Arbitrary signal transmitting method based on software radio equipment

Abstract

The invention relates to an arbitrary signal transmitting method based on software radio equipment, and belongs to the technical field of arbitrary waveform generation. The method comprises the following steps: acquiring signal data and a sampling rate of a radio signal to be transmitted; wherein the radio signal to be transmitted is a radio signal at any sampling rate; based on the signal data of the radio signal to be transmitted, the sampling rate and the master clock rate of software radio equipment, resampling the radio signal to be transmitted to obtain a resampled signal; wherein the resampling signal comprises a resampling rate and resampling signal data; and setting the sampling rate of the software radio equipment as the resampling rate, and transmitting the resampling signal data. Any signal can be transmitted without any special signal generator, and meanwhile, signal data caching is performed by using the onboard high-speed storage chip, so that the stability and the reliability of high-speed broadband signal transmission are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of arbitrary waveform generation, and in particular to an arbitrary signal transmission method based on software radio equipment. Background Art

[0002] Arbitrary signal generator is one of the most commonly used tools for electronic engineers to conduct signal simulation experiments and system testing. Since it can emit any customized signal waveform, it can meet the requirements of complex signal simulation. Currently, arbitrary signal generators are mainly special instruments or special function modules in high-end signal sources. For general electronic engineers, the cost of using such arbitrary signal generators is relatively high.

[0003] Software radio devices represented by USRP have greatly reduced the cost of signal reception and transmission and are currently one of the most widely used signal transceiver devices. When the sampling rate of the signal data to be transmitted is the sampling rate that the software radio device can work at, such signal waveforms can be directly transmitted based on the software radio device. However, for signal data with arbitrary sampling rates, current software radio devices cannot directly transmit and still require the help of arbitrary signal generators. Summary of the invention

[0004] In view of the above analysis, an embodiment of the present invention aims to provide an arbitrary signal transmission method based on a software radio device, so as to solve the problem in the prior art that the waveform of a signal transmitted by a software radio device is limited by the sampling rate of the signal data.

[0005] The purpose of the present invention is mainly achieved through the following technical solutions:

[0006] The present invention provides a method for transmitting an arbitrary signal based on a software radio device, characterized in that it comprises the following steps:

[0007] Acquire signal data and sampling rate of a radio signal to be transmitted; wherein the radio signal to be transmitted is a radio signal at any sampling rate;

[0008] Based on the signal data of the radio signal to be transmitted, the sampling rate and the main clock rate of the software radio device, the radio signal to be transmitted is resampled to obtain a resampled signal; wherein the resampled signal includes the resampled rate and the resampled signal data;

[0009] The sampling rate of the software radio device is set to the resampling rate, and the resampled signal data is transmitted.

[0010] Further, the resampling of the radio signal to be transmitted to obtain a resampled signal based on the signal data of the radio signal to be transmitted, the sampling rate and the main clock rate of the software radio device includes:

[0011] Obtaining a resampling rate based on a sampling rate of the radio signal to be transmitted and a master clock rate of a software radio device;

[0012] Based on the resampling rate, interpolating the signal data of the radio signal to be transmitted to obtain resampled signal data sample point values;

[0013] The resampled signal data sample point values ​​are filtered and amplitude normalized in sequence to obtain resampled signal data.

[0014] Further, performing an interpolation operation on the signal data of the radio signal to be transmitted comprises the following steps:

[0015] Step S1, setting the iteration index value i and the signal data subscript value n of the radio signal to be transmitted to initial values ​​0 respectively, and cyclically executing the following process, including:

[0016] When n=0, the resampled signal data sample value is calculated using the following formula:

[0017] D i =-d n (xn-1)(xn-2)(xn-3) / 6+d n+1 ·(xn)(xn

[0018] -2)(xn-3) / 2-d n+2 ·(xn)(xn-1)(xn-3) / 2

[0019] +d n+3 ·(xn)(xn-1)(xn-2) / 6

[0020] Among them, D i Represents the i-th resampled signal data sample value; d n represents the nth signal data of the radio signal to be transmitted; x represents the position of the resampled signal data sample point relative to the adjacent sample point in the signal data sequence of the radio signal to be transmitted;

