CN118112517B - Combined radar communication waveform signal construction method and combined radar communication system - Google Patents
Combined radar communication waveform signal construction method and combined radar communication system Download PDFInfo
- Publication number
- CN118112517B CN118112517B CN202410505478.3A CN202410505478A CN118112517B CN 118112517 B CN118112517 B CN 118112517B CN 202410505478 A CN202410505478 A CN 202410505478A CN 118112517 B CN118112517 B CN 118112517B
- Authority
- CN
- China
- Prior art keywords
- signal
- waveform
- lfm
- information
- lfm waveform
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000004891 communication Methods 0.000 title claims abstract description 74
- 238000010276 construction Methods 0.000 title description 9
- 230000000739 chaotic effect Effects 0.000 claims abstract description 72
- 238000000034 method Methods 0.000 claims abstract description 38
- 238000001514 detection method Methods 0.000 claims abstract description 28
- 238000012545 processing Methods 0.000 claims abstract description 27
- 239000011159 matrix material Substances 0.000 claims description 33
- 230000005540 biological transmission Effects 0.000 claims description 26
- 238000004364 calculation method Methods 0.000 claims description 12
- 230000008054 signal transmission Effects 0.000 claims description 5
- 230000006870 function Effects 0.000 abstract description 21
- 230000009977 dual effect Effects 0.000 abstract description 12
- 230000008447 perception Effects 0.000 abstract description 3
- 238000013461 design Methods 0.000 description 13
- 230000014509 gene expression Effects 0.000 description 10
- 238000004088 simulation Methods 0.000 description 7
- 238000010586 diagram Methods 0.000 description 5
- 238000001228 spectrum Methods 0.000 description 5
- 230000008569 process Effects 0.000 description 4
- 230000001427 coherent effect Effects 0.000 description 3
- 230000008878 coupling Effects 0.000 description 3
- 238000010168 coupling process Methods 0.000 description 3
- 238000005859 coupling reaction Methods 0.000 description 3
- 108010003272 Hyaluronate lyase Proteins 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 230000003111 delayed effect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- NAWXUBYGYWOOIX-SFHVURJKSA-N (2s)-2-[[4-[2-(2,4-diaminoquinazolin-6-yl)ethyl]benzoyl]amino]-4-methylidenepentanedioic acid Chemical compound C1=CC2=NC(N)=NC(N)=C2C=C1CCC1=CC=C(C(=O)N[C@@H](CC(=C)C(O)=O)C(O)=O)C=C1 NAWXUBYGYWOOIX-SFHVURJKSA-N 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000005312 nonlinear dynamic Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000001902 propagating effect Effects 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000013468 resource allocation Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Landscapes
- Radar Systems Or Details Thereof (AREA)
Abstract
The invention relates to the technical field of communication perception, in particular to a method for constructing a joint radar communication waveform signal and a joint radar communication system. The method comprises the following steps: acquiring a chaotic sample signal, an information symbol and a pulse repetition period; acquiring an LFM waveform, and dividing the LFM waveform into a plurality of sub-LFM waveforms; performing operation processing on the chaotic sample signal and the sub LFM waveform to obtain a reference signal; carrying out operation processing on the chaotic sample signal, the information symbol, the pulse repetition period and the sub LFM waveform to obtain an information bearing signal; according to the information bearing signal and the reference signal, a transmitting signal is constructed, and the technical problems that a waveform signal output by a traditional DCSK system can only be used for communication and cannot be used for detecting a target, and dual functions of communication and target detection are difficult to realize are solved.
Description
Technical Field
The invention relates to the technical field of communication perception, in particular to a method for constructing a joint radar communication waveform signal and a joint radar communication system.
Background
Chaos is a special form of non-linear dynamic motion that was first discovered in the end of the 19 th century. The chaotic signal is widely applied to the spread spectrum communication field because of the characteristics of wide band, random-like property, easy generation, good autocorrelation/cross correlation and the like. At present, research on chaotic communication is mainly focused on chaotic digital communication, wherein coherent chaotic modulation and noncoherent chaotic modulation are the most focused. Because the coherent chaotic modulation communication system needs the chaotic synchronization of a receiver, the initial value sensitivity of the chaotic signal makes the synchronization of a receiving end difficult to realize. Therefore, incoherent chaotic communication systems not requiring chaotic synchronization are receiving more and more attention. And differential chaotic shift keying (DIFFERENT CHAOS SHIFT KEYING, DCSK) is taken as a typical representative of a non-coherent chaotic communication system and is widely studied.
However, the waveform signal output by the conventional DCSK system can only be used for communication, and cannot be used for detecting a target, and it is difficult to realize dual functions of communication and target detection.
Disclosure of Invention
The invention provides a combined radar communication waveform signal construction method and a combined radar communication system, which are used for solving the technical problems that a waveform signal output by a traditional DCSK system can only be used for communication and cannot be used for detecting a target, and the dual functions of communication and target detection are difficult to realize.
The invention provides a method for constructing a joint radar communication waveform signal, which comprises the following steps:
Acquiring a chaotic sample signal, an information symbol and a pulse repetition period;
acquiring an LFM waveform, and dividing the LFM waveform into a plurality of sub-LFM waveforms;
calculating the chaotic sample signal and the sub LFM waveform to obtain a reference signal;
Calculating the chaotic sample signal, the information symbol, the pulse repetition period and the sub-LFM waveform to obtain an information bearing signal;
and constructing a transmitting signal according to the information carrying signal and the reference signal.
