A method and system for synchronously identifying signal source and interference based on optical fiber sensing system

Abstract

The present invention belongs to the technical field of signal processing of optical fiber sensing system, and discloses a method for synchronously identifying information source and interference based on optical fiber sensing system, comprising: representing the transmitting pulse as an information pulse and a protection pulse for double pulse transmission; performing information source phase shift demodulation measurement on the receiving pulse, and L The received pulses after the demodulation of the source phase shift are accumulated and jointly sparsely represented. The source signal is identified according to the sparse vector obtained by the solution; the interference signal accumulation measurement is performed on the received pulse to obtain the sparse representation of the interference accumulation signal, and the interference event is identified according to the interference event feature vector. The present invention designs a dual-pulse transmission scheme based on the protection pulse, and the echo light pulse establishes two synchronous processing branches, which synchronously completes the improvement of the information transmission signal-to-interference ratio and the identification of the interference event, which can increase the equivalent information bandwidth of the optical fiber sensing system, and improve the information transmission efficiency and interference identification accuracy of the optical fiber sensing system.

Description

Technical Field

[0001] The present invention belongs to the technical field of signal processing of optical fiber sensing systems, and the present invention relates to a method and system for synchronously identifying a signal source and interference based on an optical fiber sensing system. Background Art

[0002] In optical fiber communication, interference suppression is a necessary design link, which is of great significance to ensure communication quality, improve communication distance, reduce bit error rate, increase communication bandwidth and improve security. On the other hand, while optical fiber is a communication medium, it can also be used as a perception system to effectively perceive environmental changes, intrusion disturbances and other events. The advantages of using optical fiber for perception and detection include high sensitivity, wide spectrum range, anti-electromagnetic interference, long-distance transmission, distributed perception, miniaturization, lightweight and concealment, making it an advanced and feasible technical choice in many fields. Improving the information transmission efficiency and interference identification accuracy of optical fiber sensing systems has always been the research focus in this field. Summary of the invention

[0003] The purpose of the present invention is to provide a method and system for synchronously identifying a signal source and interference based on a fiber optic sensing system, design a dual-pulse emission scheme based on a protection pulse, establish two synchronous processing branches for echo light pulses, and synchronously complete the improvement of the information transmission signal-to-interference ratio and the identification of interference events, which can increase the equivalent information bandwidth of the fiber optic sensing system and improve the information transmission efficiency and interference identification accuracy of the fiber optic sensing system.

[0004] The technical solution to achieve the purpose of the present invention is:

[0005] A method for synchronously identifying a signal source and interference based on an optical fiber sensing system comprises the following steps:

[0006] S01: The transmission pulse is represented as an information pulse and a protection pulse for double pulse transmission;

[0007] S02: performing source phase shift demodulation measurement on the received pulse, accumulating L received pulses after source phase shift demodulation, performing joint sparse representation, and identifying the source signal according to the sparse vector obtained by solving;

[0008] S03: performing interference signal accumulation measurement on the received pulse to obtain a sparse representation of the interference accumulation signal, and performing interference event recognition according to the interference event feature vector.

[0009] In the preferred technical solution, the information pulse and the protection pulse in step S01:

[0010]

[0011] Among them, s iis the i-th source signal pulse carrying communication information, ξ(·) is the phase shift operator, which indicates the operation of phase shifting the signal. is the phase offset of the i-th information pulse, Δφ i is the phase offset of the i-th protection pulse.

[0012] In the preferred technical solution, in step S02, the measurement matrix Φ is demodulated by the source phase shift I The received pulse is demodulated to measure the source phase shift. The source phase shift demodulation measurement matrix Φ I :

[0013]

[0014] in,

[0015] In a preferred technical solution, the method of accumulating the received pulses after phase shift demodulation of L signal sources in step S02 includes:

[0016] The L received pulses are combined into a received pulse matrix:

[0017] R=[r1,r2,…,r L ]

[0018] The receiving pulse r i =p i +q i +j i , j i is the interference signal term in the i-th received pulse;

[0019] The pulse matrix after source phase shift demodulation measurement is:

[0020] Y=Φ I R

[0021] Among them, the i-th pulse is:

[0022]

[0023] Then, the columns of the Y matrix are superimposed, which is equivalent to accumulating the received pulses after phase shift demodulation of L signal sources. The accumulated signal is:

[0024]

[0025] According to the information pulse phase offset The definition of , the phase of the interference term in the above formula will be anisotropic, and we have:

[0026]

[0027] The accumulated signal is further rewritten as:

[0028]

[0029] The coherent accumulation of L pulses is obtained.

