Non-coherent encoding and decoding method for a pointer type spatial position distribution

Abstract

The application discloses a non-coherent coding and decoding method for a pointer type space position distribution, and relates to the technical field of optical communication. The method comprises the following steps: determining a plurality of groups of binary sequences of information to be transmitted; determining target pointer values corresponding to the groups of binary sequences respectively according to a mapping relationship between the pointer values and the binary sequences; determining a composite light field corresponding to each target pointer value; emitting each composite light field to a receiving end in a fixed transmission sequence; collecting a plurality of light intensity distribution images; identifying a central spot formed by a vortex light beam and a shifted spot formed by a spatially shifted light beam in each light intensity distribution image; determining a decoding pointer value of each light intensity distribution image based on a preset reference direction and the central spot and the shifted spot of each light intensity distribution image; and converting each decoding pointer value according to the mapping relationship to obtain a decoding binary sequence in a fixed receiving sequence. The application can effectively improve the decoding accuracy.

Description

Technical Field

[0001] This application relates to the field of optical communication technology, and in particular to an incoherent encoding and decoding method for pointer-based spatial location distribution. Background Technology

[0002] Wireless optical communication has seen rapid development and application in recent years due to its abundant available spectrum resources, lack of frequency licensing, ease of deployment, and high transmission rates. However, current traditional methods of information encoding and decoding based on frequency, phase, time, and polarization resources have reached their limits, and further improvements in communication speed and capacity have encountered bottlenecks. Spatial resources, as a dimension resource that has not yet been fully developed, have become an important approach to solving the communication capacity crisis.

[0003] Vortex beams have orthogonal characteristics due to the orbital angular momentum (OAM) they carry, and theoretically, the orbital angular momentum can take on an infinite number of modes. Combining vortex beams with different OAM values ​​into a single optical path can achieve multiplexing and transmission of information.

[0004] However, existing communication systems based on OAM multiplexing generally rely on coherent detection technology to distinguish different OAM modes at the receiver. But coherent detection has stringent requirements for optical path collimation and transmission environment stability, resulting in low decoding accuracy and making it difficult to promote and apply on a large scale in practical engineering. Summary of the Invention

[0005] The purpose of this application is to provide an incoherent encoding and decoding method with pointer-based spatial location distribution, which can improve decoding accuracy.

[0006] To achieve the above objectives, this application provides an incoherent encoding and decoding method for pointer-based spatial location distribution, comprising: Determine multiple sets of binary sequences of information to be sent; wherein, the multiple sets of binary sequences have a fixed sending order; Based on the preset mapping relationship between spatial location distribution pointer values ​​and binary sequences, determine the target pointer values ​​corresponding to each group of binary sequences; A composite optical field with pointer-like spatial position distribution characteristics corresponding to each target pointer value is determined; wherein, the composite optical field is obtained by incoherent superposition of a spatially shifted beam and a vortex beam, and the target position of the spatially shifted beam is determined by the target pointer value; According to the fixed transmission order, each composite optical field is transmitted to the receiving end in sequence; Multiple light intensity distribution images corresponding to the composite light field are acquired by the receiving end; wherein the multiple light intensity distribution images have a fixed receiving order; Identify the central spot formed by the vortex beam and the offset spot formed by the spatially shifted beam in each light intensity distribution image; Based on the preset reference direction and the center spot and offset spot of each light intensity distribution image, the decoding pointer value of each light intensity distribution image is determined; According to the fixed receiving order, the values ​​of each decoding pointer are converted according to the mapping relationship to obtain the decoded binary sequence.

[0007] Optionally, determining the multiple sets of binary sequences of information to be sent specifically includes: Determine the UTF-16 binary sequence of the information to be sent; The UTF-16 binary sequence is divided into multiple sets of binary sequences according to a preset length; wherein the length of each set of binary sequences is the preset length.

[0008] Optionally, the UTF-16 binary sequence is a 16-bit binary number, the binary sequence is a 4-bit binary number, and the preset length is 4.

[0009] Optionally, determining a composite light field with pointer-like spatial position distribution characteristics corresponding to a target pointer value specifically includes: Based on the target pointer value, determine the discrete position number of the spatial displacement beam on the preset annular trajectory; wherein, the center of the annular trajectory is the center of the vortex beam; The target position of the spatial displacement beam on the circular trajectory is determined according to the discrete position number; The spatially displaced beam located at the target position and the vortex beam located at the center of the circular trajectory are incoherently superimposed to generate a composite light field with pointer-like spatial position distribution characteristics.

[0010] Optionally, after identifying the central spot formed by the vortex beam and the offset spot formed by the spatially shifted beam in each intensity distribution image, the method further includes: Obtain a preset transparent decoding dial; wherein, the transparent decoding dial is marked with multiple scale marks, and the scale marks are distributed at preset angular intervals on a circle with the center of the dial as the center; The transparent decoding dial is overlaid on each light intensity distribution image, and the center of the dial is aligned with the center light spot in the light intensity distribution image. The offset light spot in each light intensity distribution image is identified by the scale mark pointed to by the transparent decoding dial as the decoding pointer value. Then, according to the fixed receiving order and the mapping relationship, the decoding pointer values ​​are converted to obtain the decoded binary sequence.

[0011] Optionally, the marking method of the scale marks on the transparent decoding dial is as follows: The starting mark is the position directly above the center of the dial; The scale markings are sequentially increased clockwise according to the preset angular intervals until the number of scale markings on the transparent decoding dial is the same as the number of discrete positions contained in the circular trajectory.

[0012] Optionally, based on a preset reference direction and the center and offset spots of a target light intensity distribution image, the decoding pointer value of the target light intensity distribution image is determined, specifically including: A Cartesian coordinate system is established with the center spot of the target light intensity distribution image as the origin, based on a preset reference direction; wherein the positive direction of the x-axis of the Cartesian coordinate system is the preset reference direction. Obtain the line connecting the central light spot and the offset light spot; Determine the current angle between the connecting line and the positive direction of the x-axis of the Cartesian coordinate system; The decoding pointer value of the target light intensity distribution image is determined based on the current angle.

[0013] Optionally, the formula for calculating the decoding pointer value of the target light intensity distribution image is: ; Where j represents the decoding pointer value of the target light intensity distribution image. This indicates the current angle.

[0014] Optionally, the step of converting the values ​​of each decoding pointer according to the fixed receiving order and the mapping relationship to obtain the decoded binary sequence specifically includes: Based on the preset mapping relationship between spatial location distribution pointer values ​​and binary sequences, determine the decoded binary subsequence corresponding to each decoding pointer value; Multiple sets of decoded binary subsequences are concatenated according to the fixed receiving order to obtain the decoded binary sequence.

[0015] Optionally, after obtaining the decoded binary sequence, the method further includes: The decoded binary sequence is decoded to obtain the decoded information corresponding to the decoded binary sequence.

[0016] According to the specific embodiments provided in this application, the following technical effects are disclosed: This application provides a pointer-based incoherent encoding and decoding method for spatially distributed signals. It utilizes the central spot formed by a vortex beam as a positioning reference and relies on the spatial orientation of the offset spot to achieve signal demodulation. This eliminates the need to detect beam phase, avoiding the channel interference problem inherent in traditional methods that rely on coherent detection for phase identification. By establishing a unified orientation reference using the central spot, the orientation of the offset spot can be stably determined, reducing judgment errors caused by optical path jitter and beam transmission offset. Combined with a pre-defined mapping relationship, encoding and decoding are completed in an orderly manner, reducing misjudgments and effectively improving decoding accuracy. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A flowchart illustrating an incoherent encoding and decoding method for pointer-based spatial location distribution provided in one embodiment of this application; Figure 2 A Gaussian bright spot pointer-type spatial location distribution area planning map is provided as an embodiment of this application; Figure 3 A topological load provided in one embodiment of this application Two-dimensional phase distribution diagram of the vortex beam; Figure 4 A topological load provided in one embodiment of this application The intensity distribution of the vortex beam and the intensity distribution of the Gaussian beam; Figure 5 A phase hologram corresponding to the distribution of a Gaussian beam relative to a vortex beam at different positions is provided in one embodiment of this application; Figure 6 This application provides an embodiment of light intensity distribution at different pointer-type spatial locations and its corresponding binary encoding sequence; Figure 7 An angle provided for an embodiment of this application Diagram of the included angle; Figure 8 This application provides a schematic diagram of decoding based on captured light intensity according to an embodiment of the present application; Figure 9 A transparent decoding dial is provided for a decoding process design in one embodiment of this application. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. 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.