Optionally, the calculating the chaotic sample signal and the sub LFM waveform to obtain a calculation formula of the reference signal is:
；
Wherein S 0 (T) is a reference signal, x i is an ith chaotic sample signal, T c is a period of a sub LFM waveform, f 0 is an initial frequency of the LFM waveform signal, μ is a chirp slope of the LFM waveform signal, T is a time instant at which the LFM waveform signal is currently located, and i=0, 1, …, β -1, m are constants.
Optionally, the calculating the chaotic sample signal, the information symbol, the pulse repetition period and the sub LFM waveform to obtain a calculation formula of an information bearing signal is:
；
wherein, For the mth information carrying signal, f 0 is the initial frequency of the LFM waveform signal, μ is the chirp slope of the LFM waveform signal, T is the current time of the LFM waveform signal, b M is the mth information symbol, T p is the pulse repetition period, x i is the ith chaotic sample signal, T c is the period of the sub-LFM waveform, and M is a constant.
Optionally, the expression of the transmission signal is:
。
optionally, the step of acquiring the information symbol includes:
Acquiring information bits;
And dividing the information bits by adopting a bit divider to obtain a plurality of information symbols.
Optionally, the constructing a transmission signal according to the information carrying signal and the reference signal further includes:
the transmit signal is sent to a receiver module.
Optionally, the method further comprises:
when the receiver module receives the transmitting signal, the receiver module carries out signal demodulation on the transmitting signal to obtain modulation bits;
And when the receiver module receives the transmitting signal, performing target detection on the transmitting signal to obtain a target speed and a target distance.
Optionally, when the receiver module receives the transmission signal, performing target detection on the transmission signal to obtain a target speed and a target distance specifically includes:
analyzing the transmitting signal to obtain Doppler frequency shift, time delay and wavelength of an echo signal;
calculating the target speed according to the Doppler frequency shift and the wavelength;
and calculating the target distance according to the time delay and the light speed.
Optionally, when the receiver module receives the transmission signal, the receiver module performs signal demodulation on the transmission signal, and the obtaining the modulation bit specifically includes:
analyzing the transmitting signals to obtain a plurality of pulse signals;
Multiplying the first pulse signal with the conjugated replica signal of the LFM waveform according to the signal transmission sequence from front to back to obtain a first processing signal; multiplying each pulse signal except the first pulse signal in the pulse signals with the conjugated copy signal of the LFM waveform to obtain each second processing signal;
Performing a real part calculation on the first processing signal to obtain a first matrix;
Performing a real part calculation on each second processing signal to obtain a second matrix;
According to the first matrix and the transposed matrix of the second matrix, calculating to obtain a first vector;
And detecting the numerical value of each element in the first vector by adopting a detector to obtain the modulation bit corresponding to each element.
Another aspect of the present invention provides a joint radar communication system, which is characterized by comprising a transmitter module and a receiver module; the transmitter module is used for executing the method; the receiver module is configured to perform the method as described above.
From the above technical scheme, the invention has the following advantages:
The invention provides a method for constructing a joint radar communication waveform signal, which comprises the steps of obtaining a chaotic sample signal, an information symbol and a pulse repetition period; acquiring an LFM waveform, and dividing the LFM waveform into a plurality of sub-LFM waveforms; performing operation processing on the chaotic sample signal and the sub LFM waveform to obtain a reference signal; carrying out operation processing on the chaotic sample signal, the information symbol, the pulse repetition period and the sub LFM waveform to obtain an information bearing signal; and constructing a transmitting signal according to the information carrying signal and the reference signal.
In the invention, the acquisition of the chaotic sample signal, the information symbol and the pulse repetition period is realized by acquiring the chaotic sample signal, the information symbol and the pulse repetition period; the LFM waveform is divided into a plurality of sub-LFM waveforms by acquiring the LFM waveform, so that the period of the divided sub-LFM waveform is identical with the period of the chaotic sample signal, and technical support is provided for embedding the information symbol into the sub-LFM waveform; the chaotic sample signal and the sub LFM waveform are calculated to obtain a reference signal, so that the construction of the reference signal is realized; the chaotic sample signal, the information symbol, the pulse repetition period and the sub-LFM waveform are calculated to obtain an information bearing signal, so that the information symbol is embedded into the sub-LFM waveform, and the information bearing signal carries data information corresponding to the information symbol, thereby realizing dual functions of communication and target detection; and constructing a transmitting signal according to the information bearing signal and the reference signal, thereby completing the integral construction of the combined radar communication waveform signal, enabling the obtained transmitting signal to meet the functions of communication and target detection, and solving the technical problems that the waveform signal output by the traditional DCSK system can only be used for communication and cannot be used for detecting targets, and the dual functions of communication and target detection are difficult to realize.
Drawings
In order to more clearly illustrate the embodiments of the invention or the technical solutions of the prior art, the drawings which are used in the description of the embodiments or the prior art will be briefly described, it being obvious that the drawings in the description below are only some embodiments of the invention, and that other drawings can be obtained according to these drawings without inventive faculty for a person skilled in the art.