[0030] In a preferred technical solution, the method for identifying the source signal in step S02 includes:

[0031] First, construct the source dictionary, which is:

[0032] Ψ=[ζ1,ζ1e -jπt ζ2,ζ2e -jπt …,ζ Q ,ζ Q e -jπt ]

[0033] Among them, i ,i=1,…Q is the atom of the source dictionary, Q is the number of atoms in the dictionary;

[0034] Obtain a sparse representation model of the accumulated signal:

[0035]

[0036] Among them, θ is a sparse vector, and the sparse vector θ has a structured sparse characteristic, in which the non-zero elements appear in groups, showing a block sparse feature;

[0037] The sparse vector θ is obtained by solving the problem, and the source signal is identified according to the position and value of the non-zero elements in θ.

[0038] In a preferred technical solution, the method for accumulating and measuring interference signals in step S03 includes:

[0039] The interference accumulation is performed on each column of the received pulse matrix R. The signal after interference accumulation is:

[0040]

[0041] Among them, j i is the interference signal term in the i-th received pulse;

[0042] According to the information pulse phase offset According to the definition of , the phases of the information pulse term and the protection pulse term are anisotropic, and we have:

[0043]

[0044] The signal after interference accumulation is further rewritten as:

[0045]

[0046] In a preferred technical solution, the method for identifying interference events in step S03 includes:

[0047] Create a dictionary of interference events:

[0048] Ψ J =[ρ1,ρ2,…,ρ M ]

[0049] Among them, ρ m ,m=1…M represents the event atom of the interference event dictionary, M is the number of atoms in the interference event dictionary, and the event atom is an empirical event, which is the type of interference that has occurred or is foreseeable;

[0050] Get the sparse representation of the interference accumulation signal:

[0051]

[0052] Among them, Θ is the interference event feature vector;

[0053] The solution is obtained, and the information of the interference event is obtained through the position and value of the non-zero elements in Θ, thus completing the interference identification.

[0054] The present invention also discloses a signal source and interference synchronization identification system based on an optical fiber sensing system, comprising:

[0055] A dual pulse transmission module represents the transmission pulse as an information pulse and a protection pulse for dual pulse transmission;

[0056] The source signal identification module performs source phase shift demodulation measurement on the received pulse, accumulates L received pulses after source phase shift demodulation, performs joint sparse representation, and identifies the source signal based on the sparse vector obtained by solving;

[0057] The interference event identification module performs interference signal accumulation measurement on the received pulses to obtain a sparse representation of the interference accumulation signal, and performs interference event identification based on the interference event feature vector.

[0058] In the preferred technical solution, the information pulse and the protection pulse in the dual pulse transmission module are:

[0059]

[0060] Among them, s i is the i-th source signal pulse carrying communication information, ξ(·) is the phase shift operator, which indicates the operation of phase shifting the signal. is the phase offset of the i-th information pulse, Δφ i is the phase offset of the i-th protection pulse.

[0061] The present invention further discloses a computer storage medium on which a computer program is stored. When the computer program is executed, the above-mentioned method for synchronously identifying a signal source and interference based on an optical fiber sensing system is implemented.

[0062] Compared with the prior art, the present invention has the following significant advantages:

[0063] 1. The present invention designs a dual-pulse emission scheme based on a protection pulse. The echo light pulse establishes two synchronous processing branches, which simultaneously completes the improvement of the information transmission signal-to-interference ratio and the identification of interference events, and can increase the equivalent information bandwidth of the optical fiber sensing system, and improve the information transmission efficiency and interference identification accuracy of the optical fiber sensing system.

