CN106526625A - Frequency discriminating method and frequency discriminating device based on energy - Google Patents

Abstract

The invention discloses a frequency discriminating method based on energy. In a GNSS receiver tracking channel, three local complex carrier signals exist, namely an advanced complex carrier S-E, an instant complex carrier S-P and a lagged complex carrier S-L, wherein the frequency fp of the instant complex carrier is supposed to same with the frequency of a receiving signal. Each local carrier signal is related with a local instant PN code signal. Related energy of each channel is calculated. A frequency difference between the local signal and a received signal is discriminated by means of a relation between a frequency residual error and related energy, thereby realizing frequency tracking of a traditional navigation signal, sufficiently exerting performance of a new mechanism navigation signal and improving tracking sensitivity of a receiver. The invention further provides a method for realizing the method. The device utilizes energy frequency discrimination and therefore has larger traction range and higher noise interference resistance. Therefore the frequency discriminating method and the device have relatively high commercial value.

Description

A kind of frequency identification method and device based on energy

Technical field

The present invention relates to satellite fix, signal trace, the communications field, are related to a kind of based on the letter such as signal energy The frequency of breath differentiates, the method and apparatus of signal trace.

Background technology

For GLONASS (Global Navigation Satellite System, GNSS) receiver For, its main task is exactly to maintain local signal and receive synchronous between signal.With GNSS systems The extensive application of system, increasing service and application requirement operation of receiver are in rugged environment, such as high Dynamic, weak signal environment etc..Under high dynamic environment, the signal intensity for receiving is very fast, receiver Track loop allows for reflecting in time this change to realize accurate tracking, otherwise, signal easily occurs and loses Lock and cause system cisco unity malfunction.When signal is blocked, such as the woods block, the environment such as interior, Signal energy sharp-decay causes signal to noise ratio (Signal Noise Ratio, SNR) very low.These harshnesses should The performance of receiver is put forward higher requirement with environment.

In general, in receivers, by a carrier tracking loop tracking the load of the signal for receiving Ripple, tracked by a code tracking loop signal for receiving pseudo noise code (Pseudo Random Code, PRN).For carrier tracking loop, phaselocked loop (Phase Locked Loop) is usually used to track Carrier phase passes through FLL (Frequency Locked Loop) to track carrier frequency.Went out in recent years Show some using kalman filter method to realize carrier track, they improve to a certain extent Tracking accuracy and system robustness, but modern valency is too high and be difficult to widely apply in fact.In FLL, Descriminator realizes the measurement of frequency residual error by differentiating the phase contrast of two neighboring epoch.Phaselocked loop is compared, by In FLL for absolute phase difference insensitive, therefore it can tolerate bigger frequency departure, generally use In the case of capture turns tracking or high dynamic.Additionally, the ability of the extraneous coloured noise of its antagonism is also relatively locked Phase ring is projected, therefore, requiring in the face of increasingly harsher applied environment, an excellent FLL is more suitable for In the performance for improving receiver.

Mainly have currently for the frequency discriminator of navigation satellite signal frequency-tracking：Four-quadrant ATAN (ATAN2), two quadrant ATAN (ATAN), intersection dot product (Cross-point, CP) and symbol cross Dot product (Decision Directed Cross-point, DDCP) etc..These descriminators are all based on adjacent two The phase contrast of individual epoch come realize frequency differentiate.Additionally due to being also modulated with data on navigation satellite signal Information, when data symbol changes, can introduce the SPA sudden phase anomalies of carrier signal, therefore, connecing ATAN or DDCP is adopted in receipts machine generally.In recent years, some more advanced time division multiplex (Time Division Data Multiplexing, TDDM) navigation signal and no data (Pilot) navigation signal be employed In modern GNSS system.For these New System navigation signals, original descriminator based on phase contrast The performance of navigation signal can not be given full play to, so as to cause receiver performance to decline.

The content of the invention

In view of this, the deficiencies in the prior art, the present invention are overcome to provide a kind of frequency discriminating side based on energy Method and device, by tracking satellite navigation signal, are differentiated using the relation between frequency residual sum correlation energy Go out local signal and receive the frequency difference between signal, can both realize the frequency-tracking of conventional navigation signal, The performance of New System navigation signal can be given full play to again, improve the tracking sensitivity of receiver.

