CN107070832A - A kind of high dynamic UAV TT ＆ C signal carrier tracking method - Google Patents
A kind of high dynamic UAV TT ＆ C signal carrier tracking method Download PDFInfo
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- CN107070832A CN107070832A CN201611195523.1A CN201611195523A CN107070832A CN 107070832 A CN107070832 A CN 107070832A CN 201611195523 A CN201611195523 A CN 201611195523A CN 107070832 A CN107070832 A CN 107070832A
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2647—Arrangements specific to the receiver only
- H04L27/2655—Synchronisation arrangements
- H04L27/2657—Carrier synchronisation
- H04L27/266—Fine or fractional frequency offset determination and synchronisation
-
- 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
- G01S19/00—Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
- G01S19/01—Satellite radio beacon positioning systems transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
- G01S19/13—Receivers
- G01S19/24—Acquisition or tracking or demodulation of signals transmitted by the system
- G01S19/29—Acquisition or tracking or demodulation of signals transmitted by the system carrier including Doppler, related
-
- 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
- G01S19/00—Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
- G01S19/01—Satellite radio beacon positioning systems transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
- G01S19/13—Receivers
- G01S19/35—Constructional details or hardware or software details of the signal processing chain
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/0014—Carrier regulation
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L7/00—Arrangements for synchronising receiver with transmitter
- H04L7/02—Speed or phase control by the received code signals, the signals containing no special synchronisation information
- H04L7/033—Speed or phase control by the received code signals, the signals containing no special synchronisation information using the transitions of the received signal to control the phase of the synchronising-signal-generating means, e.g. using a phase-locked loop
Abstract
The present invention provides a kind of high dynamic UAV TT ＆ C signal carrier tracking method, including：I, Q two paths of data tectonic knot function I (k)+jQ (k) that intermediate-freuqncy signal is formed through Digital Down Convert, the orthogonal local trace carrier wave that variable digital controlled oscillator is produced constructs plural formBy I (k)+jQ (k) withCarry out complex mixing；Calculated using the real and imaginary parts of complex mixing result and obtain identification result；Loop filter adjusts control parameter according to identification result, and control result is sent into variable digital controlled oscillator；Variable digital controlled oscillator adjusts frequency control word and phase control words according to control result, returns to the first step, realizes closed-loop control.The present invention has preferably taken into account the requirement of dynamic and tracking accuracy, with preferable dynamically adapting ability, constringency performance and tracking accuracy, while having the advantages that computation complexity is low is easy to Project Realization, with good application value.
Description
Technical field
The present invention relates to wireless communication field, more particularly, to a kind of high dynamic UAV TT ＆ C signal carrier track side
Method.
Background technology
Due to the particularity of Telemetry System of UAV, its composition includes repeater satellite, ground control station, unmanned aerial vehicle platform three
Part, system communication distance is remote, unmanned aerial vehicle platform movement velocity is fast, therefore the signal that unmanned aerial vehicle platform is received has extremely low letter
The features such as ratio, high-doppler dynamic of making an uproar.According to the special usage scenario of unmanned plane and mission requirements background, UAV's telecomma
The requirement of real-time of process for system processing is very high.In Telemetry System of UAV, carrier tracking loop is most fragile in receiver
One ring, the receiver losing lock that high dynamic signal is caused is often that as caused by carrier tracking loop losing lock, will cause whole survey first
System communication link is controlled to interrupt.
In Telemetry System of UAV using it is more be QPSK modulation systems, QPSK is the modulation system of suppressed carrier,
Receiver end needs to realize carrier track by the way of coherent demodulation, recovers coherent carrier, this coherent carrier Ying Yufa
The carrier wave of sending end, with frequency, keeps certain synchronized relation in frequency in phase.That is, it has two processes：One is to carry
The capture of wave frequency rate, two be the tracking of carrier phase.
Realize that carrier auxiliary typically there are two methods：One kind is open loop restoring method, and it is the frequency deviation directly to receiving and dispatching carrier wave
Estimated with phase error, effective supplement is given in demodulation；Another is closed loop restoring method, frequently with digital phase-locked loop
To realize the capture and tracking of carrier wave.For open loop approach, lock in time is short, simple in construction, and computational efficiency is high, but synchronous essence
Degree is not high；And closed-loop fashion can reach higher synchronization accuracy, systematic function is preferable, but the time that it sets up is longer.
