Chaotic communication sensing integrated signal processing method, device and communication system

Abstract

The application discloses a chaotic communication and sensing integrated signal processing method and device and a communication system. The scheme provided by the application divides an information bit sequence into a modulation bit sequence, an index bit sequence and a PPM bit sequence, processes an initial signal vector by combining a pulse position modulation technology, optimizes spectral utilization by double control of the modulation bit and the index bit, segments the initial modulation signal according to PPM orders and generates a signal vector, and offsets the signal vector in the time domain by combining a shift matrix. The scheme utilizes the good autocorrelation characteristics and the low cross-correlation characteristics of an LFM signal, and on the basis of the original DCSK-LFM modulation mode, combines pulse position modulation and index modulation, so that the same carrier can carry more information, thereby improving the transmission rate when applied to a JRC system and the overall performance of the communication system.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a signal processing method, apparatus and communication system integrating chaotic communication and sensing. Background Technology

[0002] Chaotic signals are widely used in spread spectrum communication due to their quasi-randomness, ease of generation, and good autocorrelation / cross-correlation properties. Currently, research on chaotic communication mainly focuses on chaotic digital communication. Among all chaos-based communication systems, incoherent chaotic communication schemes that do not require chaotic synchronization have received increasing attention. Differential Chaos Shift Keying (DCSK) is a typical representative of incoherent chaotic communication systems.

[0003] In recent years, due to the limited and fixed nature of radio spectrum resources, the demand for spectrum from commercial communications has grown exponentially, placing additional pressure on radar applications and forcing radar and communications to share spectrum. Meanwhile, in terms of hardware, wireless communication and radar sensing systems are becoming increasingly similar in hardware architecture (such as high-frequency bands and antenna arrays), channel characteristics, and signal processing. The boundaries between these two systems are becoming increasingly blurred, laying the foundation for integrating radar and communication functions into a single system, forming the basis for Joint Radar and Communication (JRC) technology.

[0004] Although the existing DCSK-LFM technology can be directly used in JRC systems, it generally suffers from low data transmission rates in practical applications. Summary of the Invention

[0005] This application provides a signal processing method, device, and communication system integrating chaotic communication and sensing, which solves the technical problem of low data transmission rate in the existing DCSK-LFM technology used in JRC systems.

[0006] To address the aforementioned technical problems, the first aspect of this application provides a signal processing method integrating chaotic communication and sensing, applied to a transmitter terminal, comprising:

[0007] Acquire chaotic signals and information bit sequences;

[0008] The information bit sequence is segmented to obtain a modulation bit sequence, an index bit sequence, and a PPM bit sequence, wherein the index bit sequence is used to determine the carrier signal that carries the information.

[0009] Based on the modulation bit sequence and the index bit sequence, the signal is modulated in combination with the time-delayed chaotic signal to obtain the initial modulation signal;

[0010] Based on the initial modulation signal and combined with the preset PPM modulation order information, the initial modulation signal is divided into several information-carrying signal segments, and then based on each of the information-carrying signal segments, the initial signal vector corresponding to the initial modulation signal is obtained.

[0011] Based on the PPM bit sequence and combined with a preset shift matrix, the initial signal vector is pulse position modulated to obtain the information-carrying signal;

[0012] The information-carrying signal is integrated with the reference signal to obtain the transmitted signal, wherein the reference signal is specifically generated based on the chaotic signal.

[0013] Preferably, the information bit sequence is segmented to obtain a modulation bit sequence, an index bit sequence, and a PPM bit sequence, specifically including:

[0014] The information bit sequence is segmented according to a preset bit sequence segmentation threshold to obtain a modulation bit sequence, an index bit sequence, and a PPM bit sequence in sequence, wherein the number of sequence elements contained in the modulation bit sequence, the index bit sequence, and the PPM bit sequence matches the bit sequence segmentation threshold.

[0015] Preferably, based on the PPM bit sequence and a preset shift matrix, the initial signal vector is pulse-position modulated to obtain the information-carrying signal, including:

[0016] Based on the preset correspondence between PPM bits and shift matrices, the target shift matrix corresponding to the PPM bits of the initial modulation signal is determined.

[0017] Based on the target shift matrix, the initial signal vector is pulse position modulated to obtain the information-carrying signal.

[0018] Preferably, the formula for calculating the initial modulation signal is as follows:

[0019]

[0020] In the formula, Let x be the initial modulation signal at time t. i The signal is chaotic, β is the spreading factor, μ is the chirp slope, and T is the chirp slope. c For each chaotic signal, T is the chip cycle. p For the pulse repetition period, b m Let a be the m-th element of the index bit sequence. mLet m be the m-th element of the modulated bit sequence.

[0021] The second aspect of this application provides a signal processing method integrating chaotic communication and sensing, applied to a receiver terminal, comprising:

[0022] In response to a received signal, the received signal is decomposed to obtain a reference signal and an information-bearing signal, wherein the received signal is a signal sent from the transmitter terminal to the receiver terminal;

[0023] According to the preset PPM modulation order information, the reference signal is divided into several reference signal segments, so as to obtain a reference signal vector based on each reference signal segment;

[0024] The reference signal vector is inversely modulated with a preset shift matrix to obtain a demodulated reference signal;

[0025] The information-carrying signal is multiplied by the demodulation reference signal and the demodulation reference conjugate signal to obtain a first product value and a second product value. Then, the sum of the first product value and the second product value in their respective time domains is calculated to obtain a first initial decision variable and a second initial decision variable.