[0021] When 1≤n≤N-3, the resampled signal data sample value is calculated using the following formula:

[0022] D i =-d n-1 ·(xn)(xn-1)(xn-2) / 6+d n (x-n+1)(xn-1)(xn-2) / 2-d n+1 (x-n+1)(xn)(xn-2) / 2+d n+2(x-n+1)(xn)(xn-1) / 6

[0023] Wherein, N represents the number of signal data of the radio signal to be transmitted;

[0024] When n=N-2, the resampled signal data sample value is calculated using the following formula:

[0025] D i =-d n-2 -2·(x-n+1)(xn)(xn-1) / 6+d n-1 (x-n+2)(xn)(xn-1) / 2-d n (x-n+2)(x-n+1)(xn-1) / 2+d n+1 (x-n+2)(x-n+1)(xn) / 6

[0026] When n=N-1, the resampled signal data sample value is calculated using the following formula:

[0027] D i =-d n-3 (x-n+2)(x-n+1)(xn) / 6+d n-2 (x-n+3)(x-n+1)(xn) / 2-d n-1 (x-n+3)(x-n+2)(xn) / 2+d n (x-n+3)(x-n+2)(x-n+1) / 6

[0028] The iteration index value i is incremented by 1;

[0029] Calculate a signal data subscript value n of the radio signal to be transmitted based on the iteration index value i, the sampling rate and the resampling rate of the radio signal to be transmitted;

[0030] Step S2: When the signal data index value n of the radio signal to be transmitted is equal to the number N of the signal data of the radio signal to be transmitted, the loop of step S1 is ended.

[0031] Further, based on the iteration index value i, the sampling rate and the resampling rate of the radio signal to be transmitted, the signal data subscript value n of the radio signal to be transmitted is calculated using the following formula:

[0032]

[0033] Wherein, i represents the iteration index value; R old represents the sampling rate of the radio signal to be transmitted; R new represents the resampling rate; Indicates rounding down.

[0034] Furthermore, the position of the resampled signal data sample point relative to the adjacent sample point in the signal data sequence of the radio signal to be transmitted is calculated using the following formula:

[0035] x=i×R old / R new

[0036] Wherein, i represents the iteration index value; R old represents the sampling rate of the radio signal to be transmitted; R new represents the resampling rate.

[0037] Further, based on the sampling rate of the radio signal to be transmitted and the master clock rate of the software radio device, the resampling rate is obtained using the following formula:

[0038]

[0039] Among them, R master Indicates the master clock rate of the software radio device; R old represents the sampling rate of the radio signal to be transmitted; Indicates rounding down.

[0040] Furthermore, the resampled signal data sample point values ​​are digitally low-pass filtered to obtain filtered signal data; wherein the normalized cutoff frequency of the digital low-pass filter is the sampling rate / resampling rate of the radio signal to be transmitted.

[0041] Furthermore, the amplitude of the filtered signal data is normalized using the following formula to obtain the resampled signal data:

[0042] maxI=max(abs(real(F0,F1,F2,…,F i ,…)))

[0043] maxQ=max(abs(imag(F0,F1,F2,…,F i ,…)))

[0044] maxIQ=max(maxI,maxQ)

[0045]

[0046] Among them, real() means taking the real part of a complex sequence; imag() means taking the imaginary part of a complex sequence; abs() means taking the absolute value of a real sequence; max() means taking the maximum value of a real sequence; F irepresents the signal data after the i-th filter; S i Represents the signal data after the i-th resampling.

[0047] Furthermore, transmitting the resampled signal data includes: transmitting the resampled signal data to a data cache chip of a software radio device for storage.

[0048] Furthermore, transmitting the resampled signal data also includes transmitting the resampled signal data in the data cache chip of the software radio device through a field programmable gate array chip.

[0049] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0050] 1. The present invention effectively solves the contradiction between the sampling frequency of any signal data and the working sampling frequency of the software radio device by resampling the signal data to be transmitted, so that the software radio device can transmit signals at any sampling rate.