Phaselocked loop (PLL) directly tracks carrier phase, with good Phase Tracking precision and noise resisting ability, but
In the case of high dynamic, because the influence of Doppler frequency shift is larger, PLL tracking accuracy will be reduced, can only be by increasing ring
Road bandwidth is tackled.And the increase of loop bandwidth will necessarily cause the increase of noise, therefore it can also influence tracking accuracy.FLL
(FLL) it is tracking carrier frequency, the output of frequency discriminator is carrier frequency tracking error, with preferable dynamic.
Based on PLL and FLL advantage, realize that carrier wave and Phase Tracking are general using the mode that FLL and PLL is combined at present
All over a kind of mode used, current the more commonly used FLL as shown in Figure 1 aids in the design frame chart of PLL carrier tracking loops, and it is led
Including：The modules such as variable NCO (digital controlled oscillator), frequency mixer, low pass filter, frequency discriminator, phase discriminator, loop filter.
Although this mode being combined has its advantage, but there is also many shortcomings：This carrier tracking loop needs to use substantial amounts of number
The realization of word unit, such as wave filter (FIR), digital multiplier, digital addition and subtraction musical instruments used in a Buddhist or Taoist mass, and frequency discrimination algorithm and phase demodulation algorithm ratio
It is more complicated, it is related to the multiplication and division arithmetic for arriving very much trigonometric function, is unfavorable for Project Realization.
The content of the invention
It is an object of the invention to：There is provided a kind of high dynamic UAV TT ＆ C signal for the problem of existing for prior art
Carrier wave tracing method, a large amount of modules need to be used by solving existing tracking ring, and algorithm is complicated, the problem of being unfavorable for Project Realization.
The goal of the invention of the present invention is achieved through the following technical solutions：
A kind of high dynamic UAV TT ＆ C signal carrier tracking method, it is characterised in that the method comprising the steps of：
1) I, Q two paths of data tectonic knot function I (k)+jQ (k) for being formed intermediate-freuqncy signal through Digital Down Convert, will
The orthogonal local trace carrier wave construction plural form that variable digital controlled oscillator is produced
2) by I (k)+jQ (k) withCarry out complex mixing；
3) calculated using the real and imaginary parts of complex mixing result and obtain identification result；
4) loop filter adjusts control parameter according to identification result, and control result is sent into variable numerical control vibration
Device；
5) variable digital controlled oscillator adjusts frequency control word and phase control words, return to step 1 according to control result), it is real
Existing closed-loop control.
As further technical scheme, the step of obtaining identification result is：By the real part of complex mixing result be designated as U1,
Imaginary part is designated as U2, and U1 is added with U2 and obtains U3, and U1 and U2 are subtracted each other and obtain U4；U1 symbol and U3 symbol are subjected to XOR
Result and U2 symbol and U4 symbol carry out the result of XOR and carry out XOR again and obtain identification result.
As further technical scheme, the loop filter includes FLL loop filter and cycle of phase-locked loop is filtered
Ripple device, after identification result is obtained, first determine whether FLL loop filter after adjustment control parameter the frequency that exports whether
Less than threshold value：If so, then cycle of phase-locked loop wave filter adjusts control parameter and output control result according to control result, it is variable
Digital controlled oscillator is according to control result adjustment phase place control word；If it is not, then variable digital controlled oscillator is according to FLL loop filtering
The control result adjustment frequency control word of device output.
As further technical scheme, the FLL loop filter is that first-order loop wave filter or second-order loop are filtered
Ripple device or third order PLL path filter.
As further technical scheme, the cycle of phase-locked loop wave filter is that first-order loop wave filter or second-order loop are filtered
Ripple device or third order PLL path filter.
Compared with prior art, the main beneficial effect of the present invention and advantage are as follows：
1st, optimizing structure design, saves hardware resource
The present invention is optimized by tectonic knot function pair Digital Down Convert part, it is to avoid making for low pass filter
With；For frequency discrimination algorithm and phase demodulation algorithm diversity and the complexity realized, frequency discrimination algorithm and phase demodulation algorithm are optimized, will
It unites two into one, and saves substantial amounts of hardware resource；The control that loop passes through frequency-tracking thresholding so that FLL and phaselocked loop
Asynchronously work.These optimization designs to loop structure, all greatly save hardware resource.