FIG. 1 is a schematic block diagram of a transceiver of a conventional DCSK system;
fig. 2 is a flowchart of steps of a method for constructing a joint radar communication waveform signal according to an embodiment of the present invention;
FIG. 3 is a flowchart illustrating steps of a method for constructing a joint radar communication waveform signal according to another embodiment of the present invention;
fig. 4 is a schematic block diagram of a transmitter module in a joint radar communication system according to an embodiment of the present invention;
Fig. 5 is a schematic block diagram of a receiver module in the joint radar communication system according to the embodiment of the present invention;
FIG. 6 is a graph comparing bit error rate performance of an embodiment of the present invention with a conventional DCSK scheme under Gaussian channel conditions;
FIG. 7 is a distance tangent plane plot of a fuzzy function of a conventional LFM waveform;
Fig. 8 is a distance tangent plane diagram of a blur function of a transmission signal according to an embodiment of the present invention.
Detailed Description
The schematic block diagrams of the transceiver and transmitter of the conventional DCSK system are shown in fig. 1, and the transmitter of the system realizes modulation of information symbols by transmitting two continuous chaotic signals. Wherein the first segment signal is used as a reference signal and the second segment signal is used as an information bearing signal. When the transmission symbol is "+1", the second segment signal is identical to the first segment signal; when the transmission symbol is "0", the second-segment signal is an inverted signal of the first-segment signal. Specifically, when the DCSK system transmits the ith information bit b i, the signal expression transmitted by the DCSK system is:
（1）
in equation (1), β represents the length of the chaotic sequence serving as the reference signal, In DCSK system, its spread spectrum factor。
At the receiving end, in order to recover the information bit b i, the received signal r i,k and the delayed signal r i,k-β thereof are subjected to a correlation operation, so as to obtain a decision variable z i, which can be expressed as:
（2）
Finally, the decision variable output by the correlator is input into the decision device to recover the information bit, and the decision rule is as follows:
（3）
In recent years, as available spectrum resources are increasingly scarce, this has forced the development of multifunctional devices that share spectrum. Among the developed multifunctional devices, a joint radar communication system (Joint Radar and Communication, JRC) capable of integrating radar and communication functions on a unified hardware platform has recently been attracting attention. In JRC systems, the design of the waveform plays a critical role. JRC waveform designs can be divided into two categories: waveform designs where the resource allocations do not overlap and completely uniform waveform designs. The first type of waveform design is designed mainly by methods such as time division multiplexing, frequency division multiplexing, space division multiplexing and code division multiplexing. These methods inevitably cause interference between communications and radar, and have problems of poor spectrum and energy efficiency, low communication rate, and the like. While the second type of waveform design maximizes the integration gain. Wherein the second type of waveform design can be subdivided into three types: communication-centric designs, perception-centric designs, and joint designs. Communication-centric designs are designed to implement sensing functions on existing communication waveforms, with a main typical representation being designed with orthogonal frequency division multiplexing (Orthogonal Frequency Division Multiplexing, OFDM) waveforms; the sensing-centric design mainly integrates communication functions into existing sensing waveforms, and takes a linear frequency modulation (Linear Frequency Modulation, LFM) signal as a typical representative, while the joint design is to redesign a new waveform to realize both communication and sensing functions.
Because the traditional DCSK system can only be used for communication and cannot be used for detecting targets, the traditional DCSK system has only a single function, cannot realize the dual functions of communication and target detection, and is difficult to adapt to a JRC system. Furthermore, a single communication device or a radar device has no advantages in terms of cost, power consumption, and hardware size, as compared to a device in which both are integrated.
Therefore, the embodiment of the invention provides a combined radar communication waveform signal construction method and a combined radar communication system, which construct a brand-new DCSK-LFM integrated waveform suitable for a JRC system by utilizing a DCSK system and an LFM waveform, realize dual functions of sensing and communication, and solve the technical problems that waveform signals output by the traditional DCSK system can only be used for communication and cannot be used for detecting targets, and the dual functions of communication and target detection are difficult to realize.
In order to make the objects, features and advantages of the present invention more comprehensible, the technical solutions in the embodiments of the present invention are described in detail below with reference to the accompanying drawings, and it is apparent that the embodiments described below are only some embodiments of the present invention, but not all embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Referring to fig. 2, the method for constructing a joint radar communication waveform signal provided by the present invention includes:
101. and acquiring chaotic sample signals, information symbols and pulse repetition periods.
It should be noted that, in this embodiment, the chaotic sample signal is obtained from the chaotic signal generator, and the information symbol is obtained from the bit divider. The pulse repetition period is used to adjust the data rate and maximum detection distance of the system. The pulse repetition period may be set in advance according to actual conditions. The system refers to a joint radar communication waveform system as shown in fig. 4 and 5 to which the present embodiment is applied.
Specifically, in the present embodiment, β chaotic sample signals are acquired from a chaotic signal generator, wherein a signal period of each chaotic sample signal is equal to a duration T b of a reference signal.
102. An LFM waveform is acquired and divided into a number of sub-LFM waveforms.
In this embodiment, an LFM waveform with a pulse width of T is obtained, and the LFM waveform is divided into β sub-LFM waveforms with a signal period of T c, where the pulse width of the LFM waveform is the same as the period of the chaotic sample signal, i.e., t=t b=βTc.