[0020] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] In one exemplary embodiment, such as Figure 1 As shown, a pointer-based spatial location distribution incoherent encoding and decoding method is provided. This method is executed by a computer device, specifically by a terminal or server alone, or by both a terminal and a server. In this embodiment, it includes the following steps 101 to 108. Wherein: Step 101: Determine multiple sets of binary sequences of information to be sent.

[0022] In this embodiment, multiple sets of binary sequences have a fixed transmission order. The information to be transmitted can be a string, and each symbol contained in the string is converted into a corresponding UTF-16 binary sequence, resulting in a binary sequence of "01" combinations.

[0023] As an optional implementation, step 101, determining the multiple sets of binary sequences of information to be sent, may include: Determine the UTF-16 binary sequence of the information to be sent; The UTF-16 binary sequence is divided into multiple sets of binary sequences according to a preset length; wherein the length of each set of binary sequences is the preset length.

[0024] In this implementation method, the information to be transmitted is processed using a UTF-16 binary sequence and encoded in segments of a fixed preset length. UTF-16 encoding is compatible with various types of text and symbol information, making it more widely applicable. The uniform length grouping rule simplifies the optical field matching logic at the transmitting end, and also facilitates the receiving end to reassemble and splice the decoded binary sequence according to the same rules. This standardizes the data interaction format between the encoding and decoding ends, reduces the probability of data splicing errors, and ensures complete information restoration.

[0025] In this embodiment of the application, the UTF-16 binary sequence is a 16-bit binary number, the binary sequence is a 4-bit binary number, and the preset length is 4.

[0026] For example, transmitting the string "Bo" " as an example, the symbols "博", "B", "o", " " correspond to UTF-16 binary sequences sequentially being "0101001101011010", "0000000001000010", "0000000001101111", "0010011101100101".

[0027] Then, the UTF-16 binary sequences are divided into groups of 4 bits in left-to-right order, and the obtained multiple groups of binary sequences are {0101}, {0011}, {0101}, {1010}, {0000}, {0000}, {0100}, {0010}, {0000}, {0000}, {0110}, {1111}, {0010}, {0111}, {0110}, {0101}.

[0028] In step 102, target pointer values respectively corresponding to each group of binary sequences are determined according to a preset mapping relationship between spatial position distribution pointer values and binary sequences.

[0029] In the embodiment of the present application, the preset mapping relationship between spatial position distribution pointer values and binary sequences may be a comparison table of spatial position distribution pointer values and binary sequences, as shown in Table 1 below: Table 1 Comparison Table of Spatial Position Distribution Pointer Values and Binary Sequences

[0030] Wherein, j represents the spatial position distribution pointer value (i.e., the target pointer value).

[0031] Through the comparison table of spatial position distribution pointer values and binary sequences formulated in Table 1, all the multiple groups of 4-bit binary sequences are finally mapped into target pointer values: {j=6, j=4, j=6, j=11}, {j=1, j=1, j=5, j=3}, {j=1, j=1, j=7, j=16}, {j=3, j=8, j=7, j=6}. The correspondence table of to-be-sent information, UTF-16 binary sequences and target pointer values is shown in Table 2, and all the original string information to be transmitted is converted into corresponding target pointer values.

