A method, apparatus, device and medium for designing an orthogonal chirp division multiplexing signal

Abstract

The application discloses a kind of orthogonal chirp division multiplexing signal design method, device, equipment and medium, it is related to communication technical field, for solving the problem of poor anti-interference capability of existing integrated sensing system. The method is applied to signal sending end, comprising: sequentially through the processing of input chirp signal stream by serial / parallel module and mapping module, obtain first data stream;Through the orthogonal chirp division multiplexing OCDM signal modulation of the first data stream by discrete fresnel inverse transform IDFnT module, obtain second data stream;Through frequency hopping FH module, the frequency hopping FH data stream is obtained by processing second data stream;Sequentially through the processing of frequency hopping FH data stream by prefix module, parallel / serial module and digital / analog module, obtain target FH / OCDM signal stream;The target FH / OCDM signal stream is sent to wireless channel by antenna, to determine a kind of anti-interference capability strong integrated sensing communication waveform scheme for high-speed motion scene.

Description

Technical Field

[0001] This application relates to the field of communication technology, and provides a design method, apparatus, device and medium for orthogonal chirped multiplexing signals. Background Technology

[0002] With the continuous development of mobile communication technology, product development processes are placing increasingly higher demands on measurement accuracy, bandwidth, and real-time analysis capabilities. Furthermore, to improve spectrum efficiency, reduce costs, and enhance system robustness and reliability, integrated sensing systems combining radar and data communication functions, with the core objective of integrating communication and sensing, are gradually becoming one of the research hotspots for next-generation mobile communication technology (6G). In the existing 3GPP standards, Orthogonal Frequency Division Multiplexing (OFDM) is the basic signal transmission scheme for current mobile communication. However, in the free-space wireless transmission process of integrated sensing systems in high-speed motion scenarios, signal transmission is affected by various factors such as time dispersion and Doppler shift. Moreover, OFDM subcarriers are cosine signals, which are highly sensitive to Doppler shift; when the channel is a dual-select channel, its performance will be severely affected.

[0003] Therefore, determining a communication waveform scheme with strong anti-interference capability for high-speed motion scenarios has become an urgent problem to be solved. Summary of the Invention

[0004] This application provides a design method, apparatus, device, and medium for orthogonal chirped multiplexed signals to solve the problem of poor anti-interference capability in existing integrated communication and sensing systems.

[0005] On the one hand, an orthogonal chirped multiplexing signal design method is provided, which is applied to the signal transmitting end and includes:

[0006] The input chirp signal stream is processed sequentially through a serial / parallel module and a mapping module to obtain the first data stream;

[0007] The first data stream is modulated with an orthogonal chirped multiplexing (OCDM) signal using the Discrete Fresnel Inverse Transform (IDFnT) module to obtain the second data stream;

[0008] The second data stream is processed by frequency hopping module to obtain frequency hopping FH data stream;

[0009] The frequency-hopping FH data stream is processed sequentially through a prefixing module, a parallel / serial module, and a digital / analog module to obtain the target FH / OCDM signal stream;

[0010] The target FH / OCDM signal stream is transmitted to the wireless channel via an antenna.

[0011] Optionally, the step of performing frequency hopping (FH) processing on the second data stream through the frequency hopping module to obtain a frequency hopping (FH) data stream includes:

[0012] The second data stream is subjected to frequency hopping (FH) processing using a preset frequency hopping strategy in the frequency hopping module to obtain the frequency hopping FH data stream; wherein the preset frequency hopping strategy is obtained based on oscilloscope spectrum quality perception.

[0013] Optionally, the step of performing frequency hopping (FH) processing on the second data stream using a preset frequency hopping strategy in the frequency hopping module to obtain the frequency hopping FH data stream includes:

[0014] Perform logtistic mapping on the second data stream to generate a sequence of chaotic simulated values ​​corresponding to the second data stream;

[0015] The chaotic simulation value sequence is subjected to frequency hopping processing to obtain the frequency hopping FH data stream; wherein, the frequency hopping FH data stream is a frequency hopping sequence.

[0016] Optionally, the chaotic simulation value sequence is represented by the following formula (1):

[0017] X=[x(0),x(1),x(2),...,x(L'-1)]

[0018] x(n+1)=1-2x 2 (n),-1 <x(n)<1,n=0,1,2,...,L'-1 (1)

[0019] The frequency-hopping FH data stream is represented by the following formula (2):

[0020] d k =-cos(kπ / Nh),k=1,2,...,Nh,

[0021] η: if d k-1 <x(n)≤d k (2)

[0022] Where x(0) is the initial value in the interval [-1,1]; Nh is a positive integer that divides the continuous interval (-1,1) into Nh non-overlapping intervals (-1,d1], (d1,d2],..., (d...d...). Nh-1 ,1) interval; η is the frequency hopping mapping relationship; s(n) is the nth frequency point in the frequency hopping FH data stream.

