CN105954775A - Inertial acceleration assisted receiver tracking loop algorithm - Google Patents

Abstract

The invention relates to an inertial acceleration assisted receiver tracking loop algorithm. According to the main technical characteristics, the method comprises the following steps that: frequency mixing is carried out on digital intermediate frequency signals to obtain homodromous I path signals and quadrature Q path signals; a homodromous advancing signal IE, a homodromous lag signal IL, a quadrature advancing signal QE and a quadrature lag signal QL pass through a code loop discriminator to obtain a code phase error, the code phase error is smoothed by a code loop filter, and the smoothed code phase error is added to faid/M so as to control a local C/A code generator in a feedback manner; a homodromous instant signal IP and a quadrature instant signal QP pass through a phase discriminator to obtain a loop phase error, the loop phase error is smoothed by a loop filter to obtain a carrier phase error, and the carrier phase error is added to faid to correct a local carrier generator. According to the invention, the dynamic stress borne by the loop is eliminated, the loop is enabled to realize stable tracking of a large dynamic environment under a small bandwidth, the dynamic performance of the loop is substantially improved, and the interference resistance of the loop is effectively improved.

Description

Inertial navigation acceleration auxiliary reception machine tracking algorithm

Technical field

The invention belongs to field of navigation technology, especially a kind of inertial navigation acceleration auxiliary reception machine track loop is calculated Method.

Background technology

Under high dynamic environment, GNSS signal carrier frequency and code frequency can be accelerated by carrier fair speed Degree, acceleration affects, and produces the biggest Doppler frequency shift, Doppler frequency shift rate of change and Doppler's frequency Move secondary change rate.For common receiver, in order to keep loop-locking must increase loop bandwidth. The increasing of loop bandwidth is introduced into broadband noise, and loop will be caused to lose when noise level increases to a certain degree Lock.In order to solve the most lower high loop tracks problem, some scholars propose to use second order FLL to assist three rank The carrier track algorithm of phaselocked loop.The feature of this algorithm is the thresholding that second order FLL is switched to third order pll It is difficult to determine, and when carrier movement change ratio is time very fast, loop can be caused constantly to switch, affect the steady of loop Qualitative.Also having some scholars to propose adaptive loop circuit optimum bandwidth and arrange algorithm, this algorithm is also required to bandwidth It is continually changing, affects loop stability.Some scholars are also had to propose loop tracks algorithm based on fuzzy control With loop tracks algorithm based on Kalman filtering, these algorithms the most fundamentally solve loop and are subjected to Dynamic stress problem, when carrier dynamic arrive to a certain degree after, loop is all by losing lock.

Fig. 1 gives tradition and defends and lead track loop schematic diagram, as can be seen from the figure: after A/D changes Digital medium-frequency signal, by obtaining I road signal and orthogonal Q road signal in the same direction after mixing, respectively with in advance Code E, instantaneous code P, delayed code L obtain after being correlated with and peel off carrier wave and six road signals of pseudo noise code: surpass in the same direction Front signal I_E, real-time signal I in the same direction_P, delay signal I in the same direction_L, orthogonal anticipating signal Q_E, orthogonal instant letter Number Q_P, orthogonal delay signal Q_L。I_E、I_L、Q_E、Q_PCode phase error, warp is obtained through code ring descriminator Cross feedback control this locality C/A code generator after filtering.I_P、Q_PLoop phase error is obtained by phase discriminator, After loop filter is smooth, in order to correct local carrier generator.In convention carrier track loop, In the case of outside climatic environment is certain, loop stability is mainly by carrier dynamic and the shadow of external interference Ring.When carrier dynamic is excessive, excessive owing to introducing track loop error, track loop losing lock will be caused. External interference is excessive also leads to track loop losing lock.Increase track loop bandwidth and can promote loop dynamics Can, but it is introduced into bigger noise jamming.

Summary of the invention

In place of it is an object of the invention to make up the deficiencies in the prior art, it is provided that a kind of inertial navigation acceleration auxiliary connects Receipts machine tracking algorithm, the problem that solution track loop dynamic property and bandwidth requirement exist contradiction.