[0051] 2. Compared with the existing interpolation methods, the interpolation method used in the resampling process of the present invention handles the boundary value problem separately, so that the complexity of the interpolation calculation is low and the performance is also guaranteed to a certain extent. In addition, through the high-fidelity resampling process, it is ensured that the signal can maintain the original waveform characteristics after resampling, thereby ensuring the quality of signal transmission.

[0052] 3. The present invention utilizes the onboard data cache chip of the software radio device to cache the signal data and then uses FPGA (field programmable gate array chip) to transmit it. Compared with the existing solution of repeatedly sending data to FPGA in real time and then transmitting it by FPGA in real time, the stability and reliability of high-speed broadband signal transmission are greatly improved, and the problem of lost samples when the signal rate is high is avoided.

[0053] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0055] Figure 1 It is a flowchart of a method for transmitting an arbitrary signal based on a software radio device in an embodiment of the present invention;

[0056] Figure 2 Schematic diagram of the structure of a signal data file in an embodiment of the present invention. DETAILED DESCRIPTION

[0057] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0058] A specific embodiment of the present invention discloses a method for transmitting an arbitrary signal based on a software radio device, such as Figure 1 As shown, the following steps 1 to 3 are included:

[0059] Step 1: Acquire signal data and sampling rate of a radio signal to be transmitted; wherein the radio signal to be transmitted is a radio signal at any sampling rate.

[0060] Specifically, the signal data of the radio signal to be transmitted may be signal data collected in an actual environment or signal data manually created using a signal generation tool or software according to specific test requirements or application scenarios. In this embodiment, the signal data of the radio signal to be transmitted, the number of sample points of the signal data, and the sampling rate are pre-stored in a Figure 2 In the signal data file shown, the sampling rate (Sampling Rate) indicates the number of times the analog signal is sampled per second. In this embodiment, it is represented by a 32-bit unsigned integer, and the unit is Hz. The number of signal samples (Number of Samples) indicates the total number of discrete signal points captured in a sampling process. The number of samples directly affects the representation accuracy of the signal and the highest frequency that can be detected. In this embodiment, it is represented by a 32-bit unsigned integer. The signal data (Signal Data) represents the specific value of each sampling point. These values ​​are the digital representation of the amplitude of the analog signal at a specific time point. In digital signal processing, these data can be used for further analysis, processing and reconstruction of the original signal.

[0061] Specifically, the signal data of the radio signal to be transmitted is represented alternately by an in-phase component and an orthogonal component, and the nth in-phase component I n and the quadrature component Q n The signal data sample d n as follows:

[0062] d n =I n +j×Q n

[0063] Wherein, the subscript n is an integer from 0 to N-1; N is the number of signal data of the radio signal to be transmitted; j is an imaginary unit; I n and Q n All are represented by 16-bit signed integers.

[0064] Step 2: resampling the radio signal to be transmitted to obtain a resampled signal based on the signal data of the radio signal to be transmitted, the sampling rate and the master clock rate of the software radio device; wherein the resampled signal includes the resampling rate and the resampled signal data, including steps 21 to 23:

[0065] Step 21: Obtain a resampling rate based on the sampling rate of the radio signal to be transmitted and the master clock rate of the software radio device.

[0066] Specifically, the software radio device can usually only work at specific sampling frequencies or integer multiples of these frequencies. If the sampling frequency of the original signal data does not match the sampling frequency supported by the device, directly using the original signal data will cause signal distortion or failure to transmit. Therefore, by calculating a resampling frequency that is closest to the original sampling frequency and supported by the device, the original characteristics of the signal can be maintained to the greatest extent possible, avoiding signal distortion caused by sampling frequency mismatch.

[0067] Further, based on the sampling rate of the radio signal to be transmitted and the master clock rate of the software radio device, the resampling rate is obtained using the following formula:

[0068]

[0069] Among them, R master Indicates the master clock rate of the software radio device; R old represents the sampling rate of the radio signal to be transmitted; Indicates rounding down.

