Low peak-to-average envelope ratio communication radar integrated waveform generation method and device

Abstract

The application relates to a low peak-to-mean envelope ratio (PMEPR) communication radar integrated waveform generation method and device, and relates to the technical field of signal detection and communication.The method comprises the following steps: constructing a first kind of complete complementary sequence according to a mapping function, an orthogonal Golay sequence set and an orthogonal matrix; and a radar subsystem uses the first kind of complete complementary sequence to generate a communication radar integrated waveform according to MCPC and MCCDMA.The complete complementary sequence with low column PMEPR is used to suppress the PMEPR of the waveform, and the low PMEPR communication radar integrated waveform is generated based on MCPC and MCCDMA, so that the long-standing problem of high PMEPR of a multi-carrier signal is solved; simulation analysis and test show that the waveform generated by the method has good ambiguity function and PMEPR performance, is more suitable for a communication radar integrated system, can be applied to a multi-user situation, can improve system performance, can reduce the hardware cost of a transmitting end and can prolong the service life of equipment.

Description

Technical Field

[0001] This invention relates to the field of signal detection and communication technology, and in particular to a low peak-to-average envelope ratio integrated waveform generation method and apparatus for communication and radar. Background Technology

[0002] An integrated communication-radar system is a system that simultaneously possesses both communication and radar functions. It is used to modulate and transmit communication and radar signals concurrently, and is widely used in intelligent transportation, military, and detection networks. The integrated design allows for mutual enhancement of the capabilities of both systems. Furthermore, the hardware resources, time-domain waveforms, and frequencies of both systems overlap, making the signal characteristics less distinct. Because traditional single-carrier waveforms have low spectral efficiency, while multi-carrier technology combines the extremely high spectral efficiency of Orthogonal Frequency Division Multiplexing (OFDM) with the orthogonality of Code Division Multiple Access (CDMA), offering greater reliability, security, and resistance to multipath interference and Doppler effects, multi-carrier technology has been increasingly incorporated into radar waveform design.

[0003] Currently, high-performance waveform design remains one of the core issues in integrated communication and radar systems. Although multi-carrier phase coding (MCPC) technology has been widely used in radar waveform design, multi-carrier signals have always suffered from the peak-to-average envelope ratio (PMEPR) problem, which affects system performance. Reference 1, "Sharma S, Melvasalo M, Koivunen V. Multicarrier DS-CDMA Waveforms for Joint Radar-CommunicationSystem[C] / / 2020 IEEE Radar Conference (RadarConf20). IEEE, 2020: 1-6", proposes an integrated communication and radar waveform based on MCPC technology, using variable spreading factor codes and Gold sequences. However, this waveform scheme is not suitable for multi-user scenarios. Furthermore, the PMEPR of the waveform is proportional to the number of subcarriers, which results in a very short lifespan for power amplifiers in practical applications and reduces the symbol efficiency of the waveform. Summary of the Invention

[0004] One objective of this invention is to provide a method for generating integrated communication and radar waveforms with low peak-to-average envelope ratio (PMEPR). This method utilizes the PMER of a fully complementary sequence suppression waveform with low PMER quantity to generate an integrated communication and radar waveform with low PMER, thus solving the long-standing problem of PMER in multi-carrier signals and being applicable to multi-user scenarios.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a low peak-to-average envelope ratio integrated communication radar waveform generation method, comprising the following steps: constructing a first type of fully complementary sequence based on a mapping function, an orthogonal Gray sequence set, and an orthogonal matrix; using the first type of fully complementary sequence in the radar subsystem; and generating an integrated communication radar waveform based on MCPC and MCCDMA.

[0006] Furthermore, the above method also includes the step of constructing a second type of perfectly complementary sequence based on the q-ary generalized Boolean function, and the communication subsystem using either the first or the second type of perfectly complementary sequence.

[0007] Furthermore, the above method also includes the following steps:

[0008] (i) The communication subsystem uses the first or second fully complementary sequence for spread spectrum, and the radar subsystem transmits the first fully complementary sequence. After the signal processing is completed, the communication subsystem and the radar subsystem add scrambling codes to maintain the randomness between the subsystems.

[0009] (ii) After the signals from the communication subsystem and the radar subsystem are combined, the combined signal is modulated onto multiple carriers by fast Fourier transform and then transmitted, thereby generating a low peak-to-average envelope ratio integrated communication and radar waveform in the form of MCPC.