The present invention solves it and technical problem is that and take techniques below scheme to realize:

A kind of inertial navigation acceleration auxiliary reception machine tracking algorithm, comprises the following steps:

Step 1, digital medium-frequency signal are by obtaining I road signal and orthogonal Q road signal in the same direction after mixing；

Step 2, I road signal and orthogonal Q road signal respectively with advanced code E, instantaneous code P, delayed code L phase Obtain behind pass and peel off carrier wave and six road signals of pseudo noise code: anticipating signal I in the same direction_E, real-time signal I in the same direction_P, Delay signal I in the same direction_L, orthogonal anticipating signal Q_E, orthogonal real-time signal Q_P, orthogonal delay signal Q_L；

Step 3, in the same direction anticipating signal I_E, delay signal I in the same direction_L, orthogonal anticipating signal Q_E, orthogonal delayed Signal Q_LCode phase error is obtained, this code phase error code after Loop filter through code ring descriminator Phase error adds f_aid/ M feedback control this locality C/A code generator；

Step 4, in the same direction real-time signal I_P, orthogonal real-time signal Q_PLoop phase error is obtained by phase discriminator, The carrier phase error that this loop phase error obtains after loop filter is smooth is plus f_aidTo local carrier Generator is modified；

Wherein, f_aidAssisting information for inertial navigation acceleration, M represents the ratio of carrier frequency and code frequency.

Described inertial navigation acceleration auxiliary information f_aidFor Doppler, above-mentioned inertial navigation acceleration auxiliary information is directly passed through Inertial navigation information and defend the information of leading and be calculated.

Advantages of the present invention and good effect be:

1, carrier tracking loop and code tracking loop are assisted, from all by the present invention by introducing inertial navigation acceleration On solve the dynamic stress problem that loop is subjected to so that loop can realize big dynamic under the least bandwidth The tenacious tracking of state environment, the significant increase dynamic of loop.Owing to loop dynamics is by inertial navigation acceleration Auxiliary information makes up, and loop bandwidth can arrange smaller, thus is effectively improved the anti-interference energy of loop Power.

2, the present invention passes through inertial navigation acceleration estimated loop Doppler frequency shift rate of change, have compressed loop and needs carrying Dynamic, it is ensured that DVB is in height dynamically lower normal work, and improve that receiver can bear is dynamic State scope.

3, the aspects such as universality, dynamic, anti-interference and inertial navigation estimation error impact are carried out by the present invention Simulation Evaluation, the simulation results show correctness of algorithm, prove that proposing algorithm compares traditional algorithm simultaneously Dynamic is greatly promoted, and capacity of resisting disturbance promotes 5dB-8dB, can tolerate that bigger inertial navigation assists information error, Lay a good foundation for algorithm engineering.

Accompanying drawing explanation

Fig. 1 is tradition track loop schematic diagram；

Fig. 2 is that inertial navigation acceleration assists track loop schematic diagram；

Fig. 3 is inertial navigation acceleration subcarrier track loop schematic diagram；

Fig. 4 is phaselocked loop acceleration threshold and equivalent noise bandwidth relation schematic diagram；

Fig. 5 is phaselocked loop acceleration thresholding and equivalent noise bandwidth relation schematic diagram；

Fig. 6 is that No. 2 stars follow the tracks of result schematic diagram；

Fig. 7 is that No. 7 stars follow the tracks of result schematic diagram；

Fig. 8 is that No. 8 stars follow the tracks of result schematic diagram；

Fig. 9 is that No. 10 stars follow the tracks of result schematic diagram；

Figure 10 is that No. 15 stars follow the tracks of result schematic diagram；

Figure 11 is that No. 29 stars follow the tracks of result schematic diagram；

Figure 12 is that No. 26 stars follow the tracks of result schematic diagram；

Figure 13 be at the uniform velocity time the inertial navigation acceleration lower loop tracks result schematic diagram of auxiliary；

Figure 14 be at the uniform velocity time without the lower loop tracks result schematic diagram of auxiliary；

Figure 15 is the lower loop tracks result schematic diagram of inertial navigation acceleration auxiliary during acceleration 50g；

The lower loop tracks result schematic diagram of nothing auxiliary when Figure 16 is acceleration 50g；

