Vector signal analyzer data rate conversion method

Abstract

The invention relates to the technical field of vector signal analysis and processing, in particular to a vector signal analyzer data rate conversion method, which mainly comprises the following steps of: acquiring # imgabs0 # time domain data from the first data of the time domain data to obtain a first data group with the length of # imgabs1 #; after discrete Fourier transform is carried out on the first data set, inverse Fourier transform is carried out to obtain second time domain data, and the problems that a time domain filter with large time domain processing insertion and extraction multiples consumes computing resources and reduces real-time performance can be effectively solved. A time domain signal is converted to a frequency domain, and is converted to a time domain after frequency domain processing. The method is not limited by interpolation multiples and extraction multiples, fractional multiple resampling can be processed, and computing resources and computing time are not remarkably increased.

Description

Technical Field

[0001] The present invention relates to the technical field of vector signal analysis and processing, and in particular to a data rate conversion method for a vector signal analyzer. Background Art

[0002] The swept frequency spectrum analyzer is a traditional frequency domain measurement instrument. It is a swept tuned superheterodyne spectrum analyzer based on the traditional structure. The emergence of the swept frequency spectrum analyzer enabled engineers to perform frequency domain measurements decades ago.

[0003] However, traditional swept frequency analysis can only perform scalar measurements and only provide information related to the frequency and amplitude of the input signal. The analysis of digital modulation signals needs to provide the frequency information, amplitude information and phase information of the signal at the same time; compared with traditional swept frequency analysis, the phase information is added, which makes vector signal analysis a powerful tool for digital modulation signal analysis.

[0004] IQ analysis is an important mode of vector signal analyzer, which can measure the spectrum, envelope amplitude, IQ amplitude, IQ vector and phase of digital modulation signal. In IQ analysis, the data rate required by the user and the analysis bandwidth are in a fixed relationship, but in vector analyzer, the data rate given by the baseband signal processing module is usually not just right, so data rate conversion is required. Therefore, data rate conversion is an important technology that needs to be solved in vector signal analysis.

[0005] At present, data rate conversion is all processed by decimation in the time domain, and most of them are fractional decimation. This requires interpolation before decimation. For example, if the data rate of 1.5ARB (ARB: analysis bandwidth) is decimated to 1.25ARB, the decimation multiple is 5 / 6. Then it is necessary to first perform 5-fold interpolation, then filtering, and finally 6-fold decimation. The order of the filter is related to the insertion multiple and the decimation multiple. When the insertion multiple and the decimation multiple are both small, the filter order is low, and time domain filtering can be achieved; but in some extreme cases, according to the data rate conversion relationship, the decimation multiple and the insertion multiple may be relatively large. At this time, the filter order may be thousands or even tens of thousands. It consumes a lot of computing resources and reduces real-time performance. Summary of the invention

[0006] The purpose of the present invention is to provide a vector signal analyzer data rate conversion method to solve the above problems in the prior art.

[0007] The present invention is achieved through the following technical solutions: In a first aspect, the present invention provides a vector signal analyzer data rate conversion method, comprising: The RF signal enters the RF front end for amplitude conditioning and filtering; After amplitude conditioning and filtering, the RF signal enters the frequency conversion module and is converted into an analog intermediate frequency signal; The analog intermediate frequency signal is converted into a digital intermediate frequency signal after analog-to-digital conversion, and the digital intermediate frequency signal is transmitted to the baseband signal processing module; The digital intermediate frequency signal is converted into a digital baseband signal through a baseband signal processing module, an analysis bandwidth set by a user is obtained, two decimation multiples are selected, and first time domain data with a first data rate and a second data rate is obtained; Calculating a least common multiple of the first data rate and the second data rate, and calculating an insertion multiple and a subtraction multiple of the least common multiple; Start acquiring from the first data of the first time domain data time domain data, and the length is a first data group, performing discrete Fourier transform on the first data group, and then performing inverse Fourier transform to obtain second time domain data; From the second time domain data Start to obtain data time domain data, and the length is a second data group, performing discrete Fourier transform on the second data group, and then performing inverse Fourier transform to obtain third time domain data; The first time domain data data and the third time domain data To The data of the fourth time domain data are composed of the fourth time domain data. Start to obtain data time domain data, and the length is a third data group, performing discrete Fourier transform on the third data group, and then performing inverse Fourier transform to obtain fifth time domain data; The first time domain data data and the fifth time domain data To The data constitute the sixth time domain data; The sixth time domain data after data rate conversion is output to the IQ analysis module, and spectrum analysis, IQ amplitude display, IQ Vector display and phase calculation are performed on it to complete the IQ analysis of the signal.