[0026] The first decision variable and the second decision variable are calculated based on the first initial decision variable and the second initial decision variable. Then, the demodulation result of the modulation bit sequence of the information-carrying signal is determined based on the comparison result of the first decision variable and the second decision variable. The first decision variable is the square of the absolute value of the first initial decision variable, and the second decision variable is the square of the absolute value of the second initial decision variable.

[0027] Preferably, the calculation expression for the demodulation result of the modulation bit sequence is as follows:

[0028]

[0029]

[0030] In the formula, , , These are the demodulation results for the m-th element of the modulation bit sequence, the index bit sequence, and the PPM bit sequence, respectively. For the first decision variable and the second decision variable The output of the argmax function.

[0031] Preferably, the formula for calculating the demodulation reference signal is as follows:

[0032]

[0033] In the formula, The demodulation reference signal, The reference signal vector, Let Q be the Qth shift matrix, where Q is the PPM modulation order.

[0034] A third aspect of this application provides a signal processing device integrating chaotic communication sensing, applied to a transmitter terminal, comprising:

[0035] The basic signal acquisition unit is used to acquire chaotic signals and information bit sequences;

[0036] A bit sequence segmentation unit is used to segment the information bit sequence into a modulation bit sequence, an index bit sequence, and a PPM bit sequence, wherein the index bit sequence is used to determine the carrier signal that carries the information.

[0037] An initial modulation unit is used to perform signal modulation based on the modulation bit sequence and the index bit sequence, combined with a time-delayed chaotic signal, to obtain an initial modulation signal.

[0038] The signal vector generation unit is used to divide the initial modulation signal into several information-carrying signal segments based on the initial modulation signal and combined with preset PPM modulation order information, and then obtain the initial signal vector corresponding to the initial modulation signal based on each of the information-carrying signal segments.

[0039] The pulse position modulation unit is used to perform pulse position modulation on the initial signal vector according to the PPM bit sequence and in combination with a preset shift matrix to obtain the information carrying signal.

[0040] A transmission signal generation unit is used to integrate the information-carrying signal with a reference signal to obtain a transmission signal, wherein the reference signal is specifically generated based on the chaotic signal.

[0041] The fourth aspect of this application provides a signal processing device integrating chaotic communication and sensing, applied to a receiver terminal, comprising:

[0042] A signal receiving response unit is configured to decompose the received signal in response to a received signal to obtain a reference signal and an information carrying signal, wherein the received signal is a signal sent from a transmitter terminal to a receiver terminal;

[0043] The reference signal vector decomposition unit is used to divide the reference signal into several reference signal segments according to the preset PPM modulation order information, so as to obtain a reference signal vector according to each reference signal segment.

[0044] The pulse position demodulation unit is used to perform pulse position inverse modulation on the reference signal vector and a preset shift matrix to obtain a demodulated reference signal;

[0045] The initial decision variable determination unit is used to multiply the information-carrying signal with the demodulation reference signal and the demodulation reference conjugate signal respectively to obtain a first product value and a second product value, and then calculate the sum of the first product value and the second product value in their respective time domains to obtain the first initial decision variable and the second initial decision variable.

[0046] The modulation bit demodulation unit is used to calculate a first decision variable and a second decision variable based on the first initial decision variable and the second initial decision variable, and then determine the demodulation result of the modulation bit sequence of the information carrying signal based on the comparison result of the first decision variable and the second decision variable, wherein the first decision variable is the square of the absolute value of the first initial decision variable, and the second decision variable is the square of the absolute value of the second initial decision variable.

[0047] The fifth aspect of this application provides a chaotic communication system, including: a transmitter terminal and a receiver terminal, wherein the transmitter terminal and the receiver terminal are communicatively connected;

[0048] The transmitter terminal includes: a first memory and a first processor. The first memory stores first program code, which is used to implement a signal processing method for integrated chaotic communication and sensing as provided in the first aspect of this application. The first processor is used to read and execute the first program code.

[0049] The receiver terminal includes a second memory and a second processor. The second memory stores second program code, which is used to implement a signal processing method for integrated chaotic communication and sensing as provided in the second aspect of this application. The second processor is used to read and execute the second program code.

[0050] As can be seen from the above technical solutions, this application has the following advantages:

[0051] The solution provided in this application utilizes the good autocorrelation and low cross-correlation characteristics of LFM signals. By segmenting the information bit sequence into modulation bit sequence, index bit sequence, and PPM bit sequence, and processing the initial signal vector with pulse position modulation technology, the spectral utilization is optimized through dual control of modulation bits and index bits. The initial modulation signal is segmented according to the PPM order to generate a signal vector. The signal vector is then shifted in the time domain using a shift matrix. Additional information bits are transmitted through pulse position modulation and index modulation, allowing the same carrier to carry more information, thereby improving the transmission rate and the overall performance of the communication system. Attached Figure Description

[0052] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0053] Figure 1 This is a block diagram of the architecture of a traditional DCSK-LFM transmitter.