[0023] Optionally, the preset frequency hopping strategy is represented by the following formula (3):

[0024] f p,k =f k +sVf,s∈[0,N h -1] (3)

[0025] Among them, f p,k f is the center frequency of the k-th Chirp signal after frequency hopping; k Let V be the initial physical frequency of the k-th Chirp signal; Vf is the frequency hopping sequence interval, satisfying...

[0026] Optionally, the Chirp signal is represented by the following formula (4):

[0027]

[0028] Where y(t) is the Chirp signal, p is the Chirp signal modulation rate, m is the Chirp signal modulation frequency, and j0 is the initial phase.

[0029] Optionally, the target FH / OCDM signal is represented by the following formula (5):

[0030]

[0031] Among them, s p (t) represents the target FH / OCDM signal, N f x is the number of Chirp signals. p (k) represents the symbol on the k-th sub-channel, Ψ p,k (t) represents orthogonal Chirp signals. Let f be the frequency hopping mapping factor in the k-th sub-channel. p,k This indicates that the k-th Chirp signal is in the Nth... h The physical frequency in each frequency hopping state, N h This represents the number of frequency hopping points.

[0032] On the one hand, an orthogonal chirped multiplexing signal design device is provided, the device being applied at a signal transmitting end, comprising:

[0033] The first processing unit is used to process the input chirp signal stream sequentially through a serial / parallel module and a mapping module to obtain a first data stream;

[0034] The chirped signal modulation unit is used to perform orthogonal chirped demultiplexing (OCDM) signal modulation on the first data stream through the discrete inverse Fresnel transform (IDFnT) module to obtain the second data stream;

[0035] The frequency hopping (FH) processing unit is used to perform frequency hopping (FH) processing on the second data stream through the frequency hopping module to obtain a frequency hopping (FH) data stream.

[0036] The second processing unit is used to process the frequency-hopping FH data stream sequentially through a prefixing module, a parallel / serial module, and a digital / analog module to obtain the target FH / OCDM signal stream;

[0037] The signal stream transmission unit is used to transmit the target FH / OCDM signal stream to the wireless channel via an antenna.

[0038] On one hand, an electronic device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement any of the methods described above.

[0039] On the one hand, a storage medium is provided that stores computer program instructions thereon, which, when executed by a processor, implement any of the methods described above.

[0040] Compared with the prior art, the beneficial effects of this application are as follows:

[0041] In this application, when designing an orthogonal chirp division multiplexing (OCDM) signal, for the signal transmitter, firstly, the input chirp signal stream can be processed sequentially through a serial / parallel module and a mapping module to obtain a first data stream; then, the first data stream can be modulated with an orthogonal chirp division multiplexing (OCDM) signal through a discrete inverse Fresnel transform (IDFnT) module to obtain a second data stream; next, the second data stream can be processed with a frequency hopping (FH) module to obtain a frequency hopping (FH) data stream; then, the frequency hopping (FH) data stream can be processed sequentially through a prefixing module, a parallel / serial module, and a digital / analog module to obtain a target FH / OCDM signal stream; finally, the target FH / OCDM signal stream can be transmitted to the wireless channel through an antenna.

[0042] Therefore, in this application, since the target FH / OCDM signal stream is obtained by combining frequency hopping FH technology and OCDM signal modulation, compared with traditional OFDM and OCDM, this application not only has a lower bit error rate and better transmission performance, but also effectively avoids strong interference frequency bands while homogenizing / avoiding the impact of channel fading and sudden interference on the communication system. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0044] Figure 1 An electronic device provided in an embodiment of this application;

[0045] Figure 2 A schematic diagram of an orthogonal chirped multiplexing signal design method provided in an embodiment of this application;

[0046] Figure 3 A schematic diagram of the framework of the FH / OCDM system transceiver model provided in the embodiments of this application;

[0047] Figure 4 A test simulation diagram illustrating the bit error rate performance of a single user under a static Rayleigh channel, provided in an embodiment of this application.

[0048] Figure 5 A test simulation diagram illustrating the bit error rate performance of a multi-user system under a high-speed multipath Rayleigh channel, as provided in an embodiment of this application.