Figure 17 is that inertial navigation acceleration assists track loop dynamic schematic diagram；

Figure 18 is to assist track loop dynamic schematic diagram without inertial navigation；

Figure 19 is to follow the tracks of knot under at the uniform velocity direct route and different Doppler frequency shift rate of change errors during signal to noise ratio-19dB Really schematic diagram；

Figure 20 is to follow the tracks of knot under at the uniform velocity direct route and different Doppler frequency shift rate of change errors during signal to noise ratio-36dB Really schematic diagram；

Figure 21 is acceleration 50g and follows the tracks of under different Doppler frequency shift rate of change errors during signal to noise ratio-19dB Result schematic diagram；

Figure 22 is acceleration 50g and follows the tracks of under different Doppler frequency shift rate of change errors during signal to noise ratio-36dB Result schematic diagram.

Detailed description of the invention

Below in conjunction with accompanying drawing, the embodiment of the present invention is further described:

A kind of inertial navigation acceleration auxiliary reception machine tracking algorithm, is auxiliary at inertial navigation acceleration as shown in Figure 2 Help realization on receiver tracking loop circuit, comprise the following steps:

Digital medium-frequency signal after A/D changes, by obtaining I road signal and orthogonal Q in the same direction after mixing Road signal, relevant to advanced code E, instantaneous code P, delayed code L respectively after obtain and peel off carrier wave and pseudo noise code Six road signals: anticipating signal I in the same direction_E, real-time signal I in the same direction_P, delay signal I in the same direction_L, orthogonal advanced letter Number Q_E, orthogonal real-time signal Q_P, orthogonal delay signal Q_L.Anticipating signal I in the same direction_E, delay signal in the same direction I_L, orthogonal anticipating signal Q_E, orthogonal delay signal Q_LObtain code phase error through code ring descriminator, pass through Code ring phase error after Loop filter controls local C/A code plus inertial navigation acceleration feedback of auxiliary information and sends out Raw device.Real-time signal I in the same direction_P, orthogonal real-time signal Q_PObtain loop phase error by phase discriminator, pass through Local carrier is jointly sent out by the carrier phase error after loop filter is smooth plus inertial navigation acceleration auxiliary information Raw device is modified.Wherein, f_aidRepresent the inertial navigation acceleration auxiliary information using inertial navigation accelerometer to calculate, M Represent the ratio of carrier frequency and code frequency.

Inertial navigation acceleration auxiliary information f in the present invention_aidFor Doppler, inertial navigation acceleration auxiliary information can be straight Connect to utilize inertial navigation information and defend the information of leading and be calculated.

Analyzing the advantage of inertial navigation acceleration auxiliary for convenience, Fig. 3 is right as a example by second order carrier loop wave filter The present invention is described further that (Fig. 3 only gives in Fig. 2 the output of carrier loop descriminator and sends out to local carrier Inertial navigation acceleration subcarrier track loop schematic diagram before raw device input).Fig. 3 adds for inertial navigation in dotted line frame Velocity aid part, θ_iS () represents that the transmission of input and phase of received signal are poor, s is Laplace operator, θ₀(s) Represent that transmission and the phase of received signal of output are poor,Being inertial navigation auxiliary filter coefficient, e (s) is that inertial navigation adds The error that velocity aid introduces, w (s) is the thermal noise etc. in former track loop, and F (s) is former tracking ring The filtering loop coefficient on road.

$F\left(s\right)=K_0\frac{{\mathrm{\τ}}_2+1}{{\mathrm{\τ}}_{1}s}---\left(1\right)$

In formula, K₀For the gain of loop filter, τ₁And τ₂For filter time constant.