[0054] Figure 2 This is a block diagram of the architecture of a traditional DCSK-LFM receiver.

[0055] Figure 3 This is a flowchart illustrating an embodiment of a signal processing method for integrated chaotic communication and sensing applied on the transmitter side, as provided in this application.

[0056] Figure 4 This application provides a logic block diagram of an embodiment of a signal processing method for integrated chaotic communication sensing applied on the transmitter side.

[0057] Figure 5 This is a flowchart illustrating an embodiment of a signal processing method for integrated chaotic communication and sensing applied on the receiver side, as provided in this application.

[0058] Figure 6 This application provides a logic block diagram of an embodiment of a signal processing method for integrated chaotic communication sensing applied on the receiver side.

[0059] Figure 7 This is a comparison of the bit error rate performance of the proposed scheme and the traditional DCSK-LFM scheme in a Gaussian white noise channel.

[0060] Figure 8 This is a schematic diagram of an embodiment of a signal processing device for chaotic communication and sensing integration applied on the transmitter side, provided in this application.

[0061] Figure 9 This is a schematic diagram of an embodiment of a signal processing device for chaotic communication and sensing integration applied on the receiver side, provided in this application. Detailed Implementation

[0062] In traditional incoherent chaotic communication systems, when using a single-carrier modulation architecture, the symbol transmission rate is limited by the time-frequency characteristics of the chaotic signal itself, resulting in a limited amount of effective information that can be carried per unit time.

[0063] The transmitter block diagram of the DCSK-LFM scheme is as follows: Figure 1 As shown. In this system, the transmitter sends a total of N = M + 1 pulses, where M is the number of information symbols. The first pulse is used to transmit the reference signal, and the remaining pulses are used to transmit the information-bearing signal. When the transmitted bit is "1", the information-bearing signal is the same as the reference signal; when the transmitted bit is "0", the information-bearing signal is the inverse version of the reference signal. The expression for its transmitted signal S(t) is:

[0064]

[0065] Where, x i (i = 0,1,…,β-1) is a chaotic signal, β is the spreading factor, f0 is the initial frequency, μ is the chirp slope, and T c For each chaotic signal, T is the chip cycle. p For the pulse repetition period, b m Let m be the information bits, where m = 1, 2, ..., M.

[0066] Figure 2 This is a block diagram of the receiver for the DCSK-LFM scheme. Its principle is as follows: After the transmitted signal reaches the target, the DCSK-LFM receiver demodulates the received waveform; simultaneously, the transmitted signal is also reflected back to the JRC transceiver for signal processing to obtain information such as the target's speed and distance. The received signal r(t) can be expressed as:

[0067]

[0068] Where n j,i (t) (j = 0,1,…,M) represents the additive white Gaussian noise with zero mean and variance N0 / 2 corresponding to the (i+1)th sub-waveform of the (j+1)th pulse waveform. In the DCSK-LFM scheme, the received first pulse signal r0(t) is multiplied by the conjugate copy of the LFM signal. Then, the processed signal is subjected to the real part operation, and the final signal is stored as a reference signal in the matrix. Then, the same operation is performed on the remaining pulse signals, and the results are stored in the matrix as information-carrying signals. In the middle. Finally, z = A × B T Output to the detector ([·]) T (For transpose) When the detector detects a corresponding element greater than "0", the corresponding modulation bit is "1"; when the detector detects a corresponding element less than "0", the corresponding modulation bit is "0". Therefore, the m-th estimated modulation bit... It can be represented as:

[0069]

[0070] Where z m Let m be the m-th element in vector z.

[0071] In JRC systems, DCSK-LFM technology, due to its fixed carrier allocation mechanism, can only carry a single bit of information through amplitude and phase modulation per symbol period, making it difficult to exceed theoretical limits in terms of bandwidth utilization and information entropy density. The static allocation mode of carrier resources increases the cost of maintaining signal orthogonality and further exacerbates inter-symbol interference in multipath channel environments, severely restricting system throughput improvement.

[0072] In view of this, embodiments of this application provide a signal processing method, apparatus, and communication system integrating chaotic communication and sensing. The aim is to provide an improved DCSK-LFM (PPM-IM-DCSK-LFM) scheme for JRC systems based on the linear frequency modulation (LFM) (DCSK-LFM) waveform of DCSK, combined with pulse position modulation (PPM) and index modulation (IM), thereby solving the technical problem of low data transmission rate in existing DCSK-LFM schemes used in JRC systems.

[0073] To make the inventive objectives, features, and advantages of this application more apparent and understandable, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0074] Please see Figure 3 and Figure 4 This application provides an embodiment of a signal processing method integrating chaotic communication and sensing, which is applied to the transmitter terminal side. The method includes:

[0075] Step 101: Obtain the chaotic signal and information bit sequence;

[0076] Step 102: Perform bit sequence segmentation on the information bit sequence to obtain the modulation bit sequence, index bit sequence, and PPM bit sequence respectively;

[0077] It should be noted that the modulation bit sequence contains the main communication information and is used for DCSK modulation, the index bit sequence is used to determine the carrier signal that carries the information, and the PPM bits are used for pulse position modulation.

