Orbital angular momentum channel capacity improving method combining beam steering and partial receiving
By employing a combined beam steering and partial reception method in the OAM communication system, the problems of strong divergence of high OAM mode signals and limited receiving arrays were solved, thereby improving channel capacity and achieving effective reception of mode signals.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-15
- Publication Date
- 2026-03-24
AI Technical Summary
In OAM communication systems, high OAM mode signals have strong divergence, which means that the receiving array cannot receive all OAM beams in the case of misalignment, and the spatial size of the receiving array is limited and cannot be expanded. Existing technologies cannot effectively solve this problem.
A combined beam steering and partial reception method is adopted. The electric field intensity is represented by constructing a spherical coordinate system, the phase of the antenna array elements is adjusted, beam steering is performed in combination with the channel matrix model, and the matrix dimension mismatch is handled by zero-padding method to achieve signal demultiplexing and avoid expanding the radius of the receiving array.
Despite the misalignment of the transceiver arrays and the limited availability of the receiver array, the channel capacity of the orbital angular momentum communication system was improved, overcoming the spatial deployment limitations of the receiver array and effectively receiving signals of various modes.
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Figure CN121727604A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of orbital angular momentum wireless communication technology, specifically to a method for enhancing the capacity of orbital angular momentum channels by combining beam steering and partial reception. Background Technology
[0002] Orbital angular momentum (OAM) is an inherent physical quantity of electromagnetic waves and a new dimension of wireless transmission, representing one of the key potential technologies for 6G. Vortex electromagnetic waves carrying orbital angular momentum are a novel physical dimension and transmission carrier, distinct from traditional plane electromagnetic waves. They possess a large number of orthogonal OAM eigenstates, enabling high-quality, high-capacity information transmission with limited channel resources through entirely new information transmission methods, revolutionarily solving bottlenecks in 6G spectrum efficiency, transmission capacity, and anti-interference capabilities.
[0003] In OAM communication systems, OAM signal reception is a crucial component. However, because higher OAM mode values result in stronger divergence, the receiving array may fail to receive all OAM modes when the signal transmission distance is long or the transmitting and receiving antenna arrays are misaligned. To address this issue, the receiving UCA radius can typically be increased to meet the receiving radius requirements for all transmission modes. However, space constraints within the receiving array make this impractical in real-world communication environments. Summary of the Invention
[0004] To address the shortcomings of existing technologies, this invention proposes a method for enhancing the capacity of orbital angular momentum channels by combining beam steering and partial reception, in order to solve the aforementioned technical problems.
[0005] A method for enhancing the channel capacity of orbital angular momentum through combined beam steering and partial reception includes: Obtain the basic parameters of the transceiver array of the orbital angular momentum communication system; Based on the basic parameters of the transceiver array, beam steering processing is performed on the orbital angular momentum beam at the transmitting end to obtain the orbital angular momentum beam signal after steering. Partial reception processing is performed on the orbital angular momentum beam signal after the turn to complete the demultiplexing of the orbital angular momentum signal.
[0006] Furthermore, the step of performing beam steering processing on the orbital angular momentum beam at the transmitting end based on the basic parameters of the transceiver array to obtain the steered orbital angular momentum beam signal includes: A spherical coordinate system with a uniform circular array is constructed, and the electric field intensity at the target point within the spherical coordinate system is characterized to obtain the expression for the initial electric field intensity. The initial electric field strength expression is simplified to obtain the simplified electric field strength expression; The main lobe direction angle of the orbital angular momentum beam is determined based on the simplified electric field intensity expression, thus obtaining the target main lobe direction angle; The divergence angle of the orbital angular momentum beam is obtained by solving for the divergence angle of the target main lobe direction angle. The offset angle caused by the misalignment of the transceiver array is calculated by combining the spatial position parameters of the transceiver array, and the target offset angle is obtained. Based on the spatial orientation angle of the target receiving point and the divergence angle of the target, the phase of each antenna element of the transmitting uniform circular array is adjusted to obtain the adjusted phase; The electric field strength at the target receiving point is updated based on the adjusted phase to obtain the updated electric field strength. By combining the general channel matrix model of orbital angular momentum, the channel response between the transmitting and receiving antenna elements is calculated to obtain the target channel response; Beam steering is performed on the target channel response to obtain the orbital angular momentum beam signal after steering.