[0070] For example, in the USRP X310, the master clock rate R master Select 200MHz, if R old The reading is 24MHz, then R is calculated new The above formula ensures that the resampling rate is an integer multiple of the master clock rate while being as close to the original sampling rate as possible.

[0071] Step 22: Based on the resampling rate, interpolate the signal data of the radio signal to be transmitted to obtain resampled signal data sample point values.

[0072] Specifically, based on the resampling rate and the signal data of the radio signal to be transmitted, the signal samples can be regenerated without changing the signal spectrum characteristics, thereby maintaining the integrity and continuity of the signal. Meanwhile, if the original signal data is simply resampled (such as directly discarding or copying some samples), signal distortion may occur. The interpolation operation can transition the samples more smoothly and reduce the distortion caused by resampling.

[0073] Further, performing an interpolation operation on the signal data of the radio signal to be transmitted comprises the following steps:

[0074] Step S1, setting the iteration index value i and the signal data subscript value n of the radio signal to be transmitted to initial values ​​0 respectively, and cyclically executing the following process, including:

[0075] When n=0, the resampled signal data sample value is calculated using the following formula:

[0076] D i =-d n (xn-1)(xn-2)(xn-3) / 6+d n+1 ·(xn)(xn

[0077] -2)(xn-3) / 2-d n+2 ·(xn)(xn-1)(xn-3) / 2

[0078] +d n+3 ·(xn)(xn-1)(xn-2) / 6

[0079] Among them, D i Represents the i-th resampled signal data sample value; d n represents the nth signal data of the radio signal to be transmitted; x represents the position of the resampled signal data sample point relative to the adjacent sample point in the signal data sequence of the radio signal to be transmitted;

[0080] When 1≤n≤N-3, the resampled signal data sample value is calculated using the following formula:

[0081] D i =-d n-1 ·(xn)(xn-1)(xn-2) / 6+d n ·(x-n+1)(xn

[0082] -1)(xn-2) / 2-d n+1 (x-n+1)(xn)(xn-2) / 2

[0083] +d n+2(x-n+1)(xn)(xn-1) / 6

[0084] Wherein, N represents the number of signal data of the radio signal to be transmitted;

[0085] When n=N-2, the resampled signal data sample value is calculated using the following formula:

[0086] D i =-d n-2 -2·(x-n+1)(xn)(xn-1) / 6+d n-1 (x-n+2)(xn)(xn-1) / 2-d n (x-n+2)(x-n+1)(xn-1) / 2+d n+1 (x-n+2)(x-n+1)(xn) / 6

[0087] When n=N-1, the resampled signal data sample value is calculated using the following formula:

[0088] D i =-d n-3 (x-n+2)(x-n+1)(xn) / 6+d n-2 (x-n+3)(x-n+1)(xn) / 2-d n-1 (x-n+3)(x-n+2)(xn) / 2+d n (x-n+3)(x-n+2)(x-n+1) / 6

[0089] The iteration index value i is incremented by 1;

[0090] Calculate a signal data subscript value n of the radio signal to be transmitted based on the iteration index value i, the sampling rate and the resampling rate of the radio signal to be transmitted;

[0091] Step S2: When the signal data index value n of the radio signal to be transmitted is equal to the number N of the signal data of the radio signal to be transmitted, the loop of step S1 is ended.

[0092] Specifically, when n=0, n=N-2 and n=N-1, the boundary values ​​of the signal data of the radio signal to be transmitted are processed, and when 1≤n≤N-3, the internal values ​​of the signal data of the radio signal to be transmitted are processed. The above interpolation process estimates the value of the middle point through four known adjacent sampling points, and calculates the weighted average between the original sample points adjacent to each new sample point position. The interpolation formula used applies different weights according to different sample point positions (such as boundaries or middle positions), so that the resampled signal data can be as close to the original signal as possible to generate a smooth and continuous signal waveform.