[0078] It should be noted that chaotic signals refer to non-periodic signals with quasi-random characteristics. Specifically, they can be generated by nonlinear dynamical systems, utilizing their good autocorrelation and cross-correlation as the basis for spread spectrum, providing a basic signal source with high security and anti-interference capabilities.

[0079] Bit sequence segmentation refers to splitting the original information bit sequence into three sub-sequences: modulation, index, and pulse position. Specifically, a fixed bit width can be divided using a preset segmentation length threshold. Parallel information transmission can be achieved by independently allocating carrier resources and modulation parameters, thereby increasing the information carrying capacity per unit symbol.

[0080] Assuming the transmitter in this embodiment transmits a total of A series of pulses, the first of which is a reference signal generated based on a chaotic signal, can be described as follows:

[0081]

[0082] in, The signal is chaotic, and β is the spreading factor. For each chaotic signal, the chip cycle is defined, and T is the pulse width of the LFM signal. The remaining pulse serves as the information carrier signal. The combination of the chaotic signal and the LFM signal is the same as in the DCSK-LFM scheme. The difference is that in this scheme, the information bit d is divided into three parts. The first part is the modulation bit d1, used for DCSK modulation. Before IM and PPM, when the transmitted bit is "1", the information carrier signal is the same as the reference signal; when the transmitted bit is "0", the information carrier signal is opposite to the reference signal. The second part is the index bit d2, used to determine the carrier signal as the information carrier signal. The third part is the PPM bit d3, which is... It means that, among them The value is in PPM bits, determined by the modulation order of PPM. For example, when the modulation order... When =2, It consists of one bit; when When =4, It consists of two bits; similarly, it can be known that... Depend on It consists of bits.

[0083] Step 103: Based on the modulation bit sequence and the index bit sequence, combine the time-delayed chaotic signal to perform signal modulation to obtain the initial modulation signal;

[0084] Step 104: Based on the initial modulation signal and combined with the preset PPM modulation order information, the initial modulation signal is divided into several information-carrying signal segments, and then the initial signal vector corresponding to the initial modulation signal is obtained based on each information-carrying signal segment.

[0085] Step 105: Based on the PPM bit sequence and combined with the preset shift matrix, pulse position modulation is performed on the initial signal vector to obtain the information-carrying signal;

[0086] It should be noted that the initial modulated signal is obtained by modulating the modulation bit sequence and the index bit sequence in combination with the time-delayed chaotic signal. The time delay processing enhances the signal's anti-interference capability, and the dual control optimizes the spectral utilization. Based on the initial modulated signal and the PPM modulation order information, the initial modulated signal is divided into multiple information-carrying signal segments, and an initial signal vector is generated. The initial signal vector refers to converting the time-domain signal into a multi-dimensional vector form, which can be achieved through segmented sampling or matrix recombination. Vectorization operations are used to adapt to the multi-dimensional offset requirements of pulse position modulation, enabling the embedding of multiple bits of information within the same carrier.

[0087] Based on the PPM bit sequence and a preset shift matrix, the initial signal vector is pulse position modulated to obtain the information-carrying signal. The shift matrix achieves precise signal offset in the time domain, allowing the same carrier to carry more information. The shift matrix is ​​a mathematical matrix that defines the pulse position offset rules; it can be implemented using a cyclic shift matrix or a permutation matrix. Matrix operations control the position offset of the signal vector elements, enabling a single carrier to carry pulse position modulation information.

[0088] After the above-mentioned operations, the final information carrier modulation signal is obtained.

[0089] Step 106: Integrate the information-carrying signal with the reference signal to obtain the transmitted signal.

[0090] The reference signal is specifically generated based on a chaotic signal.

[0091] It should be noted that, next, the information-carrying signal is integrated with the reference signal generated based on the chaotic signal to form a complete transmitted signal. The reference signal utilizes the synchronization characteristics of the chaotic signal to reduce the demodulation complexity at the receiver.

[0092] This embodiment achieves a significant increase in spectral efficiency through multi-dimensional bit segmentation and joint modulation mechanisms. Information bits are decomposed into three independently controllable subsequences: modulation, indexing, and pulse position. These subsequences control carrier allocation, modulation scheme, and time offset, respectively, allowing multiple sets of information to be transmitted simultaneously within a single symbol period. A multi-carrier system is constructed by combining the time-delay orthogonal characteristics of chaotic signals. Carrier resources are dynamically allocated using index bits, overcoming the single-carrier limitation of traditional chaotic communication. By combining pulse position modulation with vectorization processing, an information layer is further superimposed in the time domain, forming a three-dimensional modulation structure, significantly improving data transmission rate without increasing bandwidth.

[0093] Furthermore, the information bit sequence segmentation mentioned in step 102 of this application specifically includes the following steps:

[0094] According to the preset bit sequence segmentation threshold, the information bit sequence is segmented into a modulation bit sequence, an index bit sequence, and a PPM bit sequence in sequence.

[0095] The number of sequence elements contained in the modulation bit sequence, index bit sequence, and PPM bit sequence is matched with the bit sequence segmentation threshold.

