters to carry out jamming. Therefore, the technical solution disclosed in this embodiment of the invention converts user data into a pseudo-random sequence through data grouping and mapping, improving the concealment of the integrated radar-communication signal and making it difficult for the jammer to grasp the parameters of the integrated radar-communication signal, thus preventing effective jamming.

[0054] Furthermore, in the technical solution disclosed in the embodiments of the present invention, the pulse modulation unit includes a pulse waveform generation module, a pulse amplitude modulation module, and an integration module;

[0055] The pulse waveform generation module is used to generate a pulse waveform γ(t) and output it to the pulse amplitude modulation module;

[0056] The pulse amplitude modulation module is connected to the phase shift mapping module. It uses pulse amplitude modulation to load each bit of the cyclic shift state of the i-th pseudo-random sequence onto the pulse waveform γ(t) and outputs it to the integration module.

[0057] The integration module integrates the received signal and outputs it to the nonlinear unit.

[0058] Furthermore, in the technical solution disclosed in the embodiments of the present invention, in the spread spectrum modulation unit, through the selection mapping module, each data combination of the p-bit selection mapping group is mapped to a pseudo-random sequence selected from N pseudo-random sequences for modulation. That is, the pseudo-random sequences mapped to different data combinations of the selection mapping group are different, thereby making the pseudo-random sequences used by different data groups different. Preferably, the N pseudo-random sequences are mutually orthogonal or quasi-orthogonal. The radar communication integrated receiving system can utilize the orthogonal or quasi-orthogonal relationship between different pseudo-random sequences to match and receive useful signals based on their correlation. However, for repeater jamming signals, especially repeater jamming signals across data groups, since the pseudo-random sequences used by different data groups are different and mutually orthogonal or quasi-orthogonal, that is, the pseudo-random sequence carried by the repeater jamming signal and the pseudo-random sequence carried by the jammed signal satisfy the orthogonal or quasi-orthogonal relationship, the repeater jamming signal after correlation reception processing has a low correlation value, which will convert the repeater jamming signal into a low power spectral noise signal. To implement effective forwarding jamming, the entire jamming process must be completed within a single data packet's time. However, the time of a single data packet is extremely short, forcing the jamming platform to be very close to the target platform, which is difficult to achieve in a real battlefield environment. Therefore, the technical solution disclosed in this invention can effectively suppress forwarding jamming.

[0059] Furthermore, in the technical solution disclosed in the embodiments of the present invention, the nonlinear unit includes a carrier frequency control module, a phase control module, and a nonlinear modulation module;

[0060] The carrier frequency control module is used to generate a pseudo-random carrier frequency signal f. c And output to the nonlinear modulation module;

[0061] The phase control module is used to generate pseudo-random phase signals. And output to the nonlinear modulation module;

[0062] The nonlinear modulation module is connected to the integration module and uses the received integrated signal as an additional phase of the cubic nonlinear frequency modulated signal; the nonlinear modulation module modulates the signal according to the pseudo-random carrier frequency signal f. c and the pseudo-random phase signal A radar-communication integrated signal is generated and output to the power amplifier unit. The radar-communication integrated signal is:

[0063]

[0064] Among them, f c Let B be the carrier frequency of the integrated radar-communication signal, B be the signal bandwidth factor, and T be the signal time factor. The j-th bit data is the k-th cyclic shift state of the i-th pseudo-random sequence participating in modulation, where k is a positive integer, k = 0, 1, 2, ..., M-1, j is a positive integer, j = 1, 2, ..., M, and i is a positive integer, i = 1, 2, ..., N.

[0065] To further prevent the integrated radar-communication signal from coherently accumulating with repeater-type interference signals in both the time and frequency domains, in the technical solution disclosed in this invention, the phase control module generates a pseudo-random phase signal. The values ​​are uniformly distributed random numbers ranging from [-π, π], and each bit of the i-th pseudo-random sequence in the cyclic shift state is statistically independent, thereby further increasing the coherent difference between the integrated signal and the repeater jamming. The combination of orthogonal pseudo-random sequences and pseudo-random phases avoids coherent accumulation of the radar communication integrated signal and the repeater jamming signal in the time and frequency domains, thus further improving the anti-interference capability. During signal processing at the receiving end, the pseudo-random phase can be corrected through phase compensation. Phase compensation is a common technique for those skilled in the art and will not be elaborated upon here.