[0008] Preferably, the step of calculating the insertion multiple and the extraction multiple of the least common multiple comprises:

[0009]

[0010] In the formula, is the insertion multiple, is the extraction multiple, is the least common multiple, is the first data rate, is the second data rate.

[0011] Preferably, the performing discrete Fourier transform comprises:

[0012]

[0013] In the formula, For the k point frequency domain signal, k The value range is [0, N -1]; is the time domain data set, The time domain data set data, the value range is [0, N -1]; is the rotation factor, is an imaginary number, is the number of DFT points, is the discrete Fourier transform; It also includes the discarding of frequency domain signal data, the number of discarded data is:

[0014]

[0015] In the formula, is the number of discards, is the insertion multiple, is the extraction multiple, for and The ratio of , and is an integer.

[0016] Preferably, the performing inverse Fourier transform comprises:

[0017] In the formula, is the time domain data, is the inverse Fourier transform.

[0018] Preferably, it also includes:

[0019]

[0020]

[0021] In the formula, , and is a natural number, is the number of transformations of the Fourier transform.

[0022] In a second aspect, the present invention provides a vector signal analyzer data rate conversion system, comprising: The preprocessing module is configured to receive the RF signal entering the RF front end, perform amplitude conditioning and filtering; the signal after amplitude conditioning and filtering enters the frequency conversion module and is converted into an analog intermediate frequency signal; the analog intermediate frequency signal is converted into a digital intermediate frequency signal after analog-to-digital conversion, and the digital intermediate frequency signal is transmitted to the baseband signal processing module, the RF signal is obtained, and the RF signal is converted into an intermediate frequency signal, and the intermediate frequency signal is transmitted to the baseband signal processing module; the digital intermediate frequency signal is converted into a digital baseband signal through the baseband signal processing module, the analysis bandwidth set by the user is obtained, two extraction multiples are selected, and the first time domain data with a data rate of a first data rate and a second data rate is obtained; the least common multiple of the first data rate and the second data rate is calculated, and the insertion multiple and the extraction multiple of the least common multiple are calculated; The time domain data processing module is configured to obtain the first data of the first time domain data starting from the first data time domain data, and the length is a first data group, performing discrete Fourier transform on the first data group, and then performing inverse Fourier transform on the first data group to obtain second time domain data; and obtaining second time domain data from the first Start to obtain data time domain data, and the length is a second data group, performing discrete Fourier transform on the second data group, and then performing inverse Fourier transform to obtain third time domain data; The output module is configured to output the first time domain data data and the third time domain data To The data of the fourth time domain data are composed of the fourth time domain data. Start to obtain data time domain data, and the length is The third data group is subjected to discrete Fourier transform and then inverse Fourier transform to obtain fifth time domain data; the front of the first time domain data is data and the fifth time domain data To The data are combined into sixth time domain data, and the sixth time domain data is output; The main control module is connected with the pre-processing module, the time domain data processing module and the output module, and is used to execute the above-mentioned vector signal analyzer data rate conversion method.

[0023] In a third aspect, the present invention provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned vector signal analyzer data rate conversion method when executing the computer program.

[0024] In a fourth aspect, the present invention provides a computer-readable storage medium storing a computer program, wherein the computer program, when executed by a processor, implements the above-mentioned vector signal analyzer data rate conversion method.

[0025] The technical solution of the present invention has at least the following advantages and beneficial effects: The data rate conversion algorithm provided by the present invention can effectively solve the problem that the time domain filter with large insertion and decimation multiples in time domain processing consumes computing resources and reduces real-time performance. The time domain signal is first transformed into the frequency domain, and then transformed into the time domain after frequency domain processing. It is not limited by the interpolation multiple and the decimation multiple, and can process the fractional resampling without significantly increasing computing resources and computing time. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0029] The terms "first, second" and the like in the specification and claims of this application and the above drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. The naming or numbering of steps in this application does not mean that the steps in the method flow must be executed in the time / logical sequence indicated by the naming or numbering. The named or numbered process steps can be changed in the execution order according to the technical purpose to be achieved, as long as the same or similar technical effects can be achieved.