103. And calculating the chaotic sample signal and the sub LFM waveform to obtain a reference signal.
In this embodiment, each chaotic sample signal is multiplied by each sub LFM waveform to obtain the reference signal S 0 (t) transmitted by the first pulse.
104. And calculating the chaotic sample signal, the information symbol, the pulse repetition period and the sub LFM waveform to obtain an information bearing signal.
It should be noted that, in this embodiment, the procedure of obtaining the information carrying signal is similar to that of the reference signal, and the difference is that, when the information carrying signal is generated, each chaotic sample signal needs to be multiplied by one information symbol b m, and a new signal period is obtained by using the pulse repetition period. Where b m is the mth information symbol, b m e { -1, +1}, m=1, 2, …, M.
Therefore, in this embodiment, the chaotic sample signal, the information symbol, the pulse repetition period and the sub LFM waveform are subjected to operation processing to obtain the information bearing signal, so that the information symbol and the pulse repetition period are embedded into the LFM waveform, thereby realizing dual functions of communication and target detection.
105. A transmit signal is constructed from the information bearing signal and the reference signal.
In this embodiment, the information-bearing signal and the reference signal are configured to be a transmission signal, and the transmission signal is sent by the transmitter module to the receiver module.
Wherein, in signal transmission, the transmitter module transmits n=m+1 pulses altogether, the first pulse being used for transmitting the reference signal and the remaining pulses being used for transmitting the information-bearing signal.
In the embodiment of the invention, the acquisition of the chaotic sample signal, the information symbol and the pulse repetition period is realized by acquiring the chaotic sample signal, the information symbol and the pulse repetition period; the LFM waveform is obtained and divided into a plurality of sub-LFM waveforms, so that the period of the sub-LFM waveforms obtained by division is the same as the period of the chaotic sample signal, and technical support is provided for embedding the information symbol into the sub-LFM waveforms; the chaotic sample signal and the sub LFM waveform are calculated to obtain a reference signal, so that the construction of the reference signal is realized; the chaotic sample signal, the information symbol, the pulse repetition period and the sub-LFM waveform are calculated to obtain an information bearing signal, so that the information symbol is embedded into the sub-LFM waveform, and the information bearing signal carries data information corresponding to the information symbol, thereby realizing dual functions of communication and target detection; and the transmitting signal is constructed according to the information bearing signal and the reference signal, thereby completing the integral construction of the combined radar communication waveform signal, enabling the obtained transmitting signal to meet the functions of communication and target detection, and solving the technical problems that the waveform signal output by the traditional DCSK system can only be used for communication and can not be used for detecting targets, and the dual functions of communication and target detection are difficult to realize.
Referring to fig. 3, the method for constructing a joint radar communication waveform signal according to another embodiment of the present invention includes the steps of:
201. acquiring a chaotic sample signal, an information symbol and a pulse repetition period;
it should be noted that, the description of the chaotic sample signal and the pulse repetition period may refer to step 101, and will not be described herein.
In one example, the step of obtaining the information symbol includes:
S1, acquiring information bits;
it should be noted that, the information bits in the embodiment are the same as those adopted in the existing DCSK system, and specifically, reference may be made to the existing DCSK system, which is not described herein again.
S2, dividing the information bits by a bit divider to obtain a plurality of information symbols.
In this embodiment, the bit divider divides the information bit b into a total of b 1、b2、b3……bM information symbols.
202. Acquiring an LFM waveform, and dividing the LFM waveform into a plurality of sub-LFM waveforms;
it should be noted that, step 202 may specifically refer to step 102, which is not described herein.
203. Calculating the chaotic sample signal and the sub LFM waveform to obtain a reference signal;
in this embodiment, the chaotic sample signal is multiplied by the sub LFM waveform to obtain the reference signal S 0 (t).
The calculation formula of the reference signal S 0 (t) is as follows:
（4）
Wherein S 0 (T) is a reference signal, x i is an ith chaotic sample signal, T c is a period of a sub LFM waveform, f 0 is an initial frequency of the LFM waveform signal, μ is a chirp slope of the LFM waveform signal, T is a time instant at which the LFM waveform signal is currently located, and i=0, 1, …, β -1, m are constants.
204. Calculating the chaotic sample signal, the information symbol, the pulse repetition period and the sub LFM waveform to obtain an information bearing signal;
it should be noted that, the chaotic sample signal is delayed, and the chaotic sample signal obtained after the delay is multiplied by the information symbol and the sub LFM waveform to obtain the information bearing signal.
Wherein the delay time is determined based on the information symbol and the pulse repetition period. It will be appreciated that in this embodiment, there are M information symbols b 1、b2、b3……bM, which correspond to the information-bearing signal, for example, the first signal symbol b 1 is used to calculate the first information-bearing signal S 1 (t), where the delay time may be obtained by multiplying the pulse repetition period by the subscript of the information symbol. For example, the latency of the chaotic sample signal is 1T p when the first information-bearing signal is calculated, 2T p when the second information-bearing signal is calculated, and so on.