For reaching above-mentioned purpose, the technical scheme is that what is be achieved in that：

The invention provides a kind of frequency identification method based on energy, methods described：

In GNSS receiver tracking channel, locally there are three road complex carrier signal signals, respectively advanced road is multiple Carrier wave S_E, instant road complex carrier signal S_P and delayed road complex carrier signal S_L；Three tunnels (three tunnels are not limited to, can be according to According to application needs be adjusted for five tunnels it is even more many) local replica pseudo-code signal, respectively advanced code C_E, That is time-code C_P and delayed code C_L；

The satellite navigation signals of outside input are received, first will input satellite-signal and three road complex carrier signal letters Number S_E, S_P and S_L are mixed；

Advanced C_E, the instant C_P replicated by the mixing results of described instant road complex carrier signal S_P and code ring Related operation is carried out with delayed C_L pseudo-codes, I_PE, I_PP, I_PL, Q_PE, Q_PP and Q_PL is obtained；

By described advanced road complex carrier signal S_E mixing results and delayed road complex carrier signal S_L mixing results respectively with The instant road C_P pseudo-codes replicated by code ring carry out related operation, obtain I_EP, I_LP, Q_EP and Q_LP；

According to the coherent integration time T of setting_I, described correlation result is respectively fed to into integration-remover In carry out time span for T_ICoherent integration, obtain I_PES, I_PPS, I_PLS, Q_PES, Q_PPS, Q_PLS, I_EPS, I_LPS, Q_EPS and Q_LPS；

The multichannel coherent integration value that integration-remover is exported calculates each road correlation energy in sending into energy calculation unit Value, obtains PE²、PP²、PL²、EP²And LP²；

Described coherent integration results I_PPS and Q_PPS are sent in carrier phase descriminator carries out carrier wave phase Potential difference is estimated；

By the PE²、PP²、PL²Energy value carries out code phase difference estimation in sending into code descriminator；

By the PP²、EP²And LP²Energy value carries out carrier frequency difference estimation in sending into frequency discriminator；

Corresponding estimated value is respectively fed to into phase-locked loop filter, frequency-locked loop wave filter and code loop filtering Device.Switch phaselocked loop and FLL working condition in the presence of loop selection control.

By filtered feedback parameter, carrier wave digital controlled oscillator and pseudo-code digital controlled oscillator is fed back to respectively, is entered And the real-time regulation of carrier phase and carrier frequency, code phase and code frequency is realized, finally realize that GNSS believes Number tracking.

Preferably, the three roads complex carrier signal signal, specially：

According to the coherent integration time T of current setting_IDetermine three-channel carrier frequency interval Δ f_d, in the range from (0, 1/T_I].Wherein, the frequency interval and delayed complex carrier signal and instant complex carrier signal of advanced complex carrier signal and instant complex carrier signal Frequency interval it is identical.

Preferably, pseudo-code signal is replicated on three tunnel, specially：

Advanced road C_E pseudo-code signals, C_E letters are produced by pseudo-code digital controlled oscillator and pseudo-code sequence generator Number delayed shift register, constant duration produce C_P and C_L respectively.Its adjacent two-way pseudo-code signal Chip determined according to current system running status, which is a typical range of from (0,1/2] chip.

Preferably, the carrier phase descriminator, specially：

Traditional carrier wave phase discriminator, such as arctan (Q/I), Q/I, Q*I or Q*sign (I) etc. can be adopted.

Preferably, the frequency discriminator, specially：

According to the relation between frequency residual sum correlation energy, by the correlation energy gauge of three road complex carrier signal branch roads Calculation obtains the estimated value of difference on the frequency, and the energy frequency descriminator that the present invention is given is

With

Preferably, the code phase descriminator, specially：

Traditional code phase descriminator, such as traditional code phase detecting method based on amplitude can be adopted

Traditional code phase detecting method based on energy

Present invention also offers the device that a kind of frequency based on energy differentiates, described device includes：Antenna, Satellite navigation signals sample quantization module, correlation intergal-removing module, error identification module, feedback control mould Block, local replica signal generation module and processor.Wherein,

The antenna is used for receiving satellite navigation signals；

The satellite navigation signals sample quantization module, for filtering, automatic growth control, by satellite-signal It is down-converted to intermediate-freuqncy signal and completes sample quantization, obtains digital medium-frequency signal；

The correlation intergal-removing module, for realizing that each road-load wave mixing, pseudo-code are related, relevant in passage Integration-remove function etc.；

The error identification module, completes this by carrier phase descriminator, frequency discriminator and code descriminator Replicate carrier wave, pseudo-code signal and receive the estimation of relevant parameter in signal in ground；

The feedback control module, realizes carrier loop parametric filtering and the filtering of code loop parameter, and is given most Terminal ring road feedback parameter；

The local replica signal generation module, for producing each road local replica complex carrier signal and pseudo-code signal；

The processor realizes the functions such as tracking channel initialization, state control, positioning calculation, time service.