[0007] Furthermore, based on the spatial orientation angle of the target receiving point and the divergence angle of the target, the phase of each antenna element of the transmitting uniform circular array is adjusted to obtain the adjusted phase, including: The azimuth angle of the center of the transmitting array and the spatial azimuth angle of the target receiving point are calibrated to obtain the calibrated azimuth angle. Based on the target divergence angle, the phase shift that needs to be adjusted for each antenna element of the uniform circular array is calculated to obtain the target phase shift. The initial phase of each antenna element is adjusted according to the target phase shift to obtain the adjusted phase.
[0008] Furthermore, partial reception processing is performed on the orbital angular momentum beam signal after the turn, completing the demultiplexing of the orbital angular momentum signal. This includes: Obtain the conventional general orbital angular momentum channel matrix and the corresponding mode demultiplexing matrix, and identify the matrix dimension mismatch problem caused by the limited number of receiving antenna array elements; To address the matrix dimension mismatch problem, the zero-padding method is used to adjust the orbital angular momentum mode solution reuse vector, resulting in the adjusted solution reuse vector. Based on the adjusted demultiplexing vector and combined with the preset receiving antenna array element conditions, demultiplexing processing is performed on signals of different orbital angular momentum modes.
[0009] Furthermore, based on the adjusted demultiplexing vector and combined with preset receiving antenna element conditions, demultiplexing processing is performed on signals of different orbital angular momentum modes, including: Verify the ratio of the number of receiving antenna array elements to the original total number of receiving antenna array elements, and ensure that the preset ratio requirement of the number of receiving antenna array elements is not less than one-quarter of the original total is met. Verify the ratio of the number of continuous phase antenna elements in the receiving antenna to the total number of elements in the original receiving antenna array, and ensure that the ratio of continuous phase antenna elements is not less than one-quarter of the original total number of continuous elements. Provided that both ratio requirements are met, demultiplexing processing is performed on signals of different orbital angular momentum modes.
[0010] Furthermore, demultiplexing processing is performed on signals with odd orbital angular momentum modes, including: The first segment of the adjusted demultiplexed vector data is adjusted according to the first preset rule to obtain the first segment adjusted data; The second segment data of the adjusted demultiplexed vector is adjusted according to the second preset rule to obtain the second segment adjusted data; The third segment data of the adjusted demultiplexed vector is adjusted according to the third preset rule to obtain the third segment adjusted data; By integrating the first segment adjustment data, the second segment adjustment data, and the third segment adjustment data, the demultiplexed odd-mode orbital angular momentum signal is obtained.
[0011] Furthermore, demultiplexing processing is performed on signals with zero orbital angular momentum modes, including: The data at the corresponding positions of the adjusted demultiplexed vector are uniformly assigned values to obtain the uniformly assigned demultiplexed vector; Based on the unified assigned demultiplexed vector, the demultiplexed zero-mode orbital angular momentum signal is obtained. Furthermore, demultiplexing processing is performed on signals with non-zero even orbital angular momentum modes, including: The fourth segment data of the adjusted demultiplexed vector is adjusted according to the fourth preset rule to obtain the fourth segment adjusted data; The fifth segment data of the adjusted demultiplexed vector is adjusted according to the fifth preset rule to obtain the fifth segment adjusted data; By integrating the fourth segment adjustment data and the fifth segment adjustment data, the non-zero even-number mode orbital angular momentum signal is demultiplexed.
