Signal modulation method, communication device, and storage medium

Abstract

The present application provides a signal modulation method, a communication device, and a storage medium, the method including modulating M+2-bit information based on a first constellation model or modulating M+3-bit information based on a second constellation model to obtain a modulation symbol, where the first constellation model includes 4*N constellation points and the second constellation model includes 8*N constellation points.

Description

[Technical Field]

[0001] This application is filed based on a Chinese patent application bearing application number 202211520120.5 and filed on November 30, 2022, and claims priority to the Chinese patent application, the entire contents of which are hereby incorporated by reference into this application.

[0002] TECHNICAL FIELD Embodiments of the present application relate to the field of communications technology, particularly, but not exclusively, to signal modulation methods, communications devices, and storage media. [Background technology]

[0003] Due to the rapid development of wireless communication technology, the demand for traffic volume, the number of terminals, and the types of terminals in mobile network applications are all showing explosive growth. Therefore, to resolve the conflict between the ever-increasing demand for wireless communication and the limited spectrum resources, it is necessary to improve spectral efficiency. Adopting a high-order modulation scheme is a commonly used method to improve spectral efficiency. In related technologies, high-order modulation schemes typically adopt pulse amplitude modulation (PAM), phase shift keying (PSK), and quadrature amplitude modulation (QAM). However, during information transmission, modulated transmission symbols are distorted by channel interference, which reduces the demodulation performance at the receiving end. Therefore, the receiving end relies heavily on pilots to compensate for the distorted transmission symbols, but the pilot overhead is too large, resulting in a reduction in transmission spectral efficiency. Therefore, how to improve the demodulation performance at the receiving end is an issue that needs to be resolved urgently. Summary of the Invention [Problem to be solved by the invention]

[0004] The embodiments of the present application provide a signal modulation method, a communication device, and a storage medium that can improve demodulation performance on the receiving side and reduce pilot overhead. [Means for solving the problem]

[0005] In a first aspect, an embodiment of the present invention provides a signal modulation method, the signal modulation method comprising:

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[0006] In a second aspect, an embodiment of the present application further provides a communication device, the communication device including at least one processor and at least one memory for storing at least one program, wherein the at least one program, when executed by the at least one processor, realizes the signal modulation method described above.

[0007] In a third aspect, an embodiment of the present application further provides a computer-readable storage medium, the computer-readable storage medium having stored thereon computer-executable instructions for performing the signal modulation method described above.

[0008]

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[0009]

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[0010] [Figure 1(a)] 1 is a constellation corresponding to 64QAM modulation symbols according to one embodiment of the present application. [Figure 1(b)] 1 is a constellation corresponding to 64QAM modulation symbols according to one embodiment of the present application. [Figure 2]1 is a flowchart of a signal modulation method according to an embodiment of the present application; [Figure 3] FIG. 2 is a schematic diagram of a first constellation model according to an embodiment of the present application; [Figure 4] FIG. 1 is a schematic diagram of a cross-shaped constellation before and after channel rotation scaling according to an embodiment of the present application; [Figure 5] FIG. 1 is a schematic diagram of partition division on a two-dimensional plane coordinate system according to an embodiment of the present application. [Figure 6] FIG. 1 is a schematic diagram of partitioning of a cross-shaped constellation on a two-dimensional plane coordinate system according to an embodiment of the present application. [Figure 7] FIG. 2 is a schematic diagram of a second constellation model according to an embodiment of the present application; [Figure 8] FIG. 10 is a schematic diagram of a cross-shaped constellation according to another embodiment of the present application; [Figure 9] FIG. 10 is a schematic diagram of a cross-shaped constellation according to another embodiment of the present application; [Figure 10] FIG. 10 is a schematic diagram of a cross-shaped constellation according to another embodiment of the present application; [Figure 11] FIG. 10 is a schematic diagram of a cross-shaped constellation according to another embodiment of the present application; [Figure 12] FIG. 10 is a schematic diagram of a second constellation model according to another embodiment of the present application; [Figure 13] 1 is a schematic diagram illustrating the configuration of a communication device according to an embodiment of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0011] In order to more clearly understand the objectives, technical solutions and advantages of the present application, the present application will be described in more detail below in conjunction with the drawings and examples. The specific examples described herein are only used to illustrate the present application and are not used to limit the present application.

[0012] It should be noted that while a flow chart depicts a logical order, in some cases the steps shown or described may be performed in an order different from that depicted in the flow chart. In the specification, claims, and description of the drawings, "plural" (or "multiple") means two or more, and terms such as "greater than," "less than," and "exceed" are understood to be exclusive of a number, and terms such as "greater than," "less than," and "within" are understood to be inclusive of a number. References to "first," "second," etc., are merely intended to distinguish technical features and should not be understood as indicating or implying relative importance, implying the number of indicated technical features, or implying the context of indicated technical features.

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[0015] Hereinafter, examples of the present application will be further described with reference to the drawings.

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[0018] Power normalization only shrinks the entire constellation, and the constellation points in the shrunken constellation are still uniformly distributed.

[0019] Other high-order modulation schemes, such as 32QAM, 64QAM, and 256QAM, are similar to 16QAM in that the constellation points are uniformly distributed on a two-dimensional plane. Therefore, the high-order modulation schemes in the related art can fully utilize the two-dimensional signal space of complex signals. Furthermore, the demodulation methods supported by these high-order modulation schemes are simple and can guarantee performance. Therefore, these high-order modulation schemes can approximate the transmission performance limit, i.e., the Shannon limit, in a relatively simple and efficient manner. Therefore, in scenarios where there is a certain demand for high spectral efficiency, these high-order modulation schemes can be widely applied. However, these high-order modulation methods can only ensure performance when channel estimation is accurate. If the channel estimation error is large, the constellation will be distorted during demodulation (i.e., during information transmission), i.e., rotational scaling will occur. When the receiving side demodulates the received transmission symbols, the decision area will be a uniform ring or fan shape, which does not match the true distribution of points corresponding to the received symbols. In this case, the demodulation performance will be significantly reduced, the error rate will be high, and the accuracy of data transmission will be low.

[0020] Specifically, taking the case where modulation symbols are transmitted using Orthogonal Frequency Division Multiplexing (OFDM) (i.e., using OFDM subcarriers to transmit modulation symbols), after passing through a multipath channel or a frequency selective channel, the modulation symbols carried on the OFDM subcarriers are weighted with complex weights by the channel, i.e., the modulation symbols carried on the subcarriers may be distorted by the frequency selective channel. Alternatively, if a synchronization error exists on both the transmitting and receiving sides, the timing offset (i.e., time difference) and frequency offset (i.e., frequency difference) may be weighted with complex weights to the modulation symbols on the subcarriers, i.e., the modulation symbols may be distorted by the synchronization error. In high-speed mobility scenarios or satellite communication scenarios, the Doppler effect may also apply complex weights to the modulation symbols on the subcarriers, i.e., the modulation symbols may be distorted by the synchronization error.

[0021] In addition, an example of a modulation symbol being transmitted in a single-carrier manner is when the modulation symbol is transmitted directly by a time-domain symbol. In such a scenario, if there is a frequency offset or phase noise in the transceiver, the modulation symbol is weighted with a complex weight, i.e., the modulation symbol is distorted by the frequency offset or phase noise.

[0022]

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[0023] However, there are some scenarios in which it is difficult to accurately estimate the complex weights (i.e., distortion) on the modulation symbols through pilots. For example, in connectionless transmission or unscheduled transmission scenarios, pilots or reference signals are selected and set according to the demands of terminals, and therefore, when different terminals select the same pilots or the same reference signals, a phenomenon of pilot collision or reference signal collision occurs. In the case of high overload, i.e., when the number of terminals is large, the probability of pilot collision or reference signal collision occurring is high. When pilot collision or reference signal collision occurs, it becomes difficult for the receiving side, for example, a base station or a receiver, to accurately estimate the complex weights (i.e., distortion) on the modulation symbols through pilots or reference signals.

[0024] In addition, in scenarios with large synchronization errors, high-speed movement scenarios, satellite communication scenarios, or scenarios with large phase noise, the amount of rotational scaling of modulation symbols changes quickly, and in order to estimate the amount of rotational scaling applied to modulation symbols between pilots, pilots with very short time intervals must be used, which limits the accuracy of the estimation and may result in too large pilot overhead and reduced transmission spectrum efficiency.On the other hand, if the pilot density is insufficient, it becomes difficult to accurately estimate the amount of rotational scaling on modulation symbols, which may impair demodulation performance.