[0049] Figure 6 This is a schematic diagram of an orthogonal chirped multiplexing signal design device provided in an embodiment of this application.

[0050] The diagram is labeled as follows: 10-Orthogonal chirp multiplexing signal design device, 101-Processor, 102-Memory, 103-I / O interface, 104-Database, 60-Orthogonal chirp multiplexing signal design device, 601-First processing unit, 602-Chirp signal modulation unit, 603-Frequency hopping (FH) processing unit, 604-Second processing unit, 605-Signal stream transmission unit. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Unless otherwise specified, the embodiments and features in the embodiments of this application can be arbitrarily combined with each other. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than that shown here.

[0052] Definitions:

[0053] Chirp signals, also known as linear frequency modulation (LFM) signals, are among the most widely used signals in the field of sensing. Their frequency varies linearly with time, resulting in high temporal resolution and excellent target detection capabilities. Due to their wide frequency range coverage, chirp signals can effectively distinguish between close-range targets and weak signals, improving the system's anti-interference capability. Furthermore, chirp signals can significantly improve range resolution and velocity measurement accuracy in radar and communications, making them a key component of high-performance sensing systems and a subcarrier signal in OCDM systems.

[0054] Generally, the Chirp signal can be represented by the following formulas (1)-(2):

[0055]

[0056] Where s(t) is the Chirp signal, and rect(·) is the window function. Where B is the frequency modulation slope, and T is the signal bandwidth. c f is the signal pulse width, and f0 is the signal carrier frequency.

[0057] With the continuous development of mobile communication technology, product development processes are placing increasingly higher demands on measurement accuracy, bandwidth, and real-time analysis capabilities. Furthermore, to improve spectrum efficiency, reduce costs, and enhance system robustness and reliability, integrated sensing systems combining radar and data communication functions, with the core objective of integrating communication and sensing, are gradually becoming one of the research hotspots for next-generation mobile communication technology (6G). In the existing 3GPP standards, Orthogonal Frequency Division Multiplexing (OFDM) is the basic signal transmission scheme for current mobile communication. However, in the free-space wireless transmission process of integrated sensing systems in high-speed motion scenarios, signal transmission is affected by various factors such as time dispersion and Doppler shift. Moreover, OFDM subcarriers are cosine signals, which are highly sensitive to Doppler shift; when the channel is a dual-select channel, its performance will be severely affected.

[0058] Based on this, this application provides an orthogonal chirp multiplexing signal design method. In this method, for the signal transmitting end, firstly, the input chirp signal stream can be processed sequentially through a serial / parallel module and a mapping module to obtain a first data stream; then, the first data stream can be modulated with orthogonal chirp multiplexing (OCDM) signal through a discrete inverse Fresnel transform (IDFnT) module to obtain a second data stream; next, the second data stream can be processed by a frequency hopping module to obtain a frequency hopping FH data stream; then, the frequency hopping FH data stream can be processed sequentially through a prefixing module, a parallel / serial module, and a digital / analog module to obtain a target FH / OCDM signal stream; finally, the target FH / OCDM signal stream can be transmitted to a wireless channel through an antenna. Therefore, in this application, since the target FH / OCDM signal stream is obtained by combining frequency hopping FH technology and OCDM signal modulation, compared with traditional OFDM and OCDM, this application not only has a lower bit error rate and better transmission performance, but also effectively avoids strong interference frequency bands while homogenizing / avoiding the impact of channel fading and sudden interference on the communication system.

[0059] After introducing the design concept of the embodiments of this application, the following is a brief introduction to the application scenarios to which the technical solutions of the embodiments of this application can be applied. It should be noted that the application scenarios described below are only for illustrating the embodiments of this application and are not intended to limit the scope. In specific implementation, the technical solutions provided by the embodiments of this application can be flexibly applied according to actual needs.

[0060] like Figure 1 As shown, this is an electronic device provided in an embodiment of this application. Specifically, the electronic device can be an orthogonal chirped multiplexing signal design device 10.

