Method and system for optimizing three-dimensional constellation of communication system, medium and equipment

Abstract

The invention discloses a communication system three-dimensional constellation optimization method and system, a medium and equipment, and belongs to the technical field of communication. The method comprises the following steps: acquiring constellation points of a communication system; taking the constellation points as vertexes of a cube, and obtaining a constellation skeleton based on the constellation points; adding a base point to the center of the constellation skeleton, taking the center of each surface of the constellation skeleton as a symmetric center to obtain a surface center symmetric point symmetric to the base point, and obtaining a new constellation skeleton based on the constellation point, the base point and the surface center symmetric point; taking the center of one surface of the new constellation skeleton as a symmetric center to obtain a corner symmetric point symmetric with the base point, and obtaining a three-dimensional constellation based on the constellation point, the base point, the surface center symmetric point and the corner symmetric point; performing global translation on the three-dimensional constellation to obtain a translated three-dimensional constellation; and performing bit mapping optimization on the translated three-dimensional constellation to obtain an optimized three-dimensional constellation. The performance index of the constellation diagram and the transmission reliability of a communication system are effectively improved.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a method, system, medium and device for optimizing a three-dimensional constellation of a communication system. Background Art

[0002] With the continuous advancement of modern communication technology, especially the rapid development of optical communication and wireless communication, data transmission rate and system reliability have become important indicators for measuring the performance of communication systems. In order to cope with the growing demand for user data and the improvement of spectrum efficiency, constellation design has played an increasingly important role in communication. Traditional constellation design is often based on two-dimensional space, such as 16 or 64 quadrature amplitude modulation (16-QAM, 64QAM). When the number of modulation points in the communication system increases, the minimum Euclidean distance of the two-dimensional constellation gradually decreases, resulting in limitations in anti-noise performance, making it difficult to meet the needs of high spectrum efficiency and larger data capacity. Therefore, constellation design expands from two dimensions to three dimensions and higher dimensions to improve the efficiency and anti-interference ability of data transmission.

[0003] In order to break through the bottleneck of two-dimensional constellation design, three-dimensional constellation design has gradually been used in optical communication and wireless communication systems. Three-dimensional constellations can utilize higher dimensions and improve the minimum Euclidean distance of constellation points through reasonable geometric structure optimization, thereby improving the constellation gain index (CFM, Constellation Figure of Merit). The CFM value is an important parameter to measure the anti-noise performance of the constellation. The higher the CFM value, the greater the minimum Euclidean distance between constellation points in the communication system under the same average power conditions, and the lower the bit error rate. Existing three-dimensional constellation designs usually improve the CFM value through geometric shaping (GS), trying to maximize the number of adjacent point pairs with the minimum Euclidean distance. These designs mainly focus on the geometric allocation within the constellation diagram, but often ignore the global optimization of the overall position of the constellation, and fail to give full play to the potential of the three-dimensional space, resulting in the system performance being difficult to achieve the optimal level.

[0004] In the bit mapping of constellation points, the mapping method directly affects the bit error rate of the system. The bit difference between adjacent constellation points is called the Hamming distance. The smaller the Hamming distance of the system, the lower the bit error rate. In a two-dimensional constellation, Gray code mapping can achieve the Hamming distance of adjacent constellation points to be 1, but it is difficult to achieve in a three-dimensional constellation. This is because in three-dimensional space, there are more adjacent points for each constellation point, and it is difficult to ensure that all bit differences are 1. In addition, the design of a three-dimensional constellation also needs to increase the minimum Euclidean distance adjacent point pairs, thereby reducing the average power and improving the CFM value, which further increases the complexity of the constellation diagram and makes Gray code mapping more difficult. Therefore, when optimizing the bit mapping, the Hamming distance of adjacent constellation points should be minimized to reduce the generation of bit errors. Most of the mapping optimizations in the prior art are local optimizations, which are difficult to achieve global optimization, resulting in large bit differences between adjacent constellation points, thereby increasing the bit error rate and limiting the improvement of the overall performance of the communication system. In terms of global optimization, since it is necessary to consider the geometric distance and mapping relationship of the constellation points at the same time, the traditional exhaustive search or local iterative optimization method is prone to fall into the local optimum and it is difficult to achieve the overall optimal performance. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a method, system, medium and device for optimizing a three-dimensional constellation of a communication system, by adjusting the constellation points as a whole, finding the optimal arrangement mode, introducing a bit mapping optimization strategy, and reasonably configuring the bit mapping relationship of the constellation points to reduce the bit error rate of the system.