[0066] Furthermore, in the technical solution disclosed in this embodiment of the invention, the nonlinear unit constructs a nonlinear frequency-modulated signal based on a cubic power, and on this basis, the integral signal of the pulse modulation module is used as an additional phase of the cubic nonlinear frequency-modulated signal to form an integrated radar-communication signal. The cubic frequency domain characteristics make the radar modulation signal exhibit nonlinear characteristics, thereby reducing the sidelobe amplitude of the radar modulation signal, reducing the signal distortion generated when the radar signal is filtered and radiated by the antenna, thereby improving the SNR (signal-to-noise ratio) of the radar signal, giving it strong anti-electromagnetic interference capability during channel transmission, and thus expanding its applicable application environment.

[0067] Therefore, the technical solution disclosed in the embodiments of the present invention uses nonlinear frequency modulation signals to design radar signals, which can improve the reliability of its transmission. On this basis, it is further integrated with communication modulation signals to achieve better radar detection performance and data transmission performance.

[0068] Furthermore, in the technical solution disclosed in the embodiments of the present invention, the pseudo-random carrier frequency signal f generated by the carrier frequency control module c It is from the frequency hopping sequence [f1,f2,…,f MThe carrier frequency of the transmitted radar-communication integrated signal is pseudo-randomly selected, and each bit of the cyclic shift state of the i-th pseudo-random sequence is statistically independent, thereby causing the carrier frequency of the transmitted radar-communication integrated signal to pseudo-randomly jump at a preset frequency point, realizing the pulse frequency agility of the radar-communication integrated signal. For the jammer to implement effective suppression jamming, the jamming signal must be able to track the frequency changes of the radar-communication integrated signal in the frequency domain. However, since the pseudo-random carrier frequency changes generated by the carrier frequency control simulation are controlled by a key, it is difficult for the jammer to implement suppression jamming. Regarding the pseudo-random carrier frequency signal f... c How to extract from the frequency hopping sequence [f1,f2,…,f…] M The pseudo-random selection in the middle can be achieved using frequency hopping technology, which is a common technique for those skilled in the art and will not be elaborated here.

[0069] As can be seen from the above analysis, the technical solution disclosed in the embodiments of the present invention can effectively combat deceptive interference, relay interference and suppression interference, and effectively improve the anti-interference capability of radar communication integrated signals.

[0070] In existing technologies, improving a system's anti-jamming capability through spread spectrum typically sacrifices its information transmission capability. Furthermore, in the current field of radar-communication integration, information transmission is limited to loading information through the amplitude, frequency, and phase parameters of the transmitted waveform. This information loading method is highly constrained, resulting in low information transmission efficiency for the system.

[0071] To further improve the system's information transmission efficiency, the inventors abandoned the traditional method of loading data using parameters and expanded the ways to load data using transmitted waveforms. They employed three methods simultaneously to load information: pseudo-random sequence selection mapping, pseudo-random sequence phase shift mapping, and pulse amplitude modulation, thereby effectively improving the system's information transmission efficiency.

[0072] The pseudo-random sequence selection mapping, namely the selection mapping module of the spread spectrum modulation unit, maps the p-bit selection mapping group generated by the data grouping module to select the i-th pseudo-random sequence from N pseudo-random sequences for modulation according to a one-to-one mapping relationship. Each data combination of the p-bit selection mapping group can only be mapped to one pseudo-random sequence, and the pseudo-random sequences mapped by any two data combinations are different.

[0073] The pseudo-random sequence phase shift mapping, namely the phase shift mapping module of the spread spectrum modulation unit, maps the q-bit phase shift mapping group generated by the data grouping module to the cyclic shift state of the i-th pseudo-random sequence according to a one-to-one mapping relationship. Each data combination of the q-bit phase shift mapping group can only be mapped to one cyclic shift state of the i-th pseudo-random sequence, and the cyclic shift states mapped by any two data combinations are different.

[0074] Pulse amplitude modulation, that is, the pulse amplitude modulation module of the pulse modulation unit loads each bit of the cyclic shift state of the i-th pseudo-random sequence onto the pulse waveform γ(t) generated by the pulse waveform generation module in sequence.