[0061] The orthogonal chirp multiplexing signal design device 10 can be used for orthogonal chirp multiplexing signal design, and can be, for example, a personal computer (PC), server, or laptop. The orthogonal chirp multiplexing signal design device 10 may include one or more processors 101, memory 102, I / O interfaces 103, and database 104. Specifically, the processor 101 can be a central processing unit (CPU) or a digital processing unit, etc. The memory 102 can be volatile memory, such as random-access memory (RAM); the memory 102 can also be non-volatile memory, such as read-only memory, flash memory, hard disk drive (HDD), or solid-state drive (SSD); or the memory 102 can be any other medium capable of carrying or storing desired program code in the form of instructions or data structures that can be accessed by a computer, but is not limited thereto. The memory 102 can be a combination of the aforementioned memories. The memory 102 can store some program instructions of the orthogonal chirp multiplexing signal design method provided in the embodiments of this application. When these program instructions are executed by the processor 101, they can be used to implement the steps of the orthogonal chirp multiplexing signal design method provided in the embodiments of this application, thereby solving the problem of poor anti-interference capability in existing integrated sensing systems. The database 104 can be used to store data related to serial / parallel modules, mapping modules, IDFnT modules, frequency hopping modules, prefixing modules, parallel / serial modules, and digital / analog modules involved in the solutions provided in the embodiments of this application.

[0062] In this embodiment, the orthogonal chirp demultiplexing signal design device 10 can acquire the chirp signal stream through the I / O interface 103. Then, the processor 101 of the orthogonal chirp demultiplexing signal design device 10 will determine a strong anti-interference integrated communication waveform scheme for high-speed motion scenarios according to the program instructions of the orthogonal chirp demultiplexing signal design method provided in this embodiment of the application stored in the memory 102. In addition, serial / parallel modules, mapping modules, IDFnT modules, frequency hopping modules, prefixing modules, parallel / serial modules, and digital / analog modules can be stored in the database 104.

[0063] Of course, the methods provided in the embodiments of this application are not limited to... Figure 1 The application scenarios shown can also be used in other possible scenarios, and this application embodiment does not impose any limitations. Figure 1The functions that the various devices in the application scenarios shown can achieve will be described in subsequent method embodiments, and will not be elaborated on here. Below, the methods of the embodiments of this application will be described in conjunction with the accompanying drawings.

[0064] like Figure 2 The diagram shown is a schematic representation of an orthogonal chirped multiplexing signal design method provided in this application embodiment. This method is applied to the signal transmitting end and can be used to... Figure 1 The orthogonal chirped multiplexing signal design device 10 is used to execute this method. Specifically, the process flow is described below.

[0065] Step 201: The input chirp signal stream is processed sequentially through the serial / parallel module and the mapping module to obtain the first data stream.

[0066] like Figure 3 The diagram shown is a schematic of a framework for an FH / OCDM system transceiver model provided in this application embodiment. Based on this FH / OCDM system transceiver model, when acquiring a new FH / OCDM signal, for the signal transmitting end, firstly, the input chirped signal (bit stream) can be converted from serial to parallel using a "serial / parallel module" to obtain the corresponding parallel data stream.

[0067] Then, the parallel data stream can be phase-modulated by the mapping (phase modulation) module to obtain the corresponding first data stream. In the embodiments of this application. Specifically, unlike OFDM technology, the OCDM technology of this application can use a set of Chirp signals with the same bandwidth as subcarriers, and replace the Inverse Fast Fourier Transform (IFFT) with the Inverse Discrete Fresnel Transform (IDFnT) to load the communication information onto the amplitude and phase of a set of orthogonal Chirp signals for overlapping multiplexing in the time and frequency domain, thereby realizing high-speed data transmission. For ease of representation, a set of Chirp signals y(t) can be simplified and represented by the following formula (3):

[0068]

[0069] Where p is the chirp signal modulation rate; m is the chirp signal modulation frequency; and j0 is the initial phase.

[0070] Since each element in an N′N Discrete Fourier Transform (DFT) matrix can be represented by the following formula (4):

[0071]

[0072] Where a and b are the a-th row and b-th column of the DFT matrix, respectively; N is the DFT transform dimension, which can be the number of chirp signals in the OCDM system.

[0073] Therefore, each element in an N′N DFnT matrix can be represented by the following formula (5):

[0074]

[0075] Therefore, the DFnT matrix can be written as q1 + DFT + q2, where, This means that the DFnT matrix can be understood as consisting of a DFT matrix with two additional phases. Furthermore, for the k-th Chirp signal ψ... k (t) can be expressed using the following formula (6):

[0076]

[0077] in, Let be the slope of the k-th Chirp signal.

[0078] In the OCDM system of this application, the amplitude and phase of each chirp signal can be symbol-mapped modulation, such as pulse amplitude modulation (PAM), phase shift keying (PSK), and quadrature amplitude modulation (QAM). Furthermore, depending on the modulation format, different symbols can be selected in codebook c to modulate the information bits.