Assume inertial navigation acceleration can the Doppler frequency shift rate of change of error free estimation carrier wave, i.e. e (s) is 0. Then have

θ₀(s)=H₁(s)θ_i(s)+H₂(s)w(s) (2)

Wherein,

$H_1\left(s\right)=\frac{\left(\frac{a}{s+a}\right){\mathrm{\τ}}_1{s}^2+K_0{\mathrm{\τ}}_{2}s+K_0}{{\mathrm{\τ}}_1{s}^2+K_0{\mathrm{\τ}}_{2}s+K_0}---\left(3\right)$

$H_2\left(s\right)=\frac{K_0{\mathrm{\τ}}_{2}s+K_0}{{\mathrm{\τ}}_1{s}^2+K_0{\mathrm{\τ}}_{2}s+K_0}---\left(4\right)$

By formula (4) it can be seen that when the bandwidth of inertial navigation system trends towards infinity, i.e. during a → ∞, system passes Delivery function H₁(s) → 1, if this explanation inertial navigation system bandwidth sufficiently large, inertial navigation acceleration auxiliary carrier wave with Track ring just can be to follow the tracks of any motor-driven form of carrier.

In like manner understanding, as long as inertial navigation system bandwidth is enough, the code ring of inertial navigation acceleration auxiliary also can follow the tracks of load Any motor-driven form of body.

Below the performance of this patent is analyzed:

1, inertial navigation acceleration auxiliary track loop error:

Conventional phase locked loops experience 1 σ tracking threshold is represented by

In formula, σ_PLLRepresent total phaselocked loop tracking error, σ_iRepresent total phase jitter variance, θ_eRepresent lock The steady track error of phase ring.The most total phaselocked loop tracking error includes thermal noise errorMachinery vibration Caused frequency of oscillation shakeAnd Ai Lan mean square deviationThree kinds,

${\mathrm{\σ}}_i=\sqrt{{\mathrm{\σ}}_{tPLL}^2+{\mathrm{\σ}}_v^2+{\mathrm{\σ}}_A^2}---\left(6\right)$

Thermal noise meansquaredeviationσ_tPLLEstimation equation be:

In formula, B_LFor loop bandwidth, C/N₀For carrier-to-noise ratio, unit is Hz, T_cohFor coherent integration time, one As be 1 millisecond, λ is wavelength.Knowable to above formula, thermal noise is unrelated with loop exponent number.User movement and connecing The phase jitter mean square deviation of the receiver reference oscillating frequency that the machinery vibration of receiving apparatus causes and Ai Lan mean square deviation Relative thermal noise error is less, ignores here.

Use ω_nRepresent characteristic frequency, bandwidth the representative value of the first-order loop determined is B_L/ 0.25, second-order loop Representative value is B_L/ 0.53, the representative value on third order PLL road is B_L/0.7845.Loop filter for different rank comes Saying, phaselocked loop dynamic stress error is represented by:

Single order ring:

${\mathrm{\θ}}_{e1}=\frac{1}{{\mathrm{\ω}}_n}\frac{dR}{dt}=\frac{1}{B_L/0.25}\frac{dR}{dt}=0.25\·\frac{dR}{B_{L}dt}---\left(8\right)$

Second order loop:

${\mathrm{\θ}}_{e2}=\frac{1}{{\mathrm{\ω}}_n^2}\frac{d^{2}R}{{\mathrm{dt}}^2}=\frac{1}{{(B_L/0.53)}^2}\frac{d^{2}R}{{\mathrm{dt}}^2}=0.2809\·\frac{d^{2}R}{B_L^2{\mathrm{dt}}^2}---\left(9\right)$

${\mathrm{\θ}}_{e3}=\frac{1}{{\mathrm{\ω}}_n^3}\frac{d^{3}R}{{\mathrm{dt}}^3}=\frac{1}{{(B_L/0.7845)}^3}\frac{d^{3}R}{{\mathrm{dt}}^3}=0.4828\·\frac{d^{3}R}{B_L^3{\mathrm{dt}}^3}---\left(10\right)$

The dynamic stress error threshold calculating phaselocked loop according to formula (5) is

θ_e≤45°-3σ_i (11)

Thus obtain the acceleration of phaselocked loop further and acceleration thresholding is

In formula, g represents acceleration of gravity.Fig. 4 and Fig. 5 gives phaselocked loop acceleration threshold, acceleration Thresholding and the relation of equivalent noise bandwidth.

Knowable to Fig. 4 and Fig. 5, in the case of carrier-to-noise ratio 35dB Hz, second-order PLL can bear Peak acceleration is less than 2g, and the maximum acceleration that third order pll can bear is less than 21g.

After using inertial navigation acceleration auxiliary, the dynamic stress that phaselocked loop is subjected to is made up by inertial navigation auxiliary information, Only be subjected to thermal noise error and inertial navigation auxiliary data-evaluation error, i.e. phaselocked loop 1 σ tracking threshold is

In formula, θ_errorRepresenting inertial navigation auxiliary data-evaluation error, it is unrelated with the dynamic of carrier, is therefore protecting In the case of card inertial navigation auxiliary precision of information, Satellite Tracking loop can bear any dynamic.

2, Doppler frequency shift rate of change calculates

Inertial navigation acceleration to defend lead receiver tracking loop circuit auxiliary mainly use inertial navigation provide carrier acceleration letter The satellite position information estimation carrier Doppler shift change that breath, carrier positions information and satellite ephemeris provide Rate (owing to satellite accelerations is the least, ignore), with the Doppler frequency shift rate of change of estimation to carrier track Assist.The specific formula for calculation of Doppler frequency shift rate of change is

${\stackrel{\·}{f}}_{aid}=\frac{1}{\mathrm{\λ}}{a}_r{J}_s---\left(15\right)$

In formula,Representing carrier Doppler shift rate of change, λ represents the carrier wavelength of satellite-signal, a_rRepresent Receiver antenna acceleration, I_sFor the unit vector on satellite to receiver sight line, i.e.

$I_s=\frac{X_s-X_r}{|X_s-X_r|}---\left(16\right)$

In formula: X_sFor satellite position, X_rFor receiver location, | | represent delivery.

3, universality simulation analysis

Universality emulation purpose is to investigate whether inertial navigation acceleration auxiliary has all Satellite Tracking simultaneously viewed Effect, satellite-signal is from satellite signal simulator collection.In emulation, the initial velocity of carrier is north orientation 10m/s, adds Speed is north orientation 10g.The satellite that now can capture has 2,5,7,8,10,15,26,29.According to The now relative position of satellite and carrier, the acceleration value being mapped on each star line is about successively 71m/s²、23m/s²、67m/s²、19m/s²、15m/s²、24m/s²、0.16m/s²、7m/s².Defend and lead tracking Loop use third order pll follow the tracks of, loop bandwidth is 2Hz, add and be not added with inertial navigation acceleration auxiliary loop with Track result is as shown below.

From Fig. 6-11 it can be seen that when carrier is the biggest, third order pll is difficult under this noise bandwidth Realize tenacious tracking.After increasing inertial navigation acceleration auxiliary, loop is capable of tenacious tracking.Visible, increase Inertial navigation acceleration auxiliary can improve the dynamic property of Satellite Tracking loop.

From Figure 12, when carrier dynamic is less, when assisting without inertial navigation acceleration, narrow track loop bandwidth Also can realize the tenacious tracking of loop, similar with using inertial navigation acceleration auxiliary tracking result, i.e. inertial navigation is accelerated The DeGrain of degree auxiliary.It is to say, in the case of carrier dynamic is little, it is not necessary to use inertial navigation to add Velocity aid.

Complex chart 6-Figure 12 understand assisted by inertial navigation acceleration, defend lead track loop can be in less bandwidth The lower realization tenacious tracking to large dynamic range.Additionally, inertial navigation acceleration auxiliary can be to synchronization institute The track loop having satellite effectively assists, it was demonstrated that the universality of algorithm and correctness.

4, anti-interference assessment

Based on self-editing intermediate-freuqncy signal data, the anti-interference of inertial navigation acceleration auxiliary tracking algorithm is commented Estimate.This emulation generates intermediate-freuqncy signal more preferable than real satellite signal, the most do not consider that concrete each algorithm is anti-dry Disturb ability, only focus on and assist track loop capacity of resisting disturbance difference with or without inertial navigation acceleration.Make an uproar added by signal Sound is white Gaussian noise, and sample rate is 62MHz, selects at the uniform velocity direct route and two kinds of typical environment of 50g to examine Examine.The judgement foundation that loop stability is followed the tracks of is chosen for no data dislocation and sentences.It is all 1 owing to generating data bit, with Time in view of there may be 180 ° of phase bit flippings, therefore after tenacious tracking, I road accumulated value is all to be just or all Negative.If after tenacious tracking, occur that certain I road accumulated value symbol is contrary with other, then it is assumed that can not correctly with Track.As can be seen from Figure 13 according to this judgment condition above-mentioned, when at the uniform velocity sailing through to, satellite-signal signal to noise ratio is-36dB Time, inertial navigation acceleration information secondary ring tenacious tracking；When satellite-signal signal to noise ratio is-37dB, will appear from Bit is judged by accident.Under visible inertial navigation acceleration auxiliary, loop can the signal of tenacious tracking signal to noise ratio-36dB.