[0010] Furthermore, the steps for constructing the first type of perfectly complementary sequence are as follows:

[0011] Step a: Select two Bivariate orthogonal matrix ,in It is a set of orthogonal Gray sequences;

[0012] Step b: Construct a frequency hopping sequence set: The size of the set is ,in The frequency hopping sequence set satisfies the following conditions:

[0013] (1) Each sequence is a non-repeating sequence, that is, the sequence autocorrelation function satisfies: ;

[0014] (2) The sequence set has a zero-collision region That is, the cross-correlation function satisfies: ;

[0015] Step c, construct a structure containing the number of... complementary sequence set Each complementary sequence is composed of The sequence consists of several subsequences, represented as follows: Each subsequence has a length of , is represented as: Each sequence is specifically constructed as follows:

[0016] .

[0017] Furthermore, step a also includes the step of constructing an orthogonal Gray sequence set, as follows:

[0018] Select an orthogonal Gray complement pair Each of these sequences is a Gray sequence; if If any two sequences in the sequence are orthogonal to each other, then It is a set of orthogonal Gray sequences;

[0019] Choose an initial sequence set of length L:

[0020] ;

[0021] After N iterations, we get:

[0022] ;

[0023] in , It is a 2 n The length is 2 n The set of orthogonal Gray sequences of L sequences.

[0024] Furthermore, step b also includes the steps of constructing the autocorrelation function and the cross-correlation function, as follows:

[0025] Select two sequences a and b of length N, respectively. Aperiodic correlation function of sequences a and b for:

[0026] ;

[0027] like ,but If it is an aperiodic correlation function, then ,but It is an aperiodic cross-correlation function; using Represents a sequence and The periodic cross-correlation function then has

[0028] .

[0029] Furthermore, the steps for constructing the second type of perfectly complementary sequence are as follows:

[0030] set up Assuming the graph of g(c,y) is a natural Hamiltonian path, then each g(c,y) is...

[0031] ;

[0032] in, , And π is The substitution; , where q is an even number not less than 2;

[0033] in, , , ; , , , , .

[0034] Furthermore, in the step of constructing the second type of perfectly complementary sequence, f and h satisfy the following condition:

[0035] (1) ;

[0036] in, , And π is The substitution; and It is a Hamiltonian path whose vertices are formed by... designated;

[0037] (2) ;

[0038] in, , ;

[0039] in, , where q is an even number not less than 2;

[0040] in, , , ; , , , , .

[0041] The second objective of this invention is to provide an integrated waveform generation device for communication radar with low peak-to-average envelope ratio, comprising:

[0042] The complete complementary sequence construction unit constructs the first type of complete complementary sequence based on the mapping function, the orthogonal Gray sequence set, and the orthogonal matrix.

[0043] The communication subsystem and the radar subsystem are configured such that the communication subsystem uses a first type of fully complementary sequence for spread spectrum, and the radar subsystem transmits the first type of fully complementary sequence. After signal processing, the communication subsystem and the radar subsystem are scrambled to maintain the randomness between the subsystems.

[0044] The integrated waveform generation unit combines the signals from the communication subsystem and the radar subsystem, and modulates the combined signal onto multiple carriers through a fast Fourier transform before transmission, thereby generating a low peak-to-average envelope ratio integrated communication and radar waveform in the form of MCPC.

[0045] A third objective of this invention is to provide another integrated waveform generation device for communication radar with low peak-to-average envelope ratio, comprising:

[0046] The complete complementary sequence construction unit constructs the first type of complete complementary sequence based on the mapping function, the orthogonal Gray sequence set, and the orthogonal matrix, and constructs the second type of complete complementary sequence based on the q-ary generalized Boolean function;

[0047] The communication subsystem and the radar subsystem are configured such that the communication subsystem uses a second type of fully complementary sequence for spread spectrum, and the radar subsystem transmits a first type of fully complementary sequence. After signal processing, the communication subsystem and the radar subsystem are scrambled to maintain the randomness between the subsystems.

[0048] The integrated waveform generation unit combines the signals from the communication subsystem and the radar subsystem, and modulates the combined signal onto multiple carriers through a fast Fourier transform before transmission, thereby generating a low peak-to-average envelope ratio integrated communication and radar waveform in the form of MCPC.

[0049] This invention utilizes fully complementary sequences with low column-direction PMEPR to suppress waveform PMEPR. Simultaneously, it generates integrated communication-radar waveforms with low peak-to-average envelope ratio based on MCPC and MCCDMA, solving the long-standing problem of peak-to-average envelope ratio (PMEPR) in multi-carrier signals. Simulation analysis and testing show that the waveforms generated by this method have better ambiguity function and PMEPR performance, making them more suitable for integrated communication-radar systems and multi-user applications. Furthermore, it improves system performance, reduces transmitter hardware costs, and extends equipment lifespan. Attached Figure Description

[0050] Figure 1 This is a time-frequency relationship diagram of the multi-carrier phase modulation code (MCPC) in the embodiment;

[0051] Figure 2 The image shows the ambiguity function of a single pulse in the MCPC in the embodiment. The left image shows the Doppler ambiguity function, and the right image shows the zero Doppler cross-section.