[0093] Further, based on the iteration index value i, the sampling rate and the resampling rate of the radio signal to be transmitted, the signal data subscript value n of the radio signal to be transmitted is calculated using the following formula:

[0094]

[0095] Wherein, i represents the iteration index value; R old represents the sampling rate of the radio signal to be transmitted; R new represents the resampling rate; Indicates rounding down.

[0096] Specifically, n represents the position in the signal data of the radio signal to be transmitted, and its value determines which signal data samples are selected in the original signal data for interpolation calculation. It is a direct index of the original signal data samples and is used to access the signal data value of the radio signal to be transmitted.

[0097] Furthermore, the position of the resampled signal data sample point relative to the adjacent sample point in the signal data sequence of the radio signal to be transmitted is calculated using the following formula:

[0098] x=i×R old / R new

[0099] Wherein, i represents the iteration index value; R old represents the sampling rate of the radio signal to be transmitted; R new represents the resampling rate.

[0100] Specifically, the value of the position x of the resampled signal data sample point relative to the adjacent sample point in the signal data sequence of the radio signal to be transmitted is used to represent the position offset between the signal data index value n of the radio signal to be transmitted and its adjacent sample points in the interpolation process, and x is used to calculate weights, which determine how to combine the signal data index value n of the radio signal to be transmitted and the values ​​of its adjacent sample points to generate a new interpolation sample point D i .

[0101] Step 23: filtering and amplitude normalizing the resampled signal data sample values ​​in sequence to obtain resampled signal data.

[0102] Furthermore, the resampled signal data sample point values ​​are digitally low-pass filtered to obtain filtered signal data; wherein the normalized cutoff frequency of the digital low-pass filter is the sampling rate / resampling rate of the radio signal to be transmitted.

[0103] Specifically, the low-pass filter can smooth the signal and reduce the noise and oscillation that may be generated during the resampling process. At the same time, the aliasing effect may be introduced during the resampling process, that is, the high-frequency signal components are incorrectly mapped to the low-frequency part, resulting in signal distortion. The low-pass filter can remove or reduce these high-frequency components.

[0104] It should be noted that the normalized cutoff frequency refers to the ratio of the cutoff frequency to a reference value (usually the sampling frequency of the filter) in the design of a low-pass filter. This ratio is a dimensionless quantity that describes the frequency response characteristics of the filter, especially the frequency point at which the filter begins to significantly attenuate the signal. In this embodiment, the digital normalized cutoff frequency is set to R old / R new , the purpose of which is to ensure that the filter can remove the sampling rate R higher than the sampling rate of the radio signal to be transmitted due to resampling old The high frequency components of the signal are retained while the sampling rate R of the signal is lower than that of the radio signal to be transmitted. old In this way, the resampled signal can be confined to the bandwidth of the original signal without introducing aliasing.

[0105] Furthermore, the amplitude of the filtered signal data is normalized using the following formula to obtain the resampled signal data:

[0106] maxI=max(abs(real(F0,F1,F2,…,F i ,…)))

[0107] maxQ=max(abs(imag(F0,F1,F2,…,F i ,…)))

[0108] maxIQ=max(maxI,maxQ)

[0109]

[0110] Among them, real() means taking the real part of a complex sequence; imag() means taking the imaginary part of a complex sequence; abs() means taking the absolute value of a real sequence; max() means taking the maximum value of a real sequence; F i represents the signal data after the i-th filter; S i Represents the signal data after the i-th resampling.

[0111] Specifically, the amplitude normalization process is used to normalize the filtered signal data F i Adjust the amplitude to be within the range suitable for the software radio device to avoid signal distortion or failure to transmit due to excessive or insufficient amplitude. In this way, it can ensure that the signal has an appropriate power level when transmitting while maintaining the signal quality.

[0112] Step 3: Set the sampling rate of the software radio device to the resampling rate, and transmit the resampled signal data.

[0113] Specifically, in order to ensure that signal data can be correctly and efficiently processed and transmitted while maintaining signal quality, the sampling rate of the software radio device is set to the resampling rate through the application program interface function of the software radio device, and the resampled signal data is transmitted.

[0114] Furthermore, transmitting the resampled signal data includes: transmitting the resampled signal data to a data cache chip of a software radio device for storage.