[0064] 2. With the protection pulse adopted by the present invention, the non-zero elements in the sparse vector θ appear in pairs, which improves the sparse domain energy of the source signal from the perspective of signal sparse representation. Therefore, the solution of the present invention obtains a signal-to-interference ratio close to 2L times in the signal processing branch A, further suppresses the interference signal, and improves the recognition accuracy of the source signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 A flowchart of a method for synchronously identifying a signal source and interference based on an optical fiber sensing system according to a preferred embodiment;

[0066] Figure 2 It is a principle block diagram of a signal source and interference synchronization identification system based on an optical fiber sensing system in a preferred embodiment;

[0067] Figure 3 This is a flow chart of synchronous identification and processing of information sources and interferences in a preferred embodiment. DETAILED DESCRIPTION

[0068] The principle of the present invention is as follows: starting from the two major functions of optical fiber system, communication and perception, the present invention proposes a combined processing method of echo optical pulses that simultaneously improves the effectiveness of information transmission and the accuracy of interference identification, establishes two synchronous processing branches for echo optical pulses, and synchronously completes the improvement of information transmission signal-to-interference ratio and the identification of interference events. Through the method of the present invention, the equivalent information bandwidth of the optical fiber sensing system can be increased, and the information transmission efficiency and interference identification accuracy of the optical fiber sensing system can be improved.

[0069] Embodiment 1:

[0070] like Figure 1 As shown, a method for synchronously identifying a signal source and interference based on an optical fiber sensing system comprises the following steps:

[0071] S01: The transmission pulse is represented as an information pulse and a protection pulse for double pulse transmission;

[0072] S02: performing source phase shift demodulation measurement on the received pulse, accumulating L received pulses after source phase shift demodulation, performing joint sparse representation, and identifying the source signal according to the sparse vector obtained by solving;

[0073] S03: performing interference signal accumulation measurement on the received pulse to obtain a sparse representation of the interference accumulation signal, and performing interference event recognition according to the interference event feature vector.

[0074] In one embodiment, the information pulse and the protection pulse in step S01:

[0075]

[0076] Among them, s i is the i-th source signal pulse carrying communication information, ξ(·) is the phase shift operator, which indicates the operation of phase shifting the signal. is the phase offset of the i-th information pulse, Δφ i is the phase offset of the i-th protection pulse.

[0077] In one embodiment, in step S02, the measurement matrix Φ is demodulated by the source phase shift I The received pulse is demodulated to measure the source phase shift. The source phase shift demodulation measurement matrix Φ I :

[0078]

[0079] in,

[0080] In one embodiment, the method of accumulating L received pulses after phase shift demodulation of the signal sources in step S02 includes:

[0081] The L received pulses are combined into a received pulse matrix:

[0082] R=[r1,r2,…,r L ]

[0083] The receiving pulse r i =p i +q i +j i , j i is the interference signal term in the i-th received pulse;

[0084] The pulse matrix after source phase shift demodulation measurement is:

[0085] Y=Φ I R

[0086] Among them, the i-th pulse is:

[0087]

[0088] Then, the columns of the Y matrix are superimposed, which is equivalent to accumulating the received pulses after phase shift demodulation of L signal sources. The accumulated signal is:

[0089]

[0090] According to the information pulse phase offset The definition of , the phase of the interference term in the above formula will be anisotropic, and we have:

[0091]

[0092] The accumulated signal is further rewritten as:

[0093]

[0094] The coherent accumulation of L pulses is obtained.

[0095] In one embodiment, the method for identifying the source signal in step S02 includes:

[0096] First, construct the source dictionary, which is:

[0097] Ψ=[ζ1,ζ1e -jπt ζ2,ζ2e -jπt …,ζ Q ,ζ Q e -jπt ]

[0098] Among them, i ,i=1,…Q is the atom of the source dictionary, Q is the number of atoms in the dictionary;

[0099] Obtain a sparse representation model of the accumulated signal:

[0100]

[0101] Among them, θ is a sparse vector, and the sparse vector θ has a structured sparse characteristic, in which the non-zero elements appear in groups, showing a block sparse feature;

[0102] The sparse vector θ is obtained by solving the problem, and the source signal is identified according to the position and value of the non-zero elements in θ.