[0030] Please refer to Figure 1 , a vector signal analyzer data rate conversion method, comprising: S101: The RF signal enters the RF front end for amplitude conditioning and filtering; S102: The RF signal after amplitude conditioning and filtering enters the frequency conversion module and is converted into an analog intermediate frequency signal; S103: The analog intermediate frequency signal is converted into a digital intermediate frequency signal after analog-to-digital conversion (ADC), and the digital intermediate frequency signal is transmitted to a baseband signal processing module; S104: converting the digital intermediate frequency signal into a digital baseband signal through a baseband signal processing module, obtaining an analysis bandwidth set by a user, selecting two decimation multiples, and obtaining first time domain data with a first data rate and a second data rate; in, , ,in, and are the decimation multiples of the first data rate and the second data rate, respectively, To analyze bandwidth.

[0031] S105: Calculate the least common multiple of the first data rate and the second data rate, and calculate an insertion multiple and a subtraction multiple of the least common multiple; S106: Start acquiring from the first data of the first time domain data time domain data, and the length is a first data group, performing discrete Fourier transform on the first data group, and then performing inverse Fourier transform to obtain second time domain data; S107: From the second time domain data Start to obtain data time domain data, and the length is a second data group, performing discrete Fourier transform on the second data group, and then performing inverse Fourier transform to obtain third time domain data; S108: The front of the first time domain data data and the third time domain data To The data of the fourth time domain data are composed of the fourth time domain data. Start to obtain data time domain data, and the length is a third data group, performing discrete Fourier transform on the third data group, and then performing inverse Fourier transform to obtain fifth time domain data; S109: The front of the first time domain data data and the fifth time domain data To The data are combined into sixth time domain data, and the sixth time domain data is output.

[0032] S110: The time domain data after data rate conversion enters the IQ analysis software, and performs spectrum analysis, IQ amplitude display, IQ vector display, phase calculation, etc. on it to complete the IQ analysis of the signal.

[0033] The data rate conversion algorithm provided by the present invention can effectively solve the problem that the time domain filter with large insertion and decimation multiples in time domain processing consumes computing resources and reduces real-time performance. The time domain signal is first transformed into the frequency domain, and then transformed into the time domain after frequency domain processing. It is not limited by the interpolation multiple and the decimation multiple, and can process the fractional resampling without significantly increasing computing resources and computing time.

[0034] An exemplary implementation of the present invention, and calculating the insertion multiple and extraction multiple of the least common multiple includes:

[0035]

[0036] In the formula, is the insertion multiple, is the extraction multiple, is the least common multiple, is the first data rate, is the second data rate.

[0037] In an exemplary embodiment of the present invention, performing discrete Fourier transform includes:

[0038]

[0039] In the formula, For the k point frequency domain signal, k The value range is [0, N -1]; is the time domain data set, The time domain data set data, the value range is [0, N -1]; is the rotation factor, is an imaginary number, is the number of DFT points, is the discrete Fourier transform; It also includes the discarding of frequency domain signal data, the number of discarded data is:

[0040]

[0041] In the formula, is the number of discards, is the insertion multiple, is the extraction multiple, for and The ratio of , and is an integer.

[0042] In an exemplary embodiment of the present invention, performing inverse Fourier transform includes:

[0043] In the formula, is the time domain data, is the inverse Fourier transform.

[0044] An exemplary embodiment of the present invention further includes:

[0045]

[0046]

[0047] In the formula, , and is a natural number, is the number of transformations of the Fourier transform.

[0048] In conjunction with the above method provided by the present invention, a specific example is provided to further explain: The sine signal with a frequency of 100Hz is initially sampled, the data rate is 1.3kHz, and the sampling time is 1s, so a total of 1300 data are obtained. First, assume that the data rate is to be converted to 1.1kHz. The specific steps of frequency domain resampling are as follows: The 1300 data are overlapped by 50%, each data length is 130 points, and the data are divided into 20 groups; Perform DFT on each set of 130 data points to obtain 20 sets of 130-point frequency domain data; The 20 data points in each frequency domain center are discarded, and the number of data in each group becomes 110; Perform IDFT on the obtained frequency domain data, and get 20 groups of data in total, with 110 data in each group; Take the first 55 data of each group of data and piece them together into 20*55=1100 data.

[0049] After the above processing, the original data rate of 1.3kHz is changed to 1.1kHz data. Due to the reduction of data rate, the number of 1s data is changed from 1300 to 1100, which is consistent with the change of data points caused by the change of data rate.