[0115] Specifically, the resampled signal data is transmitted to the data cache chip of the software radio device through the application program interface function of the software radio device.

[0116] Furthermore, transmitting the resampled signal data also includes transmitting the resampled signal data in the data cache chip of the software radio device through a field programmable gate array chip.

[0117] Specifically, the software radio device is controlled by an application program interface function of the software radio device to repeatedly read the resampled signal data from the data cache chip for transmission.

[0118] It should be noted that the onboard data cache chip of the software radio device has high-speed data transmission capability. The resampled signal data is cached in the data cache chip once and then transmitted through the FPGA. The software radio device supports high-speed and stable data interaction between the internal field programmable gate array chip and the data cache chip, which can effectively avoid the problem of sample point loss when the signal rate is high in the existing solution of repeatedly sending data to the FPGA in real time and then transmitting it by the FPGA in real time, thereby achieving high-speed and stable signal transmission.

[0119] For applications that need to transmit a large amount of signal data, the data cache chip also provides the necessary storage space to meet the needs of transmitting large amounts of signal data. For example, the data cache chip capacity of the USRP X310 is 1GB, and the data cache chip capacity of the USRP N310 is 2GB.

[0120] In summary, the method for transmitting an arbitrary signal based on a software radio device according to an embodiment of the present invention has the following beneficial effects:

[0121] 1. The present invention effectively solves the contradiction between the sampling frequency of any signal data and the working sampling frequency of the software radio device by resampling the signal data to be transmitted, so that the software radio device can transmit signals at any sampling rate.

[0122] 2. Compared with the existing interpolation methods, the interpolation method used in the resampling process of the present invention handles the boundary value problem separately, so that the complexity of the interpolation calculation is low and the performance is also guaranteed to a certain extent. In addition, through the high-fidelity resampling process, it is ensured that the signal can maintain the original waveform characteristics after resampling, thereby ensuring the quality of signal transmission.

[0123] 3. The present invention utilizes the onboard data cache chip of the software radio device to cache the signal data and then uses FPGA (field programmable gate array chip) to transmit it. Compared with the existing solution of repeatedly sending data to FPGA in real time and then transmitting it by FPGA in real time, the stability and reliability of high-speed broadband signal transmission are greatly improved, and the problem of lost samples when the signal rate is high is avoided.

[0124] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for transmitting an arbitrary signal based on a software radio device, characterized in that: The steps include: Acquire signal data and sampling rate of a radio signal to be transmitted; wherein the radio signal to be transmitted is a radio signal at any sampling rate; Based on the signal data of the radio signal to be transmitted, the sampling rate and the main clock rate of the software radio device, the radio signal to be transmitted is resampled to obtain a resampled signal; wherein the resampled signal includes the resampled rate and the resampled signal data; The sampling rate of the software radio device is set to the resampling rate, and the resampled signal data is transmitted.

2. The method according to claim 1, characterized in that: The resampling of the radio signal to be transmitted to obtain a resampled signal based on the signal data of the radio signal to be transmitted, the sampling rate and the main clock rate of the software radio device comprises: Obtaining a resampling rate based on a sampling rate of the radio signal to be transmitted and a master clock rate of a software radio device; Based on the resampling rate, interpolating the signal data of the radio signal to be transmitted to obtain resampled signal data sample point values; The resampled signal data sample point values ​​are filtered and amplitude normalized in sequence to obtain resampled signal data.

