CN101489153B - Monitoring apparatus and method for satellite forwarding device interference signal - Google Patents

Abstract

The present invention relates to a monitoring method of interfering signal of satellite transponder and a monitor thereof. The monitoring method adjusts the useful signal in input signal to consistent with the initial time, frequency and amplitude of local signal through adjusting the initial time, frequency and amplitude of input signal. The adjusted signal is subtracted with the local signal for counteracting the useful signal and obtaining the interfering signal. The parameter and change regularity of interfering signal are analyzed through directly analyzing the characteristic of interfering signal for obtaining the purposes of pre-amplifying the transmitter power when malicious interference exists and in-time reducing the transmitter power when the malicious interference is eliminated. The monitor of the invention comprises five modules of a time delay catching module, a time delay tracking module, a frequency deviation correcting module, a gain adjusting module and a signal counteracting module.

Description

A kind of monitoring device of satellite repeater interference signal and monitoring method

Technical field

The present invention relates to the digital video broadcast-satellite field, particularly relate to a kind of satellite repeater interference signal monitoring device and monitoring method.

Background technology

Satellite TV signal is very easy to be subjected to some unpredictalbe being not intended to or malicious interference because of its open wireless transmission.In recent years, owing to well-known reason, people have caused the attention of paying close attention to widely with height to the interference of satellite TV signal, therefore analyze the interference phenomenon and the influence of satellite TV signal and inquire into how to monitor effectively and take precautions against to disturb to have crucial meaning.

The satellite TV signal major part of China has adopted the digital transmission technology of DVB-S standard.According to the ruuning situation of reality as can be known, the DVB-S signal is received the interference that causes can reduce two kinds of situations: the one, from irresistible natural disturbance; Another kind of then be artificial malicious interference.The natural disturbance main cause is day to insult and rain declines etc.; Artificial malicious interference is meant utilizes illegal ground satellite station to the high-power wireless interference signal of telecommunication of satellite repeater transmission with legal signal same frequency band, and artificial malicious interference can be divided into dual mode: the artificial malicious interference of artificial malicious interference in arrowband and broadband.The artificial malicious interference in arrowband be interference signal be single carrier or bandwidth less than the modulation signal of normal signal, from received spectrum, can see significantly that interference signal is superimposed upon on the normal signal, at this moment signal power and carrier-to-noise ratio are constant substantially or slightly increase.Broad-band interference is spectrum signature and the duplicate interference signal of actual signal, because the operating characteristic of transponder, from received spectrum, do not observe has the existence of interference at all, and synchronous signal power and carrier-to-noise ratio do not change or only be slightly to increase.

The normal broadcasting of present stage to China's satellite television causes the interference of serious consequence and baneful influence greatly partly all to belong to the artificial malicious interference in broadband.The artificial malicious interference disguise in broadband is extremely strong, is monitored from the variation of indexs such as frequency spectrum, channel power and carrier-to-noise ratio to be difficult to be found.Traditional monitoring method is the real time monitoring that downward signal of satellite is carried out indexs such as frequency spectrum, carrier level, carrier-to-noise ratio, the error rate by ground station at present, but can not know the parameter and the Changing Pattern of interference signal like this, often can't accomplish antedating response and accurately analysis, it is many passive to have brought to work.

Summary of the invention

The objective of the invention is to overcome the deficiencies in the prior art, a kind of satellite repeater interference signal monitoring device and monitoring method are provided, analyze with parameter and Changing Pattern, so that when malicious interference is arranged, can strengthen transmitter power in advance and when malicious interference is eliminated, reduce transmitter power timely interference signal.