Present invention advantage compared with prior art is：

In the prior art, for carrier track, descriminator is all by the phase place based on two neighboring epoch Differ to realize.Due to being also modulated with data message on navigation satellite signal, when data symbol changes When, the SPA sudden phase anomalies of carrier signal can be introduced, therefore, in receivers generally adopt ATAN or The descriminator of DDCP types.In modern GNSS system, partial navigation satellite-signal is using advanced TDDM or Pilot modulation systems.For these New System navigation signals, original frequency discrimination based on phase contrast Device can not give full play to the performance of New System navigation signal due to the modulation of data message, so as to cause to receive Machine hydraulic performance decline.Thought of the present invention using Energy identifying, using the pass between frequency residual sum correlation energy System realizes that frequency error differentiates, can give full play to the advantage of New System navigation signal, while there is bigger leading Draw the ability of scope and opposing noise jamming.This present invention has higher commercial value.

Description of the drawings

Fig. 1 GNSS navigation neceiver frameworks.

Fig. 2 channels track schematic diagrams of the present invention.

Fig. 3 energy frequency discrimination methods of the present invention and carrier wave phase discriminator, the workflow diagram of code phase discriminator.

Graph of a relation between Fig. 4 frequency residual sum normalization correlation energies.

Fig. 5 energy descriminator frequency response charts of the present invention.

The apparatus structure schematic diagram of Fig. 6 embodiment of the present invention.

Specific embodiment

The inventive method differentiates according to the relational implementation frequency error between frequency residual sum correlation energy.Locally There is the carrier signal of multichannel different frequency, the signal for receiving is mixed with each road carrier signal respectively, meter Calculate each road energy and then realize that frequency differentiates and signal trace.This and traditional frequency discrimination side based on phase contrast There is difference substantially in method.It is further to technical scheme with specific embodiment below in conjunction with the accompanying drawings Elaborate.

Fig. 1 is a typical GNSS navigation neceiver framework.Receiver antenna 106 receives all visible 101 signal of satellite.Signal after filtering, amplify, after down coversion, radio-frequency front-end 102 will be with noise Navigation signal sampling, be quantized into digital medium-frequency signal IF.Baseband signal processing unit 103 is received and is processed Intermediate-freuqncy signal.As a rule, exist multiple parallel channels 107 passage 1, passage 2 ... passage n } while Process the signal of each satellite.This process both can be realized by hardware, it is also possible to realized by software. By capturing, tracking each signal, baseband signal processing module provides the measurement data 104 of each satellite.It is fixed The functions such as position, navigation calculation unit 105 are completed to position, tested the speed according to the measurement data 104 for obtaining, time service.

It is right that each treatment channel 107 in described baseband signal processing unit 103 is realized by track loop The tracking of the satellite-signal for receiving.Fig. 2 is track loop schematic diagram of the present invention based on energy frequency discrimination method, Realize the channels track loop 107 in Fig. 1.The satellite navigation signals that local reception is arrived are through down coversion, sampling After quantization, the intermediate-freuqncy signal 200 for obtaining can be expressed as：

Wherein, P is the gross energy of the signal for receiving, and the data message of d [n] expression modulation, c [n] represent pseudo- Random spreading code, f_IFMid frequency after expression down coversion, T_sRepresent sampling time interval,Expression is When carrier phase, η [n] represent thermal noise, it is generally recognized that additive white Gaussian noise.

Local carrier generator 229 produces 3 road complex carrier signal signals, S_E, S_P and S_L, its corresponding frequency Rate is respectively f_p-Δf_d, f_pAnd f_p+Δf_d, wherein Δ f_dRepresent the frequency interval between three road complex carrier signal signals, f_p Represent S_P roads complex carrier signal signal frequency.Typical complex carrier signal signal can generally pass through digital controlled oscillator (Numerical Controlled Oscillator, NCO) is produced with sine lookup table and cosine look-up table.It is defeated Enter intermediate-freuqncy signal 200 to send in complex mixer 201,202 and 203 with local carrier signal, complete carrier wave stripping From.

Local pseudo-code generator 228 produces three tunnels (as a example by this sentences three tunnels, but being not limited to three tunnels) phase place and prolongs Slow pseudo-code signal, C_E, C_P and C_L.Code-phase column pitch d can be set as required, and usually 0.5 Chip, in order to improve tracking accuracy, opposing multipath, narrow associated code phasetophase away from can continue to zoom out, such as 0.1 Chip.The typical pseudo-code signal that postpones can be realized by the displacement of shift register constant duration.Then, Immediately the mixing results of road complex carrier signal S_P pass through related respectively to three tunnel pseudo-codes C_E, C_P and C_L signals Device 207,206 is related to 208, realizes that pseudo-code is peeled off；Mixing results of advanced road complex carrier signal S_E and delayed The mixing results of road complex carrier signal S_L are related by correlator 204,205 respectively to instant road pseudo-code C_P signal, Realize that pseudo-code is peeled off.