[0096] It should be noted that, assuming a bit sequence segmentation threshold M is set in this embodiment, the three generated bit subsequences each contain M elements as follows: modulation bit d1, composed of... It means that, among them , For index bit d2, by It means that, among them ,when When it is "+1", the chirp signal is selected as the carrier of the information-carrying signal (i.e., ),when When the value is "-1", the chirp signal is selected as the carrier of the information-carrying signal (i.e., For PPM bit d3, by It means that, among them The PPM bits are determined by the modulation order of PPM. This segmentation method ensures that the number of sequence elements contained in the modulation bit sequence, index bit sequence, and PPM bit sequence are strictly matched with the preset bit sequence segmentation threshold, avoiding the problem of mismatch between the segmentation result and system parameters, and ensuring the stability and accuracy of subsequent signal processing.

[0097] In some embodiments, this application further proposes to determine the target shift matrix corresponding to the PPM bits of the initial modulation signal based on a preset correspondence between PPM bits and shift matrices; and to perform pulse position modulation on the initial signal vector based on the target shift matrix to obtain the information-carrying signal.

[0098] The predefined correspondence can be implemented using a lookup table or mapping function, such as establishing a mapping table between binary PPM bit values ​​and matrix indices. The shift matrix can adopt a cyclic shift structure, with each matrix corresponding to a specific time slot shift. For example, when the PPM modulation order Q=4, it corresponds to four different cyclic shift matrices. The number of matrix elements must match the modulation order. For example, a Q-order shift matrix is ​​a matrix group formed by cyclically right-shifting a Q×Q dimensional identity matrix. More specifically, the mapping relationship between PPM and bits is shown in Table 1:

[0099] .

[0100] The specific operation of PPM can be described by a shift matrix. Completed, among which = 1, … , For example, when = 4, no. PPM bits At that time, utilize The corresponding target shift matrix, for Pulse position modulation is performed to obtain the first Each information-carrying signal can be represented as:

[0101]

[0102] in, The signal after DCSK modulation and index modulation Divide into equal parts The signal vector of the segment, ,in, It can be written as:

[0103]

[0104] In the formula, This is the pulse repetition period.

[0105] Specifically, during pulse position modulation (PPM), the received PPM bit sequence is first matched to the corresponding shift matrix group according to a preset mapping rule. For example, when the current PPM bit value is detected as "10", the third shift matrix is ​​selected from the pre-stored matrix library as the operation operator. Then, the initial signal vector is multiplied by this matrix to achieve precise displacement of the signal's time domain position. Through this predefined mapping mechanism, each PPM bit value is uniquely mapped to a deterministic matrix operation process, eliminating the risk of phase error accumulation caused by random matrix selection.

[0106] As a preferred embodiment, the solution of this application is specifically implemented as follows:

[0107] A pre-established correspondence table between PPM bits and shift matrices is used. For example, for 2-PPM modulation, "0" bits can be set to correspond to the identity matrix, and "1" bits to correspond to the cyclic shift matrix. For 4-PPM modulation, "00", "01", "10", and "11" can be set to correspond to different degrees of cyclic shift matrices.

[0108] When performing pulse position modulation, firstly based on the initial modulation signal... The corresponding PPM bits are looked up in a preset correspondence table to determine the target shift matrix. For example, if the current PPM bits are "10", then the specific cyclic shift matrix corresponding to it is selected as the target shift matrix.

[0109] Next, the initial signal vector is multiplied by the target shift matrix to achieve precise modulation of the pulse position. The resulting pulse-position-modulated signal vector is the final information-carrying signal.

[0110] Through the above technical solution, this application achieves a unique correspondence between PPM bits and shift matrices, eliminating the uncertainty of matrix selection. This predefined mapping mechanism ensures that each PPM bit can be accurately matched to a specific shift matrix, avoiding phase offset errors that may be caused by random selection. Simultaneously, the table-based method for quickly locking the target matrix improves the efficiency of the modulation process. Furthermore, precise pulse position modulation is achieved through matrix multiplication, ensuring accurate signal positioning within the time slot window. This dual-matching mechanism based on preset rules effectively improves the accuracy and robustness of pulse position modulation, laying the foundation for subsequent signal demodulation and information extraction.

[0111] Finally, the final information carrier signal S1(t) ~ S m The signal S(t) is combined with the chaotic signal S0(t) to form the final transmitted signal S(t), which is then transmitted to the receiver via a wireless channel.

[0112] Correspondingly, this application also provides another embodiment of a signal processing method integrating chaotic communication and sensing. This embodiment is applied to the receiver terminal side, corresponding to the method applied to the transmitter terminal side described above.

[0113] Please see Figure 5 The signal processing method for integrated chaotic communication and sensing provided in this embodiment includes:

[0114] Step 201: In response to the received signal, perform signal decomposition on the received signal to obtain the reference signal and the information-carrying signal;

[0115] The received signal is the signal sent from the transmitter terminal to the receiver terminal;

[0116] Step 202: According to the preset PPM modulation order information, the reference signal is divided into several reference signal segments, so as to obtain the reference signal vector according to each reference signal segment;

[0117] Step 203: Perform pulse position inverse modulation on the reference signal vector and the preset shift matrix to obtain the demodulated reference signal;

[0118] Step 204: Multiply the information-carrying signal with the demodulation reference signal and the demodulation reference conjugate signal respectively to obtain the first product value and the second product value. Then calculate the sum of the first product value and the second product value in their respective time domains to obtain the first initial decision variable and the second initial decision variable.