Figure 14 gives when assisting without inertial navigation acceleration, defends and leads track loop simulation result, as we know from the figure when When signal to noise ratio is-31dB, track loop tenacious tracking；When signal to noise ratio is-32dB, 1954,1975, 1994,5134 occur that the erroneous judgement of I road accumulated value symbol, i.e. tradition track loop energy tenacious tracking signal to noise ratio are The satellite-signal of low-31dB.It follows that inertial navigation acceleration auxiliary allows track loop about improve 5dB Capacity of resisting disturbance.

According to above-mentioned judgment condition, from figure 15, it can be known that when acceleration is 50g, satellite-signal signal to noise ratio is During-36dB, inertial navigation acceleration information secondary ring tenacious tracking；When satellite-signal signal to noise ratio is-37dB, Will appear from bit erroneous judgement.Under visible inertial navigation acceleration auxiliary, loop can tenacious tracking signal to noise ratio-36dB Signal.

As can be seen from Figure 16, without track loop during auxiliary energy tenacious tracking, signal to noise ratio-29dB when signal to noise ratio-28dB Time after 5881 o'clock occur erroneous judgement, i.e. without assist time the minimum-28dB of tenacious tracking signal to noise ratio.It can thus be appreciated that Inertial navigation acceleration auxiliary allows track loop improve about 8dB capacity of resisting disturbance.

Knowable to above-mentioned analysis, use inertial navigation acceleration auxiliary can strengthen the capacity of resisting disturbance of track loop, And dynamic is the highest, capacity of resisting disturbance improves the most obvious.

5, dynamic assessment

Based on self-editing intermediate-freuqncy signal data, the dynamic of inertial navigation acceleration auxiliary tracking algorithm is commented Estimate.The most here only focus on or without track loop dynamic difference under aided case.Signal institute plus noise is high This white noise, Signal-to-Noise is-19dB, i.e. received signal power is-130dBm, and sample rate is 62MHz. The lower track loop simulation result of inertial navigation acceleration auxiliary is as shown in figure 17.Understand from the graph, when carrier acceleration During for 1000g, can stablize through heel track loop after a while, but stabilization time is longer；Acceleration Time less, tenacious tracking required time is shorter.Owing in reality, carrier acceleration, not over 1000g, and is examined Consider to stabilization time during acceleration 1000g the longest, do not study the property of track loop under more high acceleration Energy.

As can be seen from Figure 18, when carrier acceleration is 91g, it is capable of stable without inertial navigation information secondary ring Follow the tracks of；When carrier acceleration is 92g, gradually on weekly duty enclose 0 without inertial navigation information secondary ring I road accumulated value Fluctuation, i.e. loop no longer can tenacious trackings, say, that the load can born without inertial navigation information secondary ring maximum Body acceleration is 91g.

Contrast Figure 17 and Figure 18 understands, and uses the inertial navigation acceleration auxiliary can significant increase track loop dynamic State property.

6, carrier doppler estimation error impact evaluation

Track loop is affected by the carrier doppler error calculated to fully assess inertial navigation auxiliary information, uses Add Gauss white noise error in Doppler frequency shift rate of change true value and assist information as track loop.Choose as follows Several moving scenes as typical environment, 1) at the uniform velocity sail through to, signal to noise ratio is respectively-19dB and-36dB；2) Acceleration is 50g, and signal to noise ratio is respectively-19dB and-36dB.