Result after correlation is respectively fed in integrator 209,210,211,212,213, according to pre- The coherent integration time for first setting completes coherent integration.Coherent integration results are respectively fed to 214,215,216, 217th, each branch energy is calculated in 218.Frequency discriminator is using 214,215 and 216 energy balanes for being given Carrier frequency error；Phase-shift discriminator calculates carrier phase error using 211 coherent integration results for providing； The energy balane code phase error that code descriminator is given using 216,217 and 218.Loop filter 222, 223 and 224 carrier frequency errors for being given to 219 respectively, 220 carrier phase errors for being given and 221 to The code phase error filtering for going out, obtains the feedback estimated value of relevant parameter.According to current loop working condition, Selection control 225 completes the switching of phaselocked loop and FLL, and final carrier loop feedback parameter sends into carrier wave In generator 229, road-load ripple S_P is as far as possible synchronous with input signal immediately to make local replica.Code loop filtering The additional feedback result of device feedback result and pilot controller 226 is sent in adder 227, synthesizes final code Loop feedback result, and send in pseudo-code generator 228, make local road pseudo-code C_P immediately try one's best and input Signal synchronization.

Specifically, Fig. 3 gives the descriminator and code phase discriminator of the frequency identification method in Fig. 2 based on energy Workflow diagram.The method comprising the steps of：

Step 301, obtains input intermediate-freuqncy signal IF；

Specifically, can be obtained by 102 sample quantization of receiver radio frequency front end RF.

Step 302, produces local three roads complex carrier signal signal S_E, S_P and S_L；

Specifically, instant road S_P complex carrier signals signal frequency is f_p, advanced road S_E complex carrier signal signal frequencies are f_p-Δf_d, delayed road complex carrier signal signal frequency is f_p+Δf_d.Digital controlled oscillator and sine lookup can typically be passed through Table and cosine look-up table are realized.

Step 303, input signal are mixed with local three roads complex carrier signal signal, obtain 6 tunnel mixing results, I_E, I_P, I_L, Q_E, Q_P and Q_L；

Specifically, input signal can be mixed with local signal by complex mixer 201,202 and 203, often All there is in-phase branch and quadrature branch in individual local carrier, obtain 6 tunnel mixing results after mixing, I_E, I_P, I_L, Q_E, Q_P and Q_L.

Step 304, produces local three tunnel Phase delay pseudo-code signal at equal intervals, C_E, C_P and C_L；

Specifically, locally C_E roads pseudo-code signal can be produced by digital controlled oscillator and pseudo-code sequence generator, The delayed shift register of C_E roads signal, constant duration produce C_P and C_L respectively, this operation with Traditional delay pseudo-code signal production method is the same.

Step 305, the delay pseudo-code letter that the mixing results that the step 303 is obtained are obtained with the step 304 It is number related, peel off pseudo-code；

Specifically, I_E, I_P, I_L, Q_E, Q_P and Q_L are related to instant road pseudo-code C_P, obtain I_EP, I_PP, I_LP, Q_EP, Q_PP and Q_LP.Additionally, I_P and Q_P also with C_E and C_L It is related respectively, I_PE, I_PL, Q_PE and Q_PL is obtained,

I_E × C_P=I_EP

I_P × C_P=I_PP

I_L × C_P=I_LP

Q_E × C_P=Q_EP

Q_P × C_P=Q_PP

Q_L × C_P=Q_LP

I_P × C_E=I_PE (6)

I_P × C_L=I_PL

Q_P × C_E=Q_PE

Q_P × C_L=Q_PL

Step 306, according to the coherent integration time of setting, is concerned with to the correlated results of the step 305 Integration；

Specifically, set coherent integration time T_I, such as length identical with PN-code capture is adopted in usual GPS The 1ms of degree, is limited by the data bit rate modulated on navigation signal, and its most long coherent integration times length is 20ms.According to this coherent integration time, the correlated results coherent integration that the step 305 is obtained, obtain As a result I_EPS, I_PPS, I_LPS, Q_EPS, Q_PPS, Q_LPS, I_PES, I_PLS, Q_PES And Q_PLS.

Step 307, calculates each branch energy；

Specifically, in order to improve the ability of tracking to weak signal, except the step 306 coherent integration it Outward, generally also signal energy can further be improved by non-coherent integration.Finally give each branch energy：EP²、 LP²、PP²、PE²And PL²,

Step 308, calculates each parameter error between local signal and the signal that receives

Specifically, when local carrier is with input signal carrier frequency synchronization, there is maximum in correlation energy； When local carrier frequency is inconsistent with input signal carrier frequency, can there is correlation energy loss.Fig. 4 is Relation between normalization coherent integration results and carrier frequency shift, both meet the distribution of sinc () function, and Meet sinc between normalization coherent integration energy and carrier frequency shift²() is distributed.Using this coherent integration Relation between energy and carrier frequency shift, two kinds of feasible frequency identification methods based on energy in the present invention For

With

Wherein Δ f_dFor the frequency interval between three road complex carrier signals.Coherent integration time T according to step 306_I, One typical frequency interval Δ f_d1/ (2T can be chosen for_I), described frequency can be suitably adjusted as needed Interval, in the range from (0,1/T_I]。

For carrier phase difference, using traditional carrier phase phase discriminator, its expression formula can be

OrOrOrDeng

For code loop, delayed (Early Minus Late, EML) code mirror can be subtracted in advance using traditional Phase method.Traditional based on the code phase demodulation computational methods of amplitude can be

Based on the code phase demodulation computational methods of energy can be

The carrier wave phase demodulation that obtains, carrier wave frequency discrimination, code identified result are filtered through carrier loop, code loop filtering After provide its corresponding loop feedback parameter.According to receiver needs, it is possible to use photocarrier method code ring is tracked The robustness of receiver, pilot controller 226 in such as Fig. 2 are improved further.

In said process：

(1) input signal is mixed with local three roads complex carrier signal signal, with instant road S_P and instant road pseudo-code As a example by signal C_P signals correlation, for coherent integration time T_I, coherent integration results are

Wherein, Δ τ_{P, k}, Δ f_{P, k},Code phase error respectively between expression input signal and local replica signal, load Wave frequency error and carrier phase error, k represent k-th epoch, and R () represents the auto-correlation letter of pseudo noise code Number, Sinc ()=sin (x)/x, η_{P, I, k}And η_{P, Q, k}The noise of in-phase branch and quadrature branch is represented respectively.

(2) if ignoring the noise in coherent integration results (12), for coherent integration time is T_I's Coherent integration results, in epoch k, its energy is

Relation between its normalized energy and carrier frequency offset is shown in Fig. 4.

(3) for other two-way, advanced road complex carrier signal S_E and delayed road complex carrier signal S_L, after mixing It is related to instant road pseudo-code signal C_P signals, likewise, its energy is respectively

(4) Taylor's formula, sinc are utilized²(πΔfT_I) can be expressed as

Wherein, Θ=(π T_I)²/ 3, after coherent integration time determines, which can regard into a constant as.Fig. 4 is given First order Taylor launch after normalized energy and carrier frequency offset between relation.Therefore, input letter Number with three road complex carrier signals mixing, it is related to instant road pseudo-code signal C_P signals after result respectively can be near Seemingly it is expressed as

Wherein, H=PR²(Δτ_{P, k}) represent the ceiling capacity that instant road PP correlation intergals can reach.From formula (17), Can obtain

Further simplify, obtain based on the frequency identification method expression formula of energy be

Thus, another similar frequency discrimination method formula can also be obtained

Also it is the implementation method of energy frequency discrimination method in the present invention.Fig. 5 is energy descriminator of the present invention in different noises Frequency response chart than under.

One embodiment of the present of invention is as follows, but the invention is not limited in this implementation.

Apparatus structure schematic diagrams of the Fig. 6 for the embodiment of the present invention.As shown in fig. 6, dotted line frame interior part is real The device of the existing present invention, the present invention can be realized with this device, but is not limited to Fig. 6 shown devices.Entirely Device includes：Antenna, radio-frequency front-end RF modules, sample quantization module, correlation intergal-removing module, mistake Difference identification module, feedback control module, processor and local replica signal generation module.Wherein, antenna 601 It is responsible for receiving navigation satellite signal, 602 pairs of signals for receiving of radio-frequency front-end are amplified, filter and lower change The operation such as frequency；Sample quantization module 603 is responsible for automatic growth control, sampling, quantifies intermediate-freuqncy signal, and carries For intermediate frequency and clock signal.

Processor 608 passes through each tracking channel of bus configuration and various initiation parameters, such as gives after acquisition success The initial code phase positions that go out, initial carrier frequency etc..Correlation intergal in passage -604 receiving front-end of removing module The intermediate-freuqncy signal for being given, and the local signal produced with local replica signal generation module 607 carry out being mixed, The operations such as related, integration, removing, obtain the correlation energy value of each branch road.Error identification module 605 is pressed The error estimate of signal relevant parameter is given according to the method for the invention.Feedback control module 606 pairs is respectively joined Number estimated value is filtered, and makes corresponding adjustment according to system running state, and final feedback parameter is fed back To local replica signal generation module 607, locally generated signal is made to try one's best synchronous with the signal for receiving.Process Device reads the tracking mode parameter of satellite-signal, and then completes baseband state parameter adjustment, and control base band is normal Operation, completes the functions such as positioning, constant speed, time service.

It is implemented as：First, the interrupt interval that tracking channel is arranged according to processor, regularly to processor Application is interrupted.In this example, the present invention is realized in baseband processor, but also can be implemented by other Mode, for example：Single processing meanss, the processing meanss being integrated in other modules outside processor.Process Have no progeny in device response, processor is from satellite-signal Base-Band Processing passage Acquisition channel tracking mode parameter, described Measured value includes carrier wave measured value, code measured value, signal energy, loop-locking state etc..Processor according to These measured values estimate that current system running statuses simultaneously carry out Reasonable adjustment to baseband parameter, such as loop bandwidth, Coherent integration time etc..In base band, feedback control module is being tracked according to the baseband parameter real-time feedback control Loop, control local replica signal generation module are synchronous with the signal for receiving.

The above, but only presently preferred embodiments of the present invention, it is not intended to limit the protection of the present invention Scope.

Claims (10)

1. a kind of frequency identification method based on energy, it is characterised in that methods described includes：

In GNSS receiver tracking channel, locally there are three road complex carrier signal signals, respectively advanced road is multiple Carrier wave S_E, instant road complex carrier signal S_P and delayed road complex carrier signal S_L；Three tunnels (three tunnels are not limited to, can be according to According to application needs be adjusted for five tunnels it is even more many) local replica pseudo-code signal, respectively advanced code C_E, That is time-code C_P and delayed code C_L；Receiver receives the satellite navigation signals of outside input, with each road Complex carrier signal mixing, each road pseudo-code are related；According to the coherent integration time T of setting_I, each road correlated results is sent Time span is carried out in entering integration-remover for T_ICoherent integration；The multichannel that integration-remover is exported is concerned with Integrated value calculates each road correlation energy value in sending into energy calculation unit；By coherent integration value, each road correlation energy Value carries out carrier phase difference, carrier frequency in sending into carrier phase descriminator, frequency discriminator and code descriminator The estimation of rate difference and code phase difference；Corresponding estimated value is respectively fed to into phase-locked loop filter, frequency-locked loop Wave filter and code loop filter, switch phaselocked loop and FLL work in the presence of loop selection control State；By filtered feedback parameter, carrier wave digital controlled oscillator and pseudo-code digital controlled oscillator is fed back to respectively. The real-time regulation of carrier phase and carrier frequency, code phase and code frequency is further realized, GNSS is finally realized The tracking of signal.

2. method according to claim 1, it is characterised in that input signal and local three road complex carrier signal Signal is mixed.Three road complex carrier signal signal frequencies are respectively f_p-Δf_d, f_pAnd f_p+Δf_d, wherein Δ f_dRepresent that three tunnels are multiple Frequency interval between carrier signal, f_pRepresent S_P roads complex carrier signal signal frequency, it is assumed that with input signal carrier wave Frequency Synchronization.

Choose according to following principle at interval between three road complex carrier signal signal frequencies：When coherent integration time is T_I When, typical frequency interval Δ f_d1/ (2T can be chosen for_I), described frequency can be suitably adjusted as needed Interval, its range of accommodation are (0,1/T_I]。

3. method according to claim 1, it is characterised in that three tunnel of local replica (three tunnels are not limited to, Can according to application needs be adjusted for five tunnels it is even more many) pseudo-code signal, code phase is at intervals of d, code phase Spacing d can be set as required, usually 0.5 chip, in order to improve tracking accuracy, opposing multipath, narrow Associated code phasetophase away from can continue to zoom out, such as 0.1 chip.

4. method according to claim 1, it is characterised in that the intermediate-freuqncy signal for receiving is

Wherein, P is the gross energy of the signal for receiving, and the data message of d [n] expression modulation, c [n] represent pseudo- Random spreading code, f_IFMid frequency after expression down coversion, T_sRepresent sampling time interval,Expression is When carrier phase, η [n] represent thermal noise, it is generally recognized that additive white Gaussian noise.

5. method according to claim 1, the local three roads complex carrier signal signal described in claim 2 and Local pseudo-code signal described in claim 3, it is characterised in that output multi-channel correlated results is related to multichannel Energy, is completed in the steps below：

Step 1：Input signal is mixed with local three roads complex carrier signal signal, obtains 6 tunnel mixing results, I_E, I_P, I_L, Q_E, Q_P and Q_L；

Step 2：It is related that step 1 mixing results postpone pseudo-code signal to local three tunnel.Specifically, I_E, I_P, I_L, Q_E, Q_P and Q_L are related to instant road pseudo-code C_P, obtain I_EP, I_PP, I_LP, Q_EP, Q_PP and Q_LP.Additionally, I_P and Q_P are also related to C_E and C_L difference (if existing More multichannel pseudo-code, I_P and Q_P are also related to these road pseudo-codes), obtain I_PE, I_PL, Q_PE and Q_PL,

I_E × C_P=I_EP

I_P × C_P=I_PP

I_L × C_P=I_LP

Q_E × C_P=Q_EP

Q_P × C_P=Q_PP

Q_L × C_P=Q_LP

I_P × C_E=I_PE

I_P × C_L=I_PL

Q_P × C_E=Q_PE

Q_P × C_L=Q_PL

Step 3：Setting coherent integration time T_I, according to the correlation that step 2 is obtained by this coherent integration time As a result coherent integration, obtain I_EPS, I_PPS, I_LPS, Q_EPS, Q_PPS, Q_LPS, I_PES, I_PLS, Q_PES and Q_PLS.

