A broadband instantaneous frequency measurement method and device based on single-bit reception

Abstract

The present invention provides a broadband instantaneous frequency measurement method and device based on single-bit reception. The method directly samples the radio frequency signal through an ultra-high-speed single-bit ADC with a sampling rate of 40Gsps, and realizes instantaneous frequency measurement of 0.1GHz to 18GHz signals through an instantaneous frequency measurement method. The present invention realizes broadband instantaneous frequency measurement through time domain correlation detection technology, has the advantages of low computational complexity, wide instantaneous bandwidth, etc., and has strong versatility and engineering feasibility.

Description

Technical Field

[0001] The invention relates to digital signal processing, and in particular to a broadband instantaneous frequency measurement method and device based on single-bit reception. Background Art

[0002] Frequency is the main characterization parameter of electromagnetic wave signals. With the continuous development of electronic warfare technology and radar technology, radar signals are developing towards higher frequencies and wider frequency bands. In order to adapt to the complex electromagnetic environment of modern warfare, instantaneous frequency measurement technology is widely used in the field of electronic warfare. In order to ensure that the analog signal is converted into a digital signal without distortion, the conventional frequency measurement receiver needs to down-convert the RF signal first, and then sample and process the intermediate frequency signal after the frequency conversion. The sampling rate of the analog-to-digital converter chip (ADC) is limited, and the instantaneous bandwidth of the receiver is not higher than half of the sampling rate, so the instantaneous frequency measurement bandwidth is limited. With the continuous improvement of the level of electronic devices, the sampling rate of single-bit ADC is getting higher and higher, which can realize direct sampling and processing of RF signals. However, the ultra-high sampling rate brings greater processing pressure to the back-end digital signal processing chip. For the ultra-high sampling rate single-bit ADC, the commonly used signal instantaneous frequency measurement methods currently include the time domain frequency measurement method with delay correlation calculation as the core and the frequency domain algorithm of simplified discrete Fourier transform (DFT) or fast Fourier transform (FFT). The time domain frequency measurement method has low computational complexity and saves resources, but has poor noise resistance. The frequency domain processing method has multi-signal processing capabilities, but has a large amount of calculation, and the signal sampling rate is difficult to match with the data transmission rate, making engineering implementation difficult. Summary of the invention

[0003] The purpose of the present invention is to address the deficiencies of the above-mentioned prior art and provide a broadband instantaneous frequency measurement method and device based on single-bit reception, which performs differential calculation on the instantaneous phase and resolves the phase difference ambiguity, thereby obtaining the instantaneous frequency of the sampled signal.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] The present invention provides a broadband instantaneous frequency measurement method based on single-bit reception, comprising the following steps:

[0006] S1, the wireless and microwave components complete the reception and processing of the RF signal, and after sampling by the single-bit high-speed ADC, generate a sampled signal and output it to the FPGA;

[0007] S2, after receiving the N-point sampling signal, FPGA performs cyclic correlation calculation on the sampling signal;

[0008] S3, performing Hilbert transform on the sequence after cyclic correlation calculation to obtain the real part I(k) and imaginary part Q(k) of the transformed sequence;

[0009] S4, calculating the instantaneous phase sequence;

[0010] S5, performing differential calculation on the instantaneous phase sequence and resolving phase ambiguity;

[0011] S6, mean statistics;

[0012] S7. Calculate the instantaneous frequency.

[0013] Further, in S2, the sampling signal is cyclically correlated to be calculated as:

[0014]

[0015] Among them, S(k) is the result of cyclic correlation; N is the total number of sampling points; i is the order number of sampling points; S(i) is the original sampling signal; S k (i) is the data after the original sampling signal is circularly shifted to the right by k points.

[0016] Further, in S4, the calculation method of the instantaneous phase sequence φ(k) is:

[0017]

[0018] Furthermore, in S4, the calculation method for performing differential calculation on the instantaneous phase sequence and resolving phase ambiguity is:

[0019] If φ(k+1)-φ(k)≥π, then Δφ(k)=φ(k+1)-φ(k)-2π

[0020] If φ(k+1)-φ(k)≤-π, then Δφ(k)=φ(k+1)-φ(k)+2π

[0021] If -π<φ(k+1)-φ(k)<π, then Δφ(k)=φ(k+1)-φ(k)

[0022] Here, Δφ(k) is the phase difference calculation result of φ(k).

[0023] Further, in S6, the method of mean statistics is:

[0024]

[0025] Further, in S7, the instantaneous frequency is calculated as follows:

[0026]

[0027] Among them, f is the instantaneous frequency calculation result, f s is the sampling rate.

[0028] In addition, a broadband instantaneous frequency measurement device based on single-bit reception is used to implement a broadband instantaneous frequency measurement method based on single-bit reception.