[0119] Step 205: Calculate the first and second initial decision variables based on the first and second initial decision variables, and then determine the demodulation result of the modulation bit sequence of the information-carrying signal based on the comparison result of the first and second decision variables.

[0120] Wherein, the first decision variable is the square of the absolute value of the first initial decision variable, and the second decision variable is the square of the absolute value of the second initial decision variable.

[0121] It should be noted that, as Figure 6 As shown, the main principle analysis of the signal processing method for integrated chaotic communication and sensing on the receiver side provided in this embodiment is as follows: First, the receiver receives the reference signal. Subsequently The pulse position modulation block then processes the signal. Specifically, Divided into equal parts A segment can be represented as Then, perform related operations with the shift matrix to obtain the final result. ,in, for With the The result obtained after performing correlation operations on the shift matrices. This process can be represented as:

[0122]

[0123] After that, what will be obtained Perform conjugate operation to obtain Then and Each signal is correlated with the received information carrier signal. Specifically, they are multiplied together and then summed; this process can be represented as:

[0124]

[0125]

[0126] or

[0127]

[0128]

[0129] This allows us to obtain the decision variables for DCSK modulation. and Then, the absolute value of the summation is taken and squared. The final result is then fed into a comparator for comparison. The demodulated bit corresponding to the largest value is the closest to the initial bit. and Both are decision variables for IM and PPM.

[0130]

[0131] Based on formulas (9), (10), (13) or (11)~(13), the first IM bits and the PPM bits It can be estimated as:

[0132]

[0133] It can be seen from formula (12) that and The value depends on and The maximum value in.

[0134] The decision variable for the modulation bits is selected by the IM bits and PPM bits, and can be represented as:

[0135]

[0136] in, This is the final modulation bit decision variable. Finally, comparing it with 0, we can estimate the nth modulation bit as follows:

[0137]

[0138] The following is a data rate verification example based on the integrated signal processing method for chaotic communication and sensing provided in this application:

[0139] The PPM-IM-DCSK-LFM scheme provided in this application divides the transmission bits into three parts: DCSK modulation bits, IM bits, and PPM bits. When the transmitter sends N=M+1 pulse signals, where M is the number of pulses carrying the information signal, and there are M modulation bits, the transmission rate of the modulation bits is:

[0140]

[0141] Each information carrier signal also carries one IM bit, therefore the transmission rate of the IM bit is the same as the transmission rate of the modulation bit, that is:

[0142]

[0143] The number of PPM bits carried by each information-bearing signal is determined by its order, and can be calculated as follows: Then the transmission rate of PPM bits is:

[0144]

[0145] Combining the bit transmission rates of the above three parts, the final data transmission rate of the PPM-IM-DCSK-LFM scheme is:

[0146] (20)

[0147] When M and As the value approaches infinity, formula (18) can be simplified to:

[0148]

[0149] Therefore, the data rate of the PPM-IM-DCSK-LFM scheme is 2 + log2 of the data rate of the DCSK-LFM scheme. times.

[0150] Simulation effect comparison example: such as Figure 7 As shown, from Figure 7 It can be seen that under Gaussian white noise channels, the bit error rate performance of the PPM-IM-DCSK-LFM scheme is improved to some extent by increasing both the PPM modulation order Q and the pulse number N. Specifically, when β=128 and N=5, as Q increases from 4 to 8, the bit error rate is improved at a bit error rate of 10. -5 At that time, the bit error rate performance improved by approximately 0.7 dB. From Figure 6The results clearly show that the PPM-IM-DCSK-LFM scheme outperforms the DCSK-LFM scheme in terms of bit error rate performance. For example, with β=128 and N=5, the PPM-IM-DCSK-LFM scheme with Q=8 has a 2.7dB improvement in bit error rate performance compared to the DCSK-LFM scheme. Compared to the DCSK-LFM scheme, the PPM-IM-DCSK-LFM scheme offers a significant improvement in data transmission rate. Furthermore, the PPM-IM-DCSK-LFM scheme also demonstrates a substantial improvement in bit error rate performance.

[0151] The above is a detailed description of the embodiment of the signal processing method integrating chaotic communication and sensing provided in this application. The following is a detailed description of the embodiment of the signal processing device integrating chaotic communication and sensing provided in this application.

[0152] Please see Figure 8 This embodiment provides a signal processing device integrating chaotic communication sensing, applied to a transmitter terminal, comprising:

[0153] The basic signal acquisition unit 301 is used to acquire chaotic signals and information bit sequences;

[0154] The bit sequence segmentation unit 302 is used to segment the information bit sequence into a modulation bit sequence, an index bit sequence, and a PPM bit sequence, wherein the index bit sequence is used to determine the carrier signal that carries the information.