[0025] In scenarios where pilot channel estimation is limited, such as connectionless power transmission scenarios, scenarios with large synchronization errors, high-speed movement scenarios, satellite communication scenarios, or scenarios with large phase noise, the receiver can extract channel information from modulation symbols to improve data transmission performance. The constellations of conventional high-order modulation schemes are too dense, making it difficult for the receiver to extract channel information through modulation symbols. Therefore, the present application provides a signal modulation method that provides modulation symbols with robustness against distortion interference during the transmission process, and that, when the degree of distortion of modulation symbols is high, compensates only using the shape characteristics of the modulation constellation itself, thereby restoring demodulation performance without increasing pilot overhead and ensuring high spectral efficiency. Therefore, the embodiments of the present application can support application scenarios with high spectral efficiency and enable the receiver to more easily and accurately extract channel information through modulation symbols.

[0026] 2, which is a flowchart of a signal modulation method according to an embodiment of the present application, which may include, but is not limited to, step S110.

[0027]

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[0028]

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[0029] In this embodiment, by adopting the signal modulation method including the above step S110, the modulation symbols are obtained by modulating multiple bits of information in the data packet according to the first constellation model or the second constellation model, that is, the modulation symbols can carry multiple bits of information, thereby realizing high-order modulation. In addition, the modulation symbols modulated according to the first constellation model or the second constellation model can improve robustness against distortion interference during transmission. Furthermore, when the degree of distortion of the modulation symbols is high, compensation can be performed only by the shape characteristics of the modulation constellation itself, thereby restoring demodulation performance without increasing pilot overhead and ensuring high spectral efficiency. Therefore, the embodiment of the present application can support application scenarios with high spectral efficiency and enable the receiver to more easily and accurately extract channel information from the modulation symbols.

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[0045] Each modulation symbol (ie, each constellation point) can carry multiple bits of information, thereby achieving the effect of high-order modulation, which is advantageous for achieving high spectral efficiency.

[0046]

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[0047] In particular, each modulation symbol (i.e., each constellation point) can carry multiple bits of information, i.e., realize the effect of high-order modulation, thereby achieving high spectral efficiency. In one embodiment, each modulation symbol can carry four bits of information, i.e., four bits of information are mapped (i.e., modulated) onto one modulation symbol. In another embodiment, each modulation symbol can carry five bits, i.e., five bits of information are mapped (i.e., modulated) onto one modulation symbol.

[0048] The cross-shaped constellation corresponding to the modulation symbols has the advantage of simple geometry. Even if the modulation symbols received at the receiving end undergo channel rotation scaling, the constellation corresponding to the modulation symbols is just one rotation-scaled cross-shaped constellation, and the formed geometry is still relatively simple.

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[0051] Next, a method for estimating the rotation scaling amount will be described in detail.

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[0053] As shown in Figures 3 to 6, the receiving side divides a two-dimensional signal plane into four partitions, then adds up the constellation points in each partition (i.e., the modulation symbols corresponding to each constellation point), divides the number of constellation points in that partition (i.e., the number of modulation symbols), and then calculates the coordinates of the center of the constellation point in that partition. The cross-shaped constellation shown in the center of Figure 6 is a schematic diagram obtained by rotationally scaling the cross-shaped constellation shown in the left diagram of Figure 4.

[0054]

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[0056] In the presence of AWGN, especially when some modulation symbols are subjected to large AWGN, some modulation symbols may undergo handover. To estimate the rotational scaling amount more accurately, it is usually necessary to use two partitioning methods as shown in Figure 5. Two rotational scaling amounts for the constellation are calculated according to the above estimation method for each of the two partitioning methods, and the modulus value of the one with the larger modulus value is used as the rotational scaling amount for that constellation.

