CN113589249A - Signal processing method for calibrating direct current offset of single-frequency continuous wave Doppler radar - Google Patents
Signal processing method for calibrating direct current offset of single-frequency continuous wave Doppler radar Download PDFInfo
- Publication number
- CN113589249A CN113589249A CN202110804594.1A CN202110804594A CN113589249A CN 113589249 A CN113589249 A CN 113589249A CN 202110804594 A CN202110804594 A CN 202110804594A CN 113589249 A CN113589249 A CN 113589249A
- Authority
- CN
- China
- Prior art keywords
- signal
- doppler radar
- radar
- sampling
- data
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000003672 processing method Methods 0.000 title claims abstract description 15
- 238000005070 sampling Methods 0.000 claims abstract description 37
- 238000000034 method Methods 0.000 claims description 12
- 230000006870 function Effects 0.000 claims description 9
- 238000006073 displacement reaction Methods 0.000 claims description 2
- 230000005540 biological transmission Effects 0.000 claims 1
- 238000011478 gradient descent method Methods 0.000 description 6
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 235000010627 Phaseolus vulgaris Nutrition 0.000 description 1
- 244000046052 Phaseolus vulgaris Species 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 238000012804 iterative process Methods 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/41—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00 using analysis of echo signal for target characterisation; Target signature; Target cross-section
- G01S7/418—Theoretical aspects
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Radar Systems Or Details Thereof (AREA)
Abstract
The invention discloses a signal processing method for calibrating direct current offset of a single-frequency continuous wave Doppler radar, which comprises the steps of determining the sampling frequency of Doppler radar signals, and respectively acquiring IQ two-path signals of the Doppler radar; carrying out down-sampling processing on the original data of IQ two-path signals of the Doppler radar in parallel to obtain down-sampled radar data; performing real-time signal calibration based on an improved gradient descent algorithm on the radar data subjected to the down-sampling, and calibrating the radar data by utilizing a gram-Schmidt orthogonalization formula when IQ direct current offset within a set error range is met to obtain calibrated arc data; recovering phase information related to the target motion from the calibrated IQ signal through an arc tangent demodulation algorithm; and acquiring the motion information of the target object according to the recovered phase information related to the target motion.
Description
Technical Field
The invention belongs to the field of continuous wave radar signal processing, and particularly relates to a signal processing method for calibrating direct current offset of a single-frequency continuous wave Doppler radar.
Background
The detection principle of the Doppler radar is that the Doppler frequency shift effect is utilized to obtain the radial speed of a moving object, a zero intermediate frequency receiver of the radar mixes an echo signal and a carrier signal with the same frequency, the signal is directly converted to a baseband, the conversion process does not pass through intermediate frequency, and image frequency interference does not exist; the radar system adopts the zero intermediate frequency receiver, so that the communication system has the advantages of low cost, small volume, low power consumption, high integration level and the like.
However, zero intermediate frequency receivers have a unique dc offset problem; firstly, the isolation between the local oscillator signal port and the input of the mixer and the low noise amplifier is not perfect, the leaked local oscillator signal enters the mixer and is mixed with the entered local oscillator signal to generate a direct current component, and the effect is called local oscillator leakage; secondly, the leakage signal entering the input of the mixer or strong interference signal of the lna mixes with the local oscillator signal, thereby generating a dc component, which is called "interference self-mixing". These dc signals are superimposed on the baseband signal and interfere with the baseband signal, which is called dc offset, which is usually larger than the noise of the rf front-end and the signal-to-noise ratio is degraded, while too large dc offset may saturate the amplifier after the mixer and may not amplify the useful signal, even burning the chip.
Therefore, it is important to calibrate the dc offset of a single frequency continuous wave radar employing a zero if receiver architecture. The system needs to be additionally provided with an additional data acquisition system which comprises a digital signal processing module, a digital-to-analog conversion module and an accurate voltage source, and is complex in system design and higher in hardware cost. The Shanyue bean of florida university adopts an automatic direct current offset calibration strategy, and a system strategy is selected according to signal characteristics to improve the calibration accuracy and efficiency of direct current offset, but the signal needs to have known type characteristics.
Disclosure of Invention
In view of the above, the present invention is directed to a signal processing method for calibrating dc offset of a single-frequency continuous wave doppler radar.
In order to achieve the purpose, the technical scheme of the invention is realized as follows:
the embodiment of the invention provides a signal processing method for calibrating direct current offset of a single-frequency continuous wave Doppler radar, which comprises the following steps:
determining the sampling frequency f of the Doppler radar signalsRespectively acquiring IQ two paths of signals of the Doppler radar;
carrying out down-sampling processing on the original data of IQ two-path signals of the Doppler radar in parallel to obtain down-sampled radar data;
performing real-time signal calibration based on an improved gradient descent algorithm on the radar data subjected to the down-sampling, and calibrating the radar data by utilizing a gram-Schmidt orthogonalization formula when IQ direct current offset within a set error range is met to obtain calibrated arc data;
and performing real-time circle center search on the calibrated arc data through a least square fitting circle, subtracting useless direct current offset, and moving the circle center to the original point position.
Recovering phase information related to the target motion from the calibrated IQ signal through an arc tangent demodulation algorithm;
according to the formula
And recovering phase information related to the target motion to acquire target object motion information.
In the above scheme, the doppler radar signal sampling frequency is determined to be fsRespectively acquiring IQ two-path signals of the Doppler radar, specifically the sampling frequency f of the Doppler radar signalsThe sampling frequency f of the signal satisfying the Nyquist sampling theoremsSampling frequency fsIs the highest frequency f of the signalHMore than twice, i.e. fs＞2*fHAnd respectively acquiring IQ two paths of sampling signals of the radar.
In the above scheme, the parallel down-sampling processing is performed on the raw data of the IQ two-path signals of the doppler radar to obtain the down-sampled radar data, and the method specifically includes the following steps:
firstly, determining the step length of down-sampling;
secondly, traversing all data;
and thirdly, when the index is equal to the step length of down sampling, extracting data corresponding to the index.
In the above scheme, the gram-schmitt orthogonalization formula is:
wherein, VIAnd VQIndicating a preset DC offset initialization value, BIAnd BQRepresenting IQ baseband signals, BIOAnd BQORepresenting the IQ signal after orthogonalization, phiEIndicating a phase error, AERepresenting the amplitude error.
In the above scheme, the signal real-time calibration based on the improved gradient descent algorithm is performed on the radar data after the down-sampling, and the specific steps are as follows:
(201) at the beginning, m samples are randomly selected from all n samples, and the number of the samples is X1，X2，…，Xi,…,Xm；
(202) Setting proper initialization weight, bias and learning rate;
(203) inputting a sample, and calculating output;
(204) calculating error and mean square error;
(205) judging whether all m samples are trained;
(206) inputting a next sample;
(207) updating formula updating weight and bias;
(208) judging that all n samples are trained;
(208) selecting another m samples;
(210) and (5) reaching a convergence condition and ending iteration.
In the above scheme, the real-time circle center search of the calibrated circular arc data by fitting a circle by a least square method specifically includes:
defining an auxiliary function:
g(x，y)＝(x-xc)2+(y-yc)2-R2
least squares fitting circle formula:
wherein (x)c，yc) Denotes the center coordinates, R denotes the radius, g (x, y) denotes the auxiliary function, { xi,yiDenotes the radar IQ sample signal.
In the above scheme, the arctangent demodulation algorithm formula is as follows:
where θ (t) represents phase modulation, BIOAnd BQORepresents the IQ signal after orthogonalization, Δ x (t) represents the target micro-motion displacement, and λ represents the radar emission signal wavelength.
Compared with the prior art, the method and the device can be used for rapidly, real-timely and accurately carrying out direct current offset calibration on the single-frequency continuous wave Doppler radar and accurately acquiring the motion information of the target object.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention without limiting the invention to the proper forms disclosed. In the drawings:
fig. 1 is a block diagram of a zero if receiver architecture.
Fig. 2(a) shows local oscillator leakage self-mixing in a zero intermediate frequency receiver.
Fig. 2(b) illustrates interference self-mixing in a zero intermediate frequency receiver.
Fig. 3 is a comparison graph before and after calibration of amplitude and phase error parameters.
FIG. 4 is a flow chart of DC offset calibration for a single frequency continuous wave Doppler radar.
FIG. 5 is a flow chart of a real-time calibration algorithm of the improved gradient descent method.
In the figure: (1) a radio frequency receiving antenna; (2) a radio frequency band pass filter; (3) a low noise amplifier; (4) a mixer; (5) a 90 degree phase shifter; (6) local oscillation; (7) a low-pass filter; (8) a variable gain amplifier; (9) radar I-path signals; (10) radar Q path signals; (11) radar I or Q signals; (100) acquiring IQ signals of a Doppler radar; (101) setting an initialization value of the direct current offset; (102) down-sampling; (103) gram-schmidt orthogonalization criteria; (104) real-time calibration based on an improved gradient descent method; (105) a real-time circle center searching algorithm; (106) an arc tangent demodulation algorithm; (107) acquiring target object motion information; (201) starting; (202) initializing weight, bias and learning rate; (203) inputting a sample, and calculating output; (204) calculating error and mean square error; (205) judging that all m samples are trained; (206) inputting a next sample; (207) updating formula updating weight and bias; (208) judging that all n samples are trained; (209) selecting another m samples; (210) and (6) ending.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
The same or similar reference numerals in the drawings of the present embodiment correspond to the same or similar components; in the description of the present invention, it is to be understood that the terms "upper", "lower", "left", "right", "inner", "outer", etc. indicate orientations or positional relationships based on those shown in the drawings only for the convenience of description and the simplification of description, but do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, the terms describing the positional relationships in the drawings are only used for illustrative purposes and are not to be construed as limiting the present patent, and the specific meanings of the terms may be understood by those skilled in the art according to specific situations.
It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, article, or apparatus that comprises the element.
Referring to fig. 1, a zero intermediate frequency receiver of a radar is a block diagram, in which an echo signal and a carrier signal of the same frequency are mixed, and the signal is directly converted to a baseband without passing through an intermediate frequency. The system has a simple structure, does not have image frequency interference, but has local oscillator leakage and interference self-mixing due to the imperfection of system hardware, and referring to local oscillator leakage self-mixing in a zero intermediate frequency receiver in fig. 2(a) and interference self-mixing in the zero intermediate frequency receiver in fig. 2(b), the problem of DC offset is inevitably generated.
In order to solve the problem of direct current offset, the invention provides a signal processing method for calibrating the direct current offset of a single-frequency continuous wave Doppler radar, which can calibrate the direct current offset of the single-frequency continuous wave Doppler radar in real time, quickly and accurately to acquire the motion information of a target object.
The embodiment of the invention provides a signal processing method for calibrating direct current offset of a single-frequency continuous wave Doppler radar, which comprises the following steps, as shown in a direct current offset calibration flow chart of a single-frequency continuous wave Doppler radar in figure 4:
step 1(100), the Nyquist sampling theorem is satisfied, and the sampling frequency f of the signalsMust be the highest frequency f of the signalHMore than twice, i.e. fs＞2*fHTo get it readyCan recover the original signal and determine the sampling frequency f of the Doppler radar signalsAnd IQ two paths of signals of the radar are respectively obtained.
Step 2(101), presetting the initialization value of the direct current offset as VIAnd VQThe initialization value can be the average value of two paths of signals of the radar IQ in the oscilloscope.
And step 3, (102), meanwhile, another thread is started to perform down-sampling processing on the raw data of the Doppler radar signal. When data is collected, a digital-to-analog converter with a high sampling rate is generally adopted. In this case, down-sampling is required to reduce processing time. Usually, a "decimation" method is used, i.e. a point is decimated from a plurality of sampling points. Every D-1 point, 1 point is extracted, so that the sampling rate is reduced to fs/D。
And 4, (103) according to a radar equation, the amplitude of the baseband signal is inversely proportional to the square of the distance, and in the case of the linear motion of the target, the plane curve is approximately regarded as an arc in an ellipse. Fitting the arc line into an ellipse, calculating the width A and the height B of the arc line, and calculating the width A and the height B according to the AEThe amplitude error can be determined as B/a. C is defined as the distance between two points of the ellipse's middle intersection point, thereby determining the phase error
φE＝arc·sin(C/A)
After the error parameters are obtained, the signal is calibrated by using a gram-Schmidt orthogonalization formula, and a baseband signal B is subjected to calibrationIAnd BQAnd is represented as B after orthogonalizationIOAnd BQO. The calibration procedure is represented in matrix as:
and step 5(104), performing signal real-time calibration based on an improved gradient descent algorithm on the radar data subjected to down-sampling, and inputting the signal into Graham-Schmidt orthogonalization calibration when IQ direct current offset within a set error range is met.
Mathematically, the direction of the gradient is the direction in which the function grows at the fastest rate. Therefore, the temperature of the molten metal is controlled,if one wants to calculate the minimum of the function, one can do this using a gradient descent method. Suppose it is desired to solve for an objective function f (x) ═ f (x)1,...,xn) Can be from an initial point
Initially, an iterative process is constructed based on a learning rate η > 0: when i is greater than 0, the ratio of the total of the I,
…
wherein
Once the convergence condition is reached, the iteration ends. From the iterative formulation of the gradient descent method, the selection of the next point is related to the position of the current point and its gradient.
In a whole view, no matter the minimum value of the calculation function, an iterative relationship g needs to be constructed, that is:
that is, the iterative relationship x is satisfied for all i ≧ 0(i+1)＝g(x(i)). Therefore, the gradient descent method function g has the expression:
the flow chart of the improved gradient descent method algorithm is shown in FIG. 5:
(201) at the beginning, m samples are randomly selected from all n samples, and the number of the samples is X1，X2，…，Xi,…,Xm；
(202) Setting proper initialization weight, bias and learning rate;
(203) inputting a sample, and calculating output;
(204) calculating error and mean square error;
(205) judging whether all m samples are trained;
(206) inputting a next sample;
(207) updating formula updating weight and bias;
(208) judging that all n samples are trained;
(208) selecting another m samples;
(210) and (5) reaching a convergence condition and ending iteration.
And step 6(105), fitting a circle by using the arc data after the gram-Schmidt orthogonalization calibration, performing real-time circle center search through a minimum two-multiplication, and then subtracting useless direct current offset to move the circle center to the original point position.
And 7, recovering phase information related to the target motion from the calibrated IQ signal by using an arc tangent demodulation algorithm (106).
Step 8(107) using the formula
And acquiring the motion information of the target object.
In conclusion, the method can quickly, real-timely and accurately carry out direct current offset calibration on the single-frequency continuous wave Doppler radar and accurately acquire the motion information of the target object.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention.
Claims (7)
1. A signal processing method for calibrating direct current offset of a single-frequency continuous wave Doppler radar is characterized by comprising the following steps:
determining the sampling frequency f of the Doppler radar signalsRespectively obtain a plurality ofIQ two-path signals of the Doppler radar;
carrying out down-sampling processing on the original data of IQ two-path signals of the Doppler radar in parallel to obtain down-sampled radar data;
performing real-time signal calibration based on an improved gradient descent algorithm on the radar data subjected to the down-sampling, and calibrating the radar data by utilizing a gram-Schmidt orthogonalization formula when IQ direct current offset within a set error range is met to obtain calibrated arc data;
performing real-time circle center search on the calibrated arc data through a least square fitting circle, then subtracting useless direct current offset, and moving the circle center to the original point position;
recovering phase information related to the target motion from the calibrated IQ signal through an arc tangent demodulation algorithm;
according to the formula
And recovering phase information related to the target motion to acquire target object motion information.
2. Signal processing method of calibrating the DC offset of a Single frequency continuous wave Doppler Radar according to claim 1 wherein the Doppler radar signal is determined to have a sampling frequency fsRespectively acquiring I Q two paths of signals of the Doppler radar, specifically acquiring the sampling frequency f of the Doppler radar signalsThe sampling frequency f of the signal satisfying the Nyquist sampling theoremsSampling frequency fsIs the highest frequency f of the signalHMore than twice, i.e. fs＞2*fHAnd respectively acquiring IQ two paths of sampling signals of the radar.
3. The signal processing method for calibrating direct current offset of a single-frequency continuous wave doppler radar according to claim 1 or 2, wherein the raw data of the IQ two-path signal of the doppler radar is down-sampled in parallel to obtain down-sampled radar data, and specifically the method is implemented by the following steps:
firstly, determining the step length of down-sampling;
secondly, traversing all data;
and thirdly, when the index is equal to the step length of down sampling, extracting data corresponding to the index.
4. The signal processing method for calibrating dc offset of a single frequency continuous wave doppler radar according to claim 3, wherein the gram-schmidt orthogonalization formula is:
wherein, VIAnd VQIndicating a preset DC offset initialization value, BIAnd BQRepresenting IQ baseband signals, BIOAnd BQORepresenting the IQ signal after orthogonalization, phiEIndicating a phase error, AERepresenting the amplitude error.
5. The signal processing method for calibrating direct current offset of a single-frequency continuous wave doppler radar according to claim 4, wherein the signal real-time calibration based on the improved gradient descent algorithm is performed on the down-sampled radar data, and the specific steps are as follows:
(201) at the beginning, m samples are randomly selected from all n samples, and the number of the samples is X1，X2，…，Xi,…,Xm；
(202) Setting proper initialization weight, bias and learning rate;
(203) inputting a sample, and calculating output;
(204) calculating error and mean square error;
(205) judging whether all m samples are trained;
(206) inputting a next sample;
(207) updating formula updating weight and bias;
(208) judging that all n samples are trained;
(208) selecting another m samples;
(210) and (5) reaching a convergence condition and ending iteration.
6. The signal processing method for calibrating direct current offset of a single-frequency continuous wave doppler radar according to claim 5, wherein the real-time circle center search of the calibrated circular arc data is performed by fitting a circle by a least square method, specifically:
defining an auxiliary function:
g(x，y)＝(x-xc)2+(y-yc)2-R2
least squares fitting circle formula:
wherein (x)c，yc) Denotes the center coordinates, R denotes the radius, g (x, y) denotes the auxiliary function, { xi,yiDenotes the radar IQ sample signal.
7. The signal processing method for calibrating DC offset of single-frequency continuous wave Doppler radar according to claim 6, wherein the arctangent demodulation algorithm is as follows:
where θ (t) represents phase modulation, BIOAnd BQOThe IQ signal after orthogonalization is represented, the Delta x (t) represents the micro-motion displacement of a target, and the lambda represents the wavelength of a radar transmission signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110804594.1A CN113589249A (en) | 2021-07-16 | 2021-07-16 | Signal processing method for calibrating direct current offset of single-frequency continuous wave Doppler radar |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110804594.1A CN113589249A (en) | 2021-07-16 | 2021-07-16 | Signal processing method for calibrating direct current offset of single-frequency continuous wave Doppler radar |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113589249A true CN113589249A (en) | 2021-11-02 |
Family
ID=78247959
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110804594.1A Pending CN113589249A (en) | 2021-07-16 | 2021-07-16 | Signal processing method for calibrating direct current offset of single-frequency continuous wave Doppler radar |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113589249A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114244666A (en) * | 2021-12-20 | 2022-03-25 | 北京零壹空间电子有限公司 | Polarization diversity reception method, polarization diversity reception device, computer apparatus, and storage medium |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000171556A (en) * | 1998-12-07 | 2000-06-23 | Nissan Motor Co Ltd | Radar apparatus for vehicle |
| CN103948381A (en) * | 2014-04-09 | 2014-07-30 | 浙江大学 | Imaging method for large dynamic range Doppler biological signal |
| CN105786185A (en) * | 2016-03-12 | 2016-07-20 | 浙江大学 | Non-contact type gesture recognition system and method based on continuous-wave micro-Doppler radar |
| US20160209260A1 (en) * | 2015-01-19 | 2016-07-21 | University Of Florida Research Foundation, Inc. | Interferometric Doppler Radar and Method for Wave and Water Level Measurement |
| CN106805940A (en) * | 2015-12-02 | 2017-06-09 | 由国峰 | A kind of continuous wave bioradar sign detection means |
| CN110987150A (en) * | 2019-12-16 | 2020-04-10 | 上海交通大学 | Ultramicro amplitude vibration measurement method and system based on single-frequency continuous wave radar |
| CN111856452A (en) * | 2020-05-21 | 2020-10-30 | 重庆邮电大学 | OMP-based static human heartbeat and respiration signal separation and reconstruction method |
| CN112137604A (en) * | 2020-10-22 | 2020-12-29 | 温州大学 | Respiration and heartbeat detection method and system based on continuous wave Doppler radar |
-
2021
- 2021-07-16 CN CN202110804594.1A patent/CN113589249A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000171556A (en) * | 1998-12-07 | 2000-06-23 | Nissan Motor Co Ltd | Radar apparatus for vehicle |
| CN103948381A (en) * | 2014-04-09 | 2014-07-30 | 浙江大学 | Imaging method for large dynamic range Doppler biological signal |
| US20160209260A1 (en) * | 2015-01-19 | 2016-07-21 | University Of Florida Research Foundation, Inc. | Interferometric Doppler Radar and Method for Wave and Water Level Measurement |
| CN106805940A (en) * | 2015-12-02 | 2017-06-09 | 由国峰 | A kind of continuous wave bioradar sign detection means |
| CN105786185A (en) * | 2016-03-12 | 2016-07-20 | 浙江大学 | Non-contact type gesture recognition system and method based on continuous-wave micro-Doppler radar |
| CN110987150A (en) * | 2019-12-16 | 2020-04-10 | 上海交通大学 | Ultramicro amplitude vibration measurement method and system based on single-frequency continuous wave radar |
| CN111856452A (en) * | 2020-05-21 | 2020-10-30 | 重庆邮电大学 | OMP-based static human heartbeat and respiration signal separation and reconstruction method |
| CN112137604A (en) * | 2020-10-22 | 2020-12-29 | 温州大学 | Respiration and heartbeat detection method and system based on continuous wave Doppler radar |
Non-Patent Citations (7)
| Title |
|---|
| SINGH, ADITYA: ""Data-Based Quadrature Imbalance Compensation for a CW Doppler Radar System"", 《IEEE TRANS. ACTIONS ON MICROWAVE THEORY AND TECHNIQUES》, vol. 61, no. 4, pages 1718 - 1724 * |
| VICTOR M. LUBECKE: ""Arctangent Demodulation With DC Offset Compensation in Quadrature Doppler Radar Receiver Systems"", 《IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES》, vol. 55, no. 5, pages 1073 - 1079, XP011180988, DOI: 10.1109/TMTT.2007.895653 * |
| 刘德胜: ""基于微波雷达的手势识别技术研究"", 《硕士学位论文数据库》, no. 6 * |
| 季善玲: ""基于毫米波雷达的体征检测技术研究"", 《硕士学位论文数据库》, no. 6 * |
| 廖明杰: ""基于多普勒雷达的呼吸信号处理方法研究"", 《硕士学位论文数据库》, no. 3 * |
| 王静雨: ""连续波无线测量系统中的非线性问题研究"", 《中国博士学位论文数据库》, no. 6 * |
| 邰凡彬: ""一种基于复信号解调的生命体征探测雷达"", 《电子科技》, vol. 34, no. 6 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114244666A (en) * | 2021-12-20 | 2022-03-25 | 北京零壹空间电子有限公司 | Polarization diversity reception method, polarization diversity reception device, computer apparatus, and storage medium |
| CN114244666B (en) * | 2021-12-20 | 2023-09-12 | 北京零壹空间电子有限公司 | Polarization diversity receiving method, apparatus, computer device and storage medium |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0884836B1 (en) | In-phase and quadrature signal regeneration | |
| JP6969562B2 (en) | Digital compensation for mismatches in radar systems | |
| CN107015206B (en) | Adaptive antenna interference detection system and method | |
| US9864045B2 (en) | Radar receivers | |
| CN106940201B (en) | Optical fiber laser sensor optical carrier microwave signal digital demodulation system and demodulation method thereof | |
| KR20050096173A (en) | Systems and methods for coherent adaptive calibration in a receiver | |
| CN108169736B (en) | In-phase (I) and quadrature (Q) imbalance estimation in radar systems | |
| CN108521292A (en) | Ultra-broadband digital satellite beacon method of reseptance based on software radio and receiver | |
| CN113589249A (en) | Signal processing method for calibrating direct current offset of single-frequency continuous wave Doppler radar | |
| CN105549044A (en) | Combined positioning device and method of GNSS (Global Navigation Satellite System) based on data fusion | |
| EP1837994B1 (en) | Wideband frequency discriminator and radiolocalization receiver | |
| JPH1023086A (en) | Instrument for measuring modulation precision | |
| US6356747B1 (en) | Intermediary low-frequency frequency-conversion radiofrequency reception | |
| CN111337746A (en) | Radio frequency signal detection positioning method | |
| CN109324309B (en) | Rotary single-antenna angle measuring device and measuring method thereof | |
| US20100007548A1 (en) | Method and device for determining a distance to a target object | |
| CN112748450A (en) | Signal carrier loop tracking method of navigation satellite receiver | |
| CN116755510A (en) | FPGA implementation method and system of digital phase-locked amplifier | |
| CN110082793B (en) | Signal tracking demodulation system and method based on dual-channel receiver | |
| US8238506B2 (en) | Phase-discriminating device and method | |
| Wang et al. | A digital instantaneous frequency measurement receiver based on sub-Nyquist sampling | |
| EP1519171B1 (en) | Systems and methods for determining the spectral content of an optical signal | |
| JPH05256883A (en) | Digital method and device for analyzing frequency | |
| CN114839612A (en) | X-waveband instantaneous frequency measurement receiver and receiving method thereof | |
| US6198436B1 (en) | Integrated interferometer and instantaneous frequency measurement device and method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |