Full-scale high-performance continuous wave radar signal processing method and system

Abstract

The invention relates to a full-scale high-performance continuous wave radar signal processing method, which comprises the following steps of: setting a local oscillator signal required by target echo self-mixing, and mixing the echo signal and the local oscillator signal after a radar receives the echo signal; useless signals of the mixed signals are filtered out through a band-pass filter with the frequency band range of-B / 2-B / 2, and then complete echo signals are obtained; a difference value between a target echo signal and a self-mixing sample signal is measured by mixing the target echo signal and the self-mixing sample signal, so that distance information of a target can be calculated, and meanwhile, a reflectivity factor, a movement speed and a movement direction of the target echo signal can be calculated according to the amplitude and the phase of the target echo signal. According to the method, odd-even period interleaved receiving and frequency mixing are adopted, odd-even period data are mixed and then filtered after frequency mixing, final radar detection echo signals are obtained, it is guaranteed that all echo signals are effective data, and the detection capacity of the continuous wave radar is improved.

Description

Technical Field

[0001] The present invention relates to the field of signal processing, and in particular to a full-range high-performance continuous wave radar signal processing method and system. Background Art

[0002] Continuous wave radar is a radar system that uses the Doppler effect to detect the target reflectivity factor, movement speed, target location and other echo information by transmitting frequency modulated continuous wave signals. Because the time when target echo signals at different distances enter the radar signal processor is inconsistent, and the radar transmission signal sample remains unchanged, the radar receiving mixing cannot achieve the reception of all echo signals corresponding to the transmission cycle, and the radar detection distance is greatly reduced. Because the time when echo signals at different distances enter the radar signal processor is inconsistent, the signal processor has different valid data points when extracting the echo signal, which leads to incorrect calculated intensity information; therefore, in order to ensure the target intensity information, the traditional continuous wave radar signal processing usually adopts a calculation method that shortens the radar detection distance and ensures that the amount of valid signal data involved in the calculation is consistent. Traditional continuous wave radar signal processing not only sacrifices a large amount of detection distance, but also greatly reduces the number of valid data points involved in the calculation, reducing the radar's detection capability. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a full-range high-performance continuous wave radar signal processing method and system to solve the deficiencies of the prior art.

[0004] The object of the present invention is achieved by the following technical solution: a full-range high-performance continuous wave radar signal processing method, the method comprising: Step 1: Set the local oscillator signal required for the self-mixing of the target echo. When the radar receives the echo signal, it mixes the echo signal with the local oscillator signal. Step 2: The mixed signal is filtered through a bandpass filter with a frequency band range of -B / 2 to B / 2 to remove useless signals and obtain a complete echo signal; Step 3: By mixing the target echo signal with the self-mixing sample signal, the difference between the target echo signal and the self-mixing sample signal is measured to calculate the distance information of the target. At the same time, the reflectivity factor, movement speed and movement direction of the target echo signal can be calculated based on the amplitude and phase of the target echo signal.

[0005] The local oscillator signal required for setting the target echo self-mixing frequency includes: Set the starting frequency of the local oscillator signal to f0-B / 2, the cutoff frequency to f0+3B / 2, the bandwidth to 2B, the repetition period to 2T, the frequency modulation slope and the transmission signal suppression, the self-mixing local oscillator signal required for the target echo corresponding to the first transmission cycle is from time 0 to time 2T, and the self-mixing local oscillator signal required for the target echo signal corresponding to the second transmission cycle is from time T to time 3T, thus forming self-mixing odd-cycle and even-cycle local oscillators with an interval of T and a period of 2T.

[0006] The mixing of the echo signal and the local oscillator signal comprises: When the radar receives the echo signal, the echo signal in the odd and even cycles is mixed with the self-mixing local oscillator signal in the odd and even cycles respectively.

[0007] The duration of effective echo data that the radar can receive in each transmission cycle is T, which is irrelevant to the position of the target distance from the radar. When the data volume reaches the maximum value, the radar detection capability is the strongest. The maximum effective range of the radar is TC / 2, and the maximum effective range reaches the full scale of the transmission cycle. C is the propagation speed of electromagnetic waves.

[0008] A full-range high-performance continuous wave radar signal processing system, comprising a mixing module, a filtering module and a computing module; The mixing module is used to set the local oscillator signal required for the self-mixing of the target echo. When the radar receives the echo signal, the echo signal is mixed with the local oscillator signal. The filtering module is used to filter out useless signals from the mixed signal through a bandpass filter with a frequency range of -B / 2 to B / 2 to obtain a complete echo signal; The calculation module is used to measure the difference between the target echo signal and the self-mixing sample signal by mixing the target echo signal and the self-mixing sample signal, so as to calculate the distance information of the target, and at the same time, the reflectivity factor, movement speed and movement direction of the target echo signal can be calculated according to the amplitude and phase of the target echo signal.

[0009] The local oscillator signal required for setting the target echo self-mixing frequency includes: Set the starting frequency of the local oscillator signal to f0-B / 2, the cutoff frequency to f0+3B / 2, the bandwidth to 2B, the repetition period to 2T, the frequency modulation slope and the transmission signal suppression, the self-mixing local oscillator signal required for the target echo corresponding to the first transmission cycle is from time 0 to time 2T, and the self-mixing local oscillator signal required for the target echo signal corresponding to the second transmission cycle is from time T to time 3T, thus forming self-mixing odd-cycle and even-cycle local oscillators with an interval of T and a period of 2T.

[0010] The mixing of the echo signal and the local oscillator signal comprises: When the radar receives the echo signal, the echo signal in the odd and even cycles is mixed with the self-mixing local oscillator signal in the odd and even cycles respectively.

[0011] The present invention has the following advantages: a full-range high-performance continuous wave radar signal processing method and system, which maintains the slope of the self-mixing local oscillator and extends the self-mixing local oscillator time to ensure that the echo data of each transmission cycle can be completely received, thereby realizing the full-range detection of the continuous wave radar; adopts odd-even cycle staggered reception and mixing, mixes the odd-even cycle data after mixing and then filters to obtain the final radar detection echo signal, ensures that all echo signals are valid data, and improves the detection capability of the continuous wave radar. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic diagram of a self-mixing local oscillator of a continuous wave radar of the present invention; Figure 2 This is a schematic diagram of a continuous wave radar echo mixing signal of the present invention; Figure 3 It is a schematic diagram of the complete echo signal of the continuous wave radar of the present invention. DETAILED DESCRIPTION

[0013] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the detailed description of the embodiments of the present application provided below in conjunction with the drawings is not intended to limit the scope of protection of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application. The present invention is further described below in conjunction with the drawings.

[0014] The present invention specifically relates to a full-range high-performance continuous wave radar signal processing method, which completely solves the problem that the detection range and detection capability of the continuous wave radar cannot be achieved at the same time, and also solves the problem that the existing method loses the detection range and sacrifices the radar detection capability, and truly achieves the combination of full-cycle data validity and full-range detectable high-performance detection and full-range detection; after the radar receives the echo signal, the echo signal is mixed with the self-mixing sample signal, and the mixed signal is filtered out by a digital filter to output an echo difference frequency signal, and then the difference frequency signal is further processed to extract the amplitude information and frequency information of the echo signal, which is used to calculate the position, strength, speed and other information of the target. Specifically including the following contents: like Figure 1 As shown, the present invention designs the starting frequency of the local oscillator signal required for the self-mixing of the target echo to be f0-B / 2, the cut-off frequency to be f0+3B / 2, the bandwidth to be 2B, the repetition period to be 2T, the frequency modulation slope to be consistent with the transmission signal, the self-mixing local oscillator signal required for the target echo corresponding to the first transmission period is from time 0 to time 2T, and the self-mixing local oscillator signal required for the target echo signal corresponding to the second transmission period is from time T to time 3T. In this way, the self-mixing odd-numbered period and even-numbered period local oscillator generated by staggering with an interval of T and a period of 2T are formed.

[0015] like Figure 2 As shown in , when the radar receives the echo signal, the echo signals of odd and even cycles are mixed with the self-mixing local oscillator signals of odd and even cycles respectively; after the odd cycle echo mixing signal and the even cycle echo mixing signal are mixed, other frequency signals are filtered out by a bandpass filter with a frequency band range of -B / 2~B / 2, and finally the following is obtained: Figure 3 The complete echo signal is shown. like Figure 3 As shown in the figure, the effective echo data that the radar can receive in each transmission cycle lasts for a period of T, which is irrelevant to the position of the target distance from the radar. The data volume can reach the maximum value, and the radar detection capability is the strongest. The maximum range of the radar is TC / 2, and the maximum range reaches the full range of the transmission cycle.

[0016] For static targets, the frequency difference between the radar transmitted signal and the received target echo signal in the overlapping area of ​​the radar transmitted signal and the corresponding target echo signal in the same period is f Δ is a fixed value and is proportional to the target distance. The formula is as follows: f Δ =B×2R / TC Among them, R is the straight-line distance between the target and the radar, and C is the propagation speed of electromagnetic waves.

[0017] It can be seen from the above formula that the target distance information can be calculated by mixing the target echo signal with the self-mixing sample signal to measure the difference between the target echo signal and the self-mixing sample signal. At the same time, the reflectivity factor, movement speed and movement direction of the target echo signal can be calculated according to the amplitude and phase of the target echo signal.

[0018] After the signal processing method designed by the present invention is used for processing, a complete echo signal is finally obtained. The echo signal receiving time can meet the full-scale detection of the entire transmission cycle, ensuring the detection range of the radar; all received data are valid data, ensuring the detection capability of the radar. It effectively solves the problem of small radar detection distance caused by insufficient reception time, and realizes full-scale detection within the radar transmission cycle through complete received data; the signal processing method of the present invention also realizes that the full-scale data are all valid data, ensuring the maximum detection capability of the radar.

[0019] The above is only a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used for various other combinations, modifications and improvements, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not deviate from the spirit and scope of the present invention, and should be within the scope of protection of the claims attached to the present invention.

Claims

1. A full-range high-performance continuous wave radar signal processing method, characterized in that: The method comprises: Step 1: Set the local oscillator signal required for the self-mixing of the target echo. When the radar receives the echo signal, it mixes the echo signal with the local oscillator signal. Step 2: The mixed signal is filtered through a bandpass filter with a frequency band range of -B / 2 to B / 2 to remove useless signals and obtain a complete echo signal; Step 3: By mixing the target echo signal with the self-mixing sample signal, the difference between the target echo signal and the self-mixing sample signal is measured to calculate the distance information of the target. At the same time, the reflectivity factor, movement speed and movement direction of the target echo signal can be calculated based on the amplitude and phase of the target echo signal.

2. A full-range high-performance continuous wave radar signal processing method according to claim 1, characterized in that: The local oscillator signal required for setting the target echo self-mixing frequency includes: Set the starting frequency of the local oscillator signal to f0-B / 2, the cutoff frequency to f0+3B / 2, the bandwidth to 2B, the repetition period to 2T, the frequency modulation slope and the transmission signal suppression, the self-mixing local oscillator signal required for the target echo corresponding to the first transmission cycle is from time 0 to time 2T, and the self-mixing local oscillator signal required for the target echo signal corresponding to the second transmission cycle is from time T to time 3T, thus forming self-mixing odd-cycle and even-cycle local oscillators with an interval of T and a period of 2T.

3. A full-range high-performance continuous wave radar signal processing method according to claim 2, characterized in that: The mixing of the echo signal and the local oscillator signal comprises: When the radar receives the echo signal, the echo signal in the odd and even cycles is mixed with the self-mixing local oscillator signal in the odd and even cycles respectively.

4. A full-range high-performance continuous wave radar signal processing method according to claim 2, characterized in that: The duration of effective echo data that the radar can receive in each transmission cycle is T, which is irrelevant to the position of the target distance from the radar. When the data volume reaches the maximum value, the radar detection capability is the strongest. The maximum effective range of the radar is TC / 2, and the maximum effective range reaches the full scale of the transmission cycle. C is the propagation speed of electromagnetic waves.

5. A full-range high-performance continuous wave radar signal processing system, characterized in that: It includes a mixing module, a filtering module and a calculation module; The mixing module is used to set the local oscillator signal required for the self-mixing of the target echo. When the radar receives the echo signal, the echo signal is mixed with the local oscillator signal. The filtering module is used to filter out useless signals from the mixed signal through a bandpass filter with a frequency range of -B / 2 to B / 2 to obtain a complete echo signal; The calculation module is used to measure the difference between the target echo signal and the self-mixing sample signal by mixing the target echo signal and the self-mixing sample signal, so as to calculate the distance information of the target, and at the same time, the reflectivity factor, movement speed and movement direction of the target echo signal can be calculated according to the amplitude and phase of the target echo signal.

6. A full-range high-performance continuous wave radar signal processing system according to claim 5, characterized in that: The local oscillator signal required for setting the target echo self-mixing frequency includes: Set the starting frequency of the local oscillator signal to f0-B / 2, the cutoff frequency to f0+3B / 2, the bandwidth to 2B, the repetition period to 2T, the frequency modulation slope and the transmission signal suppression, the self-mixing local oscillator signal required for the target echo corresponding to the first transmission cycle is from time 0 to time 2T, and the self-mixing local oscillator signal required for the target echo signal corresponding to the second transmission cycle is from time T to time 3T, thus forming self-mixing odd-cycle and even-cycle local oscillators with an interval of T and a period of 2T.

7. A full-range high-performance continuous wave radar signal processing system according to claim 6, characterized in that: The mixing of the echo signal and the local oscillator signal comprises: When the radar receives the echo signal, the echo signal in the odd and even cycles is mixed with the self-mixing local oscillator signal in the odd and even cycles respectively.

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