2nd, computation complexity is low, it is easy to Project Realization
The identification algorithm of discriminator carries out frequency discrimination and phase demodulation by the present invention using the mode of symbol XOR, it is to avoid traditional
The computing of the various trigonometric functions of frequency discrimination and phase demodulation algorithm, it is easy to Project Realization.
3rd, following range is wide, fast convergence rate, and loop stability is high
The present invention realizes carrier track using the tracing mode of FLL and phaselocked loop so that system has the excellent of the two
Point, not only ensure that the dynamic range of tracking frequency but also had ensured the stability of tracking phase；The present invention is to carrier tracking loop
Optimization design causes system to save substantial amounts of hardware resource in Project Realization and improves arithmetic speed so that the receipts of loop
Hold back speed quickly.
4th, have a wide range of application, engineering use value is high
The design and implementation method of the present invention is modulated primarily directed to QPSK modulation systems, therefore nearly all using this
The present invention can be used in the system of mode, and restrictive condition is few, function admirable, it is easy to accomplish, should with very strong Practical Project
With value, from now on can further genralrlization use.
Brief description of the drawings
Fig. 1 is that FLL aids in PLL carrier tracking loop block diagrams；
Fig. 2 adds PLL carrier tracking loop block diagrams for the FLL of the present invention；
Fig. 3 adds PLL carrier tracking loop FPGA realization figures for the FLL of the present invention；
Fig. 4 is carrier tracking loop workflow diagram of the invention；
Fig. 5 tracks process simulation figure for the carrier tracking loop of the present invention；
Fig. 6 is carrier tracking loop demodulating process analogous diagram of the invention；
Fig. 7 demodulates planisphere for the carrier tracking loop of the present invention.
Embodiment
The present invention is described in detail with specific embodiment below in conjunction with the accompanying drawings.
Embodiment
For the most commonly used QPSK modulation systems of Telemetry System of UAV, its carrier wave tracing method has a lot, property
Can also there is very big difference.The present invention mainly adds PLL carrier tracking loops to optimize to set from the angle of practical engineering application to FLL
Meter, as shown in Figure 2 and Figure 3, the present invention optimize design to Digital Down Convert part in loop first, pass through tectonic knot letter
Number (i.e. complex function) avoids the use of low pass filter, reduces operand, hardware resource is saved, after Digital Down Convert
I, Q two paths of data tectonic knot signal s (t), the local quadrature carrier for then exporting NCO also tectonic knot signal is and defeated
Enter signal s (t) and realize complex multiplication, take real part data and imaginary data to carry out follow-up loop computing respectively afterwards.Then it is right
Frequency discrimination algorithm and phase demodulation algorithm are optimized in loop, it is contemplated that frequency discrimination algorithm and phase demodulation algorithm diversity and the complexity realized
Property, frequency discrimination algorithm and phase demodulation algorithm is no longer used alone, but united two into one, and it is different using Project Realization symbol is easy to
Or mode carry out frequency discrimination and phase demodulation, reduce the computing of trigonometric function, not only saved hardware resource, also improve computing speed
Degree, and then improve the carrier track speed of loop.
The workflow step of the carrier tracking loop of the present invention is as shown in figure 4, be：
1st, the intermediate-freuqncy signal Digital Down Convert for receiving Telemetry System of UAV is to quasi- base band, by I, Q two paths of data structure
Make analytical function I (k)+jQ (k) (i.e. complex function).
2nd, variable NCO (digital controlled oscillator) the orthogonal local trace carrier waves produced are also configured as corresponding plural form,
3rd, the measurement and control signal received and local trace carrier wave are subjected to complex mixing (i.e. complex multiplication).
4th, the result sub-argument after complex mixing is gone out into real and imaginary parts, through addition, subtract each other etc. operation respectively obtain U1,
U2, U3, U4, take U1, U2, U3, U4 symbol to carry out xor operation, are used as the output result of discriminator respectively.Output result is 1
Or 0.
The step of obtaining identification result be：The real part of complex mixing result is designated as U1, imaginary part and is designated as U2, by U1 and U2 phases
Plus U3 is obtained, U1 and U2 are subtracted each other and obtain U4；U1 symbol and U3 symbol are carried out to the result of XOR and U2 symbol and U4
Symbol carry out the result of XOR and carry out XOR again and obtain identification result.