[0006] To achieve the above object, the present invention is implemented by adopting the following technical solutions: In one aspect, the present invention provides a method for optimizing a three-dimensional constellation of a communication system, comprising: Obtain constellation points of the communication system; Taking the constellation points as vertices of a cube, obtaining a constellation skeleton corresponding to the cube; Adding a base point at the center of the constellation skeleton, taking the center of each face of the constellation skeleton as the symmetry center, obtaining a face-center symmetry point symmetrical to the base point, and obtaining a new constellation skeleton based on the constellation point, the base point and the face-center symmetry point; Taking the center of one of the faces of the new constellation skeleton as the symmetry center, obtaining a corner symmetry point symmetrical to the base point, and obtaining a three-dimensional constellation based on the constellation point, the base point, the face center symmetry point and the corner symmetry point; Performing a global translation on the three-dimensional constellation to obtain a translated three-dimensional constellation; The shifted three-dimensional constellation is subjected to bit mapping optimization to obtain an optimized three-dimensional constellation.

[0007] Optionally, globally translating the three-dimensional constellation to obtain a translated three-dimensional constellation includes: An optimal translation vector is calculated, and the three-dimensional constellation is globally translated using the optimal translation vector to obtain a translated three-dimensional constellation.

[0008] Optionally, the translated three-dimensional constellation is expressed as: ; ; In the formula, Represents the first The coordinates of the constellation points; Indicates the first The coordinates of the constellation points; represents the optimal translation vector; Represents the number of constellation points in a three-dimensional constellation.

[0009] Optionally, using a simulated annealing algorithm to perform bit mapping optimization on the shifted three-dimensional constellation to obtain an optimized three-dimensional constellation includes: Constructing a Euclidean distance matrix between constellation points in the translated three-dimensional constellation, and screening out a set of adjacent constellation point pairs that meet a preset minimum Euclidean distance in the Euclidean distance matrix; Using a Gray code method, initially mapping the set of adjacent constellation point pairs to generate an initial bit mapping result, and calculating a total Hamming distance of the initial bit mapping result; Exchanging the bit mapping relationship between any two constellation points in the set of adjacent constellation point pairs, generating a final bit mapping result, and calculating a total Hamming distance of the final bit mapping result; The total Hamming distance of the initial bit mapping result and the total Hamming distance of the final bit mapping result are compared to obtain an optimized three-dimensional constellation.

[0010] Optionally, the total Hamming distance is expressed as: ; In the formula, represents the total Hamming distance; Indicates adjacent constellation points; Represents a set of adjacent constellation point pairs; Indicates constellation points and The bit difference between the constellation points.

[0011] Optionally, comparing the total Hamming distance of the initial bit mapping result and the total Hamming distance of the final bit mapping result to obtain an optimized three-dimensional constellation includes: If the total Hamming distance of the final bit mapping result is less than or equal to the total Hamming distance of the initial bit mapping result, replacing the initial bit mapping result with the final bit mapping result as the optimized three-dimensional constellation; If the total Hamming distance of the final bit mapping result is greater than the total Hamming distance of the initial bit mapping result, the replacement probability of the final bit mapping result is calculated according to a preset probability calculation rule, and the initial bit mapping result is replaced by the final bit mapping result according to the replacement probability of the final bit mapping result as the optimized three-dimensional constellation.

[0012] Optionally, the replacement probability of the final bit mapping result is expressed as: ; ; In the formula, represents the replacement probability of the final bit mapping result; represents the exponential function; represents the total Hamming distance of the initial bit mapping result; The total Hamming distance representing the final bit mapping result; represents the annealing temperature; represents the initial annealing temperature; Indicates the temperature reduction coefficient.

[0013] In a second aspect, the present invention provides a communication system three-dimensional constellation optimization system, comprising: The constellation point acquisition module is used to: acquire the constellation points of the communication system; A three-dimensional constellation construction module is used to: use the constellation points as vertices of a cube to obtain a constellation skeleton corresponding to the cube; Adding a base point at the center of the constellation skeleton, taking the center of each face of the constellation skeleton as the symmetry center, obtaining a face-center symmetric point symmetrical to the base point, and obtaining a new constellation skeleton based on the constellation point, the base point and the face-center symmetric point; Taking the center of one of the faces of the new constellation skeleton as the symmetry center, obtaining a corner symmetry point symmetrical to the base point, and obtaining a three-dimensional constellation based on the constellation point, the base point, the face center symmetry point and the corner symmetry point; A global translation module, used to: perform global translation on the three-dimensional constellation to obtain a translated three-dimensional constellation; The bit mapping optimization module is used to perform bit mapping optimization on the shifted three-dimensional constellation to obtain an optimized three-dimensional constellation.