[0032] Table 2 Correspondence Table of To-be-Sent Information, UTF-16 Binary Sequences and Target Pointer Values

[0033] In step 103, composite light fields with pointer-type spatial position distribution features corresponding to each target pointer value are determined.

[0034] In this embodiment of the application, the composite light field is obtained by the incoherent superposition of a spatially shifted beam and a vortex beam, and the target position of the spatially shifted beam is determined by the target pointer value.

[0035] In this embodiment of the application, different target pointer values ​​correspond to composite light fields corresponding to different spatial light intensity distributions. Therefore, the information is ultimately mapped to different composite light fields, thereby completing the information encoding.

[0036] As an optional implementation, the method for determining a composite light field with pointer-like spatial position distribution characteristics corresponding to a target pointer value may include: Based on the target pointer value, determine the discrete position number of the spatial displacement beam on the preset annular trajectory; wherein, the center of the annular trajectory is the center of the vortex beam; The target position of the spatial displacement beam on the circular trajectory is determined according to the discrete position number; The spatially displaced beam located at the target position and the vortex beam located at the center of the circular trajectory are incoherently superimposed to generate a composite light field with pointer-like spatial position distribution characteristics.

[0037] In this implementation, the spatially shifted beam is constrained to a circular trajectory centered on the vortex beam, and multiple discrete positions are defined to correspond to different pointer values. The circular layout facilitates angle calculations at the receiver using the central vortex spot as a reference, ensuring clear position differentiation logic. The distributed coded positions along the circumference, with natural spatial intervals between the shifted spots, effectively prevents confusion between different signal spots, allowing the receiver to accurately distinguish spot positions, reducing position identification errors, and further ensuring the stability and reliability of the encoding and decoding process.

[0038] In this embodiment, information is encoded and decoded according to the spatial distribution of the light field, avoiding complex optical coherence detection and effectively realizing the encoding, decoding, and transmission of information.

[0039] The invention of the incoherent encoding and decoding method based on pointer-based spatial location distribution is as follows: Known in At the source plane, the light field expression of the vortex beam carrying orbital angular momentum can be described as follows: (1) in, Representing the polar radius and polar angle in polar coordinates, compared to Cartesian coordinates. The relationship between them is , ; Indicates the distance the light beam travels. Let be the beam waist radius. The topological charge of the vortex beam, also known as the orbital angular momentum mode number, is... At that time, the vortex beam degenerates into a normal fundamental Gaussian beam. " is the absolute value operator, " is a plural unit.

[0040] The vortex beam is distributed in a ring shape in space (e.g.) Figure 2 As shown), let the x and y coordinates of the center position of the redistributed vortex beam be... The distance between the redistributed beam center and the original center is denoted as . The angle between the two centers and the positive direction of the horizontal axis is The new beam center position for: (2) The expression for the vortex beam after position transformation is: (3) In the formula, The polar coordinates represent the beam after spatial displacement.

[0041] like Figure 2 As shown, without loss of generality, the original beam position is used as the center. Draw a ring with radius , and divide the ring into sixteen equal parts. Starting from the positive vertical axis, mark the sixteen divisions clockwise with numbers denoted as "1", "2", ..., j, ..., "16". Then, the mathematical expression for the light field on any ring of the beam is: (4) In the formula, This represents the polar coordinates of the beam at position j after spatial displacement.

[0042] Taking the center of the original beam as the origin, the horizontal direction to the right of the origin as the positive direction of the transverse axis, and using this direction as a reference, an angle is defined based on this. The sign of the angle is defined as "+" for counterclockwise rotation from the reference datum and "+" for clockwise rotation. ", rotate to the direction of the line connecting the center of the light spot at position j and the center of the original beam, and specify..." The positive angle reading value does not exceed If the reading exceeds this value, it is read in the direction of the negative value. The angle in the Cartesian coordinate system is then... for: (5) Will Substituting into formula (5), we can obtain The interval between two adjacent angle values ​​is .

