CN109194415A - Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method and angle measuring system - Google Patents
Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method and angle measuring system Download PDFInfo
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Abstract
The present invention relates to Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method and angle measuring systems, this method is based on and poor composite signal carries out second moment detection, the second moment of composite signal and the desired value of second moment are obtained first, it further obtains orientation detection signal and pitching detects signal, and then be calculated based on the normalized angle measurement estimated value of second moment, the angle measurement accuracy of OFDM data chain has been obviously improved relative to conventional method；Furthermore Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method of the present invention, angle-measuring method is designed for wideband OFDM signal, suitable for injection frequency channel receiver, angle tracking is assisted without signals such as other PCM/FM, CDMA or BPSK/QPSK, it is three-in-one that remote measuring and controlling data-link can be achieved, with anti-multipath performance, system architecture is simplified, has saved signal band resource.
Description
Technical field
The present invention relates to digital wireless communication transmission technique fields, in particular to Unmanned Aerial Vehicle Data Link middle width strip ofdm signal
Angle-measuring method and angle measuring system.
Background technique
In Unmanned Aerial Vehicle Data catenary system, ground control station needs to realize airborne communication terminal accurate direction, angle tracking
System mainly includes that manual tracking, program tracking and three kinds of modes of autotracking, autotracking are the angle tracking modes of current mainstream,
Both the above mode is substantially better than in terms of the precision and robustness and reaction speed of tracking.Autotracking is broadly divided into according to principle
Five kinds of modes such as step trakcing, conical scanning tracking, single-pulse track, phase-array scanning tracking and multi-beam tracking.Frequently with
The fast single-pulse track system of tracking velocity, compares the reception signal from two or more antenna beams, extracts day
Angular deviation information between line and target determines the position of target accordingly.Monopulse technology is divided into " than width " and " than phase "
Two kinds of fundamental types.Phase comparison monopulse is more demanding to the phase equalization of receiving channel.Amplitude-comparison monopulse is to receiving channel
Phase equalization requires lower.
Under single-pulse track system, single-pulse track system can be divided into according to radio-frequency channel quantity: triple channel simple venation
Punching, two-channel monopulse and Single Channel Monopulse Angle Tracking Systems.In contrast to multichannel pulse angle tracking system, single channel list
Pulse angle tracking system has that system structure is simple, and the low advantage of complexity is especially in practical engineering applications related to
Channel backup problem, single-pulse single-channel are undoubtedly best solution.Traditional single pulse angle tracking mostly uses greatly PCM-FM
Impulse modulation, BPSK, QPSK or CDMA spread-spectrum signal etc. have the waveform of permanent envelop forms.Single channel angle tracking receiver base band
The essence of signal processing is exactly to demodulate to amplitude-modulated signal, and according to corresponding sequential relationship, isolate orientation and pitch angle
Error signal.Demodulating common method for amplitude-modulated signal has envelope detection and two kinds of synchronous detection, and envelope detection is realized opposite
Simply.
In a kind of patent " angle-measuring method patent authorization number for unmanned plane of the auspicious of Wednesday Wen Zhangya: CN 102156275
B, 2012 " devise the array antenna that tracking accuracy is 0.11 °, meet UAV TT & C's precision and be generally less than 0.2 ° and wants
It asks.It is adopted in document " Wang Shan coral single channel angle tracking receiver baseband signal processing technique Xian Electronics Science and Technology University 2012 "
It is demodulated with angular error signal of the synchronous demodulation method to low signal-to-noise ratio.In document, " Song Ning general's pulse spreads angle tracking system
System is studied and the FPGA design realization Chongqing: University Of Chongqing, the influence of signal amplitude is eliminated in 2014 ", using carrier signal
Error signal is normalized in amplitude influences factor Ⅴ.Document " Liu Jiaxing broadband signal angle tracking and four-way simple venation
Rush scheme [J] Spacecraft TT&C journal, 2011,30 (5): 20-25. " low carrier-to-noise ratio carry out angle capture, according to road signal
And the normalized signal on poor road, four-way pulse scheme is devised with psk signal for FM modulation.China Electronics's science and technology collection
Its patent " Li Qiang, the method that Min Jie single channel detects input signal phase difference and relative amplitude, patent where group the 54th
Grant number: ZL 200610102076.0,2006 ", " the tracking receiver digital demodulation apparatus such as Li Qiang, patent authorization number: ZL
200610102075.6,2006 years ", " a kind of design method of self-tracking signal source with single channel and single pulse system of the such as Zhang Ximing,
Reception demodulation and modulating signal source method have been separately designed in patent authorization number: CN 101707578 B, 2009 ".
As high-speed digital transmission bit rate rises in the order of magnitude, the angle tracking problem of broadband signal more and more causes to pay close attention to, special
Be not under the low elevation angle environment Unmanned Aerial Vehicle Data Link need using can anti-multipath jamming OFDM system, the equal ratio characteristic of higher peak
Challenge is proposed to the angle measurement of the Unmanned Aerial Vehicle Data catenary system using OFDM.On the one hand method in above-mentioned document cannot be used directly
In the angle measurement of high peak-to-average power ratio ofdm signal, single-pass is not on the other hand suitable for using the normalization processing method of the factor or four-way
Road Monopulse estimation.