[0057]

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[0058] Here, the rotation scaling amount of the second constellation model can be estimated by the following partitioning method: First, a two-dimensional plane (i.e., a two-dimensional signal plane) is divided into eight partitions, and specifically, each of the four quadrants is further divided into two equal partitions, where the region between the half line from the zero point (i.e., the origin) in the 0° direction and the half line from the zero point (i.e., the origin) in the 45° direction is partition 1, the region between the half line from the zero point (i.e., the origin) in the 45° direction and the half line from the zero point (i.e., the origin) in the 90° direction is partition 2, the region between the half line from the zero point (i.e., the origin) in the 90° direction and the half line from the zero point (i.e., the origin) in the 135° direction is partition 3, and the region between the half line from the zero point (i.e., the origin) in the 135° direction and the half line from the zero point (i.e., the origin) in the 135° direction is partition 4. The area between the half-line in the 180° direction from the zero point (i.e., the origin) and the half-line in the 225° direction from the zero point (i.e., the origin) is partition 4; the area between the half-line in the 180° direction from the zero point (i.e., the origin) and the half-line in the 225° direction from the zero point (i.e., the origin) is partition 5; the area between the half-line in the 225° direction from the zero point (i.e., the origin) and the half-line in the 270° direction from the zero point (i.e., the origin) is partition 6; the area between the half-line in the 270° direction from the zero point (i.e., the origin) and the half-line in the 315° direction from the zero point (i.e., the origin) is partition 7; and the area between the half-line in the 315° direction from the zero point (i.e., the origin) and the half-line in the 360° direction from the zero point (i.e., the origin) is partition 8.

[0059] According to the above-mentioned partitioning method, the receiver divides the two-dimensional signal plane into multiple partitions, and then adds up the constellation points in each partition (i.e., the modulation symbols corresponding to each constellation point), and then divides by the number of constellation points in that partition (i.e., the number of modulation symbols), to calculate the coordinate of the center of the constellation point in that partition. That is, by simply performing a few simple additions and subtractions on the constellation point coordinates, it is possible to determine the partition to which each constellation point belongs, and there is no need for complex multiplication operations, so a simple effect can be achieved. In addition, by simply calculating the center of the constellation point in each partition, the constellation rotation scaling amount, that is, the rotation scaling amount that all modulation symbols have undergone, can be obtained.

[0060] The rotation and scaling amount of the modulation symbol includes a rotation amount and a scaling amount.

[0061] Therefore, the multiple modulation symbols obtained by the first constellation model or the second constellation model can form a simple constellation with a single geometric shape, and even after the modulation symbols are subjected to channel interference and rotational scaling distortion occurs, the formed constellation still appears as a simple geometric pattern, which is highly resistant to distortion interference during the transmission process, and the distortion can be estimated and compensated for solely by the shape characteristics of the constellation, thereby restoring demodulation performance without increasing pilot overhead and ensuring high-frequency spectral efficiency. Therefore, the embodiments of the present application can ensure high spectral efficiency while simultaneously improving the demodulation performance of the receiving side.

[0062] The signal modulation method according to the above embodiment will now be described in detail using a specific example.

[0063] Example 1:

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[0068] In order to improve the transmission performance of the four closest constellation points in this cross-shaped constellation, the distance between adjacent constellation points among the four closest constellation points can be increased to expand the formed cross-shaped constellation outward, preventing the distribution of the four closest constellation points from becoming too dense. This reduces the impact of AWGN on the constellation points (i.e., modulation symbols) and improves the robustness of the cross-shaped constellation.

[0069]

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[0071] Example 2:

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[0075] If this constellation needs to be power normalized, the entire constellation can be multiplied by a normalization factor (scaling factor), i.e., each constellation point in the constellation can be multiplied by a normalization factor (scaling factor), thereby obtaining a power-normalized constellation.

[0076] Example 3:

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[0077]

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[0078] If this constellation needs to be power normalized, the entire constellation can be multiplied by a normalization factor (scaling factor), i.e., each constellation point in the constellation can be multiplied by a normalization factor (scaling factor), thereby obtaining a power-normalized constellation.

[0079] Example 4:

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[0081] Example 5:

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[0083] Example 6:

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[0084] The star constellation shown in the right diagram of FIG. 12 can be formed by generally extending outward the width of the constellation points of the four arms (semi-rays passing through the origin in the 45°, 135°, 225°, and 315° directions) of the star constellation shown in the center diagram of FIG. 12, thereby making the constellation point distribution of the star constellation more uniform and improving the demodulation performance. However, in order to increase the average power of the constellation, a second constellation model in which the additional offset amount β of a single arm is 0 can also be adopted in some scenarios, and this is not specifically limited here.