[0155] The initial modulation unit 303 is used to modulate the signal according to the modulation bit sequence and the index bit sequence, combined with the time-delayed chaotic signal, to obtain the initial modulation signal.

[0156] The signal vector generation unit 304 is used to divide the initial modulation signal into several information-carrying signal segments based on the initial modulation signal and combined with the preset PPM modulation order information, and then obtain the initial signal vector corresponding to the initial modulation signal based on each information-carrying signal segment.

[0157] The pulse position modulation unit 305 is used to perform pulse position modulation on the initial signal vector according to the PPM bit sequence and in combination with the preset shift matrix to obtain the information carrying signal.

[0158] The transmission signal generation unit 306 is used to integrate the information-carrying signal and the reference signal to obtain the transmission signal, wherein the reference signal is specifically generated based on the chaotic signal.

[0159] Please see Figure 9 This application provides an integrated signal processing device for chaotic communication and sensing, applied to a receiver terminal, comprising:

[0160] The signal receiving response unit 401 is used to decompose the received signal in response to the received signal to obtain a reference signal and an information carrying signal, wherein the received signal is the signal sent from the transmitter terminal to the receiver terminal;

[0161] The reference signal vector decomposition unit 402 is used to divide the reference signal into several reference signal segments according to the preset PPM modulation order information, so as to obtain the reference signal vector according to each reference signal segment.

[0162] The pulse position demodulation unit 403 is used to perform pulse position inverse modulation on the reference signal vector and the preset shift matrix to obtain the demodulated reference signal;

[0163] The initial decision variable determination unit 404 is used to multiply the information carrying signal with the demodulation reference signal and the demodulation reference conjugate signal respectively to obtain the first product value and the second product value, and then calculate the sum of the first product value and the second product value in their respective time domains to obtain the first initial decision variable and the second initial decision variable.

[0164] The modulation bit demodulation unit 405 is used to calculate the first decision variable and the second decision variable based on the first initial decision variable and the second initial decision variable, and then determine the demodulation result of the modulation bit sequence of the information carrying signal based on the comparison result of the first decision variable and the second decision variable.

[0165] Wherein, the first decision variable is the square of the absolute value of the first initial decision variable, and the second decision variable is the square of the absolute value of the second initial decision variable.

[0166] In addition, this application also provides a chaotic communication system, including: a transmitter terminal and a receiver terminal, wherein the transmitter terminal and the receiver terminal are communicatively connected;

[0167] The transmitter terminal includes: a first memory and a first processor. The first memory stores first program code, which is used to implement a signal processing method for integrated chaotic communication and sensing as described in any one of claims 1 to 4. The first processor is used to read and execute the first program code.

[0168] The receiver terminal includes: a second memory and a second processor. The second memory stores second program code, which is used to implement a signal processing method for integrated chaotic communication and sensing as described in any one of claims 5 to 7. The second processor is used to read and execute the second program code.

[0169] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the terminals, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0170] In the several embodiments provided in this application, it should be understood that the disclosed terminals, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, or indirect coupling or communication connection between devices or units, and may be electrical, mechanical, or other forms.

[0171] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0172] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0173] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0174] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0175] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0176] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A signal processing method for chaos communication and sensing integration, applied to a transmitter terminal, characterized in that, The method comprises the following steps: acquiring a chaotic signal and an information bit sequence; performing bit sequence segmentation on the information bit sequence to obtain a modulation bit sequence, an index bit sequence, and a PPM bit sequence, wherein the index bit sequence is used to determine a carrier of an information-bearing signal; modulating a signal according to the modulation bit sequence and the index bit sequence in combination with a chaotic signal subjected to time delay processing to obtain an initial modulation signal; dividing the initial modulation signal into a plurality of information-bearing signal segments based on the initial modulation signal and in combination with preset PPM modulation order information, and obtaining an initial signal vector corresponding to the initial modulation signal based on each information-bearing signal segment; performing pulse position modulation on the initial signal vector according to the PPM bit sequence in combination with a preset shift matrix to obtain an information-bearing signal. The method of performing bit sequence segmentation on the information bit sequence to obtain a modulation bit sequence, an index bit sequence, and a PPM bit sequence specifically comprises the following steps:

2. The signal processing method of claim 1, wherein performing bit sequence segmentation on the information bit sequence according to a preset bit sequence segmentation quantity threshold to sequentially obtain a modulation bit sequence, an index bit sequence, and a PPM bit sequence, wherein the modulation bit sequence, the index bit sequence, and the PPM bit sequence contain a number of sequence elements that matches the bit sequence segmentation quantity threshold. The method of performing pulse position modulation on the initial signal vector according to the PPM bit sequence in combination with a preset shift matrix to obtain an information-bearing signal specifically comprises the following steps:

3. The signal processing method of claim 1, wherein determining a target shift matrix corresponding to a PPM bit corresponding to the initial modulation signal according to a preset correspondence between PPM bits and shift matrices; performing pulse position modulation on the initial signal vector according to the target shift matrix to obtain an information-bearing signal. The calculation formula of the initial modulation signal is specifically as follows:

4. The signal processing method of claim 1, wherein, The method comprises the following steps: In the formula, is the initial modulation signal at time t, x i is a chaotic signal, β is a spreading factor, μ is a chirp slope, T c is a chip period of each chaotic signal, T p is a pulse repetition period, b m is the mth element of the index bit sequence, a m is the mth element of the modulation bit sequence.