Figure 19 gives when at the uniform velocity sailing through to, and signal to noise ratio is-19dB, Doppler's frequency that track loop can be tolerated Move the analogous diagram of rate of change estimation difference.It can be seen that when Doppler frequency shift rate of change error is 141Hz/s Time, loop can tenacious tracking；When Doppler frequency shift rate of change error is 142Hz/s, bit is 3726 Erroneous judgement occurs at Dian.It is taken as that in such cases, the maximum doppler frequency rate of change that loop can be tolerated Estimation difference is 141dB/Hz.

Figure 20 gives when at the uniform velocity sailing through to, and signal to noise ratio is-36dB, Doppler's frequency that track loop can be tolerated Move the analogous diagram of rate of change estimation difference.It can be seen that when Doppler frequency shift rate of change error is 100Hz/s Time, loop can tenacious tracking, without bit judge by accident；When Doppler frequency shift rate of change error is 101Hz/s Time, bit occur at 5007 erroneous judgement, it is taken as that loop can tolerate in such cases the most most General Le frequency displacement rate of change error is 100Hz/s.

When Figure 21 gives acceleration 50g, signal to noise ratio is-19dB, the Doppler that track loop can be tolerated The analogous diagram of frequency displacement rate of change estimation difference.It can be seen that when Doppler frequency shift rate of change error is 111Hz/s Time, loop can tenacious tracking；When Doppler frequency shift rate of change error is 112Hz/s, bit is 3034 At 3042, erroneous judgement occurs.It is taken as that in such cases, the maximum doppler frequency that loop can be tolerated Rate of change estimation difference is 111dB/Hz.

When Figure 22 gives acceleration 50g, signal to noise ratio is-36dB, the Doppler that track loop can be tolerated The analogous diagram of frequency displacement rate of change estimation difference.It can be seen that when Doppler frequency shift rate of change error is 81Hz/s Time, loop can tenacious tracking；When Doppler frequency shift rate of change error is 82Hz/s, bit is 3153 At 5580, erroneous judgement occurs.It is taken as that in such cases, the maximum doppler frequency that loop can be tolerated Rate of change estimation difference is 81dB/Hz.

Understanding from Figure 19 to Figure 22, Satellite Tracking loop can tolerate that bigger Doppler frequency shift rate of change is estimated Calculating error, i.e. common inertial navigation can meet Satellite Tracking loop demand.

It is emphasized that embodiment of the present invention is illustrative rather than determinate, therefore The present invention includes the embodiment being not limited to described in detailed description of the invention, every by those skilled in the art's root Other embodiments drawn according to technical scheme, also belong to the scope of protection of the invention.

Claims (2)

1. an inertial navigation acceleration auxiliary reception machine tracking algorithm, it is characterised in that comprise the following steps:

Step 1, digital medium-frequency signal are by obtaining I road signal and orthogonal Q road signal in the same direction after mixing；

Step 2, I road signal and orthogonal Q road signal respectively with advanced code E, instantaneous code P, delayed code L phase Obtain behind pass and peel off carrier wave and six road signals of pseudo noise code: anticipating signal I in the same direction_E, real-time signal I in the same direction_P, Delay signal I in the same direction_L, orthogonal anticipating signal Q_E, orthogonal real-time signal Q_P, orthogonal delay signal Q_L；

Step 3, in the same direction anticipating signal I_E, delay signal I in the same direction_L, orthogonal anticipating signal Q_E, orthogonal delayed Signal Q_LCode phase error is obtained, this code phase error code after Loop filter through code ring descriminator Phase error adds f_aid/ M feedback control this locality C/A code generator；

Step 4, in the same direction real-time signal I_P, orthogonal real-time signal Q_PLoop phase error is obtained by phase discriminator, The carrier phase error that this loop phase error obtains after loop filter is smooth is plus f_aidTo local carrier Generator is modified；

Wherein, f_aidAssisting information for inertial navigation acceleration, M represents the ratio of carrier frequency and code frequency.

A kind of inertial navigation acceleration auxiliary reception machine tracking algorithm the most according to claim 1, it is special Levy and be: described inertial navigation acceleration auxiliary information f_aidFor Doppler, above-mentioned inertial navigation acceleration auxiliary information is direct By inertial navigation information with defend the information of leading and be calculated.