A multi-band signal generation apparatus and method

Abstract

The application provides a multi-band signal generation device and method, the method first utilizes digital signal processing technology to pre-process the signal, including modulation, arbitrary rate interpolation filtering, local mixing and other operations, to realize preliminary adjustment of the signal spectrum. Then, through a multi-phase synthesis filter bank technology, multiple pre-processed signals are combined together to form a synthesized signal with multi-band characteristics. Experimental results show that the generated signal has the characteristics of high precision, low distortion, high resource utilization and multi-band, and can be widely applied in communication, radar, electronic countermeasure and other fields. The method not only improves the efficiency and precision of signal generation, but also provides a new idea and method for the development of multi-band signal processing technology.

Description

Technical Field

[0001] This application relates to the field of signal processing technology, and in particular to a multi-band signal generation apparatus and method. Background Technology

[0002] With the continuous development of technologies such as communication, radar, and electronic countermeasures, the application of multi-band signals is becoming increasingly widespread. Multi-band signals refer to signals whose spectrum contains multiple different frequency components, which can be distributed across different frequency bands. Generating high-quality multi-band signals is crucial for realizing these technological applications.

[0003] Currently, multi-band signal generation mainly employs two methods: analog signal generation and digital signal generation. While analog signal generation is simple to implement, it struggles with complex and dynamic spectrum adjustments, suffers from low accuracy and stability, and experiences a sharp increase in hardware costs as the number of signals increases. Traditional digital signal generation methods, while overcoming these issues, typically require separate modulation, interpolation filtering, and mixing operations for each frequency band. These operations often consume significant resources in the FPGA, including LUTs, DSPs, and RAM, resulting in low signal generation efficiency.

[0004] To address the aforementioned issues, this application proposes a multi-band signal generation method that combines digital signal processing and waveform synthesis techniques to generate multi-band signals with complex spectral characteristics. Summary of the Invention

[0005] In view of the above problems, embodiments of this application provide a multi-band signal generation apparatus and method to overcome or at least partially solve the above problems.

[0006] In a first aspect, embodiments of this application provide a multi-band signal generation method, the method comprising: Obtain N raw input signals; The N original input signals are preprocessed to obtain the first filtered signals and mixing data for multiple channels; A polyphase synthesis filter bank is obtained by cascading IFFT and polyphase filtering operations, and the mixing data from multiple channels is synthesized and filtered using the polyphase synthesis filter bank. Generate a synthetic signal with multi-band characteristics.

[0007] Optionally, the preprocessing of the N original input signals to obtain the first filtered signal for multiple channels includes: The N original input signals are scaled using a gain controller; By interpolating and filtering each scaled signal using an arbitrary multiplier interpolation filter, N first filtered signals with the same sampling rate are obtained. The N first-filtered signals are mixed to obtain N mixed data.

[0008] Optionally, the arbitrary-rate interpolation filter is a Farrow interpolation filter.

[0009] Optionally, the polyphase synthesis filter bank consists of N polyphase filters, and the polyphase synthesis filter bank is as follows: ; in, The Nth order inverse Fourier transform matrix is ​​represented by IFFT; Each polyphase filter is: ; in, Represents filter The multiphase components; K is the overlap factor, N is the number of elementary filters, k represents the time-domain coefficient index of the elementary filter, and n represents the index of the elementary filter; This represents a delay operator with a delay of l.

[0010] Secondly, embodiments of this application provide a multi-band signal generation apparatus, the apparatus comprising: The signal input module is used to acquire N raw input signals; The preprocessing module is used to preprocess N original input signals to obtain the first filtered signal for multiple channels; The polyphase synthesis filter module is used to obtain a polyphase synthesis filter bank by cascading IFFT and polyphase filtering operations, and then perform synthesis filtering operations on the first filtered signals of multiple channels through the polyphase synthesis filter bank. The generation module is used to generate synthesized signals with multi-band characteristics.

[0011] Furthermore, the preprocessing module includes: The gain control module is used to scale the N original input signals using a gain controller; The sampling rate matching module is used to interpolate and filter each scaled signal through an arbitrary multiplier interpolation filter to obtain N first filtered signals with the same sampling rate. The mixing module is used to perform mixing processing on N first filtered signals to obtain N mixed data.

[0012] The specific beneficial effects are as follows: First, this application utilizes digital signal processing technology to perform filtering, modulation, gain control, arbitrary-rate interpolation filtering (Farrow), and local mixing on the original signal to achieve preliminary spectrum adjustment. By setting different parameters such as gain parameters, the ratio of the input to output sampling rate of the Farrow module, mixing frequency, IFFT length, and filter bandwidth, it can flexibly meet the generation requirements of signals with different frequency bands and speeds.

[0013] Secondly, this application performs IFFT channelization on the preprocessed signals, then filters them using a high-performance polyphase filter, and finally synthesizes the sub-channels, thereby effectively fusing the signals of each frequency band to generate a synthesized signal with multi-frequency band characteristics.

[0014] In summary, this application enables the rapid and efficient generation of signals across multiple frequency bands, producing signals with high precision, low distortion, and high efficiency. Therefore, it possesses significant application value and practical importance. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a block diagram of a conventional analog multi-band signal generation provided in the embodiments of this application.

[0017] Figure 2 This is a block diagram of conventional digital multi-band signal generation provided in the embodiments of this application.

[0018] Figure 3 This is a logic block diagram of the novel multi-band signal generation method provided in the embodiments of this application.

[0019] Figure 4 This is a logic block diagram of arbitrary sampling rate transformation based on the resampling principle provided in the embodiments of this application.

[0020] Figure 5 This is a schematic diagram illustrating the principle of time-domain interpolation with arbitrary multiplier factors provided in the embodiments of this application.

[0021] Figure 6 This is a structural diagram of an arbitrary-rate interpolation filter based on the Farrow structure provided in the embodiments of this application.

[0022] Figure 7 This is the key code of the traditional digital multi-band signal generation method provided in the embodiments of this application.

[0023] Figure 8 This is the key code of the novel multi-band signal generation method of the present invention provided in the embodiments of this application.

[0024] Figure 9 This is a simulation verification diagram of the multi-band signal generated according to the embodiments of this application; Figure 9 In the image: (a) is a time-domain signal simulation comparison of the traditional digital multi-band signal generation method and the new multi-band signal generation method; (b) is a frequency-domain signal simulation comparison of the traditional digital multi-band signal generation method and the new multi-band signal generation method. Detailed Implementation

[0025] Exemplary embodiments of this application will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of this application are shown in the drawings, it should be understood that this application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of this application and to fully convey the scope of this application to those skilled in the art.

[0026] Example 1: Refer to Figure 1 , Figure 1 This is a block diagram of a traditional analog multi-band signal generation method, which suffers from low signal generation accuracy and high cost. Figure 2 This is a block diagram of a traditional digital multi-band signal generation method, which suffers from low signal generation efficiency. To overcome the shortcomings of these two traditional multi-band signal generation methods, this application provides a multi-band signal generation method that combines... Figure 3 The method may include: Step 1: Obtain N raw input signals.

[0027] like Figure 3 First, acquire N raw input signals m at different rates. i (k) (i=0,…,N-1), where k represents the sampling point index of the input signal; Step 2: Scale all the original input signals using a gain controller.

[0028] Step 3: Filter each scaled signal using an arbitrary multiplier interpolation filter (Farrow) to obtain N first filtered signals with the same sampling rate.

[0029] Step 4: Perform frequency mixing on the N first filtered signals, shifting the spectrum of the N first filtered signals to the corresponding frequencies to obtain N mixed data; Step 5: Implement a multiphase synthesis filter bank by cascading IFFT and polyphase filtering operations to synthesize and filter N mixing data from N channels to generate a synthesized signal with multi-band characteristics. Specifically, from Figure 3 As can be seen in the embodiments of this application, the novel multi-band signal transmission structure is unique in that it incorporates an arbitrary-rate interpolation filter, a local mixer, and a gain controller. These components work together to allow for flexible configuration of the frequency, rate, and amplitude within each sub-channel. After signal preprocessing, each channel then passes through a polyphase synthesis filter bank to generate the multi-band signal. This flexibility brings significant advantages to the novel multi-band signal transmitter, enabling it to better adapt to various application scenarios and meet different signal processing needs.

[0030] Furthermore, common interpolation filters include linear interpolators, parabolic interpolators, Lagrange interpolators, and high-performance interpolators composed of optimal low-pass filters. Among these, the most widely used is the cubic interpolator with a Farrow structure. The arbitrary-rate interpolation filter in this invention is a Farrow difference filter, such as... Figure 6 As shown, it only requires four consecutive input signals closest to the optimal interpolation time to calculate the interpolation value.

[0031] In principle, arbitrary rate conversion can be easily achieved by passing the input digital signal through an ideal analog reconstruction low-pass filter, and then resampling at the filter's output. A block diagram illustrating the sampling rate conversion principle of an arbitrary rate interpolation filter can be found here. Figure 4 Assuming the sampling period of the original input signal is The input signal is Sampling rate After passing through a digital-to-analog converter and an analog low-pass filter, a reconstructed analog output signal is obtained. : (1) Among them, T s The sampling period is represented by m, where m represents a sampling period of T. s The corresponding sampling point index, This represents an analog low-pass filter. Indicates time; For output Assuming at every time Then it is resampled again, and the data after resampling is Then we have: (2) in, For resampled output, T i The sampling period corresponding to the resampling is k, and the sampling point index corresponding to the resampling is k. As can be seen, a DAC and an analog filter are used in the sampling rate conversion process to realize the analog reconstruction of the signal. However, the impulse response of an ideal analog low-pass filter... It has an infinite duration, therefore if the input sequence is known The sampling period of the input signal and the sampling period of the output. Therefore, interpolation algorithms can be used in the digital domain to approximate the value. For the response, common interpolation algorithms include linear interpolation, parabolic interpolation, and Lagrange interpolation.

[0032] Therefore, the base point m is introduced. k and fractional interval The interpolation formula can be rewritten as: (3) Where N1 and N2 represent the current interpolation base point m, respectively. k The first N1 original sampling points and the last N2 original sampling points.

[0033] The base point is the distance from the interpolation point on the objective timeline. The most recent previous one Location; The fractional interval, i.e., the interpolation point. On the objective timeline The distance afterwards is Location; Introduction and Used to represent and The adjustment relationship between them, in terms of time, is as follows: Figure 5 As shown. Among them, It determines the calculation of k interpolations of Each signal sample value; The interpolation estimation point was indicated, and it was determined how it would be used to calculate... of Each interpolation filter impulse response value. Generally... It is an irrational number, therefore It is also an irrational number, and it changes with each interpolation.

[0034] Another key technology introduced in this invention is the polyphase synthesis filter bank, assuming the transmission filter It includes A finite impulse response filter with several coefficients, the transmission filter The z-transform is: (4) Where l represents the time-domain coefficient index of the filter. Represents the time-domain coefficients of the filter. This represents a delay operator with a delay of l. Assumption , It can be decomposed into N elementary filters. Therefore, it generates a polyphase network: (5) Where K is the overlap factor, N is the number of elementary filters, k represents the time-domain coefficient index of the elementary filter, and n represents the index of the elementary filter. At this time, use Indicates by conduct The filter derived from the frequency shift: (6) Using polyphase representation, Represented as: (7) in, Represents filter Multiphase components; Through the Frequency shifting the response yields a uniform filter bank. Since it is composed of... It is derived from this, therefore The prototype filter is called a filter bank.

[0035] If all filters are derived from the prototype filter... The frequency shift factor is derived from this, so the filter bank has the following expression: ; in, The Nth order inverse Fourier transform matrix is ​​represented by IFFT.

[0036] Simulation Case Figure 7 and Figure 8 These are the key codes from MATLAB simulations of the traditional digital multi-band signal generation method and the novel multi-band signal generation method proposed in this invention. Figure 9 The time-frequency diagrams of the two generation methods are presented, and their performance in practical applications is revealed through comparison.

[0037] pass Figure 9A comparison of the simulation results in (a) and (b) shows that the time-domain signal characteristics of the novel implementation are basically consistent with those of the traditional implementation. In the frequency domain, the spectral characteristics of the three main signal components of the two implementations are highly consistent. For other invalid image signals generated by the upsampling process, the novel implementation proposed in this invention has better suppression performance than the traditional implementation. Furthermore, compared with the traditional implementation, the novel multi-band signal transmission structure exhibits significant advantages in resource efficiency, parameter flexibility, and cost savings. By introducing arbitrary-rate interpolation filters, local mixers, gain controllers, and polyphase synthesis filter banks, the novel transmission structure can generate multi-band signals more efficiently while providing greater parameter configuration flexibility, thereby effectively reducing generation costs.

[0038] Example 2: This application also provides a multi-band signal generation device, which may include: The signal input module is used to acquire N raw input signals; The preprocessing module is used to preprocess N original input signals to obtain the first filtered signal for multiple channels; The polyphase synthesis filter module is used to obtain a polyphase synthesis filter bank by cascading IFFT and polyphase filtering operations, and then perform synthesis filtering operations on the first filtered signals of multiple channels through the polyphase synthesis filter bank. The generation module is used to generate synthesized signals with multi-band characteristics.

[0039] Furthermore, the preprocessing module includes: The gain control module is used to scale the N original input signals using a gain controller; The sampling rate matching module is used to interpolate and filter each scaled signal through an arbitrary multiplier interpolation filter to obtain N first filtered signals with the same sampling rate. The mixing module is used to perform mixing processing on N first filtered signals to obtain N mixed data.

[0040] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0041] This application describes embodiments of methods and apparatus according to flowchart illustrations and / or block diagrams. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing terminal device to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing terminal device, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0042] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing terminal device to operate in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0043] These computer program instructions can also be loaded onto a computer or other programmable data processing terminal equipment, causing a series of operational steps to be performed on the computer or other programmable terminal equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable terminal equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the functions specified in one or more boxes. Although preferred embodiments of the embodiments of this application have been described, those skilled in the art, once they learn the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of this application.

[0044] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only 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 terminal device 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 terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0045] The multi-band signal generation apparatus and method provided in this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for generating multi-band signals, characterized in that, The method includes: Obtain N raw input signals; The N original input signals are preprocessed to obtain the first filtered signals and mixing data for multiple channels; A polyphase synthesis filter bank is obtained by cascading IFFT and polyphase filtering operations, and the mixing data from multiple channels is synthesized and filtered using the polyphase synthesis filter bank. Generate a synthetic signal with multi-band characteristics.

2. The method according to claim 1, characterized in that, The preprocessing of N original input signals to obtain first filtered signals for multiple channels includes: The N original input signals are scaled using a gain controller; By interpolating and filtering each scaled signal using an arbitrary multiplier interpolation filter, N first filtered signals with the same sampling rate are obtained. The N first-filtered signals are mixed to obtain N mixed data.

3. The method according to claim 2, characterized in that, The arbitrary rate interpolation filter is a Farrow interpolation filter.

4. The method according to claim 1, characterized in that, The polyphase synthesis filter bank consists of N polyphase filters, and the polyphase synthesis filter bank is as follows: ； in, The Nth order inverse Fourier transform matrix is ​​represented by IFFT; Each polyphase filter is: ； in, Represents filter The multiphase components; K is the overlap factor, N is the number of elementary filters, k represents the time-domain coefficient index of the elementary filter, and n represents the index of the elementary filter; This represents a delay operator with a delay of l.

5. A multi-band signal generation device, characterized in that, The device includes: The signal input module is used to acquire N raw input signals; The preprocessing module is used to preprocess N original input signals to obtain the first filtered signal for multiple channels; The polyphase synthesis filter module is used to obtain a polyphase synthesis filter bank by cascading IFFT and polyphase filtering operations, and then perform synthesis filtering operations on the first filtered signals of multiple channels through the polyphase synthesis filter bank. The generation module is used to generate synthesized signals with multi-band characteristics.

6. The apparatus according to claim 5, characterized in that, The preprocessing module includes: The gain control module is used to scale the N original input signals using a gain controller; The sampling rate matching module is used to interpolate and filter each scaled signal through an arbitrary multiplier interpolation filter to obtain N first filtered signals with the same sampling rate. The mixing module is used to perform mixing processing on N first filtered signals to obtain N mixed data.

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