5th, loop filter adjusts control parameter according to identification result：When identification result is 1, corresponding control parameter is carried out
Inversion operation (i.e. control parameter is negative), when identification result is 0, then corresponding control parameter carries out not needing inversion operation (i.e.
Control parameter is just).
6th, the control result that loop filter is exported is sent into variable numerical control to vibrate, variable digital controlled oscillator is according to control
As a result frequency control word and phase control words are adjusted, so as to change the frequency and phase of local quadrature carrier, return to step 2 is real
Existing closed-loop control.
Loop filter includes FLL loop filter and cycle of phase-locked loop wave filter, and loop filter 1 is FLL
Loop filter, loop filter 2 is cycle of phase-locked loop wave filter.After identification result is obtained, FLL loop is first determined whether
Whether the frequency that wave filter is exported after adjustment control parameter is less than threshold value：If so, then cycle of phase-locked loop wave filter is according to control
Result adjustment control parameter processed and output control result, variable digital controlled oscillator is according to control result adjustment phase place control word；If
No, then the control result that variable digital controlled oscillator is exported according to FLL loop filter adjusts frequency control word.Threshold value is
Manually set according to actual conditions.
Wherein, FLL loop filter can be using first-order loop wave filter or second-order loop filter or the filter of third order PLL road
Ripple device；Cycle of phase-locked loop wave filter can also use first-order loop wave filter or second-order loop filter or third order PLL path filter.
Second order filter is all used in the present embodiment, so each wave filter is only with two parameters of regulation, while having taken into account system realization
Complexity and algorithm performance.
According to above-mentioned method flow, programmable logic device (FPGA) is used for the platform of realizing of digitized processing, such as Fig. 3
It is shown, Project Realization is carried out to the carrier tracking loop after optimization.
The carrier tracking loop after optimization is emulated using ModelSim simulation softwares, as a result as shown in Figure 5.From Fig. 5
In as can be seen that before before 0.15ms, FLL plays a major role, and is in a short period of time reduced to the frequency deviation of input signal
In the operating frequency range of phaselocked loop.Start phaselocked loop after 0.15ms, then phase-locked loop is restrained after 0.1ms, in steady
State is determined, so as to complete to demodulate the synchronization of carrier frequency and phase.In terms of simulation result, the Digital Costas Loop table after optimization
Good carrier frequency and Phase Tracking performance is revealed.
UAV TT ＆ C's signal of reception is demodulated using the carrier tracking loop after optimization design, the result after demodulation
As shown in Figure 6.
From fig. 6 it can be seen that there is not aliased distortion and distortion in demodulator output baseband waveform, I, Q with modulation
Two-way base band data is matched completely, and demodulation is completely correct.Corresponding demodulation planisphere is as shown in Figure 7.From the result of Project Realization
As can be seen that designed carrier tracking loop complies fully with the requirement of engineering.
By the Project Realization of traditional scheme and prioritization scheme, the present invention compared for the two and use FPGA hardware resource feelings
Condition, as shown in table 1.By table 1 it can be seen that the scheme digital demodulation processing entirety after optimization can reduce by more than 10% resource,
Capable of reducing using to Block RAM 9%, the use to multiplier can reduce by 20% hardware resource.The program is larger to be reduced
Operand, improves the utilization rate of FPGA hardware resource.
The FPGA hardware resource comparison table of table 1
The foregoing is merely illustrative of the preferred embodiments of the present invention, is not intended to limit the invention, it is noted that all
Any modifications, equivalent substitutions and improvements made within the spirit and principles in the present invention etc., should be included in the guarantor of the present invention
Within the scope of shield.
Claims (5)
1. a kind of high dynamic UAV TT ＆ C signal carrier tracking method, it is characterised in that the method comprising the steps of：
1) I, Q two paths of data tectonic knot function I (k)+jQ (k) for being formed intermediate-freuqncy signal through Digital Down Convert, will be variable
The orthogonal local trace carrier wave construction plural form that digital controlled oscillator is produced
2) by I (k)+jQ (k) withCarry out complex mixing；
3) calculated using the real and imaginary parts of complex mixing result and obtain identification result；
4) loop filter adjusts control parameter according to identification result, and control result is sent into variable digital controlled oscillator；
5) variable digital controlled oscillator adjusts frequency control word and phase control words, return to step 1 according to control result), realization is closed
Ring is controlled.