Summary of the invention
It is an object of the invention to overcome the above-mentioned deficiency of the prior art, Unmanned Aerial Vehicle Data Link middle width strip ofdm signal is provided
Angle-measuring method, this method is based on and poor composite signal carries out second moment detection, is obtained based on the normalized orientation of second moment, pitching
Angle measurement estimated value improves angle measurement accuracy of the data-link using ofdm signal when relative to conventional method.
Another object of the present invention is that providing Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle measuring system.
Above-mentioned purpose of the invention is achieved by following technical solution:
Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method, comprising:
The sum that the ofdm signal and the received radiofrequency signal of receiving antenna sent according to unmanned plane obtains after handling with difference
Road signal and poor road signal, calculate the second moment of composite signal and the desired value of second moment；
It by the second moment of the composite signal, is detected with low-frequency square-wave, and is got in low frequency square wave cycle inner product
Orientation detection signal and pitching detect signal；
According to the desired value of the second moment of the composite signal, the orientation detection signal and pitching detect signal, calculate
It obtains based on the normalized angle measurement estimated value of second moment.
In above-mentioned Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method, according to unmanned plane send ofdm signal,
Obtain after handling with difference with the received radiofrequency signal of receiving antenna and road signal and difference road signal, calculate the two of composite signal
The specific method is as follows for the desired value of rank square and second moment:
(1.1), the signal that receiving antenna receives that unmanned plane is sent is expressed as multiple radiofrequency signals, is sent according to unmanned plane
Ofdm signal obtains and road signal, gun parallax road signal and trim road signal after handling with difference；
(1.2), gun parallax road signal and trim road signal be multiplied after modulation by low-frequency square-wave to described and
Road signal carries out amplitude modulation, coupled later to obtain composite signal；
(1.3), the second moment of composite signal is calculated according to the composite signal；
(1.4), the second moment desired value of composite signal is obtained according to the second moment of the composite signal.
In above-mentioned Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method, unmanned plane is sent in the step (1.1)
Ofdm signal pass through wireless channel numerical expression are as follows:
Wherein: n is integer, 0≤n≤Ns- 1, NsFor positive integer, the FFT size that OFDM modulation uses is indicated；When X (k) is
Domain signal, H (k) are the frequency domain response for sending signal experience channel, EsTo send signal power, z (n) is signal noise in time domain.
In above-mentioned Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method, receiving antenna is connect in the step (1.1)
It receives the signal that unmanned plane is sent and is expressed as multiple radiofrequency signals, according to the ofdm signal that unmanned plane is sent, after being handled with difference
To the specific method is as follows with road signal, gun parallax road signal and trim road signal:
The more loudspeaker of receiving end antenna or multimode feed receive the signal U (t) that unmanned plane is sent, and are expressed as 4 radiofrequency signals
U1(t)、U2(t)、U3(t)、U4(t), it is obtained and road signal U after being handled with difference∑(t), gun parallax road signal UΔA(t), trim
Road signal UΔE(t) it is respectively as follows:
Wherein: s (t) is the analog waveform of signal s (n), AmFor signal amplitude, μ is antenna difference road sense figure slope,
ω is carrier frequency, and d is antenna spacing, and λ is wavelength, and A is that target deviates the angle of electric axis in orientation, E is that target is inclined in pitching
Angle from electric axis,For signal phase, t is time variable.
In above-mentioned Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method, by the orientation in the step (1.2)
Poor road signal, which is multiplied after modulation with trim road signal by low-frequency square-wave, carries out amplitude modulation to described and road signal, coupled later
Obtaining composite signal, the specific method is as follows:
By the gun parallax road signal UΔA(t) and trim road signal UΔE(t) pass through low-frequency square-wave g1(t)、g2(t) phase
Multiply modulation, to and road signal U∑(t) amplitude modulation is carried out, it is coupled later to obtain composite signal U∑Δ(t):
Wherein: s (t) is the analog waveform of signal s (n), and G is amplitude modulation parameter, low-frequency square-wave g1(t)、g2(t) it is expressed as follows:
Wherein: T is low frequency square wave cycle.
In above-mentioned Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method, according to the conjunction in the step (1.3)
At signal calculate composite signal second moment the specific method is as follows:
Wherein: M2For the second moment of composite signal.
In above-mentioned Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method, according to the conjunction in the step (1.4)
Obtaining the second moment desired value of composite signal at the second moment of signal, the specific method is as follows:
Due to A2+E2=θ2, θ is that target deviates electrical boresight of antenna angle, setting A and E be desired for 0, θ be desired for 0, obtain
To the second moment desired value of composite signal are as follows:
Wherein: C { M2Be composite signal second moment desired value；C{|s(t)|2Be pair | s (t) |2Seek desired value.