[0075] In this way, parameters such as pseudo-random sequence selection, pseudo-random sequence cyclic shift state, and pulse amplitude can be fully utilized to simultaneously carry data, thereby improving the information transmission efficiency of the system. Furthermore, to reduce the peak-to-average power ratio (PAPR) of the modulated signal, the time-domain superposition method of multi-carrier modulation technology is abandoned. The nonlinear unit uses the integral form of the signal formed by pseudo-random sequence selection mapping, pseudo-random sequence phase shift mapping, and pulse amplitude modulation as an additional phase of the nonlinear frequency-modulated signal. This achieves integrated radar-communication signal design, giving the nonlinear radar signal constant envelope characteristics. When transmitted to the channel, the radar system has high power utilization and a long target detection range, solving the problem of reduced radar performance caused by the PAPR in existing technologies.

[0076] When loading data with pulse amplitude, the pulse form has a significant impact on the main lobe energy concentration of the modulated signal; the better the main lobe energy concentration, the better the target detection performance, and vice versa. In the technical solution disclosed in the embodiments of this invention, the pulse waveform generated by the pulse waveform generation module is a long spherical wave function γ(t); preferably, the γ(t) is a 0th-order long spherical wave function with a time-bandwidth product factor of c = 4π. In this case, the main lobe energy concentration of the modulated signal can reach over 99%, providing strong anti-interference capability when used for channel transmission. Moreover, the γ(t) also has a large time-bandwidth characteristic, and its high energy concentration makes it beneficial for improving target detection resolution when used in radar applications.

[0077] Furthermore, in the technical solution disclosed in this embodiment of the invention, the selection mapping module of the spread spectrum modulation unit completes the first information loading through pseudo-random sequence selection mapping. The pseudo-random sequence selection mapping refers to selecting a pseudo-random sequence from N pseudo-random sequences to participate in modulation. Which pseudo-random sequence to select from the N pseudo-random sequences is unknown and has a certain probability, thus allowing information to be carried. For example, when selecting a pseudo-random sequence from four types, the probability of any one of the pseudo-random sequences appearing is one-quarter. According to information theory, it can carry two bits of information, i.e. In the technical solution disclosed in the embodiments of the present invention, when the selection mapping module performs pseudo-random sequence selection mapping, it maps each data combination of the p-bit selection mapping group to select the i-th pseudo-random sequence from the N pseudo-random sequences generated by the pseudo-random sequence generation module for modulation according to a one-to-one mapping relationship, wherein p and N satisfy the following relationship: symbol This indicates rounding down. When N=4, p=2.

[0078] Preferably, in the technical solution disclosed in the embodiments of the present invention, the N pseudo-random sequences are bipolar pseudo-random sequences, which are pairwise orthogonal or quasi-orthogonal, and each sequence has M bits.

[0079] In existing technologies, when using pseudo-random sequences to modulate and load information, the information is typically carried using both the positive and negative phase states of the pseudo-random sequence. Therefore, only 1 bit of information can be carried. To further improve the system's information carrying capacity and transmission efficiency, the technical solution disclosed in this invention abandons the two phase states of the pseudo-random sequence used in the prior art. The phase shift mapping module of the spread spectrum modulation unit utilizes the cyclic shift state of the pseudo-random sequence to load information, thereby increasing the number of states and improving the information carrying capacity. The pseudo-random sequence output by the selection mapping module is cyclically shifted, and its cyclic shift state is used to achieve the second information loading, i.e., phase shift mapping. The cyclic shift of the pseudo-random sequence is either a cyclic left shift or a cyclic right shift, with 1 bit of data shifted in each cycle. In the technical solution disclosed in the embodiments of the present invention, the phase shift mapping module maps each data combination of the q-bit phase shift mapping group output by the data grouping module to the cyclic left shift state of the i-th pseudo-random sequence according to a one-to-one mapping relationship. Each data combination of the q-bit phase shift mapping group can only be mapped to one cyclic left shift state of the i-th pseudo-random sequence, and the cyclic left shift states mapped by any two data combinations are different. Furthermore, q and M satisfy the following relationship: symbol This indicates rounding down. For example, by choosing a pseudo-random sequence with 8 bits after mapping, i.e., M = 8, then q = 3.