[0079] Therefore, as Figure 3 As shown, the parallel data stream can be phase-modulated using a mapping module to obtain the corresponding first data stream. That is, it can be assumed that the OCDM system has N Chirp signals, and the time-domain form of the transmitted Chirp signals can be represented by the following formula (7):

[0080]

[0081] Where x(k) is the symbol on the k-th sub-channel, x(k)∈ χ.

[0082] Step 202: Modulate the first data stream with orthogonal chirped multiplexing (OCDM) signal using the Discrete Fresnel Inverse Transform (IDFnT) module to obtain the second data stream.

[0083] In this application example, after the mapping module completes the mapping of the transmitted Chirp signal, the Discrete Inverse Fresnel Transform (IDFnT) module can be used to perform Orthogonal Chirped Multiplexing (OCDM) signal modulation on the first data stream to obtain a discrete second data stream, that is, a discrete Chirp signal can be obtained. Specifically, the discrete Chirp signal s can be represented by the following formula (8):

[0084] s = f H x (8)

[0085] Among them, f H Let x represent an IDFnT matrix, x = [x0, x1, ..., xnT]. N-1 ] T This is the vector of the transmitted Chirp signal.

[0086] Accordingly, since the DFnT matrix is ​​a unitary matrix, the signal can be recovered at the receiving end by taking the inverse operation and transmitted, and expressed by the following formula (9):

[0087] x c =fs=x (9)

[0088] Step 203: Perform frequency hopping (FH) processing on the second data stream using the frequency hopping module to obtain the frequency hopping (FH) data stream.

[0089] To enhance the interference resistance and security of the communication system, in this embodiment, the second data stream can be frequency-hopped (FH) processed using a preset frequency-hopping strategy in the frequency-hopping module to obtain a frequency-hopped (FH) data stream, i.e., as shown below. Figure 3 As shown, after obtaining the discrete Chirp signal, the discrete Chirp signal can be frequency-hopped (FH) by using the preset frequency hopping strategy in the frequency hopping module to control the center frequency jump of the OCDM signal; wherein, the preset frequency hopping strategy is obtained based on the oscilloscope's spectrum quality perception, and the preset frequency hopping strategy can be expressed by the following formula (10):

[0090] f p,k =f k +sVf,s∈[0,N h -1] (10)

[0091] Among them, f p,k f is the center frequency of the k-th Chirp signal after frequency hopping; k Let f be the initial physical frequency of the k-th Chirp signal, and f k The optimal usable frequency band starting frequency is obtained after the oscilloscope measures, analyzes, and makes decisions on the entire Chirp signal; Vf is the frequency hopping sequence interval, satisfying...

[0092] Furthermore, when performing frequency hopping processing on the second data stream using a preset frequency hopping strategy, a chaotic logtistic frequency hopping strategy can be used to select the currently available frequency point.

[0093] That is, firstly, a logtistic mapping can be performed on the second data stream to generate a sequence of chaotic simulated values ​​corresponding to the second data stream. In this embodiment, the sequence of chaotic simulated values ​​can be represented by the following formula (11):

[0094] X=[x(0),x(1),x(2),...,x(L'-1)]

[0095] x(n+1)=1-2x 2 (n),-1 <x(n)<1,n=0,1,2,...,L'-1 (11)

[0096] Where x(0) is the initial value in the interval [-1,1].

[0097] Then, frequency hopping processing can be performed on the chaotic simulation value sequence to obtain a frequency-hopping FH data stream; where the frequency-hopping FH data stream is a frequency-hopping sequence. Specifically, let Nh be a positive integer, and divide the continuous interval (-1, 1) into Nh non-overlapping intervals (-1, d1], (d1, d2], ..., (d...). Nh-1 1) An interval, where the interval boundary d k It can be expressed using the following formula (12):

[0098] d k =-cos(kπ / Nh),k=1,2,…,Nh (12)

[0099] Furthermore, the frequency-hopping FH data stream (chaotic frequency-hopping sequence - Nh-ary discrete sequence) S = [s(0), s(1), ..., s(L'-1)] can be represented by the following formula (13) corresponding to the frequency-hopping mapping relationship η:

[0100] η: if d k-1 <x(n)≤d k (13)

[0101] Where η is the frequency hopping mapping relationship; s(n) is the nth frequency point in the frequency hopping FH data stream.

[0102] Step 204: Process the frequency-hopping FH data stream sequentially through the prefix module, parallel / serial module, and digital / analog module to obtain the target FH / OCDM signal stream.