[0029] Further, including:

[0030] Antenna: used to receive radio frequency signals and convert received electromagnetic wave signals into electrical signals;

[0031] Microwave components: including low noise amplifiers, bandpass filters and amplifiers;

[0032] The low noise amplifier input terminal is connected to the antenna;

[0033] The output end of the low noise amplifier is connected to the input end of the band pass filter to achieve low noise amplification of the signal;

[0034] The bandpass filter performs bandpass filtering on the low-noise amplified signal;

[0035] The amplifier amplifies the filtered signal and converts it into a radio frequency output signal.

[0036] Furthermore, it also includes:

[0037] Digital components: including 40Gsps single-bit ADC and FPGA;

[0038] The input end of the 40Gsps single-bit ADC is connected to the output end of the amplifier to perform analog-to-digital conversion on the RF output signal to output a sampling signal;

[0039] The FPGA receives the sampling signal of the 40Gsps single-bit ADC and performs frequency measurement, and finally outputs the frequency measurement result.

[0040] The beneficial effects of the present invention are as follows: the method directly samples 0.1 GHz to 18 GHz signals, calculates the instantaneous phase of the sampled signal through time domain processing, performs differential calculation on the instantaneous phase and resolves the phase difference ambiguity, thereby obtaining the instantaneous frequency of the sampled signal. The method has the advantages of wide instantaneous bandwidth, strong anti-noise ability, low computational complexity and high feasibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 A block diagram of a broadband instantaneous frequency measurement device based on single-bit reception according to the present invention;

[0042] Figure 2 This is the frequency measurement data processing process of Example 1. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0044] Please refer to a broadband instantaneous frequency measurement method based on single-bit reception, comprising the following steps:

[0045] S1, the wireless and microwave components complete the reception and processing of the RF signal, and after sampling by the single-bit high-speed ADC, generate a sampled signal and output it to the FPGA;

[0046] S2, after receiving the N-point sampling signal, FPGA performs cyclic correlation calculation on the sampling signal;

[0047] S3, performing Hilbert transform on the sequence after cyclic correlation calculation to obtain the real part I(k) and imaginary part Q(k) of the transformed sequence;

[0048] S4, calculating the instantaneous phase sequence;

[0049] S5, performing differential calculation on the instantaneous phase sequence and resolving phase ambiguity;

[0050] S6, mean statistics;

[0051] S7. Calculate the instantaneous frequency.

[0052] In S2, the sampling signal is cyclically correlated and calculated as:

[0053]

[0054] Among them, S(k) is the result of cyclic correlation; N is the total number of sampling points; i is the order number of sampling points; S(i) is the original sampling signal; S k (i) is the data after the original sampling signal is circularly shifted to the right by k points.

[0055] In S4, the calculation method of the instantaneous phase sequence φ(k) is:

[0056]

[0057] In S4, the calculation method for performing differential calculation on the instantaneous phase sequence and resolving phase ambiguity is:

[0058] If φ(k+1)-φ(k)≥π, then Δφ(k)=φ(k+1)-φ(k)-2π

[0059] If φ(k+1)-φ(k)≤-π, then Δφ(k)=φ(k+1)-φ(k)+2π

[0060] If -π<φ(k+1)-φ(k)<π, then Δφ(k)=φ(k+1)-φ(k)

[0061] Here, Δφ(k) is the phase difference calculation result of φ(k).

[0062] In S6, the method of mean value statistics is:

[0063]

[0064] In S7, the instantaneous frequency is calculated as follows:

[0065]

[0066] Among them, f is the instantaneous frequency calculation result, f s is the sampling rate.

[0067] like Figure 1 As shown, a broadband instantaneous frequency measurement device based on single-bit reception includes:

[0068] Antenna 1: used to receive radio frequency signals and convert received electromagnetic wave signals into electrical signals;

[0069] Microwave component: including a low noise amplifier 201, a band pass filter 202 and an amplifier 203;

[0070] The input end of the low noise amplifier 201 is connected to the antenna 1;

[0071] The output end of the low noise amplifier 201 is connected to the input end of the band pass filter 202 to achieve low noise amplification of the signal;

[0072] The bandpass filter 202 performs bandpass filtering on the low-noise amplified signal;

[0073] The amplifier 203 amplifies the filtered signal and converts it into a radio frequency output signal.

[0074] A broadband instantaneous frequency measurement device based on single-bit reception, further comprising:

[0075] Digital components: including 40Gsps single-bit ADC3 and FPGA4;

[0076] The input end of the 40Gsps single-bit ADC is connected to the output end of the amplifier to perform analog-to-digital conversion on the RF output signal to output a sampling signal;

[0077] The FPGA receives the sampling signal of the 40Gsps single-bit ADC and performs frequency measurement, and finally outputs the frequency measurement result.