[0043] By combining formulas (2) and (5), the coordinates of the light spot center at position j can be obtained. for: (6) This invention sets the topological charge of the vortex beam on the annulus. Topological load at the original center location By superimposing the vortex beam on the ring with the original vortex beam at the center, the superimposed light field distribution can be obtained: (7) In the formula, It is a constant, taking values ​​between 0 and 1. When, it indicates that there is only a vortex beam whose original position has not been shifted. When, it represents the synthesis of the initial position and the shifted beam.

[0044] Phase distribution function corresponding to superimposed light fields We can obtain: (8) Figure 3 Showing when That is, without shifting, the topological load The original two-dimensional phase distribution diagram of the vortex beam. Figure 4 When , ( Figure 4 (a) and ( Figure 4 (b) Two-dimensional distribution diagram of beam intensity. Figure 4 (c) is when , , , The image shows the light intensity distribution. It illustrates different light intensity distribution patterns and the light intensity distribution at different locations.

[0045] To obtain the pointer-style spatial position distribution light field, the parameters are... , , Substitute into formula (8), and then sequentially... , , ..., Substituting into the formula, the phase holograms corresponding to the distribution of the Gaussian beam relative to the vortex beam at different positions are calculated, as follows: Figure 5 As shown. Comparison Figure 3 and Figure 5It can be seen that, compared with the phase hologram of a single vortex beam, the phase hologram obtained by superimposing the phase of a shifted Gaussian beam shows a circular region with a phase value of zero on the single vortex phase hologram. Figure 5 (As shown by the white dashed line in the middle).

[0046] When a Gaussian beam shines Figure 5 After generating the phase holograms, the corresponding diffraction spots are obtained through optical field diffraction, such as... Figure 6 As shown. Figure 6 Display pointer value Two-dimensional light intensity distribution of the superimposed light field for different numerical values. Comparison. Figure 2 and Figure 6 It can be seen that different positions correspond to different pointer values. Therefore, information can be encoded according to different spot shapes. Specifically, the corresponding pointer value is first subtracted by 1 and then converted into a 4-bit binary value. For example, when the pointer value is... When, the corresponding 4-bit binary number is "0000", when When the time is specified, the corresponding 4-bit binary number is "1011", as shown in Table 1.

[0047] Step 104: According to the fixed transmission order, each composite optical field is transmitted to the receiving end in sequence.

[0048] Step 105: Acquire multiple light intensity distribution images corresponding to the composite light field received by the receiving end.

[0049] In this embodiment of the application, at the receiving end of the communication system, multiple different pointer-type light intensity distribution images corresponding to the composite light field can be received, and the multiple light intensity distribution images have a fixed receiving order.

[0050] Step 106: Identify the central spot formed by the vortex beam and the offset spot formed by the spatially shifted beam in each light intensity distribution image.

[0051] In the received light intensity map, a rectangular coordinate system is established with the center of the vortex beam spot as the origin of the plane coordinate system, such as... Figure 6 As shown, then the center of the vortex beam spot... Center of spatially displaced beam Connect and read Connect the lines to the established Cartesian coordinate system. The angle between the right angles along the positive direction of the axis is denoted as... According to the settings Read the rules, and finally according to Solve for the corresponding pointer value .

[0052] As an optional implementation, after step 106, the following steps may also be performed: Obtain a preset transparent decoding dial; wherein, the transparent decoding dial is marked with multiple scale marks, and the scale marks are distributed at preset angular intervals on a circle with the center of the dial as the center; The transparent decoding dial is overlaid on each light intensity distribution image, and the center of the dial is aligned with the center light spot in the light intensity distribution image. The offset light spot in each light intensity distribution image is identified by the scale mark pointed to by the transparent decoding dial as the decoding pointer value. Then, according to the fixed receiving order and the mapping relationship, the decoding pointer values ​​are converted to obtain the decoded binary sequence.

[0053] This implementation method uses a transparent decoding dial with circular scale markings for signal demodulation. Simply aligning the center of the dial with the center spot in the image allows direct reading of the decoding pointer value by observing the scale indicated by the offset spot. This eliminates the need for complex coordinate calculations and angle determination, simplifying data processing at the receiving end. It supports both automatic recognition via image processing equipment and manual visual interpretation, broadening the demodulation implementation options and reducing the system's hardware and algorithm computation requirements.

[0054] Optionally, the marking method for the scale on the transparent decoder dial is as follows: The starting mark is the position directly above the center of the dial; The scale markings are sequentially increased clockwise according to the preset angular intervals until the number of scale markings on the transparent decoding dial is the same as the number of discrete positions contained in the circular trajectory.

[0055] This implementation standardizes the scale arrangement of the transparent decoding dial, setting a fixed starting position and numbering it sequentially clockwise, ensuring a one-to-one correspondence between the dial scale numbers and discrete positions on the transmitter's circular trajectory. The transmitting and receiving ends use a consistent angle reference and numbering order, eliminating recognition errors caused by inconsistent reference directions, reducing the risk of sequence number mismatches during decoding, eliminating the need for additional angle correction, and improving the convenience and consistency of the dial-matching decoding method.

[0056] For example, in addition to reading The present invention further designs a simpler decoding scheme based on the angle calculation pointer value method. For example... Figure 9 As shown, first draw a transparent dial. The dial scale starts from the top center of the dial and is marked as the scale value "1". The scale is then divided into angular intervals. The scale values ​​are incremented sequentially in a clockwise direction: "2", ..., "16". After capturing the coded light spot, a Cartesian coordinate system is established with the vortex beam spot in each captured intensity map as the center. Set the origin of the coordinate system Center of Gaussian spot after spatial displacement distribution Connect the dial, then cover the light spot with the transparent dial, aligning the center of the dial with the center of the vortex beam in the light spot. Observe directly at this point. By connecting the pointer to the dial scale value, the pointer value can be directly obtained. Then, by finding the mapping relationship between the pointer value and the binary sequence, the original information can be restored, thus achieving decoding.

[0057] Step 107: Based on the preset reference direction and the center spot and offset spot of each light intensity distribution image, determine the decoding pointer value of each light intensity distribution image.

[0058] As an optional implementation, the method for determining the decoding pointer value of the target light intensity distribution image based on a preset reference direction and the center and offset light spots of a target light intensity distribution image may include: A Cartesian coordinate system is established with the center spot of the target light intensity distribution image as the origin, based on a preset reference direction; wherein the positive direction of the x-axis of the Cartesian coordinate system is the preset reference direction. Obtain the line connecting the central light spot and the offset light spot; Determine the current angle between the connecting line and the positive direction of the x-axis of the Cartesian coordinate system; The decoding pointer value of the target light intensity distribution image is determined based on the current angle.

[0059] In this implementation method, a unified coordinate system is established with the central light spot as the origin and a preset reference direction as the positive x-axis. The decoded pointer value is obtained by solving the angle between the line connecting the central light spot and the offset light spot. The standardized coordinate construction rules make the angle calculation logic regular and unified, which facilitates automated decoding through program calculations and reduces manual intervention. Relying on quantified angles to complete position determination has higher resolution accuracy compared to visual dial recognition, weakens the error caused by subjective interpretation, and helps to stably obtain accurate pointer values.

[0060] In this embodiment of the application, the formula for calculating the decoding pointer value of the target light intensity distribution image is as follows: (9) Where j represents the decoding pointer value of the target light intensity distribution image. This indicates the current angle.

[0061] Step 108: Convert each decoding pointer value according to the mapping relationship in the fixed receiving order to obtain a decoded binary sequence.

[0062] As an optional implementation, the manner of step 108 for converting each decoding pointer value according to the mapping relationship in the fixed receiving order to obtain a decoded binary sequence may include: Determine the decoded binary subsequence corresponding to each decoding pointer value according to the preset mapping relationship between the spatial position distribution pointer values and the binary sequences; Splice the multiple groups of decoded binary subsequences in the fixed receiving order to obtain a decoded binary sequence.