3. The method according to claim 2, characterized in that: Performing an interpolation operation on the signal data of the radio signal to be transmitted comprises the following steps: Step S1, setting the iteration index value i and the signal data subscript value n of the radio signal to be transmitted to initial values ​​0 respectively, and cyclically executing the following process, including: When n=0, the resampled signal data sample value is calculated using the following formula: D i =-d n ·(x-n-1)(x-n-2)(x-n-3) / 6+d n+1 ·(x-n)(x-n -2)(x-n-3) / 2-d n+2 ·(x-n)(x-n-1)(x-n-3) / 2+d n+3 ·(x-n)(x-n-1)(x-n-2) / 6 Among them, D i Represents the i-th resampled signal data sample value; d n represents the nth signal data of the radio signal to be transmitted; x represents the position of the resampled signal data sample point relative to the adjacent sample point in the signal data sequence of the radio signal to be transmitted; When 1≤n≤N-3, the resampled signal data sample value is calculated using the following formula: D i =-d n-1 ·(xn)(xn-1)(xn-2) / 6+d n ·(x-n+1)(xn -1)(x-n-2) / 2-d n+1 ·(x-n+1)(x-n)(x-n-2) / 2+d n+2 ·(x-n+1)(x-n)(x-n-1) / 6 Wherein, N represents the number of signal data of the radio signal to be transmitted; When n=N-2, the resampled signal data sample value is calculated using the following formula: D i =-d n-2 -2·(x-n+1)(x-n)(x-n-1) / 6+d n-1 ·(x-n +2)(x-n)(x-n-1) / 2-d n ·(x-n+2)(x-n+1)(x-n-1) / 2+d n+1 ·(x-n+2)(x-n+1)(x-n) / 6 When n=N-1, the resampled signal data sample value is calculated using the following formula: D i =-d n-3 ·(x-n+2)(x-n+1)(x-n) / 6+d n-2 ·(x-n+3)(x -n+1)(x-n) / 2-d n-1 ·(x-n+3)(x-n+2)(x-n) / 2+d n ·(x-n+3)(x-n+2)(x-n+1) / 6 The iteration index value i is incremented by 1; Calculate a signal data subscript value n of the radio signal to be transmitted based on the iteration index value i, the sampling rate and the resampling rate of the radio signal to be transmitted; Step S2: When the signal data index value n of the radio signal to be transmitted is equal to the number N of the signal data of the radio signal to be transmitted, the loop of step S1 is terminated.

4. The method according to claim 3, characterized in that: Based on the iteration index value i, the sampling rate and the resampling rate of the radio signal to be transmitted, the signal data subscript value n of the radio signal to be transmitted is calculated using the following formula: Wherein, i represents the iteration index value; R old represents the sampling rate of the radio signal to be transmitted; R new represents the resampling rate; Indicates rounding down.

5. The method according to claim 4, characterized in that: The position of the resampled signal data sample point relative to the adjacent sample point in the signal data sequence of the radio signal to be transmitted is calculated using the following formula: x=i×R old / R new Wherein, i represents the iteration index value; R old represents the sampling rate of the radio signal to be transmitted; R new represents the resampling rate.

6. The method according to any one of claims 2 to 5, characterized in that: Based on the sampling rate of the radio signal to be transmitted and the master clock rate of the software radio device, the resampling rate is obtained using the following formula: Among them, R master Indicates the master clock rate of the software radio device; R old represents the sampling rate of the radio signal to be transmitted; Indicates rounding down.

7. The method according to claim 2, characterized in that: The resampled signal data sample point values ​​are digitally low-pass filtered to obtain filtered signal data; wherein the normalized cutoff frequency of the digital low-pass filter is the sampling rate / resampling rate of the radio signal to be transmitted.

8. The method according to claim 7, characterized in that: The filtered signal data is subjected to amplitude normalization processing using the following formula to obtain resampled signal data: maxI=max(abs(real(F0,F1,F2,…,F i ,…))) maxQ=max(abs(imag(F0,F1,F2,…,F i ,…))) maxIQ=max(maxI,maxQ) Among them, real() means taking the real part of a complex sequence; imag() means taking the imaginary part of a complex sequence; abs() means taking the absolute value of a real sequence; max() means taking the maximum value of a real sequence; F i represents the signal data after the i-th filter; S i Represents the signal data after the i-th resampling.

9. The method according to claim 1, characterized in that: The transmitting the resampled signal data includes: transmitting the resampled signal data to a data cache chip of a software radio device for storage.

10. The method according to claim 9, characterized in that: The transmitting the resampled signal data also includes transmitting the resampled signal data in the data cache chip of the software radio device through a field programmable gate array chip.

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