[0103] In the embodiments of this application, such as Figure 3 As shown, after obtaining the frequency-hopping FH data stream, it can be processed sequentially through a prefix module, a parallel / serial module, and a digital / analog module to obtain the target FH / OCDM signal stream. The target FH / OCDM signal is represented by the following formula (14):

[0104]

[0105] Among them, s p (t) represents the target FH / OCDM signal, N f x is the number of Chirp signals. p (k) represents the symbol on the k-th sub-channel, Ψ p,k (t) represents orthogonal Chirp signals. Let f be the frequency hopping mapping factor in the k-th sub-channel. p,k This indicates that the k-th Chirp signal is in the Nth... h The physical frequency in each frequency hopping state, N h This represents the number of frequency hopping points.

[0106] Step 205: Transmit the target FH / OCDM signal stream to the wireless channel via the antenna.

[0107] In the embodiments of this application, since the Chirp signal stream sent to the wireless channel is obtained through Discrete Fresnel Inverse Transform (IDFnT) and frequency hopping strategy, compared with the prior art, this application can not only more effectively avoid strong interference frequency bands, but also homogenize / avoid the impact of channel fading and sudden interference on the communication system.

[0108] In one possible implementation, such as Figure 3 As shown, the specific design of the signal receiver (which can be a broadband oscilloscope receiver) can correspond to the specific design of the signal transmitter. In this case, a channel estimate can be added after the analog-to-digital conversion for signal equalization processing at the receiver.

[0109] Specifically, firstly, the received chirped signal stream can be processed by an analog-to-digital module to obtain a third data stream. The received chirped signal stream can be represented by the following formula (15):

[0110]

[0111] Here, it is assumed that the channel gain of the received chirped signal stream remains constant; h(k) is the channel gain of the k-th chirped signal; and n(t) is a signal with a mean of 0 and a variance of N₀N₀. f / T cGaussian white noise signal.

[0112] Furthermore, for a multi-user multiplexed FH / OCDM system, the following situations may exist in the de-hopping module of sub-channel m at this receiver:

[0113] 1) Fully orthogonal multiplexing among multiple users. That is, in all sub-channels m m∈[0,N f -1];

[0114] 2) Multiple user collisions exist. That is, m∈[0,N f -1], the probability of a collision occurring in sub-channel m is

[0115] Then, the third data stream can be processed through the serial / parallel module to obtain the fourth data stream.

[0116] Next, the fourth data stream can be deprecated using the deprecation module to obtain the fifth data stream.

[0117] Then, the fifth data stream can be de-hopped using the de-hopping module to obtain the de-hopped data stream. The de-hopping strategy in the de-hopping module is completely synchronized with the frequency hopping strategy of the signal transmitter. That is, the results of channel detection, analysis, and decision-making at the signal receiver and signal transmitter must be kept consistent through lightweight information exchange, and the de-hopping strategy at the signal receiver must be consistent with the frequency hopping strategy at the signal transmitter. Furthermore, using the synchronized channel quality and de-hopping strategy, the center frequency of the hopping OCDM signal can be transmitted to the baseband via the de-hopping module.

[0118] Next, the de-hopping data stream can be modulated with orthogonal chirped multiplexing (OCDM) signals using the Discrete Fresnel Transform (DFnT) module to obtain the sixth data stream.

[0119] Then, the channel estimation module can be used to perform channel estimation on the third data stream to obtain the channel characteristic information corresponding to the third data stream; the channel characteristic information may include channel fading, time delay and Doppler effect, etc.

[0120] Next, the sixth data stream can be processed by equalization using the signal equalization module and the channel characteristic information corresponding to the third data stream to obtain the seventh data stream.

[0121] Finally, the seventh data stream can be processed sequentially through the decoding module and the parallel / serial module to obtain the final chirp signal stream.

[0122] In this application, in order to help readers better understand the technical solution, the technical effects of this application will be explained in detail below with reference to actual engineering tests.

[0123] 1. Test conditions and content.

[0124] This application simulates a wireless channel. The number of sub-channels is set to 64, with each sub-channel having 64 frequency hopping points and employing 4QAM modulation. To avoid ISI (Intermittent Separation), CP padding is used as a guard interval. Unless otherwise specified, analysis using a broadband oscilloscope shows that its length is greater than the maximum redundant delay of the channel. Since Zero Forcing (ZF) equalization and Minimum Mean Square Error (MMSE) equalization have the same bit error rate performance in OFDM systems, this application defaults to using ZF equalization for OFDM systems, while FH / OCDM systems use Least Squares (LS) equalization and MMSE equalization, respectively.