Step 4：In order to improve the ability of tracking to weak signal, in addition to the coherent integration described in step 3, Signal energy is further improved by non-coherent integration.Finally give each branch energy：EP²、LP²、PP²、 PE²And PL²,

${\mathrm{EP}}^2=\underset{m=1}{\overset{N_{NC}}{\Σ}}\left(I_{EPS}^2\left(m\right)+Q_{EPS}^2\left(m\right)\right)$

${\mathrm{LP}}^2=\underset{m=1}{\overset{N_{NC}}{\Σ}}\left(I_{LPS}^2\left(m\right)+Q_{LPS}^2\left(m\right)\right)$

${\mathrm{PP}}^2=\underset{m=1}{\overset{N_{NC}}{\Σ}}\left(I_{PPS}^2\left(m\right)+Q_{PPS}^2\left(m\right)\right)$

${\mathrm{PE}}^2=\underset{m=1}{\overset{N_{NC}}{\Σ}}\left(I_{PES}^2\left(m\right)+Q_{PES}^2\left(m\right)\right)$

${\mathrm{PL}}^2=\underset{m=1}{\overset{N_{NC}}{\Σ}}\left(I_{PLS}^2\left(m\right)+Q_{PLS}^2\left(m\right)\right)$

6. method according to claim 1 and the multichannel correlated results described in claim 5 and multichannel phase Close energy, it is characterised in that input signal be mixed with local three roads complex carrier signal signal, with instant road S_P and Immediately as a example by road pseudo-code signal C_P signals correlation, for coherent integration time T_I, coherent integration results are

Wherein, Δ τ_{P, k}, Δ f_{P, k},Code phase error respectively between expression input signal and local replica signal, load Wave frequency error and carrier phase error, k represent k-th epoch, and R () represents the auto-correlation letter of pseudo noise code Number, Sinc ()=sin (x)/x, η_{P, I, k}And η_{P, Q, k}The noise of in-phase branch and quadrature branch is represented respectively.

If ignoring the noise in above-mentioned coherent integration results, for coherent integration time is T_ICoherent integration As a result, in epoch k, its energy is

${\mathrm{PP}}_k^2={\mathrm{PR}}^2\left({\mathrm{\Δ\τ}}_{P,k}\right){\mathrm{Sinc}}^2\left({\mathrm{\πT}}_I{\mathrm{\Δf}}_{P,k}\right)$

For other two-way, advanced road complex carrier signal S_E and delayed road complex carrier signal S_L, after mixing also with immediately Road pseudo-code signal C_P signals are related, likewise, its energy is respectively

${\mathrm{EP}}_k^2={\mathrm{PR}}^2\left({\mathrm{\Δ\τ}}_{P,k}\right){\mathrm{Sinc}}^2\left({\mathrm{\πT}}_I\right({\mathrm{\Δf}}_{P,k}-{\mathrm{\Δf}}_d\left)\right)$

${\mathrm{LP}}_k^2={\mathrm{PR}}^2\left({\mathrm{\Δ\τ}}_{P,k}\right){\mathrm{Sinc}}^2\left({\mathrm{\πT}}_I\right({\mathrm{\Δf}}_{P,k}+{\mathrm{\Δf}}_d\left)\right)$

Using Taylor's formula, sinc²(πΔfT_I) can be expressed as

$Sinc{\left({\mathrm{\π\ΔfT}}_I\right)}^2\stackrel{\mathrm{\Δ}}{=}1-\mathrm{\Θ}{\left(\mathrm{\Δ}f\right)}^2$

Wherein, Θ=(π T_I)²/ 3, after coherent integration time determines, which can regard into a constant as.Therefore, it is defeated Enter signal and the mixing of three road complex carrier signals, it is related to instant road pseudo-code signal C_P signals after result respectively can To be approximated by

${\mathrm{PP}}_k^2=H(1-\mathrm{\Θ}{\left({\mathrm{\Δf}}_{P,k}\right)}^2)$

${\mathrm{EP}}_k^2=H(1-\mathrm{\Θ}{\left({\mathrm{\Δf}}_{P,k}-{\mathrm{\Δf}}_d\right)}^2)$