[0080] Furthermore, in the technical solution disclosed in the embodiments of the present invention, the data grouping module groups the user data, and the grouping includes a p-bit selection mapping group and a q-bit phase shift mapping group; that is, the user data is grouped according to a size of (p+q) bits, and the grouping includes a p-bit selection mapping group and a q-bit phase shift mapping group.

[0081] Preferably, in the technical solution disclosed in the embodiments of the present invention, the pseudo-random sequence generation module generates four bipolar orthogonal pseudo-random sequences, denoted as c1(t), c2(t), c3(t), and c4(t), each of which contains 8 bits of data. For example, the pseudo-random sequence c2(t) is -1, 1, 1, 1, 1, 1, -1, -1. After cyclic shifting, the pseudo-random sequence c2(t) can form eight pseudo-random sequences, denoted as c1(t), c2(t), c3(t), c4(t), c5(t), c6(t), c7(t), c8(t), c9 ... 2,0 (t), c 2,1 (t), c 2,2 (t), c2,3 (t), c 2,4 (t), c 2,5 (t), c 2,6 (t), c 2,7 (t).

[0082] Preferably, in the technical solution disclosed in the embodiments of the present invention, the data grouping module groups the user data into (2+3) bit groups, that is, the grouping includes a 2-bit selection mapping group and a 3-bit phase shift mapping group. The selection mapping module maps each data combination of the 2-bit selection mapping group to select a pseudo-random sequence from the four pseudo-random sequences for modulation according to a one-to-one mapping relationship. Each data combination of the 2-bit selection mapping group can only be mapped to one pseudo-random sequence, and the mapping relationship is shown in Table 1.

[0083] Table 1 shows the mapping relationship between the selected mapping group's data combinations and the pseudo-random sequence.

[0084] 2-bit selection mapping group data combination Pseudo-random sequence 00 <![CDATA[c1(t)]]> 01 <![CDATA[c2(t)]]> 10 <![CDATA[c3(t)]]> 11 <![CDATA[c4(t)]]>

[0085] In the technical solutions disclosed in the embodiments of the present invention, the one-to-one mapping relationship between the data combinations of the 2-bit selection mapping group and the pseudo-random sequence implemented by the selection mapping module is not limited to Table 1. As long as each data combination in the 2-bit selection mapping group has only one pseudo-random sequence corresponding to it, and the pseudo-random sequences corresponding to any two data combinations are different.

[0086] As shown in Table 1, when the data combination of the 2-bit selection mapping group is 01, the selection mapping module maps it to the second pseudo-random sequence, c2(t), thus completing the data loading of the selection mapping group. In other words, the selection mapping module represents the data combination using a pseudo-random sequence. Generally, the number of bits in the pseudo-random sequence is greater than the number of bits in the data combination, thereby achieving spectral spread, reducing the power spectral density of the signal, improving the signal's concealment capability, and making it difficult for reconnaissance equipment to detect.

[0087] As mentioned earlier, when the pseudo-random sequence c2(t) is -1, 1, 1, 1, 1, 1, -1, -1, after cyclic shifting, it can form 8 pseudo-random sequences, which can be represented as c 2,0 (t), c 2,1 (t), c 2,2 (t), c 2,3 (t), c 2,4 (t), c 2,5 (t), c 2,6 (t), c 2,7 (t), where c 2,0 (t)=c 2,0(t), i.e., the initial state; the phase shift mapping module completes the second information loading through phase shift mapping based on the selection mapping module.

[0088] The phase shift mapping module maps each data combination of the 3-bit phase shift mapping group to a cyclic shift state of the second pseudo-random sequence c2(t) according to a one-to-one mapping relationship. Each data combination of the 3-bit phase shift mapping group can only be mapped to one cyclic shift state of the second pseudo-random sequence c2(t). When the pseudo-random sequence c2(t) adopts a cyclic left shift, the mapping relationship between the data combinations of the 3-bit phase shift mapping group and the cyclic shift state of the second pseudo-random sequence c2(t) according to the one-to-one mapping relationship is shown in Table 2.