5. A signal processing method for chaos communication and sensing integration, applied to a receiver terminal, characterized in that, in response to a received signal, performing signal decomposition on the received signal to obtain a reference signal and an information-bearing signal, wherein the received signal is a signal generated and transmitted by a transmitter terminal according to the chaotic communication and perception integrated signal processing method of any one of claims 1 to 4 to the receiver terminal; dividing the reference signal into a plurality of reference signal segments according to preset PPM modulation order information to obtain a reference signal vector according to each reference signal segment; performing pulse position demodulation on the reference signal vector in combination with a preset shift matrix to obtain a demodulated reference signal; multiplying the information-bearing signal by the demodulated reference signal and a demodulated reference conjugate signal respectively to obtain a first product value and a second product value, and then calculating a sum value of the first product value and the second product value in a respective time domain to obtain a first initial decision variable and a second initial decision variable; ​ The first decision variable and the second decision variable are calculated according to the first initial decision variable and the second initial decision variable, and the modulation bit sequence demodulation result of the information bearing signal is determined according to a comparison result of the first decision variable and the second decision variable, wherein the first decision variable is an absolute value square of the first initial decision variable, and the second decision variable is an absolute value square of the second initial decision variable.

6. The signal processing method of claim 5, wherein The calculation expression of the modulation bit sequence demodulation result is specifically: wherein is a demodulation decision result of the mth element of the modulation bit sequence, is the first decision variable and the second decision variable is the output of the argmax function.

7. The signal processing method of claim 5, wherein the signal processing method is characterized by, The calculation expression of the demodulation reference signal is specifically: wherein is the demodulation reference signal, is the reference signal vector, is the Q-th shift matrix, Q is the PPM modulation order, is the Q-th component of the demodulation reference signal.

8. A signal processing device for chaos communication and sensing integration, applied to a transmitter terminal, characterized in that, Comprise: The base signal acquisition unit is used for acquiring a chaotic signal and an information bit sequence; The bit sequence segmentation unit is used for performing bit sequence segmentation on the information bit sequence to obtain a modulation bit sequence, an index bit sequence and a PPM bit sequence respectively, wherein the index bit sequence is used for determining a carrier of an information bearing signal; The initial modulation unit is used for performing signal modulation on the modulation bit sequence and the index bit sequence in combination with the chaotic signal subjected to time delay processing to obtain an initial modulation signal; The signal vector generation unit is used for dividing the initial modulation signal into a plurality of information bearing signal segments based on the initial modulation signal and in combination with preset PPM modulation order information, and obtaining an initial signal vector corresponding to the initial modulation signal based on each information bearing signal segment; The pulse position modulation unit is used for performing pulse position modulation on the initial signal vector in combination with a preset shift matrix according to the PPM bit sequence to obtain the information bearing signal; The transmitting signal generation unit is used for integrating the information bearing signal with a reference signal to obtain a transmitting signal, wherein the reference signal is specifically generated based on the chaotic signal.

9. A signal processing device for chaos communication and sensing integration, applied to a receiver terminal, characterized in that, Comprise: The signal receiving response unit is used for performing signal decomposition on a receiving signal to obtain a reference signal and an information bearing signal in response to the receiving signal, wherein the receiving signal is a signal generated and transmitted by a transmitter terminal according to the chaotic communication and sensing integrated signal processing method in any one of claims 1 to 4; The reference signal vector decomposition unit is used for dividing the reference signal into a plurality of reference signal segments according to preset PPM modulation order information, and obtaining a reference signal vector according to each reference signal segment; The pulse position demodulation unit is used for performing pulse position inverse modulation on the reference signal vector in combination with a preset shift matrix to obtain a demodulation reference signal; The initial decision variable determination unit is used for multiplying the information bearing signal with the demodulation reference signal and a demodulation reference conjugate signal respectively to obtain a first product value and a second product value, and calculating a sum value of the first product value and the second product value in a respective time domain to obtain a first initial decision variable and a second initial decision variable. A modulation bit demodulation unit is configured to calculate a first decision variable and a second decision variable according to the first initial decision variable and the second initial decision variable, and determine a modulation bit sequence demodulation result of the information bearing signal according to a comparison result of the first decision variable and the second decision variable, wherein the first decision variable is an absolute value square of the first initial decision variable, and the second decision variable is an absolute value square of the second initial decision variable.

10. A chaotic communication system, characterized by The application further provides a transmitter terminal and a receiver terminal. The transmitter terminal and the receiver terminal are communicatively connected. The transmitter terminal comprises a first memory and a first processor, the first memory stores a first program code, the first program code is used to implement the signal processing method for chaos communication and perception integration according to any one of claims 1 to 4, and the first processor is used to read and execute the first program code. The receiver terminal comprises a second memory and a second processor, the second memory stores a second program code, the second program code is used to implement the signal processing method for chaos communication and perception integration according to any one of claims 5 to 7, and the second processor is used to read and execute the second program code.

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