[0063] As an optional implementation, after the decoded binary sequence is obtained, the following step may be further performed: decoding the decoded binary sequence to obtain the decoded information corresponding to the decoded binary sequence.

[0064] For example, as shown in Figure 8 the first row, which is the light intensity pattern obtained by encoding the first symbol "Bo" of the character string "Bo", this pattern is taken as an example to explain how to perform decoding. A plane rectangular coordinate system is established with the vortex beam spot in each captured light intensity pattern as the center , the coordinate origin is connected to the center of the spatially shifted Gaussian spot , and the included angle between the connecting line and the positive direction of the axis is marked . According to formula (9), if the angle magnitude of can be read, the pointer value corresponding to the spatial position can be solved. From the spot distribution pattern in the figure, values can be read sequentially from left to right as , , , , so the corresponding pointer values can be calculated as , , , . Then according to the correspondence between the spatial position distribution pointer values and the binary sequences, the binary sequences corresponding to each pointer value can be obtained sequentially as {0101}, {0011}, {0101}, {1010}, which are combined into a 16-bit binary sequence "0101001101011010", so that the corresponding original symbol information can be recovered as "Bo", thus realizing information decoding. Similarly, the symbols "B", "o", " ​The decoding result of "" will not be repeated here.

[0065] By implementing steps 101 to 108 above, the central spot formed by the vortex beam is used as a positioning reference. Signal demodulation is achieved by relying on the spatial orientation of the offset spot, eliminating the need to detect the beam phase. This avoids the problem of channel interference that traditional schemes rely on coherent detection to identify the phase. Establishing a unified orientation reference using the central spot can stably determine the orientation of the offset spot, reducing judgment errors caused by optical path jitter and beam transmission offset. Combined with a preset mapping relationship, encoding and decoding are completed in an orderly manner, reducing misjudgments and effectively improving decoding accuracy.

[0066] This invention designs an incoherent encoding and decoding method based on spatial location distribution. It realizes the encoding and decoding of information through spatial location. The encoding and decoding scheme is simple and effective, and can effectively meet the stringent requirements of optical path collimation in coherent detection methods. The spatially shifted optical field provided in this invention is set as a Gaussian spot with zero topological charge. In fact, the topological charge of the optical field after the original position and spatial shift can take multiple modes, and the values ​​of each mode can be set and adjusted individually, which can effectively expand communication coding resources. This invention proposes a spatially distributed incoherent encoding and decoding method that can effectively utilize spatial dimension resources and is compatible with time, frequency / wavelength, polarization state, and other dimension resources. It can perform information encoding and decoding through multi-dimensional fusion and has broad application prospects for further expanding communication capacity.

[0067] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0068] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A noncoherent encoding and decoding method for pointer-based spatial location distribution, characterized in that, The method includes: Determine multiple sets of binary sequences of information to be sent; wherein, the multiple sets of binary sequences have a fixed sending order; Based on the preset mapping relationship between spatial location distribution pointer values ​​and binary sequences, determine the target pointer values ​​corresponding to each group of binary sequences; A composite optical field with pointer-like spatial position distribution characteristics corresponding to each target pointer value is determined; wherein, the composite optical field is obtained by incoherent superposition of a spatially shifted beam and a vortex beam, and the target position of the spatially shifted beam is determined by the target pointer value; According to the fixed transmission order, each composite optical field is transmitted to the receiving end in sequence; Multiple light intensity distribution images corresponding to the composite light field are acquired by the receiving end; wherein the multiple light intensity distribution images have a fixed receiving order; Identify the central spot formed by the vortex beam and the offset spot formed by the spatially shifted beam in each light intensity distribution image; Based on the preset reference direction and the center spot and offset spot of each light intensity distribution image, the decoding pointer value of each light intensity distribution image is determined; According to the fixed receiving order, the values ​​of each decoding pointer are converted according to the mapping relationship to obtain the decoded binary sequence.