[0089] Table 2. Relationship between 3-bit phase shift mapping group data combination and c2(t) cyclic shift state mapping

[0090] Serial Number Data combination of 3-bit phase shift mapping group <![CDATA[Circular left shift state of c2(t)]]> 1 000 <![CDATA[c 2,0 (t)=-1,1,1,1,1,1,-1,-1]]> 2 001 <![CDATA[c 2,1 (t)=1,1,1,1,1,-1,-1,-1]]> 3 010 <![CDATA[c 2,2 (t)=1,1,1,1,-1,-1,-1,1]]> 4 011 <![CDATA[c 2,3 (t)=1,1,1,-1,-1,-1,1,1]]> 5 100 <![CDATA[c 2,4 (t)=1,1,-1,-1,-1,1,1,1]]> 6 101 <![CDATA[c 2,5 (t)=1,-1,-1,-1,1,1,1,1]]> 7 110 <![CDATA[c 2,6 (t)=-1,-1,-1,1,1,1,1,1]]> 8 111 <![CDATA[c 2,7 (t)=-1,-1,1,1,1,1,1,-1]]>

[0091] In the technical solution disclosed in the embodiments of the present invention, in the phase shift mapping module, the one-to-one mapping relationship between the data combination in the 3-bit phase shift mapping group and the cyclic left shift state of the second pseudo-random sequence c2(t) is not limited to Table 1. As long as each data combination in the phase shift mapping group has only one pseudo-random sequence cyclic shift state corresponding to it, and the pseudo-random sequence cyclic shift states corresponding to any two data combinations are different.

[0092] As shown in Table 2, in the phase shift mapping module, when the data combination of the 3-bit phase shift mapping group is 001, it is mapped to the second cyclic shift state of the second pseudo-random sequence c2(t), i.e., c 2,1 (t), at which point sequence c 21 Each value of (t) can be represented as:

[0093]

[0094] In the technical solution disclosed in the embodiments of the present invention, after the spread spectrum modulation unit completes the selection mapping and phase shift mapping, it outputs to the pulse modulation unit. The pulse modulation module then uses pulse amplitude modulation to shift the second cyclic left state c of the second pseudo-random sequence c2(t). 2,1 Each data point of (t) The signal is sequentially applied to the long spherical wave function γ(t), and its integration result is output to the nonlinear unit. The nonlinear unit uses the received integrated signal as an additional phase of the cubic nonlinear frequency-modulated signal, and adjusts it according to the pseudo-random carrier frequency signal f generated by the carrier frequency control module.c and the pseudo-random phase signal generated by the phase control module A radar-communication integrated signal is generated and output to the power amplifier unit. The radar-communication integrated signal is:

[0095]

[0096] Among them, f c Let B be the carrier frequency of the integrated radar-communication signal, B be the signal bandwidth factor, and T be the signal time factor. The second cyclic left shift state c of the second pseudo-random sequence c2(t) 2,1 The j-th data point of γ(t), where j is a positive integer, j = 1, 2, ... 8, and γ(t) is a 0th-order long spherical wave function.

[0097] In the technical solution disclosed in the embodiments of the present invention, the generated integrated radar and communication signal expands the signal spectrum, enhances the concealment of the radar signal, improves the ability to resist deceptive interference, and can convert repeater interference into low power spectrum noise, significantly improving the ability to resist repeater interference. Through pseudo-random agility of pulse carrier frequency, the ability to resist suppression interference is improved. Moreover, the radar signal has constant envelope and low peak-to-average power ratio characteristics, which improves the power utilization of the radar power amplifier system and ensures the radar's target detection performance. On this basis, information is carried by three methods: selective mapping, phase shift mapping, and pulse amplitude, which improves the information transmission efficiency of the system and solves the problems existing in the prior art.

Claims

1. A radar-communication integrated signal generation device based on pulse frequency agility, characterized in that, Includes spread spectrum modulation unit, pulse modulation unit, nonlinear unit, and power amplifier unit; The spread spectrum modulation unit receives user data, loads the data into a pseudo-random sequence through data grouping, selection mapping, and phase shift mapping to achieve spread spectrum modulation, and outputs it to the pulse modulation unit. The pulse modulation unit performs pulse amplitude modulation, integrates the signals, and outputs them to the nonlinear unit; the nonlinear unit generates a radar-communication integrated signal with pseudo-random variable carrier frequency and phase based on a cubic nonlinear frequency modulation signal, and outputs it to the power amplifier unit. The power amplifier unit amplifies the received signal and outputs it to the antenna. The spread spectrum modulation unit includes a data packetization module, a pseudo-random sequence generation module, a selection mapping module, and a phase shift mapping module; The data grouping module groups the received user data, and the groups include... p Bit selection mapping group and q Phase shift mapping group, the p The bit selection mapping group is output to the selection mapping module, and the q The phase shift mapping group is output to the phase shift mapping module; The pseudo-random sequence generation module is used to generate N Each pair of pairwise or quasi-orthogonal pairs with a number of digits. M The pseudo-random sequence is output to the selection mapping module; The selection mapping module assigns the following data according to a one-to-one mapping relationship: p Each data combination in the bit selection mapping group is mapped to a value from the... N Selecting the nth pseudo-random sequence i A pseudo-random sequence is generated and output to the phase shift mapping module; The phase shift mapping module maps the phase shift according to a one-to-one mapping relationship. q Each data combination in the phase shift mapping group is mapped to the first... i The cyclic shift state of a pseudo-random sequence is output to the pulse modulation unit; The pulse modulation unit includes a pulse waveform generation module, a pulse amplitude modulation module, and an integration module; The nonlinear unit includes a carrier frequency control module, a phase control module, and a nonlinear modulation module; The carrier frequency control module is used to generate pseudo-random carrier frequency signals. f c And output to the nonlinear modulation module; The phase control module is used to generate pseudo-random phase signals. And output to the nonlinear modulation module; The nonlinear modulation module is connected to the integration module and uses the received integrated signal as an additional phase of the cubic nonlinear frequency modulated signal; the nonlinear modulation module adjusts the signal according to the pseudo-random carrier frequency signal. f c and the pseudo-random phase signal A radar-communication integrated signal is generated and output to the power amplifier unit. The radar-communication integrated signal is: ， in, f c The carrier frequency of the integrated radar and communication signal. B The signal bandwidth factor, T For signal time factor, For the first to participate in modulation i The nth pseudo-random sequence k The cyclic shift state of the th j Bit data, k It is a positive integer. k =0,1,2,… M -1, j It is a positive integer. j =1,2,… M, γ ( t ) is the pulse waveform generated by the pulse waveform generation module.

2. The radar-communication integrated signal generation device based on pulse frequency agility according to claim 1, characterized in that, The pulse waveform generation module is used to generate pulse waveforms. γ ( t And output it to the pulse amplitude modulation module; The pulse amplitude modulation module is connected to the phase shift mapping module, and uses pulse amplitude modulation to convert the first... i Each bit of data from the cyclically shifted state of a pseudo-random sequence is sequentially loaded into the pulse waveform. γ ( t The result is then sent to the integration module; The integration module integrates the received signal and outputs it to the nonlinear unit.

3. The radar-communication integrated signal generation device based on pulse frequency agility according to claim 1, characterized in that, The pseudo-random phase signal generated by the phase control module It is a uniformly distributed random number with values ​​ranging from [-π, π], and in the stated... i Each bit of the cyclic shift state of the pseudo-random sequence is statistically independent.

4. The radar-communication integrated signal generation device based on pulse frequency agility according to claim 1, characterized in that, The pseudo-random carrier frequency signal generated by the carrier frequency control module f c From frequency hopping sequence [ f 1, f 2,…, f M Pseudo-random selection in ] and in the ]th i Each bit of the cyclic shift state of the pseudo-random sequence is statistically independent.

5. The radar-communication integrated signal generation device based on pulse frequency agility according to claim 1, characterized in that, The cyclic shift is either a cyclic left shift or a cyclic right shift, with 1 bit of data shifted in each cycle.

6. The radar-communication integrated signal generation device based on pulse frequency agility according to claim 1, characterized in that, The number of bits in the selected mapping group p The number of pseudo-random sequences N Satisfying the relation: ,symbol This indicates rounding down to the nearest integer.

7. The radar-communication integrated signal generation device based on pulse frequency agility according to claim 1, characterized in that, The number of bits in the phase shift mapping group q The number of bits in the pseudo-random sequence M Satisfying the relation: ,symbol This indicates rounding down to the nearest integer.

8. The radar-communication integrated signal generation device based on pulse frequency agility according to claim 1, characterized in that, The pulse waveform γ ( t ) is a zero-order long spherical wave function.

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