In above-mentioned Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method, the second moment of the composite signal is used
Low-frequency square-wave is detected, and gets the specific side of orientation detection signal and pitching detection signal in low frequency square wave cycle inner product
Method are as follows:
Wherein: g1(t)、g2It (t) is low-frequency square-wave, T is low frequency square wave cycle, gAFor orientation detection signal, gEFor pitching inspection
Survey signal.
In above-mentioned Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method, according to the second moment of the composite signal
Desired value, the orientation detection signal and pitching detect signal, are calculated based on the normalized angle measurement estimated value of second moment
Method particularly includes:
Wherein: A is Azimuth measurement estimated value, and E is pitching angle measurement estimated value, gAFor orientation detection signal, gEFor pitching detection
Signal.
In above-mentioned Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method, the angle-measuring method rises according to unmanned plane
Fly-cruise-return different task the stage, if low-frequency square-wave g1(t)、g2(t) cycle T is two grades, respectively f1=1/T1、f2=1/
T2, and f1< f2；
Thresholding T is set according to AGC signal magnitude when distance change between earth station and UAV targetsaIf received
AGC signal is more than thresholding Ta, then f is chosen1, fast tracking velocity is obtained in short distance；If received AGC signal is less than thresholding
Ta, then f is chosen2, high angle measurement accuracy is obtained when remote.
In above-mentioned Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method, the f1=1/T1=1kHz, f2=1/T2
=100Hz.
Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle measuring system, including second moment desired value obtain module, detection signal
It obtains module and angle measurement estimated value obtains module, in which:
Second moment desired value obtains module: the received radio frequency of ofdm signal and receiving antenna sent according to unmanned plane is believed
Number through and difference processing after obtain and road signal and poor road signal, calculate the second moment of composite signal and the desired value of second moment,
And the second moment of the composite signal is sent to detection signal acquisition module, by the desired value of the second moment of the composite signal
It is sent to angle measurement estimated value and obtains module；
It detects signal acquisition module: the second moment that second moment desired value obtains the composite signal that module is sent is received, by institute
The second moment for stating composite signal, is detected with low-frequency square-wave, and gets orientation detection signal in low frequency square wave cycle inner product
Signal is detected with pitching, and is sent to angle measurement estimated value and obtains module；
Angle measurement estimated value obtains module: receiving the orientation detection signal that detection signal acquisition module is sent and believes with pitching detection
Number, the desired value that second moment desired value obtains the second moment for the composite signal that module is sent is received, according to the composite signal
The desired value of second moment, the orientation detection signal and pitching detect signal, are calculated based on the normalized angle measurement of second moment
Estimated value.
In above-mentioned Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle measuring system, the second moment desired value obtains module root
That the ofdm signal and the received radiofrequency signal of receiving antenna sent according to unmanned plane obtains after handling with difference and road signal and difference
Road signal, the specific method is as follows for the second moment for calculating composite signal and the desired value of second moment:
(1.1), the signal that receiving antenna receives that unmanned plane is sent is expressed as multiple radiofrequency signals, is sent according to unmanned plane
Ofdm signal obtains and road signal, gun parallax road signal and trim road signal after handling with difference；
(1.2), gun parallax road signal and trim road signal be multiplied after modulation by low-frequency square-wave to described and
Road signal carries out amplitude modulation, coupled later to obtain composite signal；
(1.3), the second moment of composite signal is calculated according to the composite signal；
(1.4), the second moment desired value of composite signal is obtained according to the second moment of the composite signal.
In above-mentioned Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle measuring system, unmanned plane is sent in the step (1.1)
Ofdm signal pass through wireless channel numerical expression are as follows:
Wherein: n is integer, 0≤n≤Ns- 1, NsFor positive integer, the FFT size that OFDM modulation uses is indicated；When X (k) is
Domain signal, H (k) are the frequency domain response for sending signal experience channel, EsTo send signal power, z (n) is signal noise in time domain.
The signal that receiving antenna receives that unmanned plane is sent in the step (1.1) is expressed as multiple radiofrequency signals, according to nothing
The ofdm signal of man-machine transmission is obtained specific with road signal, gun parallax road signal and trim road signal after handling with difference
Method is as follows:
The more loudspeaker of receiving end antenna or multimode feed receive the signal U (t) that unmanned plane is sent, and are expressed as 4 radiofrequency signals
U1(t)、U2(t)、U3(t)、U4(t), it is obtained and road signal U after being handled with difference∑(t), gun parallax road signal UΔA(t), trim
Road signal UΔE(t) it is respectively as follows:
Wherein: s (t) is the analog waveform of signal s (n), AmFor signal amplitude, μ is antenna difference road sense figure slope,
ω is carrier frequency, and d is antenna spacing, and λ is wavelength, and A is that target deviates the angle of electric axis in orientation, E is that target is inclined in pitching
Angle from electric axis,For signal phase, t is time variable.
In above-mentioned Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle measuring system, by the orientation in the step (1.2)
Poor road signal, which is multiplied after modulation with trim road signal by low-frequency square-wave, carries out amplitude modulation to described and road signal, coupled later
Obtaining composite signal, the specific method is as follows:
By the gun parallax road signal UΔA(t) and trim road signal UΔE(t) pass through low-frequency square-wave g1(t)、g2(t) phase
Multiply modulation, to and road signal U∑(t) amplitude modulation is carried out, it is coupled later to obtain composite signal U∑Δ(t):
Wherein: s (t) is the analog waveform of signal s (n), and G is amplitude modulation parameter, low-frequency square-wave g1(t)、g2(t) it is expressed as follows:
Wherein: T is low frequency square wave cycle；
According to the second moment of composite signal calculating composite signal, the specific method is as follows in the step (1.3):
Wherein: M2For the second moment of composite signal；
The tool of the second moment desired value of composite signal is obtained in the step (1.4) according to the second moment of the composite signal
Body method is as follows:
Due to A2+E2=θ2, θ is that target deviates electrical boresight of antenna angle, setting A and E be desired for 0, θ be desired for 0, obtain
To the second moment desired value of composite signal are as follows:
Wherein: C { M2Be composite signal second moment desired value；C{|s(t)|2Be pair | s (t) |2Seek desired value.
In above-mentioned Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle measuring system, the detection signal acquisition module will be described
The second moment of composite signal, is detected with low-frequency square-wave, and low frequency square wave cycle inner product get orientation detection signal with
Pitching detects signal method particularly includes:
Wherein: g1(t)、g2It (t) is low-frequency square-wave, T is low frequency square wave cycle, gAFor orientation detection signal, gEFor pitching inspection
Survey signal；
The angle measurement estimated value obtains module according to the desired value of the second moment of the composite signal, the orientation detection letter
Number with pitching detect signal, be calculated based on the normalized angle measurement estimated value of second moment method particularly includes:
Wherein: A is Azimuth measurement estimated value, and E is pitching angle measurement estimated value, gAFor orientation detection signal, gEFor pitching detection
Signal.
Compared with prior art, the present invention has the following advantages:
(1) Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method of the present invention, is based on and poor composite signal carries out second order
Square detection obtains improving OFDM data relative to conventional method based on the normalized orientation of second moment, pitching angle measurement estimated value
The angle measurement accuracy of chain；
(2) Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method of the present invention designs angle measurement for wideband OFDM signal
Method is suitable for injection frequency channel receiver, assists angle tracking without signals such as other PCM/FM, CDMA or BPSK/QPSK, can
It realizes that remote measuring and controlling data-link is three-in-one, there is anti-multipath performance, simplify system architecture, saved signal band resource；
(3) Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method of the present invention, can taking off-patrolling according to unmanned plane
Boat-return different task stage work is determined in two grades of low-frequency square-waves according to threshold value, and provides reasonable threshold value,
Fast tracking velocity is obtained in short distance, high angle measurement accuracy is obtained when remote, can obtain different tracking velocity and survey
Angular accuracy has stronger adaptability；
(4) the Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method and angle measuring system of offer of the invention, based on and
Poor composite signal carries out second moment detection, obtains the second moment of composite signal and the desired value of second moment first, further obtains
Orientation detection signal and pitching detect signal, and then are calculated based on the normalized angle measurement estimated value of second moment, party's Faxian
Angle measurement accuracy when improving data-link using ofdm signal is write, with wider applied widely.
(5) experiments have shown that, the present invention normalizes angle measurement estimation method compared to square law method in low signal-to-noise ratio 0dB-10dB
Performance is not by SNR influence, while the method for the present invention is not influenced by signal amplitude variation, is not necessarily to accurate automatic growth control, and
And the present invention normalizes angle measurement estimation method and is substantially below 0.2 ° in 0dB-20dB internal standard difference performance, meets unmanned angle tracking
Required precision.
Detailed description of the invention
Fig. 1 is Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method functional block diagram of the present invention；
Fig. 2 is the average value that the angle measurement of Unmanned Aerial Vehicle Data Link of embodiment of the present invention middle width strip ofdm signal angle-measuring method is estimated
Performance map；
Fig. 3 is that the angle measurement of Unmanned Aerial Vehicle Data Link of embodiment of the present invention middle width strip ofdm signal angle-measuring method is estimated in different frequencies
Standard deviation performance map under rate square wave.
Specific embodiment
The following further describes the present invention in detail with reference to the accompanying drawings and specific embodiments:
As shown in Figure 1 be Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method functional block diagram of the present invention, the present invention without
Man-machine data-link middle width strip ofdm signal angle-measuring method, specifically comprises the following steps:
The desired value of step (1), the second moment for calculating composite signal and second moment
Unmanned plane sends ofdm signal by the numerical expression of wireless channel
Wherein: n is integer, 0≤n≤Ns- 1, NsFor positive integer, the FFT size that OFDM modulation uses is indicated；When X (k) is
Domain signal, H (k) are the frequency domain response for sending signal experience channel, EsTo send signal power, z (n) is signal noise in time domain.
The more loudspeaker of receiving end antenna or multimode feed receive the signal U (t) that unmanned plane is sent, and are expressed as 4 radiofrequency signals
U1(t)、U2(t)、U3(t)、U4(t), it is obtained and road signal U after being handled with difference∑(t), gun parallax road signal UΔA(t), trim
Road signal UΔE(t) it is respectively as follows:
Wherein: s (t) is the analog waveform of signal s (n), AmFor signal amplitude, μ is antenna difference road sense figure slope
(difference slope), ω are carrier frequency, and d is antenna spacing, and λ is wavelength, and A is that target deviates the angle of electric axis in orientation, E is that target exists
Deviate the angle of electric axis in pitching,For signal phase, t is time variable.
By gun parallax road signal UΔA(t), trim road signal UΔE(t) pass through low-frequency square-wave g1(t)、g2(t) be multiplied modulation
Afterwards to and signal U∑(t) amplitude modulation is carried out, is later composite signal U through coupler∑Δ(t),
Wherein: s (t) is the analog waveform of signal s (n), and G is amplitude modulation parameter, value 1/4 in the present embodiment, low-frequency square-wave
g1(t)、g2(t) using T as the period:
Wherein:Input of the composite signal after down coversion and filtering, as digital receiver
Signal calculates its second moment M first2And its desired value C { M2}:
Due to A2+E2=θ2, θ is that target deviates electrical boresight of antenna angle, when azimuth angle error A, pitch angle error E are smaller,
A and E be desired for 0, θ be desired for 0, therefore second moment desired value C { M2Are as follows:
Wherein: C { M2Be composite signal second moment desired value；C{|s(t)|2Be pair | s (t) |2Seek desired value.
The second moment of step (2), the reception composite signal for obtaining step (1), with low-frequency square-wave g1(t)、g2(t) into
Row detection, and get orientation detection signal g in low frequency square wave cycle T inner productA, pitching detect signal gE:
Step (3), the second moment M for obtaining step (1)2, orientation detection signal g that step (2) obtainsA, pitching inspection
Survey signal gE, G value 1/4 is set, is calculated based on the normalized angle measurement estimated value of second moment:
Wherein: A is Azimuth measurement estimated value, and E is pitching angle measurement estimated value, gAFor orientation detection signal, gEFor pitching detection
Signal.
By step (1) ,~angle-measuring method of step (3) takes off according to unmanned plane-is cruised-is returned the different task stage,
If low-frequency square-wave g1(t)、g2(t) cycle T is two grades, respectively f1=1/T1、f2=1/T2, and f1< f2.Specifically, of the invention
Two grades of low-frequency square-wave g are set in embodiment1(t)、g2(t) cycle T is respectively f1=1/T1=1kHz, f2=1/T2=100Hz, on ground
Threshold T is set according to AGC signal magnitude when distance change between face station and UAV targetsa, according to whether being more than threshold value
Design angle measurement is worked respectively in two grades of low-frequency square-wave detection patterns, and fast tracking velocity is obtained in short distance, is obtained when remote
Obtain high angle measurement accuracy.
If received AGC signal is more than thresholding Ta, then f is chosen1=1/T1=1kHz obtains fast tracking speed in short distance
Degree；If received AGC signal is less than thresholding Ta, then f is chosen2=1/T2=100Hz obtains high angle measurement accuracy when remote.
Specifically, thresholding T in the embodiment of the present inventionaValue is determined according to AGC algorithm or module, for example, by using
When AD9361 chip is as channel module, AGC value is 100.
Embodiment 1
The Performance Simulation Results of wideband OFDM single channel monopulse angle-measuring method of the present invention are analyzed.
It is as shown in Figure 1 Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method functional block diagram of the present invention, antenna A, B,
C, the feed generation of D and road signal, orientation and trim road signal, and single channel signal, channel list are synthesized based on low-frequency square-wave
Member obtains AGC signal using AD 9361, in digital receiver, after low-frequency square-wave detects second moment signal, passes through normalizing
Change computer azimuth, pitching angular error signal, then realizes autotracking of the antenna to airbound target by antenna controller.
It is illustrated in figure 2 the angle measurement estimation of Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method of the embodiment of the present invention
Average value performance map；Be arranged angular deviation be 1 °, 2 °, low-frequency square-wave 1/T=1kHz, signal-to-noise ratio be 0dB-20dB under, OFDM
Signal FFT length is Ns=1024, effective carrier wave Nu=512, subcarrier 10kHz, from analysis of simulation result it is found that the present invention
It normalizes angle measurement estimation method and compares square law method in low signal-to-noise ratio 0dB-10dB performance not by SNR influence.It simultaneously can
Know, the method for the present invention is not influenced by signal amplitude variation, is not necessarily to accurate automatic growth control.
The angle measurement estimation for being illustrated in figure 3 Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method of the embodiment of the present invention exists
Standard deviation performance map under different frequency square wave, from analysis of simulation result it is found that square law method is in low signal-to-noise ratio 0dB-10dB
Performance is poor, and the present invention normalizes angle measurement estimation method and is substantially below 0.2 ° in 0dB-20dB internal standard difference performance, meets one
As the requirement of unmanned angular tracking accuracy.
The above, optimal specific embodiment only of the invention, but scope of protection of the present invention is not limited thereto,
In the technical scope disclosed by the present invention, any changes or substitutions that can be easily thought of by anyone skilled in the art,
It should be covered by the protection scope of the present invention.
The content that description in the present invention is not described in detail belongs to the well-known technique of professional and technical personnel in the field.
Claims (16)
1. Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method, it is characterised in that: include:
The ofdm signal and the received radiofrequency signal of receiving antenna sent according to unmanned plane obtains after handling with difference and road letter
Number and poor road signal, calculate the second moment of composite signal and the desired value of second moment；
It by the second moment of the composite signal, is detected with low-frequency square-wave, and gets orientation in low frequency square wave cycle inner product
It detects signal and pitching detects signal；
According to the desired value of the second moment of the composite signal, the orientation detection signal and pitching detect signal, are calculated
Based on the normalized angle measurement estimated value of second moment.
2. Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method according to claim 1, it is characterised in that: according to nothing
The received radiofrequency signal of ofdm signal and receiving antenna of man-machine transmission obtains after handling with difference and road signal and difference road letter
Number, the specific method is as follows for the second moment and the desired value of second moment for calculating composite signal:
(1.1), the signal that receiving antenna receives that unmanned plane is sent is expressed as multiple radiofrequency signals, the OFDM sent according to unmanned plane
Signal obtains and road signal, gun parallax road signal and trim road signal after handling with difference；
(1.2), gun parallax road signal is multiplied after modulation with trim road signal by low-frequency square-wave and described and road is believed
Number carry out amplitude modulation, it is coupled later to obtain composite signal；
(1.3), the second moment of composite signal is calculated according to the composite signal；
(1.4), the second moment desired value of composite signal is obtained according to the second moment of the composite signal.
3. Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method according to claim 2, it is characterised in that: the step
Suddenly the ofdm signal that unmanned plane is sent in (1.1) passes through the numerical expression of wireless channel are as follows:
Wherein: n is integer, 0≤n≤Ns- 1, NsFor positive integer, the FFT size that OFDM modulation uses is indicated；X (k) is time domain letter
Number, H (k) is the frequency domain response for sending signal experience channel, EsTo send signal power, z (n) is signal noise in time domain.
4. Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method according to claim 3, it is characterised in that: the step
Suddenly the signal that receiving antenna receives that unmanned plane is sent in (1.1) is expressed as multiple radiofrequency signals, the OFDM sent according to unmanned plane
Signal, through with obtain that the specific method is as follows with road signal, gun parallax road signal and trim road signal after difference processing:
The more loudspeaker of receiving end antenna or multimode feed receive the signal U (t) that unmanned plane is sent, and are expressed as 4 radiofrequency signal U1(t)、
U2(t)、U3(t)、U4(t), it is obtained and road signal U after being handled with difference∑(t), gun parallax road signal UΔA(t), trim road is believed
Number UΔE(t) it is respectively as follows:
Wherein: s (t) is the analog waveform of signal s (n), AmFor signal amplitude, μ is antenna difference road sense figure slope, and ω is
Carrier frequency, d are antenna spacing, and λ is wavelength, and A is that target deviates the angle of electric axis in orientation, E is that target deviates electricity in pitching
The angle of axis,For signal phase, t is time variable.
5. Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method according to claim 2, it is characterised in that: the step
Suddenly gun parallax road signal is multiplied after modulation by low-frequency square-wave to described and road signal with trim road signal in (1.2)
Amplitude modulation is carried out, coupled later to obtain composite signal the specific method is as follows:
By the gun parallax road signal UΔA(t) and trim road signal UΔE(t) pass through low-frequency square-wave g1(t)、g2(t) it is multiplied and adjusts
System, to and road signal U∑(t) amplitude modulation is carried out, it is coupled later to obtain composite signal U∑Δ(t):
Wherein: s (t) is the analog waveform of signal s (n), and G is amplitude modulation parameter, low-frequency square-wave g1(t)、g2(t) it is expressed as follows:
Wherein: T is low frequency square wave cycle.
6. Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method according to claim 2, it is characterised in that: the step
Suddenly according to the second moment of composite signal calculating composite signal, the specific method is as follows in (1.3):
Wherein: M2For the second moment of composite signal.
7. Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method according to claim 6, it is characterised in that: the step
Suddenly obtaining the second moment desired value of composite signal according to the second moment of the composite signal in (1.4), the specific method is as follows:
Due to A2+E2=θ2, θ is that target deviates electrical boresight of antenna angle, setting A and E be desired for 0, θ be desired for 0, closed
At the second moment desired value of signal are as follows:
Wherein: C { M2Be composite signal second moment desired value；C{|s(t)|2Be pair | s (t) |2Seek desired value.
8. Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method according to claim 1, it is characterised in that: will be described
The second moment of composite signal, is detected with low-frequency square-wave, and low frequency square wave cycle inner product get orientation detection signal with
Pitching detects signal method particularly includes:
Wherein: g1(t)、g2It (t) is low-frequency square-wave, T is low frequency square wave cycle, gAFor orientation detection signal, gEIt detects and believes for pitching
Number.
9. Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method according to claim 8, it is characterised in that: according to institute
The desired value of the second moment of composite signal is stated, the orientation detection signal and pitching detect signal, be calculated based on second moment
Normalized angle measurement estimated value method particularly includes:
Wherein: A is Azimuth measurement estimated value, and E is pitching angle measurement estimated value, gAFor orientation detection signal, gEIt detects and believes for pitching
Number.
10. Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method, feature described according to claim 1~one of 9 exist
In: the angle-measuring method takes off according to unmanned plane, and-cruise-returns to the different task stage, if low-frequency square-wave g1(t)、g2(t) all
Phase T is two grades, respectively f1=1/T1、f2=1/T2, and f1< f2；
Thresholding T is set according to AGC signal magnitude when distance change between earth station and UAV targetsaIf received AGC letter
It number is more than thresholding Ta, then f is chosen1, fast tracking velocity is obtained in short distance；If received AGC signal is less than thresholding Ta, then
Choose f2, high angle measurement accuracy is obtained when remote.
11. Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle-measuring method according to claim 10, it is characterised in that: described
f1=1/T1=1kHz, f2=1/T2=100Hz.
12. Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle measuring system, it is characterised in that: obtain mould including second moment desired value
Block, detection signal acquisition module and angle measurement estimated value obtain module, in which:
Second moment desired value obtains module: the received radiofrequency signal of ofdm signal and receiving antenna sent according to unmanned plane passes through
With obtain after difference processing and road signal and poor road signal, the second moment of composite signal and the desired value of second moment are calculated, and will
The second moment of the composite signal is sent to detection signal acquisition module, and the desired value of the second moment of the composite signal is sent
Module is obtained to angle measurement estimated value；
It detects signal acquisition module: the second moment that second moment desired value obtains the composite signal that module is sent is received, by the conjunction
It at the second moment of signal, is detected with low-frequency square-wave, and gets orientation detection signal in low frequency square wave cycle inner product and bow
Detection signal is faced upward, and is sent to angle measurement estimated value and obtains module；
Angle measurement estimated value obtains module: it receives the orientation detection signal that detection signal acquisition module is sent and detects signal with pitching,
The desired value that second moment desired value obtains the second moment for the composite signal that module is sent is received, according to the second order of the composite signal
The desired value of square, the orientation detection signal and pitching detect signal, are calculated based on the normalized angle measurement estimation of second moment
Value.
13. Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle measuring system according to claim 12, it is characterised in that: described
At the ofdm signal and the received radiofrequency signal of receiving antenna that second moment desired value acquisition module is sent according to unmanned plane pass through and are poor
Obtain after reason and road signal and poor road signal calculate the specific method of the second moment of composite signal and the desired value of second moment such as
Under:
(1.1), the signal that receiving antenna receives that unmanned plane is sent is expressed as multiple radiofrequency signals, the OFDM sent according to unmanned plane
Signal obtains and road signal, gun parallax road signal and trim road signal after handling with difference；
(1.2), gun parallax road signal is multiplied after modulation with trim road signal by low-frequency square-wave and described and road is believed
Number carry out amplitude modulation, it is coupled later to obtain composite signal；
(1.3), the second moment of composite signal is calculated according to the composite signal；
(1.4), the second moment desired value of composite signal is obtained according to the second moment of the composite signal.
14. Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle measuring system according to claim 13, it is characterised in that: described
The ofdm signal that unmanned plane is sent in step (1.1) passes through the numerical expression of wireless channel are as follows:
Wherein: n is integer, 0≤n≤Ns- 1, NsFor positive integer, the FFT size that OFDM modulation uses is indicated；X (k) is time domain letter
Number, H (k) is the frequency domain response for sending signal experience channel, EsTo send signal power, z (n) is signal noise in time domain.
The signal that receiving antenna receives that unmanned plane is sent in the step (1.1) is expressed as multiple radiofrequency signals, according to unmanned plane
The ofdm signal of transmission obtains the specific method with road signal, gun parallax road signal and trim road signal after handling with difference
It is as follows:
The more loudspeaker of receiving end antenna or multimode feed receive the signal U (t) that unmanned plane is sent, and are expressed as 4 radiofrequency signal U1(t)、
U2(t)、U3(t)、U4(t), it is obtained and road signal U after being handled with difference∑(t), gun parallax road signal UΔA(t), trim road is believed
Number UΔE(t) it is respectively as follows:
Wherein: s (t) is the analog waveform of signal s (n), AmFor signal amplitude, μ is antenna difference road sense figure slope, and ω is
Carrier frequency, d are antenna spacing, and λ is wavelength, and A is that target deviates the angle of electric axis in orientation, E is that target deviates electricity in pitching
The angle of axis,For signal phase, t is time variable.
15. Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle measuring system according to claim 13, it is characterised in that: described
Gun parallax road signal is multiplied after modulation with trim road signal by low-frequency square-wave in step (1.2), described and road is believed
Number amplitude modulation is carried out, coupled later to obtain composite signal the specific method is as follows:
By the gun parallax road signal UΔA(t) and trim road signal UΔE(t) pass through low-frequency square-wave g1(t)、g2(t) it is multiplied and adjusts
System, to and road signal U∑(t) amplitude modulation is carried out, it is coupled later to obtain composite signal U∑Δ(t):
Wherein: s (t) is the analog waveform of signal s (n), and G is amplitude modulation parameter, low-frequency square-wave g1(t)、g2(t) it is expressed as follows:
Wherein: T is low frequency square wave cycle；
According to the second moment of composite signal calculating composite signal, the specific method is as follows in the step (1.3):
Wherein: M2For the second moment of composite signal；
The specific side of the second moment desired value of composite signal is obtained in the step (1.4) according to the second moment of the composite signal
Method is as follows:
Due to A2+E2=θ2, θ is that target deviates electrical boresight of antenna angle, setting A and E be desired for 0, θ be desired for 0, closed
At the second moment desired value of signal are as follows:
Wherein: C { M2Be composite signal second moment desired value；C{|s(t)|2Be pair | s (t) |2Seek desired value.
16. Unmanned Aerial Vehicle Data Link middle width strip ofdm signal angle measuring system according to claim 12, it is characterised in that: described
Detection signal acquisition module is detected the second moment of the composite signal with low-frequency square-wave, and in low frequency square wave cycle
Integral obtains orientation detection signal and pitching detects signal method particularly includes:
Wherein: g1(t)、g2It (t) is low-frequency square-wave, T is low frequency square wave cycle, gAFor orientation detection signal, gEIt detects and believes for pitching
Number；
The angle measurement estimated value obtains module according to the desired value of the second moment of the composite signal, the orientation detection signal with
Pitching detects signal, is calculated based on the normalized angle measurement estimated value of second moment method particularly includes:
Wherein: A is Azimuth measurement estimated value, and E is pitching angle measurement estimated value, gAFor orientation detection signal, gEIt detects and believes for pitching
Number.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN112616132A (en) * | 2020-12-16 | 2021-04-06 | 同济大学 | Low-altitude air-ground unmanned aerial vehicle channel multipath tracking method based on geometric prior model |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20140218239A1 (en) * | 2013-02-05 | 2014-08-07 | King Fahd University Of Petroleum And Minerals | Single-antenna direction finding system for multi-rotor platforms |
| CN104015931A (en) * | 2014-04-22 | 2014-09-03 | 西安交通大学 | Vision localization, measurement and control method, system and experimental platform for automatic refueling dead zone of unmanned aerial vehicle |
| CN105738892A (en) * | 2016-03-23 | 2016-07-06 | 中国电子科技集团公司第十研究所 | Method for enhancing tracking convergence of angle tracking system simulator |
| CN106791354A (en) * | 2015-11-20 | 2017-05-31 | 广州亿航智能技术有限公司 | Control the intelligent display device and its control system of unmanned plane cloud platform rotation |
| CN107332800A (en) * | 2017-04-26 | 2017-11-07 | 南京理工大学 | Modulate accurate wireless transmission scheme in a kind of direction selected based on random sub carrier wave |
| CN206835101U (en) * | 2017-06-22 | 2018-01-02 | 西安爱生技术集团公司 | A kind of unmanned plane Tracking Angle Measurement zero adjuster |
-
2018
- 2018-08-31 CN CN201811007955.4A patent/CN109194415B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20140218239A1 (en) * | 2013-02-05 | 2014-08-07 | King Fahd University Of Petroleum And Minerals | Single-antenna direction finding system for multi-rotor platforms |
| CN104015931A (en) * | 2014-04-22 | 2014-09-03 | 西安交通大学 | Vision localization, measurement and control method, system and experimental platform for automatic refueling dead zone of unmanned aerial vehicle |
| CN106791354A (en) * | 2015-11-20 | 2017-05-31 | 广州亿航智能技术有限公司 | Control the intelligent display device and its control system of unmanned plane cloud platform rotation |
| CN105738892A (en) * | 2016-03-23 | 2016-07-06 | 中国电子科技集团公司第十研究所 | Method for enhancing tracking convergence of angle tracking system simulator |
| CN107332800A (en) * | 2017-04-26 | 2017-11-07 | 南京理工大学 | Modulate accurate wireless transmission scheme in a kind of direction selected based on random sub carrier wave |
| CN206835101U (en) * | 2017-06-22 | 2018-01-02 | 西安爱生技术集团公司 | A kind of unmanned plane Tracking Angle Measurement zero adjuster |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112616132A (en) * | 2020-12-16 | 2021-04-06 | 同济大学 | Low-altitude air-ground unmanned aerial vehicle channel multipath tracking method based on geometric prior model |
| CN112616132B (en) * | 2020-12-16 | 2022-04-01 | 同济大学 | Low-altitude air-ground unmanned aerial vehicle channel multipath tracking method based on geometric prior model |
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