[0103] In one embodiment, the method for accumulating and measuring interference signals in step S03 includes:

[0104] The interference accumulation is performed on each column of the received pulse matrix R. The signal after interference accumulation is:

[0105]

[0106] Among them, j i is the interference signal term in the i-th received pulse;

[0107] According to the information pulse phase offset According to the definition of , the phases of the information pulse term and the protection pulse term are anisotropic, and we have:

[0108]

[0109] The signal after interference accumulation is further rewritten as:

[0110]

[0111] In one embodiment, the method for identifying interference events in step S03 includes:

[0112] Create a dictionary of interference events:

[0113] Ψ J =[ρ1,ρ2,…,ρ M ]

[0114] Among them, ρ m ,m=1…M represents the event atom of the interference event dictionary, M is the number of atoms in the interference event dictionary, and the event atom is an empirical event, which is the type of interference that has occurred or is foreseeable;

[0115] Get the sparse representation of the interference accumulation signal:

[0116]

[0117] Among them, Θ is the interference event feature vector;

[0118] The solution is obtained, and the information of the interference event is obtained through the position and value of the non-zero elements in Θ, thus completing the interference identification.

[0119] In another embodiment, a computer storage medium stores a computer program, which, when executed, implements the above-mentioned method for synchronously identifying a signal source and interference based on an optical fiber sensing system.

[0120] The method for synchronously identifying a signal source and interference based on an optical fiber sensing system may adopt any of the above-mentioned methods for synchronously identifying a signal source and interference based on an optical fiber sensing system, and the specific implementation will not be described in detail here.

[0121] In another embodiment, Figure 2 As shown, a signal source and interference synchronization identification system based on an optical fiber sensing system comprises:

[0122] A dual pulse transmission module 10, which transmits a transmission pulse as an information pulse and a protection pulse for dual pulse transmission;

[0123] The source signal identification module 20 performs source phase shift demodulation measurement on the received pulse, accumulates L received pulses after source phase shift demodulation, performs joint sparse representation, and identifies the source signal according to the sparse vector obtained by solving;

[0124] The interference event identification module 30 performs interference signal accumulation measurement on the received pulses to obtain a sparse representation of the interference accumulation signal, and performs interference event identification according to the interference event feature vector.

[0125] Specifically, the working process of the information source and interference synchronization identification system based on the optical fiber sensing system is described as follows by taking a preferred embodiment as an example:

[0126] The present invention designs a dual-pulse emission scheme based on a protection pulse, and the specific pulse can be expressed as:

[0127]

[0128] Among them, s i is the i-th source signal pulse carrying communication information, ξ(·) is the phase shift operator defined in the present invention, which represents the operation of performing phase shift on the signal, is the phase offset of the i-th information pulse, Δφ i is the phase offset of the i-th protection pulse.

[0129] Since the detection of channel information is not considered in the present invention, the pulse delay information is not considered at the receiving end, so the information pulse and protection pulse described in formula (1) are the results of receiving synchronization and do not contain delay information. In the case of adding delay parameters, the method of the present invention is still applicable.

[0130] Let the total number of optical pulses be L, then the phase offset of the information pulse and the phase offset of the protection pulse satisfy the following definition:

[0131]

[0132] If the phase shift operator is defined as Then the transmitting pulse and the protection pulse can be expressed as:

[0133]

[0134] Based on the above dual-pulse transmission scheme, when there is an interference event in the optical fiber channel, the i-th optical pulse received by the receiving end is:

[0135] r i =p i+q i +j i (4)

[0136] where j i is the interference signal term in the i-th received pulse.

[0137] With respect to the above-mentioned receiving signal structure, the present invention adopts Figure 3 The processing flow shown.