[0125] 2. Test Result Analysis.

[0126] like Figure 4 The diagram shown is a test simulation illustration of the bit error rate performance of a single user under a static Rayleigh channel, provided in an embodiment of this application. Figure 4 It can be seen that if the channel exhibits static flat fading, meaning its characteristics remain constant across the entire communication timescale, then at low signal-to-noise ratios (SNR), the OFDM system demonstrates good bit error rate performance. However, at high SNRs, the OCDM system offers superior transmission performance, and the OCDM / MMSE system provides even better bit error rate performance. This is because MMSE equalization effectively suppresses noise (compared to ZF equalizers), and this effect is more pronounced at high SNRs.

[0127] Since high-speed movement inevitably leads to Doppler frequency shift, and actual transmission often suffers from multipath effects, resulting in time dispersion, this application, in order to demonstrate the effectiveness of the proposed transmission scheme under multi-user high-speed mobile transmission conditions, such as... Figure 5 The diagram shown is a test simulation illustration of the bit error rate performance of a multi-user system under a high-speed multipath Rayleigh channel, as provided in an embodiment of this application. Figure 5It can be seen that Nu = 5 for multiple users. Among them, the channel using the OFDM / ZF transmission scheme has completely lost its transmission performance, while the FH / OCDM transmission scheme proposed in this application still has a certain degree of transmission effectiveness under the same conditions, and the use of the MMSE equalizer scheme results in a lower bit error rate. This is because OFDM is more sensitive to Doppler frequency shift, and the Doppler frequency shift and time dispersion phenomena generated in dual-selective channels greatly affect transmission performance. OCDM, on the other hand, uses chirp subcarriers, which are not sensitive to Doppler frequency shift and can effectively resist time-selective fading even with insufficient guard interval length, thus still possessing effective transmission performance. Therefore, the FH / OCDM transmission scheme proposed in this application exhibits good transmission performance under high-speed and multipath transmission conditions.

[0128] In summary, compared with the prior art, this application has the following advantages:

[0129] (1) This application proposes a new waveform FH / OCDM design that combines FH technology and OCDM based on broadband oscilloscope-assisted analysis, which can improve the transmission reliability of communication systems in complex electromagnetic interference environments.

[0130] (2) The FH / OCDM transmission scheme of this application has a lower bit error rate and better transmission performance than traditional OFDM and OCDM in high-speed time-varying multipath channels, especially in environments where Doppler shift and time dispersion have significant effects.

[0131] Based on the same inventive concept, embodiments of this application provide an orthogonal chirped multiplexing signal design device 60, such as... Figure 6 As shown, the orthogonal chirped multiplexing signal design device 60 includes:

[0132] The first processing unit 601 is used to process the input chirp signal stream sequentially through a serial / parallel module and a mapping module to obtain a first data stream;

[0133] The chirped signal modulation unit 602 is used to perform orthogonal chirped demultiplexing (OCDM) signal modulation on the first data stream through the discrete inverse Fresnel transform (IDFnT) module to obtain the second data stream;

[0134] The frequency hopping FH processing unit 603 is used to perform frequency hopping FH processing on the second data stream through the frequency hopping module to obtain a frequency hopping FH data stream;

[0135] The second processing unit 604 is used to process the frequency-hopping FH data stream sequentially through a prefixing module, a parallel / serial module, and a digital / analog module to obtain the target FH / OCDM signal stream;

[0136] The signal stream transmission unit 605 is used to transmit the target FH / OCDM signal stream to the wireless channel via an antenna.

[0137] Optionally, the frequency hopping FH processing unit 603 is also used for:

[0138] The second data stream is processed by frequency hopping (FH) using a preset frequency hopping strategy in the frequency hopping module to obtain a frequency hopping (FH) data stream; wherein, the preset frequency hopping strategy is obtained based on the oscilloscope's spectrum quality perception.

[0139] Optionally, the frequency hopping FH processing unit 603 is also used for:

[0140] Perform logtistic mapping on the second data stream to generate a sequence of chaotic simulated values ​​corresponding to the second data stream;

[0141] Frequency hopping processing is performed on the chaotic simulation value sequence to obtain the frequency hopping FH data stream; where the frequency hopping FH data stream is a frequency hopping sequence.