In one embodiment, the information bearing signal is calculated as:
（5）
wherein, For the mth information carrying signal, f 0 is the initial frequency of the LFM waveform signal, μ is the chirp slope of the LFM waveform signal, T is the current time of the LFM waveform signal, b M is the mth information symbol, T p is the pulse repetition period, x i is the ith chaotic sample signal, T c is the period of the sub-LFM waveform, and M is a constant.
205. A transmit signal is constructed from the information bearing signal and the reference signal.
Note that, the expression of the transmission signal may be:
（6）
for transmitting signals.
206. Transmitting the transmit signal to a receiver module;
in this embodiment, the reference signal and each information-bearing signal in the transmission signal are sequentially sent to the receiver module by the transmitter module.
207. When the receiver module receives the transmitting signal, the receiver module carries out signal demodulation on the transmitting signal to obtain modulation bits;
The receiver module in this embodiment includes a demodulation receiver and a JRC transceiver. In signal transmission, the transmitter module sends the transmission signals to the demodulation receiver and the JRC transceiver, respectively. The demodulation receiver is used for demodulating the transmitted signal to obtain modulation bits. The JRC transceiver is configured to perform target detection on the transmission to obtain a target speed and a target distance.
In a specific embodiment, step 207 specifically comprises the sub-steps of:
S21, analyzing the transmitting signals to obtain a plurality of pulse signals.
It should be noted that, the transmitted signal received by the receiver module may be expressed as:
（7）
Where N j,i (t), j=0, 1, …, M, represents the additive white gaussian noise with a mean value of zero and a variance of N 0/2 corresponding to the (i+1) th sub-waveform of the (j+1) th pulse waveform.
It will be appreciated that the transmission signal, after propagating through the wireless channel and passing through the internal components of the receiver module, carries a certain noise signal, so that the expression of the transmission signal at the receiver module end is different from the expression of the transmission signal at the transmission module end.
In this embodiment, after analyzing the transmitting signal of the receiver module, a plurality of pulse signals are obtained, as shown in formula (7), where each line of expressions on the right side of the equal sign represents one pulse signal respectively.
S22, multiplying the first pulse signal with the conjugated replica signal of the LFM waveform according to the signal transmission sequence from front to back to obtain a first processing signal; and multiplying each pulse signal except the first pulse signal in the pulse signals with the conjugated copy signal of the LFM waveform to obtain each second processing signal.
In this embodiment, first, the first pulse signal is multiplied by the conjugate replica signal of the LFM waveform to obtain a first processing signal, and the remaining pulse signals are multiplied by the conjugate replica signal of the LFM waveform to obtain corresponding second processing signals. The first pulse signal refers to a signal transmitted first by the transmitter module, that is, a pulse signal received first by the receiver module, and the expression of the first pulse signal is shown as a first row expression (from top to bottom) on the right side of an equal sign of the formula (7). The rest pulse signals are shown as the expressions from the second row to the M-th row on the right side of the equal sign of the formula (7). Therefore, the pulse signals except the first pulse signal correspond to one second processing signal respectively. Wherein the number of the second processing signals is M.
S23, performing a real part operation on the first processing signal to obtain a first matrix.
In this embodiment, the first processing signal is subjected to a real part calculation, the calculated signal is used as a reference signal, and the reference signal is stored in a matrix form to obtain a first matrix. Therefore, the first matrix in this embodiment represents the reference signal, and this embodiment realizes the recovery of the reference signal by performing the operation of taking the real part of the first processing signal. Wherein the first matrix a 1×β is a matrix of 1 row and β column.
S24, performing a real part calculation on each second processing signal to obtain a second matrix.
In this embodiment, the real part of each second processing signal is calculated to obtain M corresponding signals, the M signals are converted into a matrix form to obtain M matrices of 1 row and β column, and the M matrices of 1 row and β column are used to construct a second matrix of M row and β column. Each row of elements in the second matrix corresponds to the elements in the M signals one by one, for example, the first row of elements in the second matrix is the same as the matrix corresponding to the second processing signal r 1 (t) after the first real part operation.
S25, calculating to obtain a first vector according to the transpose matrix of the first matrix and the transpose matrix of the second matrix.
In this embodiment, the transpose of the first matrix and the second matrix are multiplied to obtain the first vector.
In one example, the first vector is calculated as:
z=A×BT(8)
wherein z is a first vector.
And S26, carrying out numerical detection on each element in the first vector by adopting a detector to obtain a modulation bit corresponding to each element.
It should be noted that, according to the step S25, the calculated first vector z is a matrix, and the detector is used to detect the value of each element in the first vector z, when the value of the detected element is greater than 0, the corresponding modulation bit of the detected element is "0", and when the value of the detected element is not greater than 0, the corresponding modulation bit of the detected element is "1".
In a specific embodiment, the relation between the modulation bits and the first vector is:
（9）
for the mth modulated bit, z m is the mth element in the first vector z.
208. When the receiver module receives the transmitting signal, the transmitting signal is subjected to target detection, and the target speed and the target distance are obtained.
It should be noted that, the JRC transceiver is configured to perform target detection on the transmission signal, so as to obtain the target speed and the target distance. The target speed refers to the moving speed of the measured target. The target distance refers to the distance between the target under test and the JRC transceiver.
In this embodiment, the JRC transceiver is used as a part of radar ranging, and the echo signal of the transmitted signal needs to return to the receiver before the transmitter module transmits the next pulse waveform, so as to improve the ranging accuracy, so that the delay of the echo signal of the JRC transceiver satisfies:
（10）
（11）
Where τ echo is the echo delay, R is the target distance, c is the speed of light, and T p is the pulse repetition period.
In a specific embodiment, step 208 may specifically comprise the sub-steps of:
S31, analyzing the transmitted signals to obtain Doppler frequency shift, time delay and wavelength of echo signals.
The Doppler effect principle is utilized to analyze the transmitted signal, and Doppler frequency shift, time delay and wavelength of the echo signal are obtained.
S32, calculating the target speed according to the Doppler frequency shift and the wavelength.
It should be noted that, during the speed measurement process, when the measured target moves relative to the radar, the frequency of the echo signal changes, and the change is proportional to the speed of the target object. Thus, by measuring the frequency change (i.e., doppler shift) of the echo signal, the velocity of the target object can be calculated.
The expression of the speed measurement is as follows:
（12）
where v t is the velocity of the measured object, f d is the Doppler shift of the echo signal, and λ is the wavelength of the echo signal.
S33, calculating to obtain the target distance according to the time delay and the light speed.
It should be noted that, according to the above formula (10), the target distance can be calculated by using the time delay and the light velocity of the echo signal.
It will be appreciated that 207 and 208 do not have a sequential order, e.g. step 208 may precede step 207 or step 207 and step 208 may be performed simultaneously.
In a specific embodiment, the data rate of the system (i.e., the rate at which information bits are transmitted) is approximately equal to the inverse of the pulse repetition period.
Wherein, the relation between the data rate and the pulse repetition period is as follows:
（13）
where v is the data rate.
In another specific embodiment, the maximum detection distance of the system can be calculated by the speed of light and the pulse repetition period.
The specific calculation formula is as follows:
（14）
wherein R max is the maximum detection distance.
As can be seen from equation (14), the target distance is inversely proportional to the target speed and depends on the pulse repetition period, so that in practical application, the adjustment of the maximum ranging distance and the data rate can be achieved by adjusting the value of the pulse repetition period, for example, by increasing the pulse repetition period, remote target detection is achieved, and the target detection range is enlarged; or by reducing pulse repetition period, the transmission data rate is improved, and the communication performance is optimized.
The embodiment of the invention also provides a joint radar communication system, which comprises a transmitter module and a receiver module; the transmitter module is for performing the method of any of the embodiments described above; the receiver module is configured to perform the method of any of the embodiments described above.
Specifically, as shown in fig. 4, the principle of the transmitter module provided in this embodiment is: the chaotic signal generator generates a chaotic sample signal, the chaotic sample signal is respectively input into the delay module and the operation module, and the chaotic sample signal entering the operation module is multiplied by the sub-LFM waveform to obtain a reference signal S 0 (t). The bit divider divides the received information bit into M information symbols, and inputs the M information symbols into the operation module respectively, multiplies the M information symbols with the chaotic sample signal passing through the delay module, and then multiplies each signal obtained by multiplication with each sub LFM waveform respectively to obtain the corresponding information bearing signal. Forming each information-bearing signal and reference signal into a transmission signal。
Specifically, as shown in fig. 5, the principle of the receiver module provided in this embodiment is:
When the receiver module receives the transmission signal, the JRC transceiver positioned on the radar part performs target detection by using the transmission signal, and the target speed and the target distance are obtained. The receiver located in the communication part is used for analyzing the transmitting signal to obtain a plurality of pulse signals r 0(t)、r1(t)、……、rM (t), then multiplying the plurality of pulse signals with conjugated copies of the LFM waveform respectively to obtain a first matrix a and a second matrix B, multiplying the first matrix a with the transpose of the second matrix B to obtain a first vector z, then inputting the first vector z into the demodulator to obtain modulation bits, and finally inputting the modulation bits into the bit combiner to obtain corresponding data.
In an application example, in order to further explain the effect obtained by the embodiment of the invention, the application example carries out simulation operation based on the method for constructing the joint radar communication waveform signal, and the simulation process and the simulation result are analyzed as follows:
Before simulation, setting simulation parameters: the initial frequency f 0 =0 MHz, the pulse width t=5 mus, and the bandwidth b=40 MHz. The simulation parameters are utilized to simulate the traditional DCSK scheme and the technical scheme of the embodiment of the invention, and the simulation results are shown in figures 6-8. Fig. 6 shows the bit error rate performance of the technical scheme of the embodiment of the present invention and the conventional DCSK scheme under the gaussian channel, and as can be seen from fig. 6, the bit error rate performance of the technical scheme of the embodiment of the present invention is significantly better than that of the conventional DCSK scheme when the spreading factor is fixed at 300. For example: in Gaussian channel, the technical scheme of the embodiment of the invention has the following error rate And there is a 3dB performance improvement over the conventional DCSK scheme.