[0078] A broadband instantaneous frequency measurement device based on single-bit reception mainly includes: antenna, microwave component, digital component and power supply component. Among them, the antenna mainly realizes the reception of radio frequency signals and converts the received electromagnetic wave signals into electrical signals.

[0079] The microwave component includes a low-noise amplifier, a bandpass filter and an amplifier. The input end of the low-noise amplifier is connected to the antenna, and the output end of the low-noise amplifier is connected to the input end of the bandpass filter to achieve low-noise amplification of the signal; the bandpass filter performs bandpass filtering on the signal after low-noise amplification; and the amplifier amplifies the filtered signal and converts it into a radio frequency output signal.

[0080] The digital component includes a 40Gsps single-bit ADC and an FPGA. The 40Gsps single-bit ADC input is connected to the amplifier output to convert the RF output signal into a digital signal and output a sampled signal. The FPGA receives the sampled signal from the single-bit ADC and performs frequency measurement, and finally outputs the frequency measurement result. The power supply component provides the DC power required for the normal operation of the microwave component and the digital component.

[0081] Embodiment 1

[0082] See also Figure 2 , a broadband instantaneous frequency measurement method based on single-bit reception, the frequency measurement processing flow of the 100MHz signal is as follows: the 100MHz RF signal s(t) is bandpass filtered, the RF output data is amplified, and the sampling rate is f s =40Gsps single-bit ADC sampling to obtain single-bit sampling data s(n), cyclic correlation processing is performed on the single-bit sampling data to obtain the cyclic correlation calculation result s(k), and the Hilbert transform real part I(k) and imaginary part Q(k) are obtained after Hilbert transform. The instantaneous phase φ(k) of the Hilbert transform result is calculated, the phase difference calculation is performed and the phase ambiguity Δφ(k) is resolved, and the average statistical result is Instantaneous frequency calculation results

[0083] The above-mentioned embodiments only express the implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be based on the attached claims.

Claims

1. A broadband instantaneous frequency measurement method based on single-bit reception, characterized in that: The following steps are involved: S1, the wireless and microwave components complete the reception and processing of the RF signal, and after sampling by the single-bit high-speed ADC, generate a sampling signal and output it to the FPGA; S2, after receiving the N-point sampling signal, FPGA performs cyclic correlation calculation on the sampling signal; S3, performing Hilbert transform on the sequence after cyclic correlation calculation to obtain the real part I(k) and imaginary part Q(k) of the transformed sequence; S4, calculating the instantaneous phase sequence; S5, performing differential calculation on the instantaneous phase sequence and resolving phase ambiguity; S6, mean statistics; S7, calculate instantaneous frequency; In S2, the sampling signal is cyclically correlated and calculated as: Among them, S(k) is the result of cyclic correlation; N is the total number of sampling points; i is the order number of sampling points; S(i) is the original sampling signal; S k (i) is the data after the original sampling signal is circularly shifted to the right by k points; In S4, the calculation method of the instantaneous phase sequence φ(k) is: In S4, the calculation method for performing differential calculation on the instantaneous phase sequence and resolving phase ambiguity is: If φ(k+1)-φ(k)≥π, then Δφ(k)=φ(k+1)-φ(k)-2π If φ(k+1)-φ(k)≤-π, then Δφ(k)=φ(k+1)-φ(k)+2π If -π<φ(k+1)-φ(k)<π, then Δφ(k)=φ(k+1)-φ(k) where Δφ(k) is the phase difference calculation result of φ(k); In S6, the method of mean value statistics is: In S7, the instantaneous frequency is calculated as follows: Among them, f is the instantaneous frequency calculation result, f s is the sampling rate; A broadband instantaneous frequency measurement device based on single-bit reception, which is used to implement the broadband instantaneous frequency measurement method based on single-bit reception; include: Antenna: used to receive radio frequency signals and convert received electromagnetic wave signals into electrical signals; Microwave components: including low noise amplifiers, bandpass filters and amplifiers; The low noise amplifier input terminal is connected to the antenna; The output end of the low noise amplifier is connected to the input end of the band pass filter to achieve low noise amplification of the signal; The bandpass filter performs bandpass filtering on the low-noise amplified signal; The amplifier amplifies the filtered signal and converts it into a radio frequency output signal; Also includes: Digital components: including 40Gsps single-bit ADC and FPGA; The input end of the 40Gsps single-bit ADC is connected to the output end of the amplifier to perform analog-to-digital conversion on the RF output signal to output a sampling signal; The FPGA receives the sampling signal of the 40Gsps single-bit ADC and performs frequency measurement, and finally outputs the frequency measurement result.

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