[0012] Furthermore, after demultiplexing the orbital angular momentum signal, the process also includes: Based on the orbital angular momentum off-axis communication model, the system channel parameters after beam steering and partial reception processing are collected to obtain the target channel parameters; The channel capacity of the communication system is calculated based on the target channel parameters to obtain the final channel capacity.
[0013] The invention employing the above technical solution has the following advantages: 1. This invention is applicable to orbital angular momentum wireless communication scenarios where the transceiver arrays are misaligned and the receiving array antenna is limited. It achieves an effective improvement in the channel capacity of the orbital angular momentum communication system through a technical solution of combined beam steering and partial reception.
[0014] 2. In the beam steering stage, this invention first constructs a spherical coordinate system for a uniform circular array and characterizes the electric field intensity at the target point. Under the condition that the amplitude excitation of the antenna elements is consistent and the number of elements is large, the expression for the electric field intensity is simplified. Then, the direction angle of the main lobe of the orbital angular momentum beam is determined based on the angle corresponding to the extreme value of the correlation function, and then the beam divergence angle is solved. At the same time, the array offset angle is calculated by combining the spatial position parameters of the transceiver array. Subsequently, the phase of each antenna element at the transmitting end is adjusted according to the direction angle of the target receiving point and the beam divergence angle, the electric field intensity at the target receiving point is updated, and the channel response between the transceiver antenna elements is calculated by combining the general channel matrix model. In this way, beam steering is completed, effectively compensating for the beam deviation problem caused by array offset.
[0015] 3. In some receiving stages, this invention addresses the mismatch between the dimensions of the demultiplexing matrix and the channel matrix caused by the limited number of receiving antenna elements. The method uses zero-padding to adjust the orbital angular momentum mode demultiplexing vector. Simultaneously, while meeting the requirements for the proportion of receiving antenna elements and continuous phase antenna elements, it completes signal demultiplexing according to the corresponding adjustment rules for different orbital angular momentum modes such as odd, zero, and non-zero even numbers. This allows for effective reception of signals of various modes without expanding the radius of the receiving array, thus overcoming the spatial deployment limitations of the receiving array. Attached Figure Description
[0016] To more clearly illustrate the specific embodiments of the present invention, the accompanying drawings used in the specific embodiments will be briefly described below. In all the drawings, the elements or parts are not necessarily drawn to scale.
[0017] Figure 1 This is a schematic diagram of UCA in spherical coordinates in the orbital angular momentum channel capacity enhancement method of combined beam steering and partial reception of the present invention. Figure 2 This is a diagram of the OAM communication model in the traditional off-axis scenario in the orbital angular momentum channel capacity enhancement method of the present invention, which combines beam steering and partial reception. Figure 3 The flowchart of the method for improving the channel capacity of orbital angular momentum by combining beam steering and partial reception is as follows: Figure 1 ; Figure 4 The flowchart of the method for improving the channel capacity of orbital angular momentum by combining beam steering and partial reception is as follows: Figure 2 ; Figure 5 This is a multipath channel capacity diagram under different schemes in the orbital angular momentum channel capacity enhancement method of the present invention, which combines beam steering and partial reception. Detailed Implementation
[0018] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.
[0019] like Figures 1-5 As shown, the combined beam steering and partial reception orbital angular momentum channel capacity enhancement method of the present invention is mainly used in OAM wireless communication scenarios where the transceiver arrays are misaligned and the receiver array antennas are limited. It aims to compensate for beam deviation caused by array offset through beam steering, and simultaneously overcome the spatial deployment limitations of the receiver array through a partial reception strategy, ultimately achieving an effective improvement in the channel capacity of the OAM communication system. The method includes: Step S01: Obtain the basic parameters of the transceiver array of the orbital angular momentum communication system; Step S02: Based on the basic parameters of the transceiver array, perform beam steering processing on the orbital angular momentum beam of the transmitter to obtain the orbital angular momentum beam signal after steering. Step S03: Perform partial reception processing on the orbital angular momentum beam signal after the turn to complete the demultiplexing of the orbital angular momentum signal.