[0050] In a second aspect, the present invention further provides a vector signal analyzer data rate conversion system, comprising: The preprocessing module is configured to perform amplitude conditioning and filtering when the RF signal enters the RF front end; the signal after amplitude conditioning and filtering enters the frequency conversion module and is converted into an analog intermediate frequency signal; the analog intermediate frequency signal is converted into a digital intermediate frequency signal after analog-to-digital conversion, and the digital intermediate frequency signal is transmitted to the baseband signal processing module; the digital intermediate frequency signal is converted into a digital baseband signal through the baseband signal processing module, the analysis bandwidth set by the user is obtained, two decimation multiples are selected, and the first time domain data with data rates of the first data rate and the second data rate are obtained; the least common multiple of the first data rate and the second data rate is calculated, and the insertion multiple and the decimation multiple of the least common multiple are calculated; The time domain data processing module is configured to obtain the first data of the first time domain data starting from the first data time domain data, and the length is a first data group, performing discrete Fourier transform on the first data group, and then performing inverse Fourier transform on the first data group to obtain second time domain data; and obtaining second time domain data from the first Start to obtain data time domain data, and the length is a second data group, performing discrete Fourier transform on the second data group, and then performing inverse Fourier transform to obtain third time domain data; The output module is configured to output the first time domain data data and the third time domain data To The data of the fourth time domain data are composed of the fourth time domain data. Start to obtain data time domain data, and the length is The third data group is subjected to discrete Fourier transform and then inverse Fourier transform to obtain fifth time domain data; the front of the first time domain data is data and the fifth time domain data To The data are combined into sixth time domain data, and the sixth time domain data is output; The main control module is connected with the pre-processing module, the time domain data processing module and the output module, and is used to execute the above-mentioned vector signal analyzer data rate conversion method.

[0051] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0052] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. The computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods of various embodiments of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0053] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for converting data rate of a vector signal analyzer, characterized in that: include: The RF signal enters the RF front end for amplitude conditioning and filtering; After amplitude conditioning and filtering, the RF signal enters the frequency conversion module and is converted into an analog intermediate frequency signal; The analog intermediate frequency signal is converted into a digital intermediate frequency signal after analog-to-digital conversion, and the digital intermediate frequency signal is transmitted to the baseband signal processing module; The digital intermediate frequency signal is converted into a digital baseband signal through a baseband signal processing module, an analysis bandwidth set by a user is obtained, two decimation multiples are selected, and first time domain data with a first data rate and a second data rate is obtained; Calculating a least common multiple of the first data rate and the second data rate, and calculating an insertion multiple and a subtraction multiple of the least common multiple; Start acquiring from the first data of the first time domain data time domain data, and the length is a first data group, performing discrete Fourier transform on the first data group, and then performing inverse Fourier transform to obtain second time domain data; From the second time domain data Start to obtain data time domain data, and the length is a second data group, performing discrete Fourier transform on the second data group, and then performing inverse Fourier transform to obtain third time domain data; The first time domain data data and the third time domain data To The data of the fourth time domain data are composed of the fourth time domain data. Start to obtain data time domain data, and the length is a third data group, performing discrete Fourier transform on the third data group, and then performing inverse Fourier transform to obtain fifth time domain data; The first time domain data data and the fifth time domain data To The data constitute the sixth time domain data; The sixth time domain data after data rate conversion is output to the IQ analysis module, and spectrum analysis, IQ amplitude display, IQ Vector display and phase calculation are performed on it to complete the IQ analysis of the signal.

2. A vector signal analyzer data rate conversion method according to claim 1, characterized in that: The insertion multiple and extraction multiple of the least common multiple are calculated as follows: In the formula, is the insertion multiple, is the extraction multiple, is the least common multiple, is the first data rate, is the second data rate.

3. A vector signal analyzer data rate conversion method according to claim 2, characterized in that: The discrete Fourier transform comprises: In the formula, For the k point frequency domain signal, k The value range is [0, N -1]; is the time domain data set, The time domain data set data, the value range is [0, N -1]; is the rotation factor, is an imaginary number, is the number of DFT points, is the discrete Fourier transform; It also includes the discarding of frequency domain signal data, the number of discarded data is: In the formula, is the number of discards, is the insertion multiple, is the extraction multiple, for and The ratio is an integer.

4. A vector signal analyzer data rate conversion method according to claim 3, characterized in that: The inverse Fourier transform comprises: In the formula, is the inverse Fourier transform.

5. A vector signal analyzer data rate conversion method according to claim 4, characterized in that: Also includes: In the formula, , and is a natural number, is the number of inverse Fourier transforms.

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