[0085] The numerical values ​​shown in the examples of the present application are merely illustrative and are not specifically limited, and the values ​​can be adaptively adjusted according to the actual situation.

[0086] In the information transmission in all the above-mentioned embodiments, information is information in a broad sense, i.e., information may be traffic data, information for system control, i.e., signals, or information may include bit data that needs to be transmitted, such as traffic bit data or signaling bit data, where English expressions such as message, information, and payload can all represent information.

[0087] The receiving side in all the above-mentioned embodiments may be a base station, a receiver, an access point, etc., and is not particularly limited here.

[0088] Also, referring to FIG. 13, an embodiment of the present application further provides a communication device 100 including a memory 102, a processor 101, and a computer program stored in the memory 102 and executable by the processor 101.

[0089] The processor 101 and the memory 102 may be connected by a bus or in some other way.

[0090] Memory 102 functions as a non-transitory computer-readable storage medium for storing non-transitory software programs and non-transitory computer-executable programs. Additionally, memory 102 may include high-speed random access memory and may further include non-transitory memory such as at least one magnetic disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, memory 102 optionally includes memory located remotely from processor 101, and these remote memories may be connected to processor 101 via a network. Examples of such networks include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0091] The non-transitory software programs and instructions required to implement the signal modulation method of the above embodiment are stored in memory 102 and, when executed by processor 101, perform the signal modulation method of the above embodiment, for example, perform method step S110 of Figure 2 described above.

[0092] The above-described device embodiments are merely examples, and the units described herein as separate components may or may not be physically separated, i.e., they may be located in one place or distributed across multiple network units. To achieve the objectives of this embodiment, some or all of the modules may be selected according to actual needs.

[0093] In addition, an embodiment of the present application further provides a computer-readable storage medium, on which computer-executable instructions are stored, and the computer-executable instructions are executed by a processor or a controller, for example, by a processor in the above-mentioned device embodiment, to cause the processor to perform the signal modulation method in the above-mentioned embodiment, and to perform the method step S110 in FIG. 2 described above.

[0094] In addition, an embodiment of the present application further provides a computer program product including a computer program or computer instructions, wherein the computer program or computer instructions is stored in a computer-readable storage medium, and a processor of the computer device reads the computer program or computer instructions from the computer-readable storage medium, and the processor executes the computer program or computer instructions, thereby causing the computer device to perform the signal modulation method in the above embodiment, for example, method step S110 of FIG. 2 described above.

[0095] All or part of the steps of the methods and systems disclosed above can be implemented as software, firmware, hardware, or any suitable combination thereof. Some or all of the physical components can be implemented as software executed by a processor, such as a central processor, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on computer-readable media, which may include computer storage media (or non-transitory media) and communication media (or transitory media). As known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information, such as computer-readable instructions, data structures, program modules, or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital multifunction disks (DVDs) or other optical disk memory, magnetic cassettes, magnetic tape, magnetic disk memory or other magnetic storage devices, or any other medium accessible by a computer for storing desired information. It is also well known by those skilled in the art that communication media typically include computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transmission mechanism, and may include any information delivery media.

Claims

1. 1. A signal modulation method comprising: [Equation 1] method. 【Request 2】 【Number 2】 The method of claim 1. 【Request 3】 【Number 3】 The method of claim 2. 【Request 4】 【Number 4】 The method of claim 3. 【Request 5】 【Number 5】 The method of claim 2. 【Request 6】 【Number 6】 The method of claim 2. 【Request 7】 【Number 7】 The method of claim 2. 【Request 8】 【Number 8】 The method of claim 2. 【Request 9】 【Number 9】 The method of claim 2. 【Request 10】 【Number 10】 The method of claim 2. 【Request 11】 【Number 11】 The method of claim 1.

12. A communication device, at least one processor; at least one memory for storing at least one program, wherein: A communications device, wherein at least one said program, when executed by at least one said processor, implements the signal modulation method according to any one of claims 1 to 11.

13. A computer-readable storage medium storing computer-executable instructions for carrying out the signal modulation method according to any one of claims 1 to 11.

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