[0020] Specifically, before performing beam steering and partial reception operations, it is necessary to obtain the core fundamental parameters of the orbital angular momentum (OMG) communication system to provide data support for subsequent processing. These parameters include the array radius R of the uniform circular arrays at the transmitting and receiving ends, the total number of antenna elements N, the vertical distance D between the transmitting and receiving arrays, and the off-axis distance. ; Wavelength of the system transmitted signal The total number of OMG modes L; and the initial amplitude excitation of each antenna element. Initial azimuth angle .
[0021] In this embodiment, based on the basic parameters of the transceiver array, beam steering processing is performed on the orbital angular momentum beam at the transmitting end to obtain the redirected orbital angular momentum beam signal, including: A spherical coordinate system with a uniform circular array is constructed, and the electric field intensity at the target point within the spherical coordinate system is characterized to obtain the expression for the initial electric field intensity. The initial electric field strength expression is simplified to obtain the simplified electric field strength expression. The main lobe direction angle of the orbital angular momentum beam is determined based on the simplified electric field intensity expression, thus obtaining the target main lobe direction angle; The divergence angle of the orbital angular momentum beam is obtained by solving for the divergence angle of the target main lobe direction angle. The offset angle caused by the misalignment of the transceiver array is calculated by combining the spatial position parameters of the transceiver array, and the target offset angle is obtained. Based on the spatial orientation angle of the target receiving point and the divergence angle of the target, the phase of each antenna element of the uniform circular array is adjusted to obtain the adjusted phase. The electric field strength at the target receiving point is updated based on the adjusted phase to obtain the updated electric field strength. By combining the general channel matrix model of orbital angular momentum, the channel response between the transmitting and receiving antenna elements is calculated to obtain the target channel response; Beam steering is performed on the target channel response to obtain the orbital angular momentum beam signal after steering.
[0022] In this embodiment, the phase of each antenna element of the transmitting uniform circular array is adjusted according to the spatial orientation angle of the target receiving point and the divergence angle of the target to obtain the adjusted phase. This includes: The azimuth angle of the center of the transmitting array and the spatial azimuth angle of the target receiving point are calibrated to obtain the calibrated azimuth angle. By combining the target divergence angle, the phase shift that needs to be adjusted for each antenna element of the uniform circular array is calculated to obtain the target phase shift. The initial phase of each antenna element is adjusted according to the target phase shift to obtain the adjusted phase.
[0023] Specifically, based on the basic parameters obtained above, beam steering processing is performed on the orbital angular momentum beam of the transmitting end to compensate for the beam offset caused by the misalignment of the transceiver array. The specific implementation steps are as follows: Construct a spherical coordinate system and characterize the initial electric field intensity: First, construct a spherical coordinate system for a uniform circular array, and then define the target point within the spherical coordinate system. The electric field intensity at a given location is characterized by the following expression: in, for , The zenith angle in spherical coordinates represents the angle between the target point and the z-axis, with its value range corrected to 0 ≤ 0. ≤ for, In spherical coordinates, the azimuth angle represents the angle between the projection of the target point onto the xy plane and the x-axis, with a value range of 0 ≤ 0 ≤ 1. ≤ N is the total number of antenna elements in the uniform circular array (UCA) at the transmitter / receiver end, and is a positive integer. The signal amplitude excitation coefficient of the nth element in the UCA array at the transmitter is given by j, where j is the imaginary unit. R is the radius of the array. Let be the azimuth angle of the nth antenna element. The initial phase offset of the array element (usually taken as...) =0), For beam, This represents the OAM mode value.
[0024] Simplified expression for electric field strength: For ease of subsequent calculations, the amplitude excitation of the antenna elements of the uniform circular array is set as When the value of the electric field is 1 and the number of array elements N is large, the expression for the electric field intensity in the above formula can be further simplified as follows: in, It is a first-order Bessel function used to characterize the spatial amplitude distribution characteristics of the OAM beam.
[0025] Determine the main lobe orientation angle of the OAM beam: Based on the simplified electric field strength expression The angle corresponding to the maximum value of the first-order Bessel function is used to determine the main lobe direction angle of the OAM beam. Its expression is shown in the formula below, and the resulting angle is the target main lobe direction angle. This angle is the core direction for the concentrated propagation of OAM beam energy: in, .
[0026] Solve for the OAM beam divergence angle and array offset angle: The divergence angle of the OAM beam is solved based on the target main lobe direction angle. The modal OMA... Divergence angle of modal beam The expression is shown in the formula below, and the resulting target divergence angle reflects the spatial spread range of the OAM beam: Simultaneously, combining the vertical distance D of the transceiver array and the off-axis distance... Spatial position parameters, offset angle caused by misalignment of transceiver arrays The calculation is performed, and the expression is shown in the formula below, to quantify the degree of misalignment of the array: Adjust the phase of the transmitting antenna elements: Based on the spatial orientation angle of the target receiving point and the target divergence angle, the phase of each antenna element of the transmitting uniform circular array is adjusted. The phase shift that needs to be adjusted for the nth antenna element of the transmitting UCA is shown in the formula below: in, The radius of the transmitter's UCA. The zenith angle of the target receiving point. The azimuth angle of the target receiving point.
[0027] In the OMG off-axis transmission model, the orientation angle of the target receiving point satisfies the following formula: The specific adjustment process is as follows: First, adjust the orientation angle (0, 0) of the center of the calibration transmitting array and the spatial orientation angle of the target receiving point. The calibration is performed to obtain the calibration direction angle; then, combined with the target divergence angle, the phase shift amount that each antenna element needs to be adjusted is calculated using the phase shift formula to obtain the target phase shift amount; finally, the initial phase of each antenna element is adjusted according to the target phase shift amount to obtain the adjusted phase.
[0028] Update the electric field strength at the target receiving point and calculate the channel response: The electric field strength at the target receiving point is updated based on the adjusted phase, and the updated electric field strength expression is shown below. Combining the OAM general channel matrix model, the updated electric field strength and azimuth parameters of the transmit and receive antenna elements are substituted into the model to calculate the channel response between the transmit and receive antenna elements. The OAM channel response between the nth transmit antenna element and the mth receive antenna element is shown in the formula below, thus obtaining the target channel response: Where m is the index of the m-th element of the receiver's UCA array. Let be the azimuth angle of the m-th receiving antenna element.
[0029] Complete beam steering: The beam steering operation is completed based on the calculated target channel response, so that the main lobe of the OAM beam can be accurately aligned with the direction of the receiving array, and the OAM beam signal after steering is obtained.
[0030] In this embodiment, partial reception processing is performed on the orbital angular momentum beam signal after the turn, completing the demultiplexing of the orbital angular momentum signal. This includes: Obtain the conventional general orbital angular momentum channel matrix and the corresponding mode demultiplexing matrix, and identify the matrix dimension mismatch problem caused by the limited number of receiving antenna array elements; To address the matrix dimension mismatch problem, the zero-padding method is used to adjust the solution reuse vector of the orbital angular momentum mode, resulting in the adjusted solution reuse vector. Based on the adjusted demultiplexed vector and combined with the preset receiving antenna array element conditions, demultiplexing processing is performed on signals of different orbital angular momentum modes.