[0138] The following is the specific signal processing process of the two signal processing branches:

[0139] The purpose of the signal processing branch A is to suppress the interference signal in the received signal, improve the received signal interference ratio, and thus improve the accuracy of information transmission and source identification. In the present invention, L received pulses are composed of a received pulse matrix:

[0140] R=[r1,r2,…,r L ] (5)

[0141] Then, a source phase shift demodulation measurement matrix Φ is designed I :

[0142]

[0143] Then the pulse matrix after the source phase shift demodulation measurement is:

[0144] Y=Φ I R(7)

[0145] The i-th pulse is:

[0146]

[0147] Then, the columns of the Y matrix are superimposed, which is equivalent to accumulating the received pulses after phase shift demodulation of L signal sources. The accumulated signal is:

[0148]

[0149] According to the information pulse phase offset According to the definition of , the phase of the interference term in the above formula will be anisotropic, so:

[0150]

[0151] Therefore, formula (9) can be further rewritten as:

[0152]

[0153] While the interference energy is suppressed, the source signal pulse s iAll are superimposed in phase, thereby obtaining the coherent accumulation of L pulses, so the signal-to-interference ratio of the received signal has been improved by nearly L times.

[0154] Then, for information source identification, the present invention first constructs an information source dictionary, which is essentially an overcomplete set of possible signals sent by the sender, and is generally provided by the sender. Let the information source dictionary be:

[0155] Ψ=[ζ1,ζ1e -jπt ζ2,ζ2e -jπt …,ζ Q ,ζ Q e -jπt ] (12)

[0156] where ζ i , i=1,…Q is the atom of the source dictionary, and Q is the number of atoms in the dictionary. Thus, the following sparse representation model can be obtained:

[0157]

[0158] The sparse vector θ has a structured sparse characteristic, and the non-zero elements therein appear in groups, showing a block sparse feature. The existing optimization solution algorithm for the above sparse representation model with block sparse features is relatively mature, and the present invention can solve formula (13) by using the existing technology.

[0159] After the sparse vector θ is obtained, the source signal can be identified according to the position and value of the non-zero elements in θ.

[0160] With the protection pulse adopted by the present invention, the non-zero elements in the sparse vector θ appear in pairs, which improves the sparse domain energy of the source signal from the perspective of signal sparse representation. Therefore, the solution of the present invention obtains a signal-to-interference ratio close to 2L times in the signal processing branch A, further suppresses the interference signal, and improves the recognition accuracy of the source signal.

[0161] For the signal processing branch B, in order to identify the interference signal, the columns of the received pulse matrix R are superimposed to accumulate interference. The signal after interference accumulation is:

[0162]

[0163] According to the information pulse phase offset According to the definition of , the phases of the information pulse term and the protection pulse term in the above formula are anisotropic, so:

[0164]

[0165] Therefore, formula (14) can be further rewritten as:

[0166]

[0167] It can be seen that after the above interference accumulation process, the energy of the interference signal is coherently accumulated, which will improve the accuracy of subsequent interference identification.

[0168] Then, create a dictionary of interference events:

[0169]

[0170] Among them, ρ m , m = 1…M represents the event atom of the interference event dictionary, and M is the number of atoms in the interference event dictionary. Generally, event atoms are empirical events, usually the types of interference that have occurred or are foreseeable. Then the sparse representation of the interference accumulation signal can be obtained:

[0171]

[0172] Where Θ is the interference event feature vector. Θ is obtained by solving the above formula, and the information of the interference event can be obtained through the position and value of the non-zero elements in Θ to complete the interference identification.

[0173] Through the processing of the above two signal processing branches, the present invention simultaneously completes the transmission identification of the information source signal and the identification of the interference event, and realizes the simultaneous improvement of the identification accuracy of the information source signal and the interference event.

[0174] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principles of the present invention shall be equivalent replacement modes and shall be included in the protection scope of the present invention.

Claims

1. A method for synchronously identifying a signal source and interference based on an optical fiber sensing system, characterized in that: The following steps are involved: S01: The transmission pulse is represented as an information pulse and a protection pulse for double pulse transmission; the information pulse and the protection pulse: Among them, s i is the i-th source signal pulse carrying communication information, ξ(·) is the phase shift operator, which indicates the operation of phase shifting the signal. is the phase offset of the i-th information pulse, is the phase offset of the i-th protection pulse; S02: performing source phase shift demodulation measurement on the pulses received by the receiving end, accumulating L received pulses after source phase shift demodulation, performing joint sparse representation on the accumulated signals, and identifying the source signal according to the sparse vector obtained by solving; S03: Perform interference signal accumulation measurement on the received pulse to obtain a sparse representation of the interference accumulation signal and perform interference event identification.