2. The incoherent encoding and decoding method for pointer-based spatial location distribution according to claim 1, characterized in that, The determination of the multiple sets of binary sequences of information to be sent specifically includes: Determine the UTF-16 binary sequence of the information to be sent; The UTF-16 binary sequence is divided into multiple sets of binary sequences according to a preset length; wherein the length of each set of binary sequences is the preset length.

3. The incoherent encoding and decoding method for pointer-based spatial location distribution according to claim 2, characterized in that, The UTF-16 binary sequence is a 16-bit binary number, the binary sequence is a 4-bit binary number, and the preset length is 4.

4. The incoherent encoding and decoding method for pointer-based spatial location distribution according to claim 1, characterized in that, Determine the composite light field with pointer-like spatial position distribution characteristics corresponding to a target pointer value, specifically including: Based on the target pointer value, determine the discrete position number of the spatial displacement beam on the preset annular trajectory; wherein, the center of the annular trajectory is the center of the vortex beam; The target position of the spatial displacement beam on the circular trajectory is determined according to the discrete position number; The spatially displaced beam located at the target position and the vortex beam located at the center of the circular trajectory are incoherently superimposed to generate a composite light field with pointer-like spatial position distribution characteristics.

5. The incoherent encoding and decoding method for pointer-based spatial location distribution according to claim 4, characterized in that, After identifying the central spot formed by the vortex beam and the offset spot formed by the spatially shifted beam in each intensity distribution image, the method further includes: Obtain a preset transparent decoding dial; wherein, the transparent decoding dial is marked with multiple scale marks, and the scale marks are distributed at preset angular intervals on a circle with the center of the dial as the center; The transparent decoding dial is overlaid on each light intensity distribution image, and the center of the dial is aligned with the center light spot in the light intensity distribution image. The offset light spot in each light intensity distribution image is identified by the scale mark pointed to by the transparent decoding dial as the decoding pointer value. Then, according to the fixed receiving order and the mapping relationship, the decoding pointer values ​​are converted to obtain the decoded binary sequence.

6. The incoherent encoding and decoding method for pointer-based spatial location distribution according to claim 4, characterized in that, The marking method for the scale markings on the transparent decoding dial is as follows: The starting mark is the position directly above the center of the dial; The scale markings are sequentially increased clockwise according to the preset angular intervals until the number of scale markings on the transparent decoding dial is the same as the number of discrete positions contained in the circular trajectory.

7. The incoherent encoding and decoding method for pointer-based spatial location distribution according to claim 1, characterized in that, Based on a preset reference direction and the center and offset light spots of a target light intensity distribution image, the decoding pointer value of the target light intensity distribution image is determined, specifically including: A Cartesian coordinate system is established with the center spot of the target light intensity distribution image as the origin, based on a preset reference direction; wherein the positive direction of the x-axis of the Cartesian coordinate system is the preset reference direction. Obtain the line connecting the central light spot and the offset light spot; Determine the current angle between the connecting line and the positive direction of the x-axis of the Cartesian coordinate system; The decoding pointer value of the target light intensity distribution image is determined based on the current angle.

8. The incoherent encoding and decoding method for pointer-based spatial location distribution according to claim 7, characterized in that, The formula for calculating the decoding pointer value of the target light intensity distribution image is as follows: ； Where j represents the decoding pointer value of the target light intensity distribution image. This indicates the current angle.

9. The incoherent encoding and decoding method for pointer-based spatial location distribution according to claim 1, characterized in that, The step of converting the values ​​of each decoding pointer according to the fixed receiving order and the mapping relationship to obtain the decoded binary sequence specifically includes: Based on the preset mapping relationship between spatial location distribution pointer values ​​and binary sequences, determine the decoded binary subsequence corresponding to each decoding pointer value; Multiple sets of decoded binary subsequences are concatenated according to the fixed receiving order to obtain the decoded binary sequence.

10. The incoherent encoding and decoding method for pointer-based spatial location distribution according to claim 9, characterized in that, After obtaining the decoded binary sequence, the method further includes: The decoded binary sequence is decoded to obtain the decoded information corresponding to the decoded binary sequence.

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