[0031] In this embodiment, based on the adjusted demultiplexing vector and combined with preset receiving antenna element conditions, demultiplexing processing is performed on signals of different orbital angular momentum modes, including: Verify the ratio of the number of receiving antenna array elements to the original total number of receiving antenna array elements, and ensure that the preset ratio requirement of the number of receiving antenna array elements is not less than one-quarter of the original total is met. Verify the ratio of the number of continuous phase antenna elements in the receiving antenna to the total number of elements in the original receiving antenna array, and ensure that the ratio of continuous phase antenna elements is not less than one-quarter of the original total number of continuous elements. Provided that both ratio requirements are met, demultiplexing processing is performed on signals of different orbital angular momentum modes.
[0032] In this embodiment, demultiplexing processing is performed on signals with odd orbital angular momentum modes, including: The first segment of the adjusted demultiplexed vector data is adjusted according to the first preset rule to obtain the first segment adjusted data; The second segment data of the adjusted demultiplexed vector is adjusted according to the second preset rule to obtain the second segment adjusted data; The third segment data of the adjusted demultiplexed vector is adjusted according to the third preset rule to obtain the third segment adjusted data; By integrating the adjustment data from the first segment, the second segment, and the third segment, the demultiplexed odd-mode orbital angular momentum signal is obtained.
[0033] In this embodiment, demultiplexing processing is performed on signals with zero orbital angular momentum modes, including: The data at the corresponding positions of the adjusted demultiplexed vector are uniformly assigned values to obtain the uniformly assigned demultiplexed vector; Based on the demultiplexed vector after unified assignment, the demultiplexed zero-mode orbital angular momentum signal is obtained. In this embodiment, demultiplexing processing is performed on signals whose orbital angular momentum modes are non-zero even numbers, including: The fourth segment data of the adjusted demultiplexed vector is adjusted according to the fourth preset rule to obtain the fourth segment adjusted data; The fifth segment data of the adjusted demultiplexed vector is adjusted according to the fifth preset rule to obtain the fifth segment adjusted data; By integrating the adjustment data from the fourth segment and the fifth segment, the non-zero even-numbered mode orbital angular momentum signal is demultiplexed.
[0034] Specifically, for scenarios where the number of antenna elements at the receiving end is limited, partial reception processing is performed on the OAM beam signal after it has turned, to achieve effective demultiplexing of OAM signals of various modes. The specific steps are as follows: Identify matrix dimension mismatch issues: First, obtain the traditional general-purpose OAM channel matrix, the expression of which is shown in the formula below: in, and These are an inverse discrete Fourier transform matrix and a discrete Fourier transform matrix, respectively, used for OAM mode demultiplexing and OAM mode multiplexing. The channel matrix is represented by its (m, n)th element as follows: in, For the receiving array UCA radius, The angle associated with the receiving end.
[0035] Since the total number of receiving antenna elements N1 < N, the OAM mode demultiplexing matrix With channel matrix Dimension mismatch prevents direct OAM mode demultiplexing; this issue must be clearly identified first.
[0036] Adjusting the demultiplexing vector using zero-padding: To address the aforementioned matrix dimension mismatch issue, a zero-padding method is used to adjust the mechanical energy of the OAM mode demultiplexing vector. The adjusted demultiplexing vector, as shown in the formula below, contains effective demultiplexed data and zero-padding data, achieving dimension adaptation with the channel matrix. in, L represents the actual number of array elements available at the receiver, and L represents the total number of transmission modes in the OAM communication system.
[0037] Verify the conditions of the receiving antenna array elements: Before performing demultiplexing operations based on the adjusted demultiplexing vector, the array element conditions of the receiving antenna must be verified. First, the number of array elements N1 of the receiving antenna must be ≥ N / 4. Second, the number of continuous phase antenna units in the receiving antenna must be no less than N / 4. Subsequent mode demultiplexing operations can only be carried out if both conditions are met.