2. The method for synchronously identifying a signal source and interference based on an optical fiber sensing system according to claim 1, characterized in that: In step S02, the measurement matrix Φ is demodulated by the source phase shift. I The received pulse is demodulated to measure the source phase shift. The source phase shift demodulation measurement matrix Φ I : in, 3. The method for synchronously identifying a signal source and interference based on an optical fiber sensing system according to claim 2, characterized in that: The method for accumulating the received pulses after phase shift demodulation of L information sources in step S02 includes: The L received pulses are combined into a received pulse matrix: R＝[r1,r2,…,r L ] The receiving pulse r i =p i +q i +j i , j i is the interference signal term in the i-th received pulse; The pulse matrix after source phase shift demodulation measurement is: Y=Φ I R Among them, the i-th pulse is: Then, the columns of the Y matrix are superimposed, which is equivalent to accumulating the received pulses after phase shift demodulation of L signal sources. The accumulated signal is: According to the information pulse phase offset The definition of , the phase of the interference term in the above formula will be anisotropic, and we have: The accumulated signal is further rewritten as: The coherent accumulation of L pulses is obtained.

4. The method for synchronously identifying a signal source and interference based on an optical fiber sensing system according to claim 1, characterized in that: The method for identifying the source signal in step S02 includes: First, construct the source dictionary, which is: Ψ=[ζ1,ζ1e -jπt z2, z2e -jπt …,g Q ,g Q e -jπt ] Among them, i ,i=1,…Q is the atom of the source dictionary, Q is the number of atoms in the dictionary; Obtain a sparse representation model of the accumulated signal: Among them, θ is a sparse vector, and the sparse vector θ has a structured sparse characteristic, in which the non-zero elements appear in groups, showing a block sparse feature; The sparse vector θ is obtained by solving the problem, and the source signal is identified according to the position and value of the non-zero elements in θ.

5. The method for synchronously identifying a signal source and interference based on an optical fiber sensing system according to claim 1, characterized in that: The method for accumulating and measuring interference signals in step S03 includes: The interference accumulation is performed on each column of the received pulse matrix R. The signal after interference accumulation is: Among them, j i is the interference signal term in the i-th received pulse; According to the information pulse phase offset According to the definition of , the phases of the information pulse term and the protection pulse term are anisotropic, and we have: The signal after interference accumulation is further rewritten as:

6. The method for synchronously identifying a signal source and interference based on an optical fiber sensing system according to claim 1, characterized in that: The method for identifying interference events in step S03 includes: Create a dictionary of interference events: P J =[ρ1,ρ2,…,ρ M ] Among them, ρ m ,m=1…M represents the event atom of the interference event dictionary, M is the number of atoms in the interference event dictionary, and the event atom is an empirical event, which is the type of interference that has occurred or is foreseeable; Get the sparse representation of the interference accumulation signal: Among them, Θ is the interference event feature vector; The solution is obtained, and the information of the interference event is obtained through the position and value of the non-zero elements in Θ, thus completing the interference identification.

7. A signal source and interference synchronization identification system based on an optical fiber sensing system, characterized in that: include: A dual pulse transmission module represents the transmission pulse as an information pulse and a protection pulse for dual pulse transmission; The information pulse and the protection pulse: Among them, s i is the i-th source signal pulse carrying communication information, ξ(·) is the phase shift operator, which indicates the operation of phase shifting the signal. is the phase offset of the i-th information pulse, is the phase offset of the i-th protection pulse; The source signal identification module performs source phase shift demodulation measurement on the received pulse, accumulates L received pulses after source phase shift demodulation, performs joint sparse representation, and identifies the source signal based on the sparse vector obtained by solving; The interference event identification module performs interference signal accumulation measurement on the received pulses to obtain a sparse representation of the interference accumulation signal, and performs interference event identification based on the interference event feature vector.

8. A computer storage medium having a computer program stored thereon, characterized in that: When the computer program is executed, the method for synchronously identifying a signal source and interference based on an optical fiber sensing system according to any one of claims 1 to 6 is implemented.

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