阅读说明：本技术 一种高精度多普勒频率测速装置 (high-precision Doppler frequency speed measuring device ) 是由 魏华 何芯锐 于 2019-09-18 设计创作，主要内容包括：本发明公开了一种高精度多普勒频率测速装置,包括：信号发射台与移动接收台；所述信号发射台包括信号发生单元、信号调制单元和信号发射单元,所述信号发生单元用于构建帧格式为ZC序列和共轭ZC序列构成的信标信号,并通过信号调制单元与信号发射单元对信标信号进行发射；所述移动接收台包括信号接收单元、信号提取单元、峰值检测单元及测速单元。本发明通过提出一种构建并发射ZC序列和共轭ZC序列的信号发射台,并在移动台利用简单相关器进行峰值检测,并通过查表即可实现高精度和大范围的运动速率测定,本发明通过测量ZC序列及共轭ZC序列的多普勒频率,间接实现移动速率的检测,测量方案简单且测量精度高。(The invention discloses a high-precision Doppler frequency speed measuring device, which comprises: a signal transmitting station and a mobile receiving station; the signal transmitting station comprises a signal generating unit, a signal modulating unit and a signal transmitting unit, wherein the signal generating unit is used for constructing a beacon signal with a frame format formed by a ZC sequence and a conjugate ZC sequence and transmitting the beacon signal through the signal modulating unit and the signal transmitting unit; the mobile receiving station comprises a signal receiving unit, a signal extracting unit, a peak value detecting unit and a speed measuring unit. The invention provides a signal transmitting station for constructing and transmitting a ZC sequence and a conjugate ZC sequence, a mobile station utilizes a simple correlator to detect a peak value, and the measurement of high precision and large-range motion rate can be realized by table lookup.)

1. A high accuracy Doppler frequency speed measurement device, comprising: a signal transmitting station and a mobile receiving station; the signal transmitting station comprises a signal generating unit, a signal modulating unit and a signal transmitting unit, wherein the signal generating unit is used for constructing a beacon signal with a frame format formed by a ZC sequence and a conjugate ZC sequence and transmitting the beacon signal through the signal modulating unit and the signal transmitting unit; the mobile receiving station comprises a signal receiving unit, a signal extracting unit, a peak value detecting unit and a speed measuring unit, wherein the signal receiving unit receives beacon signals, and the received signals respectively pass through the signal extracting unit, the peak value detecting unit and the speed measuring unit to obtain the moving speed of the receiving station.

2. A high accuracy doppler frequency velocimetry apparatus as claimed in claim 1, wherein said signal modulation unit modulates the constructed beacon signal and transmits the signal through said signal transmission unit.

3. A high accuracy doppler frequency velocimeter according to claim 1, wherein said signal extraction unit comprises a signal correlator for extracting the beacon signals of ZC sequence and conjugate ZC sequence in the received signal and removing the interference signal and noise signal.

4. A high accuracy doppler frequency velocimeter according to claim 1, wherein said peak detection unit detects the peak of the received ZC sequence and conjugate ZC sequence and calculates the correlation peak time difference.

5. The device according to claim 1, wherein the speed measurement unit comprises a lower computer, which receives the time interpolation of the correlation peak, and obtains the doppler frequency of the beacon signal and the velocity of the mobile receiving station by looking up a table and fitting a curve.

6. A high accuracy doppler frequency velocimetry device as claimed in claim 1, wherein said signal transmitting unit and signal receiving unit are a transmitting antenna and a receiving antenna respectively.

Technical Field

Non-contact velocity measurement is a very important and difficult velocity measurement method in practical application, that is, when an object moves/rotates, the problem of how to measure the velocity of the object is solved. The doppler frequency measurement is an excellent method for measuring velocity, and the basic principle is to measure velocity by the doppler effect. The doppler effect indicates that waves receive higher frequencies when the source moves closer to the observer and lower frequencies when the source moves farther away from the observer, and is applicable to all types of waves, including electromagnetic waves. As shown in fig. 1, in the doppler effect of electromagnetic waves, the frequency becomes higher when the mobile station moves to a transmitting base station, and becomes lower when it moves away from the base station. Therefore, the doppler frequency measurement method is an excellent indirect method for measuring velocity, and the basic idea is that when an object moves, the velocity of the object moving can be indirectly measured by measuring the doppler frequency shift of the received electromagnetic wave.

Doppler frequency (Doppler frequency) f of radio signal_dFollowing the speed of movement v of the object and the carrier frequency f of the radio signal_cAnd the speed of light c satisfies the following equation:

Therefore, the Doppler velocity measurement and velocity measurement platform of a moving object is composed of two parts, one part is that a wireless station transmits specific wireless electromagnetic waves, and the other part is that the moving object itself performs Doppler frequency measurement on electromagnetic wave signals transmitted by the wireless station. Therefore, when the Doppler frequency of the object movement is accurately measured, the object movement velocity v can be indirectly and accurately measured. However, in the existing velocity measurement, the implementation of measuring the doppler frequency is very complicated and tedious, and for example, the commonly used methods include a passive frequency measurement method (which can be divided into a resonance method and a bridge method) and an active comparison method, which can be divided into a beat frequency method and a difference frequency method. The passive frequency measurement method (usually used for frequency rough measurement, the precision is about 1 percent, and the realization complexity is very high, the active method is to utilize the linear superposition of two signals to generate a beat frequency phenomenon, and then to measure the frequency by detecting the zero beat phenomenon, usually used for low frequency measurement, the precision is higher, but the frequency error range of the measurement is very small, and the complexity is higher.

Disclosure of Invention

The present invention is directed to a high-precision doppler frequency velocity measuring device.

A high accuracy doppler frequency velocimeter device, comprising: a signal transmitting station and a mobile receiving station; the signal transmitting station comprises a signal generating unit, a signal modulating unit and a signal transmitting unit, wherein the signal generating unit is used for constructing a beacon signal with a frame format formed by a ZC sequence and a conjugate ZC sequence and transmitting the beacon signal through the signal modulating unit and the signal transmitting unit; the mobile receiving station comprises a signal receiving unit, a signal extracting unit, a peak value detecting unit and a speed measuring unit, wherein the signal receiving unit receives beacon signals, and the received signals respectively pass through the signal extracting unit, the peak value detecting unit and the speed measuring unit to obtain the moving speed of the receiving station.

The signal modulation unit modulates the constructed beacon signal and transmits the modulated signal through the signal transmitting unit.

The signal extraction unit comprises a signal correlator which is used for respectively extracting the beacon signals of the ZC sequence and the conjugate ZC sequence in the received signal and removing the interference signal and the noise signal.

The peak value detection unit respectively detects peak values of the received ZC sequence and the conjugate ZC sequence and calculates to obtain a correlation peak value time difference.

The speed measuring unit comprises a lower computer, receives the relevant peak time interpolation, and obtains the Doppler frequency of the beacon signal and the speed of the mobile receiving station through table look-up and curve fitting.

The signal transmitting unit and the signal receiving unit are respectively a transmitting antenna and a receiving antenna.

The invention has the beneficial effects that: the invention provides a signal transmitting station for constructing and transmitting a ZC sequence and a conjugate ZC sequence, a mobile station utilizes a simple correlator to detect a peak value, and the measurement of high precision and large-range motion rate can be realized by table lookup.

Drawings

FIG. 1 is a schematic diagram of the Doppler effect principle;

FIG. 2 is a schematic representation of the relationship of the correlator output of ZC sequences and conjugate ZC sequences to the Doppler frequency;

Fig. 3 is a schematic block diagram of a signal receiving station.

Detailed Description

In order to more clearly understand the technical features, objects, and effects of the present invention, embodiments of the present invention will now be described with reference to the accompanying drawings.

In this embodiment, a high accuracy doppler frequency speed measurement device includes: a signal transmitting station and a mobile receiving station; the signal transmitting station comprises a signal generating unit, a signal modulating unit and a signal transmitting unit, wherein the signal generating unit is used for constructing a beacon signal with a frame format formed by a ZC sequence and a conjugate ZC sequence and transmitting the beacon signal through the signal modulating unit and the signal transmitting unit; the mobile receiving station comprises a signal receiving unit, a signal extracting unit, a peak value detecting unit and a speed measuring unit, wherein the signal receiving unit receives beacon signals, and the received signals respectively pass through the signal extracting unit, the peak value detecting unit and the speed measuring unit to obtain the moving speed of the receiving station.

In this embodiment, the mobile employs a simple peak detection to implement doppler frequency detection based on the beacon of the transmitting portion. On the receiving output signal of each carrier frequency, the receiving signal of the mobile station is correlated with the following two ZC sequences and conjugate ZC sequences. The signal input to the correlator after the carrier frequency signal has been down-converted can be written as y_kThe output of the correlator of the ZC sequence can be denoted c_k：Similarly, the output of a correlator for a conjugate ZC sequence can be expressed as

In this embodiment, after the ZC sequence and the conjugate ZC sequence are subjected to the doppler effect, the positions of the correlation peaks thereof are shifted according to the magnitude of the doppler frequency, as shown in fig. 2. Therefore, the present invention utilizes the Doppler frequency to change the interval distance between the ZC sequence and the peak value of the conjugate ZC sequence correlator, so as to realize the accurate measurement of the Doppler frequency of the mobile station.Thus, assuming that the time interval of the ZC sequence and the conjugate ZC sequence correlator peaks is Δ d on the time axis, the corresponding Doppler frequencies can be generated from a lookup table and function of Δ d, i.e., the measured Doppler frequency can be expressed asWhere the LUT represents a table lookup and curve fitting operation.

Through simulation test, the accuracy of measuring the Doppler frequency can reach 0.001HZ, and the Doppler frequency range which can be very measured is very wide and can reach 10KHz, so that the speed range which can be measured by the method is very wide.

Once the measured Doppler frequency is obtained by table lookup and fittingcorresponding rate of movementcan be based on measuring the Doppler frequencyThe look-up table and fit produce, that is:

The invention provides a signal transmitting station for constructing and transmitting a ZC sequence and a conjugate ZC sequence, a mobile station utilizes a simple correlator to detect a peak value, and the measurement of high precision and large-range motion rate can be realized by table lookup.

The foregoing shows and describes the general principles and broad features of the present invention and advantages thereof. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.