[0038] Demultiplexing is performed for different OAM modes: For different types of OAM modes, the adjusted demultiplexed vectors are processed according to the corresponding rules to complete the demultiplexing of each mode signal: Odd OAM mode: The segmented data of the adjusted solution reuse vector are adjusted according to the rules shown in the formula below; By integrating the three adjustment data segments, the demultiplexing of the odd-mode OAM signal is completed; Zero OAM mode: The data at the corresponding positions of the adjusted demultiplexed vector are uniformly assigned values according to the formula below; The demultiplexed vector with unified assignment is obtained, thus completing the demultiplexing of the zero-mode OAM signal; Non-zero even OAM mode: The segmented data of the adjusted solution reuse vector are adjusted according to the rules described in the formula below, that is, the fourth segment data is kept consistent with the original solution reuse data, and the fifth segment data is adjusted accordingly; By integrating the two sets of adjustment data, the demultiplexing of the non-zero even-mode OAM signal is completed.
[0039] In this embodiment, after demultiplexing the orbital angular momentum signal, the method further includes: Based on the orbital angular momentum off-axis communication model, the system channel parameters after beam steering and partial reception processing are collected to obtain the target channel parameters; The channel capacity of the communication system is calculated based on the target channel parameters to obtain the final channel capacity.
[0040] Specifically, after demultiplexing the OAM signal, the final channel capacity of the system needs to be calculated to verify the capacity improvement effect of this method. Based on the OAM off-axis communication model, the beam steering and the target channel parameters after partial reception processing are substituted into the channel capacity calculation formula shown below to obtain the final channel capacity of the system, thus completing the quantitative evaluation of the system's communication performance. in, Let be the transmit power of the i-th OAM mode. This represents noise power.
[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.
Claims
1. A method for enhancing the channel capacity of orbital angular momentum by combining beam steering and partial reception, characterized in that, include: Obtain the basic parameters of the transceiver array of the orbital angular momentum communication system; Based on the basic parameters of the transceiver array, beam steering processing is performed on the orbital angular momentum beam at the transmitting end to obtain the orbital angular momentum beam signal after steering. Partial reception processing is performed on the orbital angular momentum beam signal after the turn to complete the demultiplexing of the orbital angular momentum signal.
2. The method for improving orbital angular momentum channel capacity by combining beam steering and partial reception according to claim 1, characterized in that, The step of performing beam steering processing on the orbital angular momentum beam at the transmitting end based on the basic parameters of the transceiver array to obtain the steered orbital angular momentum beam signal includes: A spherical coordinate system with a uniform circular array is constructed, and the electric field intensity at the target point within the spherical coordinate system is characterized to obtain the expression for the initial electric field intensity. The initial electric field strength expression is simplified to obtain the simplified electric field strength expression; The main lobe direction angle of the orbital angular momentum beam is determined based on the simplified electric field intensity expression, thus obtaining the target main lobe direction angle; The divergence angle of the orbital angular momentum beam is obtained by solving for the divergence angle of the target main lobe direction angle. The offset angle caused by the misalignment of the transceiver array is calculated by combining the spatial position parameters of the transceiver array, and the target offset angle is obtained. Based on the spatial orientation angle of the target receiving point and the divergence angle of the target, the phase of each antenna element of the transmitting uniform circular array is adjusted to obtain the adjusted phase; The electric field strength at the target receiving point is updated based on the adjusted phase to obtain the updated electric field strength. By combining the general channel matrix model of orbital angular momentum, the channel response between the transmitting and receiving antenna elements is calculated to obtain the target channel response; Beam steering is performed on the target channel response to obtain the orbital angular momentum beam signal after steering.
3. The method for improving orbital angular momentum channel capacity by combining beam steering and partial reception according to claim 2, characterized in that, Based on the spatial orientation angle of the target receiving point and the divergence angle of the target, the phase of each antenna element of the transmitting uniform circular array is adjusted to obtain the adjusted phase, including: The azimuth angle of the center of the transmitting array and the spatial azimuth angle of the target receiving point are calibrated to obtain the calibrated azimuth angle. Based on the target divergence angle, the phase shift that needs to be adjusted for each antenna element of the uniform circular array is calculated to obtain the target phase shift. The initial phase of each antenna element is adjusted according to the target phase shift to obtain the adjusted phase.