${\mathrm{LP}}_k^2=H(1-\mathrm{\Θ}{\left({\mathrm{\Δf}}_{P,k}+{\mathrm{\Δf}}_d\right)}^2)$

Wherein, H=PR²(Δτ_{P, k}) ceiling capacity that instant road PP correlation intergals can reach is represented, abbreviation can be obtained

${\mathrm{EP}}_k^2-{\mathrm{LP}}_k^2=H\left(4{\mathrm{\Θ\Δf}}_{P,k}{\mathrm{\Δf}}_d\right)$

$\begin{array}{c}{\mathrm{EP}}_k^2+{\mathrm{LP}}_k^2=H(2-2\mathrm{\Θ}({\mathrm{\Δf}}_{P,k}^2+{\mathrm{\Δf}}_d^2\left)\right)\\ =2{\mathrm{PP}}_k^2-2{\mathrm{H\Θ\Δf}}_d^2\end{array}$

Further simplify, obtain based on the frequency identification method expression formula of energy be

${\mathrm{\Δf}}_{P,k}=\frac{{\mathrm{\Δf}}_d}{2}\frac{{\mathrm{EP}}^2-{\mathrm{LP}}^2}{2{\mathrm{PP}}^2-({\mathrm{EP}}^2+{\mathrm{LP}}^2)}$

Thus, another similar frequency discrimination method formula can also be obtained

${\mathrm{\Δf}}_{P,k}={\mathrm{\Δf}}_d\frac{{\mathrm{EP}}^2-{\mathrm{LP}}^2}{2{\mathrm{PP}}^2+|{\mathrm{EP}}^2-{\mathrm{LP}}^2|-({\mathrm{EP}}^2+{\mathrm{LP}}^2)}$

Carrier phase phase discriminator can be adopted

OrOrOrDeng convention carrier phase detecting method.

Code loop can subtract delayed (Early Minus Late, EML) code phase detecting method in advance using traditional,

${\mathrm{\δ}}_{cp}=(1-d)\frac{PE-PL}{PE+PL}$

Or the code phase demodulation computational methods based on energy

${\mathrm{\δ}}_{cp}=(1-d)\frac{{\mathrm{PE}}^2-{\mathrm{PL}}^2}{{\mathrm{PE}}^2+{\mathrm{PL}}^2}$

7. method according to claim 1 and energy frequency discrimination method, carrier wave phase demodulation described in claim 6 Method, code phase detecting method, it is characterised in that according to system mode, loop selection control switching phaselocked loop With FLL working condition.Filtered feedback parameter, feeds back to carrier wave digital controlled oscillator and pseudo- yardage respectively Controlled oscillator, and then the real-time regulation of carrier phase and carrier frequency, code phase and code frequency is realized, finally Realize the tracking of GNSS signal.

8. the device that a kind of frequency based on energy differentiates, described device include：Antenna, satellite navigation signals Sample quantization module, correlation intergal-removing module, error identification module, feedback control module, local replica Signal generator module and processor.

9. device according to claim 8, it is characterised in that

The antenna is used for receiving satellite navigation signals；

The satellite navigation signals sample quantization module, for filtering, automatic growth control, by satellite-signal It is down-converted to intermediate-freuqncy signal and completes sample quantization, obtains digital medium-frequency signal；

The correlation intergal-removing module, for realizing that each road-load wave mixing, pseudo-code are related, relevant in passage Integration-remove function etc.；

The error identification module, it is complete by carrier phase descriminator, energy frequency descriminator and code descriminator Into local replica carrier wave, pseudo-code signal and the estimation for receiving relevant parameter in signal；

The feedback control module, realizes carrier loop parametric filtering and the filtering of code loop parameter, and is given most Terminal ring road feedback parameter；

The local replica signal generation module, for producing each road local replica complex carrier signal and pseudo-code signal；

The processor realizes the functions such as tracking channel initialization, state control, positioning calculation, time service.

10. device according to claim 8, it is characterised in that

Processor passes through each tracking channel of bus configuration and various initiation parameters, and what is be such as given after acquisition success is first Beginning code phase, initial carrier frequency etc..The intermediate frequency that correlation intergal in passage-removing module receiving front-end is given Signal, and carry out being mixed to the local signal that local replica signal generation module is produced, related, integration, clearly Except operation is waited, the correlation energy value of each branch road is obtained.Error identification module is given according to the method for the invention Go out the error estimate of signal relevant parameter.Feedback control module is filtered to each estimates of parameters, and root Corresponding adjustment is made according to system running state, final feedback parameter is fed back to into local replica signal generation module, Locally generated signal is made to try one's best synchronous with the signal for receiving.Processor reads the tracking mode ginseng of satellite-signal Number, and then baseband state parameter adjustment is completed, control base band is normally run, and completes positioning, constant speed, time service Etc. function.