[0052] Figure 3This is a schematic diagram of a multi-carrier system in the embodiment;

[0053] Figure 4 This is a schematic diagram of the integrated communication and radar waveform generation system in the embodiment;

[0054] Figure 5 The diagram illustrates the correlation of completely complementary sequences in the example. The left diagram shows autocorrelation, and the right diagram shows cross-correlation.

[0055] Figure 6 In the example, under the single-user case (without extended scrambling code), the waveform ambiguity function and zero Doppler cross-section diagram under different sequence combinations are shown. The left figure is the ambiguity function considering Doppler frequency shift, and the right figure is the zero Doppler cross-section, which is the first group.

[0056] Figure 7 In the example, under the single-user case (without extended scrambling code), the waveform ambiguity function and zero Doppler cross-section diagram under different sequence combinations are shown. The left figure is the ambiguity function considering Doppler frequency shift, and the right figure is the zero Doppler cross-section, which is the second group.

[0057] Figure 8 In the example, under the single-user case (without extended scrambling code), the waveform ambiguity function and zero Doppler cross-section diagram under different sequence combinations are shown. The left figure is the ambiguity function considering Doppler frequency shift, and the right figure is the zero Doppler cross-section, which is the third group.

[0058] Figure 9 In the example, under the single-user case (without extended scrambling code), the waveform ambiguity function and zero Doppler cross-section diagram under different sequence combinations are shown. The left figure is the ambiguity function considering Doppler frequency shift, and the right figure is the zero Doppler cross-section, which is the fourth group.

[0059] Figure 10 The CCDF diagram of the waveform PMEPR in the embodiment is shown on the left, which is the fourth group of waveforms, and the right is the first group of waveforms.

[0060] Figure 11 The waveform ambiguity function and zero Doppler cross-section diagram in the multi-user case of the embodiment are shown in the left figure, which is the ambiguity function considering Doppler frequency shift, and the right figure is the zero Doppler cross-section, which is the first group.

[0061] Figure 12 The waveform ambiguity function and zero Doppler cross-section diagram in the multi-user case of the embodiment are shown. The left figure is the ambiguity function considering Doppler frequency shift, and the right figure is the zero Doppler cross-section, which is the second group. Detailed Implementation

[0062] To help those skilled in the art better understand the improvements of this invention compared to the prior art, the invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0063] Since multi-carrier signals have always suffered from the problem of peak average envelope ratio (PMEPR), this embodiment constructs a fully complementary sequence with low column PMEPR to design a multi-carrier-based integrated communication and radar waveform. By analyzing waveforms obtained with other sequences, it is verified that this type of waveform has a good ambiguity function and a low PMEPR, making it more suitable for integrated communication and radar systems and applicable to multi-user scenarios. It also solves the long-standing problem of peak average envelope ratio (PMEPR) in multi-carrier signals.

[0064] This embodiment proposes a fully complementary sequence for controlling the peak-to-average envelope ratio. One fully complementary sequence is constructed based on a mapping function, an orthogonal Gray sequence set, and an orthogonal matrix. Another fully complementary sequence is constructed based on a q-ary generalized Boolean function. In this embodiment, based on the MCPC structure and multi-carrier code division multiple access technology, the proposed sequence set is used to generate an integrated communication-radar waveform, and its ambiguity function and PMEPR performance are simulated and analyzed. Due to the numerical advantage and good correlation of the complementary sequence set, the performance of this waveform design scheme in a multi-user scenario is further analyzed.

[0065] The following is a detailed explanation.

[0066] 1. Basic concepts and lemmas.

[0067] Definition 1: Let a and b be two sequences of length N, represented as follows: The aperiodic correlation function of sequences a and b Defined as:

[0068] ;

[0069] like If , it is called an aperiodic correlation function. This is called an aperiodic cross-correlation function. Let... Represents a sequence and The periodic cross-correlation function then has

[0070] .

[0071] Definition 2: Let It is an orthogonal Gray complement pair (GCP), where each sequence is a Gray sequence. If If any two sequences in the sequence are orthogonal to each other, then they are said to be... It is an orthogonal Gray sequence set (OGS).

[0072] Let an OGCP of length L be the initial sequence set:

[0073] ;

[0074] After N iterations, we can obtain:

[0075] ;

[0076] in , It is a 2 n The length is 2 n OGS of L sequence.

[0077] Definition 3: The fuzzy function (AF) is defined as follows:

[0078] ;

[0079] Where s(t) represents the signal waveform function, and τ is the time delay of the signal reaching the receiving end. This represents the Doppler frequency shift caused by the relative displacement of an object. When a=b, it is called a self-ambiguity function; when a≠b, it is called a mutual ambiguity function.