4. The method for improving orbital angular momentum channel capacity by combining beam steering and partial reception according to claim 1, characterized in that, Partial reception processing is performed on the orbital angular momentum beam signal after the turn to complete the demultiplexing of the orbital angular momentum signal, including: Obtain the conventional general orbital angular momentum channel matrix and the corresponding mode demultiplexing matrix, and identify the matrix dimension mismatch problem caused by the limited number of receiving antenna array elements; To address the matrix dimension mismatch problem, the zero-padding method is used to adjust the orbital angular momentum mode solution reuse vector, resulting in the adjusted solution reuse vector. Based on the adjusted demultiplexing vector and combined with the preset receiving antenna array element conditions, demultiplexing processing is performed on signals of different orbital angular momentum modes.
5. The method for improving orbital angular momentum channel capacity by combining beam steering and partial reception according to claim 4, characterized in that, Based on the adjusted demultiplexing vector and combined with preset receiving antenna element conditions, demultiplexing processing is performed on signals of different orbital angular momentum modes, including: Verify the ratio of the number of receiving antenna array elements to the original total number of receiving antenna array elements, and ensure that the preset ratio requirement of the number of receiving antenna array elements is not less than one-quarter of the original total is met. Verify the ratio of the number of continuous phase antenna elements in the receiving antenna to the total number of elements in the original receiving antenna array, and ensure that the ratio of continuous phase antenna elements is not less than one-quarter of the original total number of continuous elements. Provided that both ratio requirements are met, demultiplexing processing is performed on signals of different orbital angular momentum modes.
6. The method for improving orbital angular momentum channel capacity by combining beam steering and partial reception according to claim 5, characterized in that, Demultiplexing is performed on signals with odd orbital angular momentum modes, including: The first segment of the adjusted demultiplexed vector data is adjusted according to the first preset rule to obtain the first segment adjusted data; The second segment data of the adjusted demultiplexed vector is adjusted according to the second preset rule to obtain the second segment adjusted data; The third segment data of the adjusted demultiplexed vector is adjusted according to the third preset rule to obtain the third segment adjusted data; By integrating the first segment adjustment data, the second segment adjustment data, and the third segment adjustment data, the demultiplexing result of the odd-mode orbital angular momentum signal is obtained.
7. The method for improving orbital angular momentum channel capacity by combining beam steering and partial reception according to claim 5, characterized in that, Demultiplexing is performed on signals with zero orbital angular momentum modes, including: The data at the corresponding positions of the adjusted demultiplexed vector are uniformly assigned values to obtain the uniformly assigned demultiplexed vector; Based on the unified assigned demultiplexed vector, the demultiplexed result of the zero-mode orbital angular momentum signal is obtained.
8. The method for improving orbital angular momentum channel capacity by combining beam steering and partial reception according to claim 5, characterized in that, Demultiplexing is performed on signals with non-zero even orbital angular momentum modes, including: The fourth segment data of the adjusted demultiplexed vector is adjusted according to the fourth preset rule to obtain the fourth segment adjusted data; The fifth segment data of the adjusted demultiplexed vector is adjusted according to the fifth preset rule to obtain the fifth segment adjusted data; By integrating the fourth segment adjustment data and the fifth segment adjustment data, the demultiplexing result of the non-zero even-number mode orbital angular momentum signal is obtained.
9. The method for enhancing the channel capacity of orbital angular momentum by combining beam steering and partial reception according to claim 1, further comprising, after demultiplexing the orbital angular momentum signal: Based on the orbital angular momentum off-axis communication model, the system channel parameters after beam steering and partial reception processing are collected to obtain the target channel parameters; The channel capacity of the communication system is calculated based on the target channel parameters to obtain the final channel capacity.