2. a kind of high dynamic UAV TT ＆ C signal carrier tracking method according to claim 1, it is characterised in that obtain
The step of identification result is：The real part of complex mixing result is designated as U1, imaginary part and is designated as U2, U1 is added with U2 and obtains U3, will
U1 and U2, which subtracts each other, obtains U4；The symbol progress that U1 symbol and U3 symbol are carried out into the result of XOR and U2 symbol and U4 is different
Or result carry out XOR again and obtain identification result.
3. a kind of high dynamic UAV TT ＆ C signal carrier tracking method according to claim 1, it is characterised in that described
Loop filter includes FLL loop filter and cycle of phase-locked loop wave filter, after identification result is obtained, and first determines whether lock
Whether the frequency that frequency ring loop filter is exported after adjustment control parameter is less than threshold value：If so, then FLL loop filtering
The control parameter of device is set to 0, and cycle of phase-locked loop wave filter adjusts control parameter and output control result according to control result, can
Become digital controlled oscillator according to control result adjustment phase place control word；If it is not, then the control parameter of cycle of phase-locked loop wave filter is set
For 0, the control result adjustment frequency control word that variable digital controlled oscillator is exported according to FLL loop filter.
4. a kind of high dynamic UAV TT ＆ C signal carrier tracking method according to claim 3, it is characterised in that frequency locking
Ring loop filter is first-order loop wave filter or second-order loop filter or third order PLL path filter.
5. a kind of high dynamic UAV TT ＆ C signal carrier tracking method according to claim 3, it is characterised in that lock phase
Ring loop filter is first-order loop wave filter or second-order loop filter or third order PLL path filter.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109714047A (en) * | 2018-12-17 | 2019-05-03 | 上海航天电子有限公司 | A method of realizing the frequency locking track loop gain of simple Larger Dynamic |
| CN113093238A (en) * | 2021-03-25 | 2021-07-09 | 中国人民解放军国防科技大学 | Carrier wave numerical control oscillator and optimization method thereof and navigation receiver |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101975957A (en) * | 2010-09-21 | 2011-02-16 | 北京航空航天大学 | Fuzzy control-based high-dynamic GPS receiver carrier tracking loop |
| CN102621563A (en) * | 2012-03-20 | 2012-08-01 | 东南大学 | GPS (global positioning system) software receiver signal tracking method based on FPGA (field programmable gate array) and system of GPS software receiver signal tracking method |
| CN104215981A (en) * | 2014-08-28 | 2014-12-17 | 四川九洲电器集团有限责任公司 | Adaptive tracking method for receiver in high-dynamic environment |
-
2016
- 2016-12-22 CN CN201611195523.1A patent/CN107070832B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101975957A (en) * | 2010-09-21 | 2011-02-16 | 北京航空航天大学 | Fuzzy control-based high-dynamic GPS receiver carrier tracking loop |
| CN102621563A (en) * | 2012-03-20 | 2012-08-01 | 东南大学 | GPS (global positioning system) software receiver signal tracking method based on FPGA (field programmable gate array) and system of GPS software receiver signal tracking method |
| CN104215981A (en) * | 2014-08-28 | 2014-12-17 | 四川九洲电器集团有限责任公司 | Adaptive tracking method for receiver in high-dynamic environment |
Non-Patent Citations (3)
| Title |
|---|
| WU WENYU: ""High dynamic carrier tracking technology based on Kalman Filter"", 《IET INTERNATIONAL RADAR CONFERENCE 2015》 * |
| 沈锋: ""基于FLL/PLL相结合的载波跟踪在导航接收机中的应用"", 《中国航海》 * |
| 陈晓鹏: ""动态环境下基于FLL/PLL相结合的载波跟踪"", 《弹箭与制导学报》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109714047A (en) * | 2018-12-17 | 2019-05-03 | 上海航天电子有限公司 | A method of realizing the frequency locking track loop gain of simple Larger Dynamic |
| CN113093238A (en) * | 2021-03-25 | 2021-07-09 | 中国人民解放军国防科技大学 | Carrier wave numerical control oscillator and optimization method thereof and navigation receiver |
| CN113093238B (en) * | 2021-03-25 | 2024-01-30 | 中国人民解放军国防科技大学 | Carrier wave numerical control oscillator, optimization method thereof and navigation receiver |
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