[0080] Definition 4: Peak-to-mean envelope ratio (PMEPR) is the ratio of the maximum value to the average value of the signal envelope, representing the magnitude of the envelope's fluctuations. The PMEPR of a discrete signal waveform is defined as follows:

[0081] ;

[0082] in It is the signal waveform function of the th. One sampled data. This represents the total number of sampling points. The value calculated in the above formula is a linear value. To obtain the value in decibels (dB),... The value of ) can be converted using the following formula.

[0083] .

[0084] 2. Integrated signal model for communication and radar.

[0085] This embodiment presents the principles of MCPC technology and MCCDMA system, and designs a multi-carrier integrated communication radar waveform based on the two technologies.

[0086] 2.1 Multicarrier phase modulation code.

[0087] The essence of MCPC signals is similar to that of OFDM and Multi-Carrier Code Division Multiple Access (MCCDMA). They all utilize multiple orthogonal subcarriers to achieve high spectral efficiency and possess good anti-interference capabilities. The time-frequency structure of MCPC is as follows: Figure 1 As shown.

[0088] Where the number of subcarriers is M, and the subcarrier spacing is f, which is t. b The reciprocal property ensures the orthogonality of subcarriers and also guarantees the phase continuity of consecutive symbols. The complex envelope function expression for a multi-carrier phase modulation code with sequence length M and number of subcarriers N is:

[0089] ;

[0090] in Indicates assignment to the first The weighting function for each subcarrier, For the first The sequence modulated on the nth subcarrier One element; The waveform of a pulse (taking a rectangular wave as an example) is expressed as follows:

[0091] .

[0092] The ambiguity function of a single pulse in MCPC exhibits the properties of an ideal thumbtack function, such as... Figure 2 As shown in the middle left figure. Its Doppler autocorrelation-free property is as follows: Figure 2 As shown in the middle right figure.

[0093] 2.2 Principle of multi-carrier signal waveform generation.

[0094] The principle block diagram of a multi-carrier system is as follows: Figure 3 As shown.

[0095] exist Figure 3 The image shows the basic principle of the transmitter in a multi-carrier baseband communication system. Among them, Represented as the first The first user's One data bit; To be assigned to the Complementary sequences of users of Each subsequence. User data bits, after serial-to-parallel conversion, are spread using different subsequences; different subsequences use different subcarrier frequencies; after being modulated onto multiple carriers via Fast Fourier Transform, they are combined and transmitted. The time-domain sampled waveform output by the transmitter... It can be represented as:

[0096] ;

[0097] In the above formula express , For sampling point parameters, For the subcarrier parameters. One user, Indicates that it is in the first The first subcarrier One data bit, Indicates the first The first subsequence Each code chip. The sampling time for each chip, For subcarrier spacing, in orthogonal frequency division multiplexing, .

[0098] 2.3 Principle of integrated radar and communication waveform generation.

[0099] The integrated waveform generation principle of radar communication based on MCPC technology and MCCDMA system is as follows: Figure 4 As shown, the waveform generation system consists of a communication and a radar subsystem: the communication subsystem uses an Variable Spread Factor Sequence (OVSF) for spread spectrum, while the radar subsystem transmits a random Gold sequence. After signal processing, both subsystems are scrambled to maintain randomness. The signals from the two subsystems are then combined and modulated onto a multi-carrier using a Fast Fourier Transform (FFT) to generate an integrated radar-communication waveform in the form of MCPC.

[0100] Depend on Figure 4 As can be seen, the system is divided into two subsystems: the communication subsystem and the radar subsystem, which are allocated P and Q subcarriers respectively. The selection and allocation of the number of subcarriers is determined by the waveform requirements. The more subcarriers a subsystem receives, the greater its bandwidth will be, thus exhibiting better performance.

[0101] 2.3.1 Communication Subsystem.

[0102] exist Figure 4 The upper and middle parts constitute the communication subsystem, which has... One subcarrier. This embodiment uses OVSF for spread spectrum, but due to the variable spreading factor of the sequence itself, and the requirement that the spreading factors of the two subsystems be equal, the communication subsystem must satisfy:

[0103] ;

[0104] in To unify the spreading factor of the system, The spread factor (sequence length) is the sequence length. This refers to the length of the user data bits. This embodiment uses complementary sequences. Since the subsequence length of a complementary sequence is constant, it is only necessary to set the subsequence length when constructing the sequence. That's it. Simultaneously, the communication subsystem uses time-domain spread spectrum. The matrix form output by the communication subsystem is:

[0105] , ;

[0106] in For spreading matrix, This is the output data matrix of the communication subsystem after scrambling.

[0107] 2.3.2 Radar Subsystem.

[0108] exist Figure 4 The lower half is the radar subsystem, which transmits a random gold sequence of length. The radar subsystem output data matrix is ​​in the following form:

[0109] ;

[0110] in, To transmit the sequence matrix, For the scrambling matrix, This is the data matrix output by the radar subsystem after scrambling.

[0111] 2.3.3 Joint waveform function expression.

[0112] The output data matrices of the two subsystems are combined and fed into the Inverse Fast Fourier Transform (IFFT) module, and the Inverse Fourier Transform (IDFT) matrix is ​​generated. for:

[0113] ;

[0114] Let the combined data matrix be The output data matrix is Its specific form is:

[0115] ;

[0116] The time-domain sampled signal expression of the system output waveform is:

[0117] ;

[0118] in For sampling point parameters, For subcarrier parameters, These are chip parameters. This refers to both the chip duration and the sampling time. The subcarrier spacing.

[0119] 3. PMEPR inhibition.

[0120] In multi-carrier systems, the superposition of time-domain signals leads to extremely high peak values ​​in the waveform envelope. The ratio of these peak values ​​to the average envelope value is called the peak-to-average envelope ratio (PMEPR). Excessively high PMEPR increases the cost of transmitter hardware and shortens equipment lifespan. This embodiment constructs a complementary sequence for the control train's PMEPR from the perspective of the sequence used in the system. Through simulation, the cumulative distribution function (CCDF) plot of the signal's PMEPR is obtained, and its effectiveness is analyzed.

[0121] 3.1 Construction of fully complementary codes with controlled average envelope ratio of column peaks.

[0122] Construction Method 1.

[0123] Step 1: Select two Bivariate orthogonal matrix ,in It is an orthogonal Gray sequence set.

[0124] Step 2: Construct a frequency hopping sequence set: The size of the set is ,in: The frequency hopping sequence set must meet the following conditions:

[0125] (1) Each sequence is a non-repeating sequence, that is, the sequence autocorrelation function satisfies: ;

[0126] (2) The sequence set has a zero-collision region That is, the cross-correlation function satisfies: ;

[0127] Step 3: Construct a structure containing a number of... complementary sequence set Each complementary sequence is composed of The sequence consists of several subsequences, represented as follows: Each subsequence has a length of , is represented as: Each sequence is specifically constructed as follows:

[0128] .

[0129] Theorem 1: Sequence Sets It is a fully complementary code and satisfies the fully complementary property.

[0130] Proof: Let Calculate the relevant function values:

[0131] .

[0132] Scenario 1: When At this point, the two sequences are the same sequence. This is due to the frequency hopping sequence. Since it is a non-repeating sequence, we can obtain: when At that time, due to the matrix The orthogonality of different rows has Therefore, the above expression is 0 at this point.

[0133] Scenario 2: When At this point, the two sequences are different sequences. At that time, according to the matrix The orthogonality of different rows can be obtained as follows: ;like According to the matrix The orthogonality of different rows has At this point, the above expression is 0.

[0134] Combining the above two cases, Theorem 1 holds. The autocorrelation and cross-correlation values ​​of the sequences are as follows: Figure 5 As shown.

[0135] In this embodiment, construction method 1 is used to construct the first type of perfectly complementary sequence.

[0136] Construction Method 2.

[0137] definition .set up

[0138] ;

[0139] ;

[0140] Additionally, the following binary vector is defined: , , , , .

[0141] The following symbols will also be used in this embodiment:

[0142] , where q is an even number not less than 2.

[0143] Theorem A: Let and These are two q-ary generalized Boolean functions (GBFs) with an algebraic degree greater than 1. Assume that f has the following properties: ,in, and It is a Hamiltonian path whose vertices are formed by... Specify, that is,

[0144] ;

[0145] in, , And π is The permutation. Let.

[0146] ;

[0147] Then,

[0148] ;

[0149] exist Generate a row with a size of The column size is complementary codes, where, or .

[0150] Theorem B: For the formula in Theorem A Define g, and assume the graph of g(c,y) (this is only the GBF of y, where ) is a natural Hamiltonian path, that is, each g(c,y) can be written as

[0151] ;

[0152] in, , And π is The permutation. Each column sequence is a Golay-Davis-Jedwab (GDJ) sequence.

[0153] Example 1: Let m = 3, n = 5, q = 4. Also, let... It is an empty set. ,

[0154] think,

[0155] ;

[0156] in,

[0157] ;

[0158] Clearly, f and h satisfy the following conditions:

[0159] ;

[0160] in, , And π is The substitution; where, and It is a Hamiltonian path whose vertices are formed by... designated;

[0161] ;

[0162] in, , .

[0163] in addition, The graph is a natural Hamiltonian path.

[0164] according to,

[0165] ;

[0166] in , generated in Supplementary complement As shown below,

[0167] ;

[0168] in, :

[0169] .

[0170] The corresponding set is complete complementary codes (CCC), that is, As shown in the table below.

[0171] .

[0172] This embodiment uses Theorem B from Construction 2 to construct the second type of perfectly complementary sequence.

[0173] 4. Simulation results.

[0174] 4.1 Experimental parameters.

[0175] Since this embodiment mainly discusses the impact of complementary codes on the waveform ambiguity function and peak-to-average envelope ratio, long scrambling codes were not included in the simulation. The experiment mainly compared the ambiguity function and peak-to-average envelope ratio when different sequence schemes were selected in the above-mentioned integrated system. The experimental parameters are shown in Table 1.

[0176] Table 1. Simulation sequence combinations and their parameters.

[0177]

[0178] In Table 1, OVSF and Gold sequences do not belong to a set due to their inherent properties; therefore, their sequence parameters represent the number of sequences and their lengths (the length of OVSF sequences varies). For complementary sequences, These represent the number of subsequences and the length of each subsequence, respectively. The first group consists of sequences from reference 1, which are classic perfectly complementary sequences and are used as a control group. The second type of perfectly complementary sequence is a sequence with zero correlation region complementarity.

[0179] The performance of the proposed schemes is judged by comparing the ambiguity functions and peak-to-average envelope ratios of different sequences with those in Reference 1. Specifically, the degree of Doppler shift suppression by different sequence schemes is evaluated by calculating the comprehensive sidelobe suppression ratio of the ambiguity function.

[0180] 4.2 Simulation results.

[0181] After combining different groups of sequences to generate waveform functions through the system described above, a fuzzy function graph is plotted using the fuzzy function formula.

[0182] 4.2.1 Fuzzy function in single-user case.

[0183] The ambiguity function and zero Doppler cross section in the single-user case (without extended scrambling code) are as follows: Figures 6 to 9 As shown.

[0184] Figures 6 to 9 This represents the waveform ambiguity function under different sequence combinations; the left figure is the ambiguity function considering Doppler frequency shift, and the right figure is the zero Doppler cross-section.

[0185] Depend on Figures 6 to 9 It can be seen that: the first group is the scheme in Reference 1; according to the fuzzy functions of the second and third groups, it can be seen that the complementary sequence of a single set is less effective than the combination of different complementary codes.

[0186] 4.2.2 Peak-to-envelope ratio.

[0187] Due to the drawbacks of multi-carrier technology, a high PMEPR is often observed. This embodiment aims to suppress the peak-to-average envelope ratio of the waveform from the perspective of sequence construction. The PMEPR for each combination is calculated based on the aforementioned sequence combination waveform function and PMEPR calculation method, as shown in Table 2.

[0188] Table 2. Waveform peak-to-average envelope ratio under different sequence combinations.

[0189]

[0190] Table 2 shows that the combined peak-to-average envelope ratio (PARR) of the first group is equal to the number of subcarriers, making it unsuitable for situations with more subcarriers. Since the PARRs of the second and third groups are below 4, and the PARR of the fourth group is below 3, and due to the definition, the PARRs of the second, third, and fourth groups all have an upper bound of 4, independent of the number of subcarriers, they are more suitable for situations with a larger number of subcarriers. The PMEPR's CCDF is as follows... Figure 10 As shown.

[0191] 4.2.3 Performance analysis in multi-user scenarios.

[0192] Due to the inherent limitations of OVSF and Gold sequences, the number of sequences they generate is far less than that of complementary sequences. Both the first and second types of perfectly complementary sequences are relatively numerous, so a mutual ambiguity function is considered in the multi-user scenario. Sequence combinations in the multi-user scenario are shown in Table 3.

[0193] Table 3 Simulation sequence combinations and parameters under multi-user conditions.

[0194]

[0195] The first type of completely complementary sequence consists of different sequences within the set, while the second type consists of different sequences within the same set (guaranteed to be different sequences). The mutual ambiguity function is as follows: Figure 11 , 12 As shown.

[0196] in, Figure 11 , 12 This is represented as a waveform ambiguity function under multi-user conditions; the left figure shows the ambiguity function considering Doppler frequency shift, and the right figure shows the zero Doppler cross-section. Figure 11 , 12 It can be seen that in a multi-user scenario, the performance of the fuzzy function in the second group is significantly better than that in the first group.

[0197] In summary, the first type (Construction 1) of fully complementary codes for the control column peak-to-average envelope ratio provided in this embodiment is a class of fully complementary sequences with low column-direction PMEPR. Applying it to the aforementioned integrated communication-radar signal model can suppress PMEPR and generate an integrated communication-radar waveform with a low peak-to-average envelope ratio. Furthermore, combining it with the second type (Construction 2) of fully complementary sequences can yield waveforms with even better ambiguity function and PMEPR performance. In addition, this embodiment proposes a set of fully complementary sequences for the control column peak-to-average envelope ratio based on an integrated communication-radar system. After combining different sequences, the system generates waveform functions and analyzes the ambiguity function performance and peak-to-average envelope ratio. When the ambiguity function performance is similar, the PMEPR of the waveform is reduced to below 4, making it more suitable for transmission in multi-carrier scenarios. Due to the large number of sequences, the case of multiple users is also considered, and a mutual ambiguity function is given. The combination of the two sequences also improves the ambiguity function performance.

[0198] Furthermore, this embodiment also proposes an integrated waveform generation device for communication radar with low peak-to-average envelope ratio, which includes:

[0199] The complete complementary sequence construction unit constructs the first type of complete complementary sequence based on the mapping function, the orthogonal Gray sequence set, and the orthogonal matrix.

[0200] The communication subsystem and the radar subsystem are configured such that the communication subsystem uses a first type of fully complementary sequence for spread spectrum, and the radar subsystem transmits the first type of fully complementary sequence. After signal processing, the communication subsystem and the radar subsystem are scrambled to maintain the randomness between the subsystems.

[0201] The integrated waveform generation unit combines the signals from the communication subsystem and the radar subsystem, and modulates the combined signal onto multiple carriers through a fast Fourier transform before transmission, thereby generating a low peak-to-average envelope ratio integrated communication and radar waveform in the form of MCPC.

[0202] This embodiment also proposes another low peak-to-average envelope ratio integrated waveform generation device for communication radar, which includes:

[0203] The complete complementary sequence construction unit constructs the first type of complete complementary sequence based on the mapping function, the orthogonal Gray sequence set, and the orthogonal matrix, and constructs the second type of complete complementary sequence based on the q-ary generalized Boolean function;

[0204] The communication subsystem and the radar subsystem are configured such that the communication subsystem uses a second type of fully complementary sequence for spread spectrum, and the radar subsystem transmits a first type of fully complementary sequence. After signal processing, the communication subsystem and the radar subsystem are scrambled to maintain the randomness between the subsystems.

[0205] The integrated waveform generation unit combines the signals from the communication subsystem and the radar subsystem, and modulates the combined signal onto multiple carriers through a fast Fourier transform before transmission, thereby generating a low peak-to-average envelope ratio integrated communication and radar waveform in the form of MCPC.

[0206] Those skilled in the art should understand that all units in the above two low peak-to-average envelope ratio integrated waveform generation devices for communication radar can be encapsulated as a virtual device of computer software / program, or some of the models or units can be made into individual integrated circuit modules, and then combined with the corresponding computer program to realize the sequential execution of each step. The present invention is not limited to a specific combination of hardware and software.

[0207] The above embodiments are preferred implementations of the present invention. In addition, the present invention can be implemented in other ways. Any obvious substitutions without departing from the concept of the present technical solution are within the protection scope of the present invention.

[0208] To facilitate understanding by those skilled in the art of the improvements of this invention over the prior art, some of the accompanying drawings and descriptions have been simplified, and for clarity, some other elements have been omitted from this application. Those skilled in the art should realize that these omitted elements may also constitute the content of this invention.

Claims

1. A low peak-to-average envelope ratio integrated waveform generation method for communication and radar, characterized in that, Includes the following steps: The first type of fully complementary sequence is constructed based on the mapping function, the orthogonal Gray sequence set, and the orthogonal matrix. The radar subsystem uses the first type of fully complementary sequence to generate an integrated communication radar waveform based on MCPC and MCCDMA. The steps for constructing the first type of perfectly complementary sequence are as follows: Step a: Select two Bivariate orthogonal matrix ,in It is a set of orthogonal Gray sequences; Step b: Construct a frequency hopping sequence set: The size of the set is ,in The frequency hopping sequence set satisfies the following conditions: (1) Each sequence is a non-repeating sequence, that is, the sequence autocorrelation function satisfies: ; (2) The sequence set has a zero-collision region That is, the cross-correlation function satisfies: ; Step c, construct a structure containing the number of... complementary sequence set Each complementary sequence is composed of The sequence consists of several subsequences, represented as follows: Each subsequence has a length of , is represented as: Each sequence is specifically constructed as follows: ； The steps for generating the integrated communication and radar waveform are as follows: The communication subsystem uses a variable spread spectrum sequence for spread spectrum, while the radar subsystem transmits a random Gold sequence. After signal processing, both subsystems are scrambled to maintain randomness. After the signals from the two subsystems are combined, the combined signal is modulated onto a multi-carrier using a fast Fourier transform to generate an integrated radar-communication waveform in the form of MCPC.

2. The low peak-to-average envelope ratio integrated waveform generation method for communication and radar according to claim 1, characterized in that, It also includes the step of constructing a second type of perfectly complementary sequence based on the q-ary generalized Boolean function, and the communication subsystem using either the first or the second type of perfectly complementary sequence.

3. The low peak-to-average envelope ratio integrated waveform generation method for communication and radar according to claim 2, characterized in that, It also includes the following steps: (i) The communication subsystem uses the first or second fully complementary sequence for spread spectrum, and the radar subsystem transmits the first fully complementary sequence. After the signal processing is completed, the communication subsystem and the radar subsystem add scrambling codes to maintain the randomness between the subsystems. (ii) After the signals from the communication subsystem and the radar subsystem are combined, the combined signal is modulated onto multiple carriers by fast Fourier transform and then transmitted, thereby generating a low peak-to-average envelope ratio integrated communication and radar waveform in the form of MCPC.

4. The low peak-to-average envelope ratio integrated waveform generation method for communication and radar according to claim 1, characterized in that, Step a also includes the step of constructing an orthogonal Gray sequence set, as follows: Select an orthogonal Gray complement pair Each of these sequences is a Gray sequence; if If any two sequences in the sequence are orthogonal to each other, then It is a set of orthogonal Gray sequences; Choose an initial sequence set of length L: ； After N iterations, we obtain: ； in , It is a 2 n The length is 2 n The set of orthogonal Gray sequences of L sequences.

5. The low peak-to-average envelope ratio integrated waveform generation method for communication and radar according to claim 1, characterized in that, Step b also includes the steps of constructing the autocorrelation function and the cross-correlation function, as follows: Select two sequences a and b of length N, respectively. Aperiodic correlation function of sequences a and b for: ； like ,but If it is an aperiodic correlation function, then ,but It is an aperiodic cross-correlation function; using Represents a sequence and For the periodic cross-correlation function, then we have 。 6. A low peak-to-average envelope ratio integrated waveform generation device for communication radar, characterized in that, include: The complete complementary sequence construction unit constructs the first type of complete complementary sequence based on the mapping function, the orthogonal Gray sequence set, and the orthogonal matrix. The steps for constructing the first type of perfectly complementary sequence are as follows: Step a: Select two bivariate orthogonal matrix ,in It is a set of orthogonal Gray sequences; Step b: Construct a frequency hopping sequence set: The size of the set is ,in The frequency hopping sequence set satisfies the following conditions: (1) Each sequence is a non-repeating sequence, that is, the sequence autocorrelation function satisfies: ; (2) The sequence set has a zero-collision region That is, the cross-correlation function satisfies: ; Step c, construct a structure containing the number of... complementary sequence set Each complementary sequence is composed of The sequence consists of several subsequences, represented as follows: Each subsequence has a length of , is represented as: Each sequence is specifically constructed as follows: ； The communication subsystem and the radar subsystem are configured such that the communication subsystem uses a first type of fully complementary sequence for spread spectrum, and the radar subsystem transmits the first type of fully complementary sequence. After signal processing, the communication subsystem and the radar subsystem are scrambled to maintain the randomness between the subsystems. The integrated waveform generation unit combines the signals from the communication subsystem and the radar subsystem, and modulates the combined signal onto multiple carriers through a fast Fourier transform before transmission, thereby generating a low peak-to-average envelope ratio integrated communication and radar waveform in the form of MCPC.

7. A low peak-to-average envelope ratio integrated waveform generation device for communication radar, characterized in that, include: The complete complementary sequence construction unit constructs the first type of complete complementary sequence based on the mapping function, the orthogonal Gray sequence set, and the orthogonal matrix, and constructs the second type of complete complementary sequence based on the q-ary generalized Boolean function; The steps for constructing the first type of perfectly complementary sequence are as follows: Step a: Select two Bivariate orthogonal matrix ,in It is a set of orthogonal Gray sequences; Step b: Construct a frequency hopping sequence set: The size of the set is ,in The frequency hopping sequence set satisfies the following conditions: (1) Each sequence is a non-repeating sequence, that is, the sequence autocorrelation function satisfies: ; (2) The sequence set has a zero-collision region That is, the cross-correlation function satisfies: ; Step c, construct a structure containing the number of... complementary sequence set Each complementary sequence is composed of The sequence consists of several subsequences, represented as follows: Each subsequence has a length of , is represented as: Each sequence is specifically constructed as follows: ； The communication subsystem and the radar subsystem are configured such that the communication subsystem uses a second type of fully complementary sequence for spread spectrum, and the radar subsystem transmits a first type of fully complementary sequence. After signal processing, the communication subsystem and the radar subsystem are scrambled to maintain the randomness between the subsystems. The integrated waveform generation unit combines the signals from the communication subsystem and the radar subsystem, and modulates the combined signal onto multiple carriers through a fast Fourier transform before transmission, thereby generating a low peak-to-average envelope ratio integrated communication and radar waveform in the form of MCPC.

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