Further, as can be seen from fig. 7 and fig. 8, when the spreading factor β=300, the main lobe widths of the waveform of the technical solution of the embodiment of the present invention and the conventional LFM waveform are both 2/B, that is, the distance resolution of the waveforms is 1/b=0.025 μs. The result also shows that the technical scheme of the embodiment of the invention can transmit information symbols while maintaining the original resolution of the LFM waveform. Compared with the traditional single waveform, the integrated waveform of the technical scheme of the embodiment of the invention has obvious advantages.
In summary, the embodiment of the invention is based on a DCSK modulation technology, uses an LFM waveform as a basic waveform of a radar, embeds an information symbol into the LFM waveform through DCSK modulation, and constructs a DCSK-LFM integrated waveform to realize the dual functions of communication and perception. The integrated waveform is capable of transmitting information symbols while maintaining the range resolution of a conventional LFM waveform. Compared with an integrated scheme designed by traditional modulation, the chaotic signal has randomness and good auto-correlation and cross-correlation properties, and the embodiment of the invention has higher safety performance in the aspect of communication. The embodiment of the invention also determines the relation between the communication rate and the maximum detection distance, and in practical application, the data rate and the maximum detection distance can be weighted by adjusting the pulse repetition period Tp, so that the DCSK-LFM integrated waveform is suitable for different scenes, the application scenes are enriched, and the DCSK-LFM integrated waveform provided by the embodiment of the invention can be applied to a JRC system, and the application range of the integrated waveform is improved. The embodiment of the invention also provides a framework of a transmitter and a receiver of the joint radar communication system, and realizes the construction of the joint radar communication system.
It will be clear to those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described systems, apparatuses and units may refer to corresponding procedures in the foregoing method embodiments, which are not repeated herein.
In the several embodiments provided in the present application, it should be understood that the disclosed systems, apparatuses, and methods may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of elements is merely a logical functional division, and there may be additional divisions of actual implementation, e.g., multiple elements or components may be combined or integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.
The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed over a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
In addition, each functional unit in the embodiments of the present invention may be integrated in one processing unit, or each functional unit may exist separately and physically, or two or more functional units may be integrated in one processing unit. The integrated units may be implemented in hardware or in software functional units.
The integrated units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention may be embodied in essence or a part contributing to the prior art or all or part of the technical solution in the form of a software product stored in a storage medium, including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods of the embodiments of the present invention. And the aforementioned storage medium includes: a usb disk, a removable hard disk, a Read-only memory (ROM), a random access memory (RAM, randomAccessMemory), a magnetic disk, or an optical disk, or other various media capable of storing program codes.
The terms "first," "second," "third," "fourth," and the like in the description of the application and in the above figures, if any, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the application described herein may be implemented, for example, in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
The above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims (8)
1. The method for constructing the joint radar communication waveform signal is characterized by comprising the following steps of:
Acquiring a chaotic sample signal, an information symbol and a pulse repetition period;
acquiring an LFM waveform, and dividing the LFM waveform into a plurality of sub-LFM waveforms;
calculating the chaotic sample signal and the sub LFM waveform to obtain a reference signal;
Calculating the chaotic sample signal, the information symbol, the pulse repetition period and the sub-LFM waveform to obtain an information bearing signal;
constructing a transmitting signal according to the information carrying signal and the reference signal;
the calculation formula for calculating the chaotic sample signal and the sub LFM waveform to obtain the reference signal is as follows:
；
Wherein S 0 (T) is a reference signal, x i is an ith chaotic sample signal, T c is a period of a sub-LFM waveform, f 0 is an initial frequency of the LFM waveform signal, mu is a chirp slope of the LFM waveform signal, T is a current time of the LFM waveform signal, ；
The calculation formula for calculating the chaotic sample signal, the information symbol, the pulse repetition period and the sub LFM waveform to obtain an information bearing signal is as follows:
；
wherein, For the mth information carrying signal, f 0 is the initial frequency of the LFM waveform signal, μ is the chirp slope of the LFM waveform signal, T is the current time of the LFM waveform signal, b M is the mth information symbol, T p is the pulse repetition period, x i is the ith chaotic sample signal, T c is the period of the sub-LFM waveform, and M is a constant.
2. The method of claim 1, wherein the transmitted signal is expressed as:
。
3. The method of claim 1, wherein the step of obtaining the information symbol comprises:
Acquiring information bits;
And dividing the information bits by adopting a bit divider to obtain a plurality of information symbols.
4. The method of claim 1, wherein constructing a transmit signal from the information-bearing signal and the reference signal further comprises:
the transmit signal is sent to a receiver module.
5. The method as recited in claim 4, further comprising:
when the receiver module receives the transmitting signal, the receiver module carries out signal demodulation on the transmitting signal to obtain modulation bits;
And when the receiver module receives the transmitting signal, performing target detection on the transmitting signal to obtain a target speed and a target distance.
6. The method of claim 5, wherein the performing target detection on the transmit signal when the receiver module receives the transmit signal, the obtaining the target speed and the target distance specifically comprises:
analyzing the transmitting signal to obtain Doppler frequency shift, time delay and wavelength of an echo signal;
calculating the target speed according to the Doppler frequency shift and the wavelength;
and calculating the target distance according to the time delay and the light speed.
7. The method of claim 5, wherein when the receiver module receives the transmission signal, the receiver module performs signal demodulation on the transmission signal, and obtaining the modulation bit specifically includes:
analyzing the transmitting signals to obtain a plurality of pulse signals;
Multiplying the first pulse signal with the conjugated replica signal of the LFM waveform according to the signal transmission sequence from front to back to obtain a first processing signal; multiplying each pulse signal except the first pulse signal in the pulse signals with the conjugated copy signal of the LFM waveform to obtain each second processing signal;
Performing a real part calculation on the first processing signal to obtain a first matrix;
Performing a real part calculation on each second processing signal to obtain a second matrix;
According to the first matrix and the transposed matrix of the second matrix, calculating to obtain a first vector;
And detecting the numerical value of each element in the first vector by adopting a detector to obtain the modulation bit corresponding to each element.
8. A joint radar communication system comprising a transmitter module and a receiver module; the transmitter module for performing the method of any of claims 1-3; the receiver module being configured to perform the method of any of claims 4-7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410505478.3A CN118112517B (en) | 2024-04-25 | 2024-04-25 | Combined radar communication waveform signal construction method and combined radar communication system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410505478.3A CN118112517B (en) | 2024-04-25 | 2024-04-25 | Combined radar communication waveform signal construction method and combined radar communication system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN118112517A CN118112517A (en) | 2024-05-31 |
| CN118112517B true CN118112517B (en) | 2024-07-09 |
Family
ID=91214046
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202410505478.3A Active CN118112517B (en) | 2024-04-25 | 2024-04-25 | Combined radar communication waveform signal construction method and combined radar communication system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN118112517B (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113791404A (en) * | 2021-09-15 | 2021-12-14 | 电子科技大学长三角研究院(衢州) | Radar ambiguity-resolving and shielding method based on orthogonal frequency division signals |
| CN114039825A (en) * | 2021-11-15 | 2022-02-11 | 南京铁道职业技术学院 | SIMO-HPO-CDSK communication method based on Rayleigh fading channel |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11582023B2 (en) * | 2021-06-14 | 2023-02-14 | Bae Systems Information And Electronic Systems Integration Inc. | Wideband featureless rateless chaotic waveform generation method |
| CN115174322B (en) * | 2022-06-20 | 2023-10-20 | 西安理工大学 | Radar communication integrated method based on chaos shaping filter |
| CN117590377A (en) * | 2023-10-30 | 2024-02-23 | 西安理工大学 | Method for realizing radar communication integrated system based on chaotic waveform |
-
2024
- 2024-04-25 CN CN202410505478.3A patent/CN118112517B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113791404A (en) * | 2021-09-15 | 2021-12-14 | 电子科技大学长三角研究院(衢州) | Radar ambiguity-resolving and shielding method based on orthogonal frequency division signals |
| CN114039825A (en) * | 2021-11-15 | 2022-02-11 | 南京铁道职业技术学院 | SIMO-HPO-CDSK communication method based on Rayleigh fading channel |
Also Published As
| Publication number | Publication date |
|---|---|
| CN118112517A (en) | 2024-05-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101512998B (en) | Device and apparatus for detection of time-frequency frequency-hopping pattern | |
| Sturm et al. | Spectrally interleaved multi‐carrier signals for radar network applications and multi‐input multi‐output radar | |
| US9735830B2 (en) | Transmission signal generating/detecting method using code sequences, communication system using the same and measurement system using the same | |
| Shah et al. | Step-frequency radar with compressive sampling (SFR-CS) | |
| JP5535024B2 (en) | Radar equipment | |
| Burel et al. | Detection of direct sequence spread spectrum transmissions without prior knowledge | |
| CN102868659B (en) | Symbol synchronization and Doppler compensation method for mobile orthogonal frequency division multiplexing (OFDM) underwater sound communication signal | |
| CN109061589A (en) | The Target moving parameter estimation method of random frequency hopping radar | |
| CN104678372B (en) | OFDM radar super-resolution distance and angle value combined estimation method | |
| CN102067544A (en) | Phy preamble format for wireless communication system | |
| CN112763985A (en) | Pulse Doppler radar sounding integrated waveform design method | |
| Yin et al. | Integrated waveform for continuous active sonar detection and communication | |
| CN109412644B (en) | Doppler frequency estimation method for direct sequence spread spectrum MSK signal | |
| CN109975775B (en) | Radar echo semi-actual measurement data simulation method | |
| CN112910499A (en) | Spread spectrum signal accurate acquisition system | |
| CN106453192B (en) | A kind of symbol timing synchronization method and system based on the complementary binary sequence pairs of shielding | |
| CN107769862A (en) | A kind of bionical low communication interception method | |
| CN104753638A (en) | Chaos spreading spectrum underwater acoustic communication method | |
| Nusenu et al. | Dual-function MIMO radar-communications employing frequency-hopping chirp waveforms | |
| CN102215184B (en) | Method and system for estimating uplink timing error | |
| CN104062641B (en) | The new method that a kind of OFDM radar range profile processes | |
| JP7266207B2 (en) | Radar device and radar method | |
| CN101738602A (en) | Echo data preprocessing method for pseudorandom sequences applied to ground penetrating radar | |
| CN118112517B (en) | Combined radar communication waveform signal construction method and combined radar communication system | |
| CN101819185B (en) | Method, system, device, transmitter and receiver for realizing pulsed ultrasonic inspection |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant |