Phase continuous generation method of digital modulation signal and electronic equipment

Abstract

The invention relates to the technical field of signal processing and test measurement, and discloses a phase continuous generation method of a digital modulation signal and electronic equipment. According to the method, differential and non-differential modulation signals are classified, a core mechanism combining differential phase closed-loop control and shaping filter state continuity processing is adopted, code element sequence adjustment, periodic continuation, constellation mapping, interpolation filtering, data interception and other steps are executed in sequence, and a complete phase continuity guarantee process is formed. The technical problems of signal distortion and high FPGA real-time generation resource consumption caused by traditional windowing processing are effectively solved, high-quality signal generation with strict and continuous phases and pure frequency spectrums is achieved, and the method has the advantages of being excellent in phase continuity, high in waveform fidelity, good in resource utilization rate, high in loop playing reliability and the like; the method is suitable for scenes of communication system testing, complex electromagnetic environment construction, navigation signal simulation and the like.

Description

Technical Field

[0001] This invention relates to the fields of signal processing technology and testing and measurement, and discloses a method for generating the phase continuity of a digital modulated signal and an electronic device thereof. Background Technology

[0002] Digitally modulated signals are central to communications, the construction of complex electromagnetic environments, and test and measurement. In these applications, it is often necessary to loop pre-generated signal waveform files to simulate continuous signal sources or perform repetitive tests. The phase characteristics of a signal are a key factor affecting its quality; achieving phase continuity when connecting the beginning and end of the waveform is crucial for avoiding spectral spurious signals, ensuring the quality of the transmitted signal, and guaranteeing correct demodulation at the receiver.

[0003] However, during the development of this invention, it was discovered that existing methods for ensuring signal continuity have significant limitations. Currently, there are two main methods: one is to window the generated waveform to smooth its amplitude changes at the beginning and end; the other is to continuously generate signal data streams in hardware such as FPGAs, completely avoiding the use of looped waveform file playback. While windowing is simple to operate, it inevitably introduces signal distortion, altering the signal's time-frequency characteristics and severely impacting the demodulation performance at the receiving end. While real-time signal generation in FPGAs avoids phase discontinuity issues in principle, it requires a continuous large amount of logic resources and processing units, resulting in high hardware costs, high system power consumption, and a lack of flexibility.

[0004] While both of the aforementioned approaches attempt to address the phase continuity problem, they are both compromises between performance and resources, generally suffering from the inherent drawback of "sacrificing quality for continuity" or "sacrificing efficiency for continuity." The industry lacks a universal method to generate high-quality digital modulation signals that can be directly used for seamless loop playback without introducing signal distortion or relying on high-intensity real-time computation. Therefore, there is an urgent need for an innovative signal generation method that can fundamentally solve the phase discontinuity problem while simultaneously ensuring signal fidelity, low resource consumption, and high versatility to meet the demands of high-standard test and measurement and communication system simulation. Summary of the Invention

[0005] This invention discloses a method and electronic device for generating phase continuity of digital modulated signals, which can realize unified processing of non-differential and differential modulated signals, precise control of phase continuity and seamless loop playback of waveforms, greatly improve the quality and reliability of signals in test, measurement and communication systems, significantly reduce the dependence of traditional solutions on windowing processing or continuous FPGA operation, and effectively solve the systemic problems of phase jump leading to spectral spurious signals, demodulation performance degradation and high system resource consumption in the prior art.

[0006] To achieve the above objectives, the present invention provides a method for generating the phase continuity of a digital modulation signal, comprising: Acquire the symbol sequence, the preset parameters of the digital modulation signal to be generated, and the parameters of the target shaping filter; If the digital modulation signal to be generated is a differential modulation signal, differential phase continuity processing is performed on the symbol sequence so that the total phase change corresponding to the processed symbol sequence is an integer multiple of 360°, and the first sequence to be extended is obtained. If the digital modulation signal to be generated is a non-differential modulation signal, then the symbol sequence is directly used as the second sequence to be extended. The first or second sequence to be extended is subjected to periodic extension processing, wherein the length of the periodic extension is determined based on the characteristics of the target shaping filter and the preset parameters of the digital modulation signal to be generated. The periodically extended sequence to be extended is sequentially subjected to constellation mapping, interpolation, and shaping filtering using a target shaping filter to generate initial waveform data. Effective data segments are extracted from the initial waveform data, wherein the starting position of the extraction is determined based on the group delay of the target shaping filter, thereby obtaining a digitally modulated signal waveform capable of continuous phase loop playback.

[0007] Preferably, differential phase continuity processing is performed on the symbol sequence, including: Calculate the total phase change of the symbol sequence; Determine whether the total phase change is an integer multiple of 360°; If not, at least one symbol in the symbol sequence is adjusted so that the total phase change corresponding to the adjusted symbol sequence is an integer multiple of 360°.

[0008] Preferably, adjusting at least one symbol in the symbol sequence includes: Based on a predefined differential phase mapping relationship, the phase difference corresponding to the symbol in the symbol sequence is determined; The first symbol in the symbol sequence is replaced with the second symbol, wherein the phase difference corresponding to the second symbol is not equal to the phase difference corresponding to the first symbol.

[0009] Preferably, a predefined differential phase mapping relationship maps symbols to fixed phase difference values.

[0010] Preferably, the predefined differential phase mapping relationship is the mapping relationship defined by DBPSK, DQPSK, π / 2-DBPSK or π / 4-DQPSK modulation scheme.

[0011] Preferably, the length of the periodic extension is determined based on the coefficient length of the target shaping filter and the oversampling factor of the digital modulation signal to be generated.

[0012] Preferably, the target shaping filter is a raised cosine filter, a root raised cosine filter, or a Gaussian filter.

[0013] Preferably, extracting a valid data segment from the initial waveform data includes: extracting a data segment with a length equal to the product of the symbol sequence length and the oversampling factor.

[0014] Preferably, when the target shaping filter is a raised cosine filter or a root raised cosine filter, the interpolation process uses zero-padding interpolation. When the target shaping filter is a Gaussian filter, the interpolation process uses hold-and-hold interpolation.

[0015] An electronic device for generating the phase continuity of a digital modulated signal includes: a processor and a memory, the processor and the memory being connected via a communication bus; wherein, the processor is used to call and execute a program stored in the memory; the memory is used to store the program, the program being used to implement the aforementioned method for generating the phase continuity of the digital modulated signal.

[0016] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention include at least the following: This invention solves the technical challenges of signal distortion and high resource consumption in real-time FPGA generation caused by traditional windowing methods through signal type-based processing and modular control mechanisms. Differential phase closed-loop control eliminates waveform jumps caused by phase accumulation non-closing; periodic extension and state truncation resolve the discontinuities at the beginning and end of the waveform caused by the initial state and truncation effect of the shaping filter; and intelligent adjustment of the symbol sequence achieves precise phase control while maintaining information validity. This method enables the generation of high-quality signals with strict phase continuity and spectral purity, significantly improving waveform fidelity and loop playback reliability, while greatly reducing computational resource requirements. It provides a high-precision, low-overhead practical solution for the fields of test and measurement and communication simulation. Attached Figure Description

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

[0018] Figure 1 This is a flowchart illustrating the overall process of continuous generation of digital modulation signal phase in this invention. Figure 2 This is a schematic diagram of the QPSK signal constellation mapping of the present invention; Figure 3 This is a flowchart of the state continuity processing of the molding filter of the present invention; Figure 4 This is a flowchart of the differential modulation signal symbol adjustment process of the present invention; Figure 5 This is a simulation result diagram of the continuity of the molding filter according to the present invention; Figure 6 This is a waveform diagram of the signal without adjusting the symbol sequence in this invention; Figure 7 This is a waveform diagram of the signal after adjusting the symbol sequence according to the present invention. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] In this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0021] To better understand this application, the technical names involved in this application are explained below: Periodic extension: The "periodic extension" mentioned in this invention refers to the operation of copying a segment of data from the tail of the original symbol sequence and adding it to the head of the sequence to form a longer sequence to be processed with continuous state at the boundary.

[0022] Differential phase continuity processing: The "differential phase continuity processing" described in this invention refers to the process of adjusting the symbol sequence of the differential modulation signal so that the cumulative phase change obtained by the sequence through a predefined differential phase mapping relationship is an integer multiple of 360°, thereby ensuring that the signal waveform is phase continuous during loop playback.

[0023] Total phase change: The “total phase change” mentioned in this invention refers to the algebraic sum of the phase differences corresponding to all symbols in a differential modulation symbol sequence according to a predefined differential phase mapping relationship.

[0024] Valid data segment: The “valid data segment” mentioned in this invention refers to the final waveform data segment corresponding to the original symbol sequence obtained after removing invalid data at the front end affected by the initial state of the filter from the initial waveform data after shaping and filtering.

[0025] Phase continuity / phase continuity: The “phase continuity” mentioned in this invention specifically refers to the characteristic that when the waveform data of a digital modulation signal is connected end to end for loop playback, the phase value of the signal does not change abruptly or jump at the connection point, presenting a smooth transition.

[0026] Group delay: The "group delay" described in this invention, for the shaping filter, has a value of The number of symbol periods is L, where L is the filter coefficient length and N is the oversampling factor.

[0027] Oversampling factor: The "oversampling factor N" mentioned in this invention refers to the ratio of the output waveform sampling rate to the input symbol rate during the digital modulation signal generation process, which is also equivalent to the interpolation factor during interpolation processing.

[0028] Constellation mapping: The "constellation mapping" described in this invention refers to the process of converting digital symbols into a point on the complex plane. For non-differential modulation, it is an "absolute mapping," where the symbol directly corresponds to a fixed phase and amplitude; for differential modulation, it is a "relative mapping," where the symbol corresponds to the amount of phase change (phase difference) relative to the previous symbol.

[0029] Example 1 As can be seen from the background technology above, in the fields of signal processing technology and test and measurement, generating digitally modulated signals with strict phase continuity and pure spectrum is the core prerequisite for achieving high-precision and high-reliability testing and simulation. However, in existing technologies, signal generation methods relying on windowing processing or real-time generation by FPGA, while alleviating the phase jump problem during waveform loop playback to some extent, have inherent limitations such as inherent signal distortion or huge system resource consumption. They cannot ensure signal quality while also taking processing efficiency into account, making them difficult to integrate into portable test equipment or large-scale channel simulation systems that have stringent requirements for waveform fidelity and resource overhead. While some local optimization schemes for specific modulation types have improved in a single stage (such as filtering or mapping), their processing flow fails to achieve end-to-end phase continuity coordinated control from symbol sequence to final waveform. This results in the generated signal being unable to simultaneously achieve key performance indicators such as phase continuity, waveform fidelity, resource utilization efficiency, and loop playback reliability. The quality of the generated signal is significantly different from the high standards required by real test scenarios, and cannot meet the application needs of high-value scenarios such as modern communication equipment R&D, complex electromagnetic environment simulation, and high-precision navigation signal simulation. Therefore, this application provides a method for generating the phase continuity of a digital modulation signal, such as... Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the method includes: S101: Obtain parameters and symbol sequences.

[0030] Specifically, we obtain input from three aspects: Original symbol sequence: that is, the binary data stream to be modulated.

[0031] Preset parameters for the digital modulation signal to be generated: including modulation type (e.g., QPSK, π / 4-DQPSK, 16QAM), symbol rate R s Oversampling factor N (i.e., interpolation factor).

[0032] Parameters of the target shaping filter include: filter type (raised cosine, root-raised cosine, or Gaussian), filter coefficient vector, and roll-off factor. (Applicable to raised cosine filters), 3dB bandwidth B (applicable to Gaussian filters), and filter coefficient length L, etc.

[0033] S102: Determine the type of digital modulation signal to be generated.

[0034] Based on the modulation type parameters obtained in step S101, determine whether the signal is a differential modulation signal (such as DBPSK, DQPSK, π / 2-DBPSK, π / 4-DQPSK, etc.). Based on the determination result, execute different branch processes: If it is a differential modulation signal, then step S103 is executed to perform the critical differential phase continuity preprocessing.

[0035] If the signal is not differentially modulated (such as QPSK, 16QAM, etc.), then proceed to step S104 and directly use the original symbol sequence as the second sequence to be extended.

[0036] S103: Perform differential phase continuity processing on the symbol sequence.

[0037] This step is the core innovation that ensures the phase continuity of the differential modulation signal during loop playback. Its goal is to make the total phase change of the processed symbol sequence an integer multiple of 360°, thereby achieving phase period closure. Please refer to [link / reference]. Figure 4 The flowchart for differential modulation signal symbol adjustment shown below details the specific steps: Calculate the total phase change of the symbol sequence.

[0038] Based on the predefined differential phase mapping relationship (as shown in Table 1), the entire original symbol sequence is traversed to calculate the phase difference corresponding to all symbols. The sum, i.e., the total phase change. .

[0039] The calculation formula is as follows: in, The value is obtained by looking up Table 1 from the current symbol value. For example, for π / 4-DQPSK, symbol 0 corresponds to 45°, symbol 1 corresponds to 135°, and so on.

[0040] Table 1 Determine whether the total phase change is an integer multiple of 360°.

[0041] calculate Remainder over 360°: judge Is it equal to 0? If it is equal to 0, it means that the current sequence already satisfies the phase periodicity, and no adjustment is needed. The original sequence is directly output to the subsequent periodic extension step. If it is not equal to 0, the subsequent steps are executed, and at least one symbol in the symbol sequence is adjusted.

[0042] Adjust at least one symbol in the symbol sequence.

[0043] The purpose of this step is to "fill in" or "reduce" the total phase change to a full cycle by fine-tuning the symbols. Its mathematical goal is to make the adjusted... .

[0044] Adjustment principle: Based on a predefined differential phase mapping relationship, find one or a group of symbols to replace. The replacement principle is: replace the first symbol in the sequence (whose corresponding phase difference is...) with the first symbol in the sequence (whose phase difference is...). Replaced with a second symbol (whose corresponding phase difference is) ),and .

[0045] Calculation of adjustment amount: The phase amount to be adjusted is the remainder calculated in the previous step. .

[0046] Adjustment strategy: based on modulation type and The value is adjusted according to predefined rules. For example, using π / 4-DQPSK: like Then a symbol 0 can be changed to 1, or 2 to 3, or 3 to 0 (according to the mapping relationship in Table 1, these operations can all produce a net phase change of +90°).

[0047] like Then a symbol 1 can be changed to 3, or 0 can be changed to 2 (these operations can produce a net phase change of -180°).

[0048] Through one or more such replacements, the remainder of the total phase change is obtained. It is corrected to 0. The symbol sequence after this optimization is called the first sequence to be extended.

[0049] S104: Perform periodic extension processing on the sequence to be extended.

[0050] This step aims to address the discontinuities at the beginning and end of the shaped filter caused by the initial state and truncation effect. Please refer to [link / reference]. Figure 3 The processing flow is as follows: The first or second sequence to be extended obtained from the above steps is periodically extended. Specifically, a code element of a certain length is added to the beginning of the sequence.

[0051] Determination of the periodic extension length: This length It is calculated precisely based on the coefficient length L and oversampling factor N of the target shaping filter.

[0052] Core principle: Group delay of the filter One symbol period. The amount of data affected by the filter's initial state (i.e., the length of the "warm-up" segment that needs to be truncated) is... 100 sample points. To ensure that the filter's state smoothly transitions to the beginning of the periodic extension when processing the end of the sequence, it needs to be extended at least 100 times before the beginning of the sequence. A symbol.

[0053] Calculation formula: Therefore, the symbol length of periodic continuation is at least The corresponding sample point length is .

[0054] S105: Constellation mapping, interpolation, and shaping filtering.

[0055] This step performs the standard digital modulation signal generation process, but has specific requirements for the interpolation method.

[0056] Constellation mapping: Each symbol in the periodically extended symbol sequence is mapped to a point on the complex plane according to its modulation type. The method described in this invention is applicable to both non-differential and differential modulation, but the constellation mapping principle differs: For non-differential modulation signals (such as QPSK): Please refer to Figure 2 The diagram shows a QPSK signal constellation mapping. This is an absolute mapping, where each symbol directly corresponds to a fixed phase. For example, symbol 0 (binary 00) is mapped to a phase of 45°, symbol 1 (binary 01) is mapped to a phase of 135°, and symbols 2 (binary 10) and 3 (binary 11) are mapped to phases of 225° and 315° respectively, regardless of the preceding or following symbols.

[0057] For differential modulation signals (such as DQPSK, π / 4-DQPSK): this is a relative mapping. Symbols are not directly mapped to absolute phase, but rather to a phase difference. (The mapping relationship is defined in Table 1).

[0058] Interpolation: Upsampling the complex signal after constellation mapping, changing the sampling rate from the symbol rate R... s Increase to target sampling rate .

[0059] Zero-padding interpolation: This method is used when the target shaping filter is a raised cosine or root-raised cosine filter. The formula is: in, This is the oversampled signal obtained after zero-padding and interpolation. It is the symbol sequence after constellation mapping, and n is the interpolated sequence index.

[0060] Preservation of interpolation: This method is used when the target shaping filter is a Gaussian filter. The formula is: in, This is the oversampled signal obtained after holding interpolation. This indicates a floor operation. That is, it maintains a floor after each sign. Two identical values.

[0061] Shaping filtering: using a target shaping filter to filter the interpolated signal ( or Convolution operations are performed to limit the bandwidth and generate initial waveform data. .

[0062] The time-domain impulse response formula for a raised cosine filter: in, It is the symbol period ( ), It is the roll-off factor, and t is a continuous time variable.

[0063] The root raised cosine filter is the square root form of the raised cosine filter.

[0064] The time-domain impulse response formula for a Gaussian filter: in, B is the 3dB bandwidth, and t is a continuous time variable.

[0065] The initial waveform data generated in this step includes a "warm-up" segment due to the initial state of the filter and periodic extension, which is invalid.

[0066] S106: Extract a valid data segment from the initial waveform data.

[0067] like Figure 3 As shown, the initial waveform data generated in step S105 In the middle, invalid data at the beginning is removed.

[0068] Truncation principle and location: The starting position of the truncation is directly determined by the group delay of the target shaping filter. Decision. As mentioned earlier, the amount of invalid front-end data that needs to be truncated is... 1 sample point.

[0069] Truncation Length: The length of the extracted valid data segment should be equal to the length of the original symbol sequence. With oversampling factor The product of, i.e. These are sample points. This data constitutes the final digitally modulated signal waveform that can be continuously looped and played back in phase.

[0070] In summary, this embodiment, through the aforementioned precise process design and mathematical safeguards, achieves unified and accurate phase continuity control of differential and non-differential modulated signals, generating high-quality signal waveforms that can be used for seamless loop playback, effectively solving all the technical problems described in the background art.

[0071] Example 2 This embodiment aims to demonstrate, through computer simulation, the effectiveness and superiority of the method described in this invention in achieving phase continuity of digital modulation signals.

[0072] Simulation parameter settings: Modulation method: 16QAM (as a representative of non-differential modulation); Oversampling factor N: 16; Target shaping filter: root-raised cosine filter; Roll-off factor 0.35; Filter coefficient length L: 161; Symbol sequence: randomly generated; Processing procedure of the method of the present invention: 1. Calculate the periodic extension length. Filter group delay. The number of symbols. Therefore, the symbol length of periodic continuation. The corresponding sample point length .

[0073] 2. Periodically extend the original symbol sequence (add 5 symbols from the end of the sequence to the beginning of the sequence).

[0074] 3. Perform constellation mapping, zero-padding interpolation (due to the use of a root-raised cosine filter), and shaping filtering on the extended sequence to generate initial waveform data.

[0075] 4. Truncate from the beginning of the initial waveform data The invalid data from each sample point (i.e., the "preheating" segment) is used to obtain the final valid waveform data.

[0076] Simulation results and analysis: Please see Figure 5 The figure shows the simulation results of the shaping filter continuity of this invention. It illustrates a partial waveform after concatenating the generated effective waveform data. As can be clearly observed from the figure, at the connection points of the waveform data (i.e., the boundary between the tail and the head of the waveform data), the amplitude and phase of the signal transition smoothly without any jumps or breaks. This result fully demonstrates that the periodic extension and data truncation method proposed in this invention effectively eliminates the influence of the initial state and truncation effect of the shaping filter, achieving perfect continuity of the waveform during loop playback.

[0077] 2. Simulation verification of the continuity of differential phase mapping This simulation is used to verify that phase period closure can be achieved by adjusting the symbol of the differential modulation signal.

[0078] Simulation parameter settings: Modulation method: π / 4-DQPSK (as a representative of differential modulation); Oversampling factor N: 16; Target shaping filter: root raised cosine filter (its state continuity processing is the same as the 16QAM example); Roll-off factor 0.35; Symbol sequence: randomly generated.

[0079] Processing procedure: 1. First, perform differential phase continuity processing on the randomly generated original symbol sequence: Based on the mapping relationship in Table 1, calculate the total phase change of the sequence. .

[0080] Calculate its remainder modulo 360° In this simulation, the calculated results are as follows: .

[0081] because The symbols need to be adjusted. According to the adjustment strategy derived for π / 4-DQPSK based on this invention, the first symbol in the sequence with a value of 2 (corresponding to a phase difference of -135° according to Table 1) needs to be adjusted. In this simulation, it is replaced with a symbol value of 1 (corresponding to a phase difference of +135°). This replacement operation introduces a net phase adjustment of +270°, correcting the total phase change to an integer multiple of 360°, thus satisfying the requirement of phase periodicity.

[0082] 2. After the above adjustments, the first 10 bits of the code sequence change from 3, 2, 1, 2, 3, 2, 2, 1, 2, 3 before the adjustment to 3, 1, 1, 2, 3, 2, 2, 1, 2, 3 after the adjustment. It can be seen that only the second code element changes from 2 to 1, modifying the original sequence to a minimum, thus ensuring phase continuity.

[0083] 3. Using the adjusted symbol sequence, perform the same periodic extension, constellation mapping, interpolation, shaping filtering, and data truncation process as in the 16QAM example to generate the final waveform.

[0084] Simulation results and analysis: Please see Figure 6This figure shows the signal waveform of the present invention without adjusting the symbol sequence. It illustrates the connection between the beginning and end of the waveform generated directly without the symbol adjustment process in step S103. It is clearly visible that there is a significant phase jump at the connection point (discontinuous step changes in the waveform). This is because the total phase change of the sequence does not satisfy an integer multiple of 360°, resulting in the waveform's beginning and end phases not closing. Such a signal cannot be used for loop playback; otherwise, it will introduce severe spectral spurious signals.

[0085] Please see Figure 7 This is a waveform diagram of the signal after adjusting the symbol sequence according to the present invention. The diagram shows the connection between the beginning and end of the waveform generated after step S103 of the present invention, where the second symbol is adjusted from 2 to 1. Figure 6 In stark contrast, the phase is strictly continuous at the connection point, and the waveform transitions smoothly without any jumps. This demonstrates that the symbol adjustment method of this invention effectively ensures the periodicity of the differential modulation signal phase, achieving seamless loop playback.

[0086] Example 3 This embodiment aims to illustrate that the application scope of the digital modulation signal phase continuity generation method provided by the present invention is not limited to the specific modulation methods or shaping filter types explicitly listed in the foregoing embodiments. Those skilled in the art should understand that the core principles of the present invention have broad applicability.

[0087] 1. General description of differential modulation signals The foregoing embodiments illustrate the processing flow of differential modulation signals using DBPSK, DQPSK, π / 2-DBPSK, and π / 4-DQPSK as examples. However, the differential phase continuity processing method described in this invention can be extended to any modulation scheme employing differential phase coding.

[0088] The principle of its universality is that as long as the modulation method has a predefined mapping relationship that maps symbols to a fixed phase difference (regardless of whether the phase difference is 45°, 90°, 135° or any other arbitrary value), it will fall within the protection scope of this invention.

[0089] For example, higher-order differential modulation schemes, such as 8-DPSK (with phase differences of 0°, 45°, 90°, 135°, 180°, 225°, 270°, and 315°), are also applicable to this invention.

[0090] For 8-DPSK, its total phase change The calculation and judgment logic is completely consistent with that described in Example 1. If the remainder is calculated... If the value is not zero, then one or more symbols in the sequence can be adjusted and replaced with another valid symbol that can generate the required phase difference compensation, thereby ensuring that the total phase change is closed to an integer multiple of 360°. Therefore, the core of the method described in this invention—calculating the total phase change and fine-tuning the symbols to ensure phase period closure—is applicable to any differential modulation signal.

[0091] 2. General Description of Shaped Filters The foregoing embodiments illustrate shaping filtering using raised cosine filters, root-raised cosine filters, and Gaussian filters as examples. However, the method described in this invention for solving the filter initial state problem through periodic extension and obtaining effective waveform data through data truncation based on group delay is applicable to any digital filter with linear phase or known group delay characteristics.

[0092] The principle of its universality lies in the fact that the length of the periodic extension depends on the group delay of the filter (or equivalently, on its coefficient length and oversampling factor), and is independent of the specific type of filter. For example, other types of filters, such as elliptic filters, Chebyshev filters, or any custom-defined finite-length unit impulse response (FIR) filters, will have the same group delay. Once determined, the corresponding periodic extension length and the amount of invalid front-end data to be truncated can be calculated.

[0093] Therefore, the core of the method described in this invention—ensuring the continuity of the filter state through periodic extension and obtaining a pure waveform through precise truncation—is applicable to any shaped filter with a definite group delay.

[0094] In summary, those skilled in the art, when applying the phase continuity generation method to other differential modulation schemes or using other types of shaping filters based on the core ideas disclosed in this invention, should not depart from the scope of protection of this invention. The foregoing examples are merely for illustrative purposes and are not intended to limit the scope of this invention.

[0095] Example 4 This application provides an electronic device in embodiment three, including: a processor and a memory, the processor and the memory being connected via a communication bus; wherein, the processor is used to call and execute a program stored in the memory; the memory is used to store the program, the program being used to implement the phase continuity generation method of digital modulation signal as provided in embodiment one of this application.

[0096] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computing software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0097] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0098] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

[0099] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for phase-continuous generation of a digitally modulated signal, characterized by, The method comprises the following steps: acquiring a symbol sequence, preset parameters of a digital modulation signal to be generated, and parameters of a target shaping filter; if the digital modulation signal to be generated is a differential modulation signal, performing differential phase continuity processing on the symbol sequence, so that a total phase change amount corresponding to the processed symbol sequence is an integer multiple of 360°, to obtain a first sequence to be extended; if the digital modulation signal to be generated is a non-differential modulation signal, directly taking the symbol sequence as a second sequence to be extended; performing periodic extension processing on the first sequence to be extended or the second sequence to be extended, wherein the length of the periodic extension is determined based on characteristics of the target shaping filter and the preset parameters of the digital modulation signal to be generated; sequentially performing constellation mapping, interpolation, and shaping filter processing by using the target shaping filter on the periodically extended sequence to be extended, to generate initial waveform data; cutting an effective data segment from the initial waveform data, wherein the starting position of the cutting is determined based on a group delay of the target shaping filter, so that a digital modulation signal waveform capable of being played in a phase-continuous loop is obtained.

2. The method of claim 1, wherein The differential phase continuity processing on the symbol sequence comprises the following steps: calculating a total phase change amount of the symbol sequence; judging whether the total phase change amount is an integer multiple of 360°; if not, adjusting at least one symbol in the symbol sequence, so that the total phase change amount corresponding to the adjusted symbol sequence is an integer multiple of 360°.

3. The method of claim 2, wherein The adjustment of the at least one symbol in the symbol sequence comprises the following steps: determining a phase difference corresponding to a symbol in the symbol sequence based on a predefined differential phase mapping relationship; replacing a first symbol in the symbol sequence with a second symbol, wherein the phase difference corresponding to the second symbol is not equal to the phase difference corresponding to the first symbol.

4. The method of claim 3, wherein The predefined differential phase mapping relationship maps a symbol to a fixed phase difference value.

5. The method of claim 4, wherein the step of generating a phase-continuous digital modulation signal is performed by the steps of: generating a phase-continuous digital modulation signal by using a look-up table, and generating a phase-continuous digital modulation signal by using a polynomial function. The predefined differential phase mapping relationship is a mapping relationship defined by a DBPSK, DQPSK, π / 2-DBPSK, or π / 4-DQPSK modulation mode.

6. The method of claim 1, wherein The length of the periodic extension is determined based on a coefficient length of the target shaping filter and an oversampling multiple of the digital modulation signal to be generated.

7. The method of claim 1, wherein The target shaping filter is a raised cosine filter, a root-raised cosine filter, or a Gaussian filter.

8. The method of claim 6, wherein the step of generating a phase-continuous digital modulated signal is performed by the steps of: The cutting of the effective data segment from the initial waveform data comprises cutting a data segment with a length being a product of a length of the symbol sequence and the oversampling multiple. ​ 9. The method of claim 7, wherein the step of generating a phase-continuous digital modulated signal is performed by the steps of: generating a phase-continuous digital modulated signal by using a look-up table and a phase-continuous digital modulated signal generation method of claim 1. When the target shaping filter is a raised cosine filter or a root-raised cosine filter, the interpolation processing adopts zero-padding interpolation. When the target shaping filter is a Gaussian filter, the interpolation processing adopts hold interpolation.

10. An electronic device for phase-continuous generation of a digitally modulated signal, characterized by The method comprises the following steps: a processor and a memory are connected through a communication bus; wherein the processor is used to call and execute a program stored in the memory; the memory is used to store a program, and the program is used to implement the method for generating a phase-continuous digital modulation signal according to any one of claims 1-9.

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