[0142] The orthogonal chirped multiplexing signal design device 60 can be used to perform... Figures 2-3 The method performed in the illustrated embodiment is described above. Therefore, the functions that each functional module of the orthogonal chirped multiplexing signal design device 60 can be referred to for the same purpose. Figures 2-3 The embodiments shown are described in detail below.

[0143] In some possible implementations, various aspects of the methods provided in this application can also be implemented as a program component comprising program code that, when run on a computer device, causes the computer device to perform the steps of the methods according to the various exemplary embodiments of this application described above. For example, the computer device may perform actions such as... Figures 2-3 The method performed in the illustrated embodiment.

[0144] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks. Alternatively, if the integrated unit of the present invention is implemented as a software functional module and sold or used as an independent part, it can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiments of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software part. This computer software part 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 methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, ROM, RAM, magnetic disks, or optical disks.

[0145] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0146] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A design method for orthogonal chirped multiplexed signals, characterized in that, The method is applied at the signal transmitting end and includes: The input chirp signal stream is processed sequentially through a serial / parallel module and a mapping module to obtain the first data stream; The first data stream is modulated with an orthogonal chirped multiplexing (OCDM) signal using the Discrete Fresnel Inverse Transform (IDFnT) module to obtain the second data stream; The second data stream is subjected to logtistic mapping to generate a chaotic simulation value sequence corresponding to the second data stream; the chaotic simulation value sequence is subjected to frequency hopping processing to obtain a frequency hopping FH data stream; wherein, the frequency hopping FH data stream is a frequency hopping sequence; The frequency-hopping FH data stream is processed sequentially through a prefixing module, a parallel / serial module, and a digital / analog module to obtain the target FH / OCDM signal stream; The target FH / OCDM signal stream is transmitted to the wireless channel via an antenna.

2. The method as described in claim 1, characterized in that, The chaotic simulation value sequence is represented by the following formula (1): （1） The frequency-hopping FH data stream is represented by the following formula (2): , （2） in, The sequence number of the chaotic simulation value sequence. Let N be the initial value in the interval [-1, 1]; Nh is a positive integer that divides the continuous interval (-1, 1) into Nh non-overlapping intervals. interval; This represents the frequency hopping mapping relationship; This refers to the nth frequency point in the frequency-hopping FH data stream.

3. The method as described in claim 1, characterized in that, The preset frequency hopping strategy is expressed by the following formula (3): （3） in, The center frequency of the k-th Chirp signal after frequency hopping; Let be the initial physical frequency of the k-th Chirp signal; The frequency hopping sequence interval satisfies , This refers to the signal pulse width.

4. The method as described in claim 1, characterized in that, The Chirp signal is represented by the following formula (4): （4） in, For Chirp signal, The chirp signal frequency modulation rate, To adjust the frequency of the Chirp signal, This is the initial phase.

5. The method as described in claim 1, characterized in that, The target FH / OCDM signal is represented by the following formula (5): （5） in, For the target FH / OCDM signal, For Chirp signal number, For the symbol on the k-th sub-channel, These are orthogonal Chirp signals. Represented as the frequency hopping mapping factor in the k-th sub-channel. This indicates that the k-th Chirp signal is in the... Physical frequency in a frequency hopping state This represents the number of frequency hopping points.

6. A design device for orthogonal chirped multiplexing signals, characterized in that, The device is used at the signal transmitting end and includes: The first processing unit is used to process the input chirp signal stream sequentially through a serial / parallel module and a mapping module to obtain a first data stream; The chirped signal modulation unit is used to perform orthogonal chirped demultiplexing (OCDM) signal modulation on the first data stream through the discrete inverse Fresnel transform (IDFnT) module to obtain the second data stream; A frequency-hopping FH processing unit is used to perform logtistic mapping on the second data stream to generate a chaotic simulated value sequence corresponding to the second data stream; and to perform frequency-hopping processing on the chaotic simulated value sequence to obtain a frequency-hopping FH data stream; wherein, the frequency-hopping FH data stream is a frequency-hopping sequence; The second processing unit is used to process the frequency-hopping FH data stream sequentially through a prefixing module, a parallel / serial module, and a digital / analog module to obtain the target FH / OCDM signal stream; The signal stream transmission unit is used to transmit the target FH / OCDM signal stream to the wireless channel via an antenna.

7. An electronic device, characterized in that, The device includes: Memory, used to store program instructions; A processor is configured to invoke program instructions stored in the memory and execute the method described in any one of claims 1-5 according to the obtained program instructions.

8. A storage medium, characterized in that, The storage medium stores computer-executable instructions for causing a computer to perform the method described in any one of claims 1-5.

Images