[0014] In a third aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, which, when executed by a processor, implement the steps of the method for optimizing a three-dimensional constellation of a communication system described in the first aspect.

[0015] In a fourth aspect, the present invention provides a computer device, comprising: Memory, for storing computer instructions; A processor is used to execute the computer instructions to implement the steps of the method for optimizing the three-dimensional constellation of the communication system according to the first aspect.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention combines geometric shaping, global position adjustment and bit mapping optimization to effectively improve the performance indicators of the constellation diagram and the transmission reliability of the communication system. A three-dimensional constellation diagram is constructed through geometric shaping so that the constellation points are evenly distributed in space. The constellation points are translated as a whole to find the optimal arrangement, thereby increasing the minimum Euclidean distance and improving the CFM value, so as to further optimize the overall geometric layout of the constellation points and ensure that the overall distribution reaches the global optimum. The randomized iteration combined with the simulated annealing algorithm is used to optimize the configuration of the bit mapping of the constellation points to minimize the bit error rate and enhance the reliability of the communication system in a noisy environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 FIG. 1 is a flow chart of a method for optimizing a three-dimensional constellation of a communication system according to an embodiment of the present invention; Figure 2 The figure shows a schematic diagram of the structure of a constellation skeleton after adding base points in one embodiment of the present invention; Figure 3 Shown is a schematic structural diagram of a new constellation framework of the present invention in one embodiment; Figure 4 The figure shows a schematic diagram of the structure of a three-dimensional constellation in one embodiment of the present invention; Figure 5 The figure shows a schematic structural diagram of a three-dimensional constellation after translation in one embodiment of the present invention; Figure 6 FIG. 1 is a schematic diagram of a simulation process of a communication system of the present invention in an embodiment; Figure 7 It is a schematic diagram showing a comparison of bit error rate performances of a three-dimensional constellation after translation of the present invention and a constellation in the prior art in one embodiment; Figure 8 FIG. 1 is a schematic diagram showing a comparison of bit error rate performances of the bit mapping of the present invention and the Gray mapping of the prior art in an embodiment. DETAILED DESCRIPTION

[0018] The technical solution of the present invention is described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations on the technical solution of the present invention. The embodiments of the present invention and the technical features in the embodiments may be combined with each other unless there is a conflict.

[0019] The term "and / or" is only a description of the association relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " generally indicates that the related objects are in an "or" relationship.

[0020] Embodiment 1, as Figure 1 As shown, this embodiment introduces a method for optimizing a three-dimensional constellation of a communication system, which combines geometric shaping, global position adjustment, and bit mapping optimization to effectively improve the performance indicators of the constellation diagram and the transmission reliability of the communication system.

[0021] The method specifically comprises the following steps: Step 1: Obtain the constellation points of the communication system.

[0022] Step 2: Use the constellation points as vertices of a cube to obtain a constellation skeleton corresponding to the cube, and add a base point at the center of the constellation skeleton.

[0023] In a specific embodiment, Figure 2 As shown, a cube with a side length of 2.3094d and a base point O are constructed. The eight vertices of the cube are A, B, C, D, E, F, G, and H, forming a constellation skeleton. The base point O is located at the center of the cube, and the cube is also a regular hexahedron.

[0024] Step 3: Taking the center of each face of the constellation skeleton as the symmetry center, obtain a face-center symmetry point symmetrical to the base point, and obtain a new constellation skeleton based on the constellation point, base point and face-center symmetry point.

[0025] In a specific embodiment, Figure 3 As shown, the six faces of the constellation skeleton are expanded with face-center symmetry. The center of each face of the constellation skeleton is taken as the symmetry point, and six points I, J, K, L, M, and N that are symmetrical to the base point O are added. The distance between these symmetry points and the base point O is 2.3094d, and the distance between these symmetry points and the four vertices of their respective symmetry faces is 2d, thus obtaining a new constellation skeleton.

[0026] Step 4: Taking the center of one of the faces of the new constellation skeleton as the symmetry center, obtain a corner symmetry point symmetrical to the base point, and obtain a three-dimensional constellation based on the constellation point, base point, face center symmetry point and corner symmetry point.

[0027] In a specific embodiment, Figure 4 As shown, for the surface BKCI, through the face-center symmetry, a point P symmetric to the base point O is added, and the distance between point P and the four points of the surface BKCI is 2d, thereby obtaining a three-dimensional constellation.

[0028] Step 5: Since the added corner symmetric points are far away from the base point, they deviate from the symmetrical distribution of the base point, resulting in an increase in the overall average power and a decrease in the CFM value. Therefore, in order to restore the symmetry of the constellation diagram and reduce the average power, it is necessary to globally translate the constellation point system, calculate the optimal translation vector, and use the optimal translation vector to globally translate the three-dimensional constellation to obtain the translated three-dimensional constellation. The translated three-dimensional constellation is as follows: Figure 5 As shown, specifically: First, the centroid position of the three-dimensional constellation is calculated as a whole, and the centroid position is used as the optimal translation vector. The centroid C is obtained by taking the average of the three-dimensional coordinates of all constellation points in the three-dimensional constellation. The centroid C is expressed as: ; In the formula, Indicates the first The coordinates of the constellation points, , , They represent the first The horizontal coordinate, vertical coordinate and vertical coordinate of each constellation point; represents the number of constellation points in the three-dimensional constellation. In this embodiment, =16.

[0029] Then, each constellation point Relative to the mass center C, the mass center C is realigned to the base point O. The first The coordinates of the constellation points It is expressed as: .

[0030] Step 6: In the bit mapping optimization of the three-dimensional constellation, the goal is to reduce the overall Hamming distance by optimizing the bit mapping relationship between the constellation points, thereby improving the communication performance of the system. Under the same symbol error rate condition, the smaller the overall Hamming distance, the lower the bit error rate. This is because a smaller Hamming distance means a smaller bit difference between adjacent constellation points, and symbol errors usually occur between adjacent points. Therefore, even if the symbol is misjudged, a smaller Hamming distance can effectively reduce the possibility of bit errors, thereby reducing the bit error rate. In order to quantify the advantages and disadvantages of the bit mapping scheme, the sum of the bit differences between all adjacent points is defined as the total Hamming distance (THD), which is expressed as: ; In the formula, Indicates adjacent constellation points; Represents a set of adjacent constellation point pairs; Indicates constellation points and The bit difference between the constellation points.

[0031] The bit mapping of the shifted three-dimensional constellation is optimized by using a simulated annealing algorithm to obtain an optimized three-dimensional constellation, which is specifically: Constructing a Euclidean distance matrix between constellation points in the translated three-dimensional constellation, and screening out a set of adjacent constellation point pairs that meet a preset minimum Euclidean distance in the Euclidean distance matrix; in this embodiment, the minimum Euclidean distance is 2d; Using a Gray code method, initially mapping the set of adjacent constellation point pairs to generate an initial bit mapping result, and calculating a total Hamming distance of the initial bit mapping result; In each iteration process, the bit mapping relationship between any two constellation points in the set of adjacent constellation point pairs is exchanged to generate a final bit mapping result, and a total Hamming distance of the final bit mapping result is calculated; If the total Hamming distance of the final bit mapping result is less than or equal to the total Hamming distance of the initial bit mapping result, replacing the initial bit mapping result with the final bit mapping result as the optimized three-dimensional constellation; If the total Hamming distance of the final bit mapping result is greater than the total Hamming distance of the initial bit mapping result, the replacement probability of the final bit mapping result is calculated according to the preset probability calculation rule, and the initial bit mapping result is replaced by the final bit mapping result according to the replacement probability of the final bit mapping result as the optimized three-dimensional constellation. Through the probability acceptance mechanism, the algorithm can jump out of the local optimal solution in the early stage of optimization. The replacement probability of the final bit mapping result is expressed as: ; ; In the formula, represents the replacement probability of the final bit mapping result; represents the exponential function; represents the total Hamming distance of the initial bit mapping result; The total Hamming distance representing the final bit mapping result; represents the annealing temperature; represents the initial annealing temperature; It represents the temperature drop coefficient; In this embodiment, the bit mapping relationship between any two constellation points in the set of adjacent constellation point pairs is exchanged iteratively for multiple times to generate a final bit mapping result, and the total Hamming distance of the final bit mapping result is calculated; Initially, the initial bit mapping result is used as the optimized three-dimensional constellation; At the initial moment of the bit mapping optimization, comparing the total Hamming distance of the initial bit mapping result with the total Hamming distance of the final bit mapping result generated by the first iteration; At other moments of the bit mapping optimization, comparing the total Hamming distance of the final bit mapping result generated by the current iteration with the total Hamming distance of the final bit mapping result generated by the new iteration; If the total Hamming distance of the final bit mapping result generated by the first iteration is less than or equal to the total Hamming distance of the initial bit mapping result, the final bit mapping result generated by the first iteration replaces the initial bit mapping result as the optimized three-dimensional constellation; if the total Hamming distance of the final bit mapping result generated by the second iteration is less than or equal to the total Hamming distance of the final bit mapping result generated by the first iteration, the final bit mapping result generated by the second iteration replaces the final bit mapping result generated by the first iteration as the optimized three-dimensional constellation; and so on; If the total Hamming distance of the final bit mapping result generated by the first iteration is greater than the total Hamming distance of the initial bit mapping result, then according to the replacement probability of the final bit mapping result, the initial bit mapping result is replaced by the final bit mapping result generated by the first iteration as the optimized three-dimensional constellation; if the total Hamming distance of the final bit mapping result generated by the second iteration is greater than the total Hamming distance of the bit mapping result generated by the first iteration, then according to the replacement probability of the final bit mapping result, the bit mapping result generated by the first iteration is replaced by the final bit mapping result generated by the second iteration as the optimized three-dimensional constellation; and so on.

[0032] The iterative process gradually reduces the controlled annealing temperature , narrowing the search range. In the later stage of iteration, the algorithm converges to the optimal solution, ensuring that the best bit mapping solution can be found, taking into account both exploration and convergence.

[0033] In summary, this embodiment firstly performs geometric shaping, including constructing a regular hexahedron and an origin point, adding face centers and corner symmetric points, and then adjusts the global position, including calculating the centroid and globally translating the constellation points, to ensure uniform distribution of the constellation points in the three-dimensional space, thereby improving the constellation gain index. Finally, bit mapping optimization is performed by using a simulated annealing algorithm, by screening a set of adjacent points and randomly exchanging the bit mapping of the constellation points, and calculating the total Hamming distance (THD) after the exchange. If the THD of the new solution is lower, it is directly accepted, otherwise the solution is accepted with a certain probability, and finally the final mapping solution is confirmed under the iteration stop condition.

[0034] Embodiment 2: This embodiment introduces a specific experimental design of a method for optimizing a three-dimensional constellation of a communication system, including the following steps: This embodiment adopts a three-dimensional structure including 16 constellation points, and through the geometric expansion of a regular hexahedron, the constellation points are made to satisfy the minimum Euclidean distance relationship with the adjacent points as much as possible. By reasonably arranging the constellation points, the minimum Euclidean distance between the constellation points is ensured to be 2d, so as to improve the constellation gain index (CFM, Constellation Figure of Merit) value.

[0035] like Figure 2 As shown, a cube with a side length of 2.3094d and a base point O are constructed. The eight vertices of the cube are A, B, C, D, E, F, G, and H, forming a constellation skeleton. The base point O is located at the center of the cube, and the cube is also a regular hexahedron.

[0036] like Figure 3 As shown, the six faces of the constellation skeleton are expanded with face-center symmetry. The center of each face of the constellation skeleton is taken as the symmetry point, and six points I, J, K, L, M, and N that are symmetrical to the base point O are added. The distance between these symmetry points and the base point O is 2.3094d, and the distance between these symmetry points and the four vertices of their respective symmetry faces is 2d, thus obtaining a new constellation skeleton.

[0037] like Figure 4 As shown, for the surface BKCI, through the face-center symmetry, a point P symmetric to the base point O is added, and the distance between point P and the four points of the surface BKCI is 2d, thereby obtaining a three-dimensional constellation.

[0038] Since the added constellation point P is far away from the base point O, it deviates from the symmetrical distribution of the base point, resulting in an increase in the overall average power and a decrease in the CFM value. Therefore, in order to restore the symmetry of the constellation diagram and reduce the average power, it is necessary to globally shift the constellation point system to obtain the shifted three-dimensional constellation, such as Figure 5 shown.

[0039] First, the centroid position of the three-dimensional constellation is calculated as a whole, and the centroid position is used as the optimal translation vector. The centroid C is obtained by taking the average of the three-dimensional coordinates of all constellation points in the three-dimensional constellation. The centroid C is expressed as: ; In the formula, Indicates the first The coordinates of the constellation points.

[0040] Then, each constellation point Relative to the mass center C, the mass center C is realigned to the base point O. The first The coordinates of the constellation points It is expressed as: .

[0041] In this embodiment, the constellation diagram is processed in the x-axis direction and the z-axis direction. The optimal overall distribution of constellation points is obtained by translation. The coordinates of the constellation points before and after translation are shown in Table 1. After the constellation is translated, the center of mass is restored to the origin of the coordinates, that is, the base point O, and the symmetry of the constellation is restored.

[0042] Table 1 Coordinates and mapping bits of constellation points before and after translation

[0043] The calculation formula of the known constellation gain index CFM is: ; In the formula, Represents the minimum Euclidean distance between constellation points; Represents the average power of the constellation points, which is calculated as the average of the squares of the distances from all constellation points to the origin.

[0044] The CFM of the traditional three-dimensional constellation based on the regular hexahedron is 0.4726, while the CFM of the three-dimensional constellation we designed is 0.86486, which is 0.3923 higher than that of the traditional three-dimensional constellation based on the regular hexahedron.

[0045] In order to quantify the quality of the bit mapping scheme, the sum of the bit differences between all adjacent points is defined as the total Hamming distance (THD), which is expressed as: ; In the formula, Indicates adjacent constellation points; Represents a set of adjacent constellation point pairs; Indicates constellation points and The bit difference between the constellation points.

[0046] A Euclidean distance matrix between constellation points in the translated three-dimensional constellation is constructed, and a set of adjacent constellation point pairs that meet a preset minimum Euclidean distance in the Euclidean distance matrix is ​​screened out. The preset minimum Euclidean distance is 2d.

[0047] The Gray code method is used to perform initial mapping on the set of adjacent constellation point pairs, generate an initial bit mapping result, and calculate the total Hamming distance of the initial bit mapping result.

[0048] In the iterative process of simulated annealing, the initial annealing temperature T0=100.0 and the minimum temperature T min =1×10 −5 , and the temperature reduction coefficient α =0.99Gradually reduce the temperature.

[0049] In each iteration process, the bit mapping relationship between any two constellation points in the set of adjacent constellation point pairs is exchanged to generate a final bit mapping result, and the total Hamming distance of the final bit mapping result is calculated.

[0050] If the total Hamming distance of the final bit mapping result is less than or equal to the total Hamming distance of the initial bit mapping result, the initial bit mapping result is replaced by the final bit mapping result as the optimized three-dimensional constellation.

[0051] If the total Hamming distance of the final bit mapping result is greater than the total Hamming distance of the initial bit mapping result, the replacement probability of the final bit mapping result is calculated according to the preset probability calculation rule, and the initial bit mapping result is replaced by the final bit mapping result according to the replacement probability of the final bit mapping result as the optimized three-dimensional constellation. Through the probability acceptance mechanism, the algorithm can jump out of the local optimal solution in the early stage of optimization. The replacement probability of the final bit mapping result is expressed as: ; ; In the formula, represents the replacement probability of the final bit mapping result; represents the exponential function; represents the total Hamming distance of the initial bit mapping result; The total Hamming distance representing the final bit mapping result; represents the annealing temperature; represents the initial annealing temperature; It represents the temperature drop coefficient; The iterative process gradually reduces the controlled annealing temperature , narrowing the search range. In the later stage of iteration, the algorithm converges to the optimal solution, ensuring that the best bit mapping solution can be found, taking into account both exploration and convergence.

[0052] The number of adjacent points and the Hamming distance of each point in the constellation before and after the simulated annealing algorithm optimization are shown in Table 2.

[0053] Table 2 Changes in Hamming distance before and after mapping optimization Constellation Points Adjacent points Mapping before optimization Optimized Mapping Hamming distance before optimization Optimized Hamming distance O 8 0000 1100 14 16 A 4 0100 1101 7 4 B 5 0110 0001 11 7 C 5 0010 0100 11 7 D 4 1010 0111 10 6 E 4 1110 1011 10 6 F 4 1100 1000 11 4 G 4 1000 0010 10 6 H 4 1001 1110 7 4 I 4 0001 0101 10 4 J 4 0101 1111 10 4 K 4 0111 0000 10 4 L 4 0011 1010 12 4 M 4 1011 0110 6 4 N 4 1111 1001 8 4 P 2 1101 0011 7 4 As can be seen from Table 2, when the Gray mapping method is used, for example: gray_codes = ["0000", "0100", "0110", "0010", "1010", "1110", "1100", "1000", "1001", "0001", "0101", "0111", "0011", "1011", "1111", "1101"], the total Hamming distance is 77. This value is obtained by dividing the sum of the Hamming distances of all adjacent points by 2, because the adjacent point pairs are bidirectional, for example, A is a neighbor of B, and B is also a neighbor of A, so the Hamming distance of each pair of adjacent points is calculated twice.

[0054] The optimized bit mapping is as follows: optimized_codes = ["1100", "1101", "0001", "0100", "0111", "1011", "1000", "0010", "1110", "0101", "1111", "0000", "1010", "0110", "1001", "0011"]. The total Hamming distance after optimization is reduced to 44.

[0055] To verify the performance advantages of the centroid-optimized three-dimensional constellation structure and bit mapping scheme proposed in this embodiment, we conducted a simulation in MATLAB software. Figure 6 As shown in the figure, it includes a transmitter, a receiver and a channel module. The transmitter completes the input of the bit stream, the mapping and modulation of the constellation points, and the receiver demodulates and demaps the received signal. AWGN noise is introduced into the channel to simulate the bit error rate performance of the communication system under different signal-to-noise ratio conditions.

[0056] Figure 7 The figure shows the bit error rate of the shifted 3D constellation and the prior art constellation at different signal-to-noise ratios. It can be seen that when the bit error rate is 3.8*10^-3, the centroid shift geometric shaping has a higher sensitivity. This shows that the centroid shift geometric shaping improves the reliability of the communication system.

[0057] Figure 8The bit error rates of the two mapping schemes, bit mapping and Gray mapping in the prior art, are shown. It can be seen that the bit error rate of the optimized bit mapping scheme is lower than that of the Gray mapping scheme. This shows that the optimized bit mapping effectively reduces the bit error rate by reducing the bit difference between adjacent constellation points.

[0058] Through the above simulation verification, the three-dimensional constellation design and bit mapping optimization scheme of the present invention not only proves the effectiveness of its performance improvement in theory, but also shows superior performance in the simulation system.

[0059] Embodiment 3: This embodiment introduces a communication system three-dimensional constellation optimization system, including: The constellation point acquisition module is used to: acquire the constellation points of the communication system; A three-dimensional constellation construction module is used to: use the constellation points as vertices of a cube to obtain a constellation skeleton corresponding to the cube; Adding a base point at the center of the constellation skeleton, taking the center of each face of the constellation skeleton as the symmetry center, obtaining a face-center symmetric point symmetrical to the base point, and obtaining a new constellation skeleton based on the constellation point, the base point and the face-center symmetric point; Taking the center of one of the faces of the new constellation skeleton as the symmetry center, obtaining a corner symmetry point symmetrical to the base point, and obtaining a three-dimensional constellation based on the constellation point, the base point, the face center symmetry point and the corner symmetry point; A global translation module, used to: perform global translation on the three-dimensional constellation to obtain a translated three-dimensional constellation; The bit mapping optimization module is used to perform bit mapping optimization on the shifted three-dimensional constellation to obtain an optimized three-dimensional constellation.

[0060] Embodiment 4: This embodiment introduces a computer-readable storage medium on which computer instructions are stored. When the computer instructions are executed by a processor, the steps of the method for optimizing the three-dimensional constellation of the communication system described in Embodiment 1 or 2 are implemented.

[0061] Embodiment 5: This embodiment introduces a computer device, including: Memory, for storing computer instructions; A processor is used to execute the computer instructions to implement the steps of the method for optimizing the three-dimensional constellation of the communication system described in embodiment 1 or 2.

[0062] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0063] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0064] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0065] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0066] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which all fall within the protection of the present invention.

Claims

1. A method for optimizing a three-dimensional constellation of a communication system, characterized in that: include: Obtain constellation points of the communication system; Taking the constellation points as vertices of a cube, obtaining a constellation skeleton corresponding to the cube; Adding a base point at the center of the constellation skeleton, taking the center of each face of the constellation skeleton as the symmetry center, obtaining a face-center symmetric point symmetrical to the base point, and obtaining a new constellation skeleton based on the constellation point, the base point and the face-center symmetric point; Taking the center of one of the faces of the new constellation skeleton as the symmetry center, obtaining a corner symmetry point symmetrical to the base point, and obtaining a three-dimensional constellation based on the constellation point, the base point, the face center symmetry point and the corner symmetry point; Performing a global translation on the three-dimensional constellation to obtain a translated three-dimensional constellation; The shifted three-dimensional constellation is subjected to bit mapping optimization to obtain an optimized three-dimensional constellation.

2. The method for optimizing a three-dimensional constellation of a communication system according to claim 1, characterized in that: The three-dimensional constellation is globally translated to obtain a translated three-dimensional constellation, comprising: An optimal translation vector is calculated, and the three-dimensional constellation is globally translated using the optimal translation vector to obtain a translated three-dimensional constellation.

3. The method for optimizing a three-dimensional constellation of a communication system according to claim 2, characterized in that: The translated three-dimensional constellation is expressed as: ； ； In the formula, Represents the first The coordinates of the constellation points; Indicates the first The coordinates of the constellation points; represents the optimal translation vector; Represents the number of constellation points in a three-dimensional constellation.

4. The method for optimizing a three-dimensional constellation of a communication system according to claim 1, characterized in that: Using a simulated annealing algorithm, bit mapping optimization is performed on the shifted three-dimensional constellation to obtain an optimized three-dimensional constellation, including: Constructing a Euclidean distance matrix between constellation points in the translated three-dimensional constellation, and screening out a set of adjacent constellation point pairs that meet a preset minimum Euclidean distance in the Euclidean distance matrix; Using a Gray code method, initially mapping the set of adjacent constellation point pairs to generate an initial bit mapping result, and calculating a total Hamming distance of the initial bit mapping result; Exchanging the bit mapping relationship between any two constellation points in the set of adjacent constellation point pairs, generating a final bit mapping result, and calculating a total Hamming distance of the final bit mapping result; The total Hamming distance of the initial bit mapping result and the total Hamming distance of the final bit mapping result are compared to obtain an optimized three-dimensional constellation.

5. The method for optimizing a three-dimensional constellation of a communication system according to claim 4, characterized in that: The total Hamming distance is expressed as: ； In the formula, represents the total Hamming distance; Indicates adjacent constellation points; Represents a set of adjacent constellation point pairs; Indicates constellation points and The bit difference between the constellation points.

6. The method for optimizing a three-dimensional constellation of a communication system according to claim 4, characterized in that: Compare the total Hamming distance of the initial bit mapping result and the total Hamming distance of the final bit mapping result to obtain an optimized three-dimensional constellation, including: If the total Hamming distance of the final bit mapping result is less than or equal to the total Hamming distance of the initial bit mapping result, replacing the initial bit mapping result with the final bit mapping result as the optimized three-dimensional constellation; If the total Hamming distance of the final bit mapping result is greater than the total Hamming distance of the initial bit mapping result, the replacement probability of the final bit mapping result is calculated according to a preset probability calculation rule, and the initial bit mapping result is replaced by the final bit mapping result according to the replacement probability of the final bit mapping result as the optimized three-dimensional constellation.

7. The method for optimizing a three-dimensional constellation of a communication system according to claim 6, characterized in that: The replacement probability of the final bit mapping result is expressed as: ； ； In the formula, represents the replacement probability of the final bit mapping result; represents the exponential function; represents the total Hamming distance of the initial bit mapping result; The total Hamming distance representing the final bit mapping result; represents the annealing temperature; represents the initial annealing temperature; Indicates the temperature reduction coefficient.

8. A communication system three-dimensional constellation optimization system, characterized in that: include: The constellation point acquisition module is used to: acquire the constellation points of the communication system; A three-dimensional constellation construction module is used to: use the constellation points as vertices of a cube to obtain a constellation skeleton corresponding to the cube; Adding a base point at the center of the constellation skeleton, taking the center of each face of the constellation skeleton as the symmetry center, obtaining a face-center symmetric point symmetrical to the base point, and obtaining a new constellation skeleton based on the constellation point, the base point and the face-center symmetric point; Taking the center of one of the faces of the new constellation skeleton as the symmetry center, obtaining a corner symmetry point symmetrical to the base point, and obtaining a three-dimensional constellation based on the constellation point, the base point, the face center symmetry point and the corner symmetry point; A global translation module, used to: perform global translation on the three-dimensional constellation to obtain a translated three-dimensional constellation; The bit mapping optimization module is used to perform bit mapping optimization on the shifted three-dimensional constellation to obtain an optimized three-dimensional constellation.

9. A computer-readable storage medium having computer instructions stored thereon, characterized in that: When the computer instructions are executed by a processor, the steps of the method for optimizing a three-dimensional constellation of a communication system according to any one of claims 1 to 7 are implemented.

10. A computer device, characterized in that: include: Memory, for storing computer instructions; A processor, configured to execute the computer instructions to implement the steps of the method for optimizing a three-dimensional constellation of a communication system according to any one of claims 1 to 7.

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