The object of the invention is achieved by following technical solution:

A kind of monitoring device of satellite repeater interference signal is characterized in that: comprise time delay trapping module, time delay tracking module, frequency offset correction module, gain regulation module and five modules of signal cancellation module, wherein:

Time delay trapping module: be used for receiving inputted signal, and the initial moment of adjustment input signal, make the initial moment of useful signal in the input signal and the initial moment basically identical of local signal, ERROR CONTROL and is exported to the time delay tracking module with adjusted signal in a sampling period;

Time delay tracking module: the signal that is used for the output of receive time delay trapping module, and the further accurate initial moment of adjusting described signal, make the initial moment of useful signal in the described signal consistent, and adjusted signal is exported to the frequency offset correction module with the initial moment of local signal;

Frequency offset correction module: be used for the signal of receive time delay tracking module output, and adjust the frequency of described signal, make the frequency of useful signal in the described signal consistent, and adjusted signal is exported to gain regulation module with the frequency of local signal;

Gain regulation module: be used to receive the signal of frequency offset correction module output, and adjust the amplitude of described signal, make the amplitude of useful signal in the described signal consistent, and adjusted signal is exported to the signal cancellation module with the amplitude of local signal;

Signal cancellation module: be used for the signal of receiving gain adjusting module output, and described signal and local signal are subtracted each other, the output interference signal.

In the monitoring device of above-mentioned satellite repeater interference signal, input signal is the signal that the signal that receives is exported after frequency mixer, LPF, AD converter and quadrature demodulation.

In the monitoring device of above-mentioned satellite repeater interference signal, local signal is the signal that local baseband signal obtains after scrambling, RS coding, convolutional interleave, convolutional encoding, constellation mapping, over-sampling and base band moulding, wherein scrambling is meant with a known Pn sequence and makes XOR, purpose is the company of preventing 0 or connects 1 situation appearance, makes the sequence randomization.

In the monitoring device of above-mentioned satellite repeater interference signal, the interference signal of output through matched filtering, extract, separate that constellation mapping, Viterbi decoding, deconvolution interweave, RS encodes and descrambling obtains required baseband interference signal, descrambling is meant with a known Pn sequence makes XOR, make the sequence randomization, energy is average, recovers former series.

A kind of monitoring method of satellite repeater interference signal is characterized in that comprising the steps:

(1) in the initial moment of adjustment input signal, make the initial moment of useful signal in the input signal and the initial moment basically identical of local signal, ERROR CONTROL is in a sampling period;

(2) in the further accurate initial moment of adjusting input signal, make the initial moment of useful signal in the input signal consistent with the initial moment of local signal;

(3) frequency of adjustment input signal makes the frequency of useful signal in the input signal consistent with the frequency of local signal;

(4) amplitude of adjustment input signal makes the amplitude of useful signal in the input signal consistent with the amplitude of local signal;

(5) will subtract each other the output interference signal through adjusted input signal of above-mentioned (1)-(4) step and local signal.

In the monitoring method of above-mentioned satellite repeater interference signal, input signal is the signal that the signal that receives is exported after frequency mixer, LPF, AD converter and quadrature demodulation.

In the monitoring method of above-mentioned satellite repeater interference signal, local signal is the signal that local baseband signal obtains after scrambling, RS coding, convolutional interleave, convolutional encoding, constellation mapping, over-sampling and base band moulding.

In the monitoring method of above-mentioned satellite repeater interference signal, the interference signal of output through matched filtering, extract, separate that constellation mapping, Viterbi decoding, deconvolution interweave, RS encodes and descrambling obtains required baseband interference signal.

The present invention compared with prior art has following advantage:

The monitoring device of satellite repeater interference signal of the present invention and monitoring method, can be by adjusting input signal, make that the useful signal in the input signal is consistent with the initial moment of local signal, frequency is identical, amplitude is identical, then input signal and local signal are subtracted each other, balance out the useful signal in the input signal, so just exposed the interference signal in the input signal, can analyze the parameter and the Changing Pattern of interference signal, so that when malicious interference is arranged, can strengthen transmitter power in advance and when malicious interference is eliminated, reduce transmitter power timely, with respect to traditional method of passing through error rate monitoring interference signal, the present invention has more initiative.

Description of drawings

Fig. 1 is the structural representation of the monitoring device of satellite repeater interference signal of the present invention;

Fig. 2 is the workflow diagram of time delay trapping module in the monitoring device of the present invention;

Fig. 3 is the workflow diagram of time delay tracking module in the monitoring device of the present invention;

Fig. 4 is the workflow diagram of frequency deviation correction module in the monitoring device of the present invention;

Fig. 5 is the workflow diagram of gain regulation module in the monitoring device of the present invention;

Fig. 6 is the workflow diagram of signal cancellation module among the present invention;

Fig. 7 is the simulation result schematic diagram of satellite repeater interference signal monitoring device of the present invention.

Embodiment

The present invention is described in further detail below in conjunction with the drawings and specific embodiments:

Be illustrated in figure 1 as the structural representation of the monitoring device of satellite repeater interference signal of the present invention, this monitoring device comprises the time delay trapping module, the time delay tracking module, the frequency offset correction module, five modules of gain regulation module and signal cancellation module, time delay trapping module receiving inputted signal wherein, and the initial moment of the whole input signal of thick step, make the useful signal in the input signal and the initial moment basically identical of local signal, ERROR CONTROL is in a sampling period, wherein input signal is that the signal that receives is through frequency mixer, LPF, the signal of exporting after AD converter and the quadrature demodulation, comprise useful signal and interference signal, local signal is that local baseband signal is through scrambling, the RS coding, convolutional interleave, convolutional encoding, constellation mapping, the signal that obtains after over-sampling and the base band moulding; The signal of time delay tracking module receive time delay trapping module output, the sampled point of adjusting the useful signal in this signal is an optimum sampling point, further accurately adjust the initial moment of signal, make the initial moment of useful signal in this signal consistent with the initial moment of local signal; The signal of frequency offset correction module receive time delay tracking module output, and adjust the frequency of this signal, make the frequency of useful signal in this signal consistent with the frequency of local signal; Gain regulation module receives the signal of frequency offset correction module output, and adjusts the amplitude of this signal, makes the amplitude of useful signal in this signal consistent with the amplitude of local signal; The signal of signal cancellation module receiving gain adjusting module output, and this signal and local signal subtracted each other, the output interference signal, the interference signal of output through matched filtering, extract, separate that constellation mapping, Viterbi decoding, deconvolution interweave, RS encodes and descrambling obtains required baseband interference signal, at last the parameter and the Changing Pattern of baseband interference signal are analyzed.

Input signal as shown in Figure 1 is the last entering signal cancellation module of signal through exporting after time delay trapping module, time delay tracking module, frequency offset correction module, four module adjustment of gain regulation module successively, this signal and local signal subtract each other in the signal cancellation module, the output interference signal, local signal is all the time as the benchmark that input signal is adjusted in whole process.

The concrete workflow of above-mentioned five modules is as follows among the present invention:

(1) time delay trapping module

With the QPSK signal is example, establishes the local useful signal S that sends ₁(t) and the interference signal S that sends ₂(t) be respectively:

S ₁(t)＝a(t)cos(2πf _ct+φ) (1)

S ₂(t)＝b(t)cos(2πf _ct+φ) (2)

Wherein: a (t) is that local baseband signal is encoded, the signal waveform behind the shaping filter, i.e. local signal, b (t) are that artificial malicious interference baseband signal is encoded, the signal waveform behind the shaping filter, i.e. interference signal, and the two average is zero, and statistics is independent; f _cBe carrier frequency; φ is a first phase.

Do not have under the synchronous situation at carrier wave, adopt incoherent envelope detection principle, promptly utilize trigonometric identity sin ²X+cos ²X=1 eliminates the influence to the time delay trapping module of frequency deviation, skew.

If input signal r (t) is:

r(t)＝S′ ₁(t)+S′ ₂(t)+n(t)

(3)

＝a′(t-τ ₁)cos(2πf′ _c1(t-τ ₁)+φ ₁)+b′(t-τ ₂)cos(2πf′ _c2(t-τ ₂)+φ ₂)+n(t)

Wherein: S ' ₁(t) be useful signal in the received signal, S ' ₂(t) be interference signal in the received signal, n (t) is a noise, a ' (t-τ ₁) be the baseband portion of the useful signal in the received signal, b ' (t-τ ₂) be the baseband portion of the interference signal in the received signal, τ ₁Be the time-delay of the useful signal in the received signal with respect to local signal, τ ₂Be the time-delay of the interference signal in the received signal with respect to local signal, f ' _cBe carrier frequency, φ is a first phase, the t express time;

As shown in Figure 2, at first input signal r (t) is carried out the mixing down-conversion,, produces I/Q two-way input signal through low-pass filtering and A/D:

r _i(k)＝a′(k-τ _1k)cos(2πΔf ₁k+Δφ ₁)+b′(k-τ _2k)cos(2πΔf ₂k+Δφ ₂)+n _i(k) (4)

r _q(k)＝a′(k-τ _1k)sin(2πΔf ₁k+Δφ ₁)+b′(k-τ _2k)sin(2πΔf ₂k+Δφ ₂)+n _q(k) (5)

Wherein: k represents sampling number, is positive integer; Δ f ₁Be the frequency difference of useful signal in the input signal and local signal, Δ f ₂Be the frequency difference of interference signal in the input signal and local signal, Δ φ ₁Be differing of useful signal in the input signal and local signal, Δ φ ₂Be differing of interference signal in the input signal and local signal, n (k) is a noise;

r _i(k), r _q(k) do relevant with local signal a (t) respectively and add up, get correlation length N result and be:

$r_1\left(k\right)=\underset{k}{\mathrm{\Σ}}[a^{\′}(k-{\mathrm{\τ}}_{1k})a\left(k\right)\cos (2\mathrm{\π\Δ}{f}_{1}k+{\mathrm{\Δ\φ}}_1)+b^{\′}(k-{\mathrm{\τ}}_{2k})a\left(k\right)\cos (2\mathrm{\π\Δ}{f}_{2}k+{\mathrm{\Δ\φ}}_2)+n_i\left(k\right)a\left(k\right)]---\left(6\right)$

$r_2\left(k\right)=\underset{k}{\mathrm{\Σ}}[a^{\′}(k-{\mathrm{\τ}}_{1k})a\left(k\right)\sin (2\mathrm{\π\Δ}{f}_{1}k+{\mathrm{\Δ\φ}}_1)+b^{\′}(k-{\mathrm{\τ}}_{2k})a\left(k\right)\sin (2\mathrm{\π\Δ}{f}_{2}k+{\mathrm{\Δ\φ}}_2)+n_q\left(k\right)a\left(k\right)]---\left(7\right)$

First on last two formula equal signs the right is the auto-correlation function of local signal, τ _1kThe auto-correlation peak value was far longer than its secondary lobe, [T in=0 o'clock _s, T _s] in its envelope be triangle, wherein T _sBe the sampling period.Second on equal sign the right is the cross-correlation of local signal a (t) and interference signal b (t), and the 3rd on equal sign the right is the cross-correlation of local signal a (t) and noise, and when k was infinitely great, cross correlation results was tending towards 0.In order to discuss conveniently, ignore back two, then:

${\mathrm{<figure-callout\; id="3"\; label="r"\; filenames="H2009100789172E00041.png"\; state="\{\{state\}\}">r</figure-callout>}}_3={\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="H2009100789172E00012.png,H2009100789172E00041.png"\; state="\{\{state\}\}">r</figure-callout>}}_1^2+{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="H2009100789172E00012.png,H2009100789172E00021.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2={\mathrm{AR}}_a^2\left({\mathrm{\&tau;}}_{1k}\right)---\left(8\right)$

Wherein A is the variation that amplitude gain causes, R _aBe the auto-correlation function of local signal, when the useful signal in the input signal and local signal are synchronous, r ₃The peak point of corresponding autocorrelator trace.With r ₃Compare with pre-set a certain thresholding, as be lower than this thresholding, then control input signals is done corresponding the slip, slides a sampling interval at every turn; As be equal to or greater than this thresholding, and then represent the time delay acquisition success, enter the time delay tracking module, ERROR CONTROL is in a sampling interval.Generally speaking, the propagation delay of radio wave in atmosphere can be gone out by satellite altitude and earth station position estimation, can earlier input signal be adjusted by this part time delay value before the time delay adjustment.The time delay that algorithm is introduced mainly is that A/D such as quantizes at the time delay that causes in the processing delay that receives of antenna emission and the receiver, and this part generally has only about tens microseconds, is very little with respect to propagation delay time.

I, Q two-way input signal through the adjusted output signal of time delay trapping module are:

r′ _i(k)＝a′(k-τ′ _1k)cos(2πΔf ₁k+Δφ ₁)+b′(k-τ _2k+τ _1k-τ′ _1k)cos(2πΔf ₂k+Δφ ₂)+n _i(k) (9)

r′ _q(k)＝a′(k-τ′ _1k)sin(2πΔf ₁k+Δφ ₁)+b′(k-τ _2k+τ _1k-τ′ _1k)sin(2πΔf ₂k+Δφ ₂)+n _q(k) (10)

(2) time delay tracking module

After time delay was caught end, ERROR CONTROL was in a sampling period.If sampling rate is 4 times of symbol rates, then the useful signal in local signal and the input signal differs 1/4 mark space, needs further accurate tracking to adjust time delay.As shown in Figure 3, adopt delay locked loop, still utilize the autocorrelation performance of local signal, construct an error signal and remove to control clock and be shifted, make the initial moment of the useful signal in local signal and the input signal consistent.

Order

For catching the signal delay that obtains, ${\mathrm{\&tau;}}_e=\mathrm{\&tau;}-\widehat{\mathrm{\&tau;}}$ Poor for actual value and time delay estimated value is with described r ' _i(k) with r ' _q(k) two paths of signals respectively with leading T _s/ 2 local signal is the relevant correlation R that obtains _a(τ _e-T _s/ 2), simultaneously with r ' _i(k) with r ' _q(k) two paths of signals respectively with hysteresis T _s/ 2 local signal is the relevant correlation R that obtains _a(τ _e+ T _s/ 2), calculate ERROR CONTROL vector e (τ _e) be:

$e\left({\mathrm{\&tau;}}_e\right)=R_a^2({\mathrm{\&tau;}}_e-T_s/2)-R_a^2({\mathrm{\&tau;}}_e+T_s/2)---\left(11\right)$

Ideally, the difference of two squares of pairwise correlation value is 0, corresponding e (τ _e)=0.The effect of time delay tracking module is exactly to adjust input signal and local signal a (t) reaches this point synchronously.Many yards accumulations are used to eliminate the influence of noise and interference signal, are equivalent to loop filter, can increase the precision of time delay tracking module.The precision of time delay tracking module and clock are adjusted step-length also relation.

The output signal of time delay trapping module through the adjusted output signal of time delay tracking module is:

r″ _i(k)＝a′(k)cos(2πΔf ₁k+Δφ ₁)+b′(k-τ _2k+τ _1k)cos(2πΔf ₂k+Δφ ₂)+n _i(k) (12)

r″ _q(k)＝a′(k)sin(2πΔf ₁k+Δφ ₁)+b′(k-τ _2k+τ _1k)sin(2πΔf ₂k+Δφ ₂)+n _q(k) (13)

Useful part through the adjusted output signal of time delay tracking module is consistent with the initial moment of local signal.

(3) frequency offset correction module

The frequency offset correction module is carried out the correction of frequency by adjusting the phase place of I, Q two-way to the output signal of time delay tracking module.

As shown in Figure 4, I, the Q two paths of signals with the output of time delay tracking module carries out the phase place rotation, generation phase demodulation error signal after phase discrimination processing.The phase demodulation error signal is sent to loop filter handles, the output of controlling digital controlled oscillator (NCO) after filtering goes to follow the tracks of the phase place of the signal of time delay tracking module output, to reach the purpose of it being carried out frequency offset correction.COEFFICIENT K 1, K2, K3 by the adjustment loop filter can satisfy the requirement of frequency offset correction module tracks precision and speed.

The output signal of time delay tracking module through the adjusted output signal of frequency offset correction module is:

r _i(k)＝a′(k)cos(Δφ′ ₁)+b′(k-τ _2k+τ _1k)cos(2π(Δf ₂-Δf ₁)k+Δφ′ ₂)+n _i(k) (14)

r _q(k)＝a′(k)sin(Δφ′ ₁)+b′(k-τ _2k+τ _1k)sin(2π(Δf ₂-Δf ₁)k+Δφ′ ₂)+n _q(k) (15)

r(k)＝r _i(k)+i*r _q(k)

＝a′(k)exp(Δφ′ ₁)+b′(k-τ _2k+τ _1k)exp(2π(Δf ₂-Δf ₁)k+Δφ′ ₂)+n(k) (16)

＝Aa″(k)+Bb″(k)exp(2πΔf′k+φ′)+n(k)

Wherein, a " (k), b " (k) has unit power, Δ f ', and φ ' is for the frequency difference of useful signal in the input signal and interference signal and differ.

(4) gain regulation module

Signal after the frequency offset correction module is supposed the corresponding a of sampled point referring to formula (16) " no intersymbol interference point (k) then can obtain:

r _k＝Aa″ _k+B″ _k+n _k (17)

Consider input signal a " (k) have unit power, and the signal to noise ratio of no intersymbol interference point is the highest after the carrier synchronization, therefore has:

$E\left(a_k^{\&prime;\&prime;2}\right)=1---\left(18\right)$

$E\left(b_k^{\&prime;\&prime;2}\right)\&le;1---\left(19\right)$

When the same homophase frequently of the carrier wave of interference signal and useful signal, when symbol is synchronous fully, have:

$E\left(b_k^{\&prime;\&prime;2}\right)=1---\left(20\right)$

According to maximal possibility estimation, can get:

$\hat{A}=\frac{1}{N}\underset{k=1}{\overset{N}{\mathrm{\&Sigma;}}}{r}_k{a}_k^{\&prime;\&prime;}-\frac{B}{N}\underset{k=1}{\overset{N}{\mathrm{\&Sigma;}}}{b}_k^{\&prime;\&prime;}{a}_k^{\&prime;\&prime;}---\left(21\right)$

Formula (21) is symbol rate when sampling maximal possibility estimation to interference signal amplitude.(k) statistics is independent to consider a " (k) and b ", and when N was big, second on formula (21) the right was very little with respect to first, and formula (21) can be approximated to be:

$\hat{A}=\frac{1}{N}\underset{k=1}{\overset{N}{\mathrm{\&Sigma;}}}{r}_k{a}_k^{\&prime;\&prime;}---\left(22\right)$

As shown in Figure 5, the output signal of frequency offset correction module through the adjusted output signal of gain regulation module is:

r(k)＝a″(k)+B/Ab″(k)exp(2πΔf′k+φ′)+n(k) (23)

(5) signal cancellation module

As shown in Figure 6, the output signal and the local signal of gain regulation module subtracted each other, get final product the interference signal S (k) in the input signal.Be that formula (23) is subtracted each other with a (k):

S(k)＝r(k)-a(k)

＝B/Ab″(k)exp(2πΔf′k+φ′)+n(k) (24)

Be without loss of generality, formula (24) be designated as:

S(k)＝Bb(k)exp(2πΔfk+φ)+n(k) (21)

S (k) again through matched filtering, extract, separate that constellation mapping, Viterbi decoding, deconvolution interweave, RS encodes and descrambling obtains baseband interference signal.

And then can analyze the parameter and the Changing Pattern of interference signal, so that when malicious interference is arranged, can strengthen transmitter power in advance and when malicious interference is eliminated, reduce transmitter power in time.

Be illustrated in figure 7 as the simulation result schematic diagram of satellite repeater interference signal monitoring device of the present invention, wherein (a) do not add frequency deviation, the useful signal in the desirable input signal of time-delay and gain loss and the autocorrelator trace of local signal, (b) be to add time-delay and gain loss, do not add the useful signal in the input signal of frequency deviation and the autocorrelator trace of local signal, (c) be to add time-delay, the useful signal in the input signal of energy loss and frequency deviation and the autocorrelator trace of local signal, (d) be the useful signal in the input signal behind frequency offset correction and the autocorrelator trace of local signal, (e) be to add time-delay, the input signal planisphere of energy loss and frequency deviation, (f) be through time delay, with the input signal planisphere behind the frequency offset correction, (g) be the planisphere of signal behind the signal cancellation, (h) be that signal carries out the adjusted planisphere of optimum sampling point to interference signal again behind the signal cancellation, correctly demodulation of interference signal as seen from the figure.

The above; only be the embodiment of the best of the present invention, but protection scope of the present invention is not limited thereto, anyly is familiar with those skilled in the art in the technical scope that the present invention discloses; the variation that can expect easily or replacement all should be encompassed within protection scope of the present invention.

The content that is not described in detail in the specification of the present invention belongs to this area professional and technical personnel's known technology.

Claims (9)

1. the monitoring device of a satellite repeater interference signal is characterized in that: comprise time delay trapping module, time delay tracking module, frequency offset correction module, gain regulation module and five modules of signal cancellation module, wherein:

Time delay trapping module: be used for receiving inputted signal, and the initial moment of adjustment input signal, the initial moment that makes useful signal in the input signal and the ERROR CONTROL in the initial moment of local signal and are exported to the time delay tracking module with adjusted signal in a sampling period;

Time delay tracking module: the signal that is used for the output of receive time delay trapping module, and the further accurate initial moment of adjusting described signal, make the initial moment of useful signal in the described signal consistent, and adjusted signal is exported to the frequency offset correction module with the initial moment of local signal;

Frequency offset correction module: be used for the signal of receive time delay tracking module output, and adjust the frequency of described signal, make the frequency of useful signal in the described signal consistent, and adjusted signal is exported to gain regulation module with the frequency of local signal;

Gain regulation module: be used to receive the signal of frequency offset correction module output, and adjust the amplitude of described signal, make the amplitude of useful signal in the described signal consistent, and adjusted signal is exported to the signal cancellation module with the amplitude of local signal;

Signal cancellation module: be used for the signal of receiving gain adjusting module output, and described signal and local signal are subtracted each other, the output interference signal.

2. the monitoring device of a kind of satellite repeater interference signal according to claim 1, it is characterized in that: described time delay trapping module is adjusted the initial moment of input signal, makes the method for ERROR CONTROL in a sampling period in the initial moment of useful signal and local signal in the input signal as follows:

A) establish the local useful signal S that sends ₁(t) and the local interference signal S that sends ₂(t) be respectively:

S ₁(t)＝a(t)cos(2πf _ct+φ)

S ₂(t)＝b(t)cos(2πf _ct+φ)

Wherein: a (t) is a local signal, and b (t) is an interference signal, f _cBe carrier frequency; φ is a first phase;

B) establishing received signal r (t) is:

r(t)＝S′ ₁(t)+S′ ₂(t)+n(t)

＝a′(t-τ ₁)cos(2πf′ _c1(t-τ ₁)+φ ₁)+b′(t-τ ₂)cos(2πf′ _c2(t-τ ₂)+φ ₂)+n(t)

Wherein: S ' ₁(t) be useful signal in the received signal, S ' ₂(t) be interference signal in the received signal, n (t) is a noise, a ' (t-τ ₁) be the baseband portion of the useful signal in the received signal, b ' (t-τ ₂) be the baseband portion of the interference signal in the received signal, τ ₁Be the time-delay of the useful signal in the received signal with respect to local signal, τ ₂Be the time-delay of the interference signal in the received signal with respect to local signal, f ' _cBe carrier frequency, φ is a first phase, the t express time;

Input signal r (t) is carried out the mixing down-conversion, behind low-pass filtering and the A/D, produce I/Q two-way input signal r _i(k) and r _q(k):

r _i(k)＝a′(k-τ _1k)cos(2πΔf ₁k+Δφ ₁)+b′(k-τ _2k)cos(2πΔf ₂k+Δφ ₂)+n _i(k)

r _q(k)＝a′(k-τ _1k)sin(2πΔf ₁k+Δφ ₁)+b′(k-τ _2k)sin(2πΔf ₂k+Δφ ₂)+n _q(k)

Wherein: k represents sampling number, is positive integer; Δ f ₁Be the frequency difference of useful signal in the input signal and local signal, Δ f ₂Be the frequency difference of interference signal in the input signal and local signal, Δ φ ₁Be differing of useful signal in the input signal and local signal, Δ φ ₂Be differing of interference signal in the input signal and local signal, n (k) is a noise;

r _i(k), r _q(k) do relevant with local signal a (t) respectively and add up, get correlation length N result and be:

$r_1\left(k\right)=\underset{k}{\mathrm{\&Sigma;}}[a^{\&prime;}(k-{\mathrm{\&tau;}}_{1k})a\left(k\right)\cos (2\mathrm{\&pi;\&Delta;}{f}_{1}k+{\mathrm{\&Delta;\&phi;}}_1)+b^{\&prime;}(k-{\mathrm{\&tau;}}_{2k})a\left(k\right)\cos (2\mathrm{\&pi;\&Delta;}{f}_{2}k+{\mathrm{\&Delta;\&phi;}}_2)+n_i\left(k\right)a\left(k\right)]$

$r_2\left(k\right)=\underset{k}{\mathrm{\&Sigma;}}[a^{\&prime;}(k-{\mathrm{\&tau;}}_{1k})a\left(k\right)\sin (2\mathrm{\&pi;\&Delta;}{f}_{1}k+{\mathrm{\&Delta;\&phi;}}_1)+b^{\&prime;}(k-{\mathrm{\&tau;}}_{2k})a\left(k\right)\sin (2\mathrm{\&pi;\&Delta;}{f}_{2}k+{\mathrm{\&Delta;\&phi;}}_2)+n_q\left(k\right)a\left(k\right)]$

Wherein: first on equal sign the right

With

Be the auto-correlation function of local signal, second on equal sign the right

With Be the cross-correlation of local signal and interference signal, the 3rd on equal sign the right

With

Be the cross-correlation of local signal and noise, when k was infinitely great, cross correlation results was tending towards 0;

C) establish:

$r_3=r_1{\left(k\right)}^2+r_2{\left(k\right)}^2={\mathrm{AR}}_a^2\left({\mathrm{\&tau;}}_{1k}\right)$

Wherein: A is the variation that amplitude gain causes, R _aBe the auto-correlation function of local signal,

When the useful signal in the input signal and local signal are synchronous, r ₃The peak point of corresponding autocorrelator trace is with r ₃Compare with pre-set a certain thresholding, as be lower than this thresholding, then control input signals is done corresponding the slip, slides a sampling interval at every turn, makes r ₃More than or equal to this threshold value, and output r ' _i(k) with r ' _q(k) two paths of signals.

3. the monitoring device of a kind of satellite repeater interference signal according to claim 1, it is characterized in that: described time delay tracking module is further accurately adjusted the initial moment of input signal, makes the method consistent with the initial moment of local signal of useful signal in the input signal as follows:

A) adopt delay locked loop, utilize the autocorrelation performance of local signal, construct the displacement of an error signal control clock, establish

For catching the signal delay that obtains, Poor for time delay actual value and time delay estimated value is with described r ' _i(k) with r ' _q(k) two paths of signals respectively with leading T _s/ 2 local signal is the relevant correlation R that obtains _a(τ _e-T _s/ 2), simultaneously with r ' _i(k) with r ' _q(k) two paths of signals respectively with hysteresis T _s/ 2 local signal a (t) is the relevant correlation R that obtains _a(τ _e+ T _s/ 2), calculate ERROR CONTROL vector e (τ _e) be:

$e\left({\mathrm{\&tau;}}_e\right)=R_a^2({\mathrm{\&tau;}}_e-T_s/2)-R_a^2({\mathrm{\&tau;}}_e+T_s/2)$

Wherein: R _aBe the auto-correlation function of local signal, T _sBe the sampling period;

B) adjust r ' _i(k), r ' _q(k) two paths of signals and local signal are synchronous, make the R of correlation described in the step a) _a(τ _e-T _s/ 2) and R _a(τ _e+ T _s/ 2) the difference of two squares is 0, i.e. e (τ _e)=0, output r " _i(k) with r " _q(k) two paths of signals.

4. the monitoring device of a kind of satellite repeater interference signal according to claim 1 is characterized in that: described frequency offset correction module is adjusted the frequency of input signal, makes the frequency of useful signal in the input signal method consistent with the local signal frequency as follows:

A) with described r " _i(k) with r " _q(k) after two paths of signals carries out the phase place rotation, carry out phase discrimination processing, produce the phase demodulation error signal;

B) the phase demodulation error signal is carried out Filtering Processing, control digital controlled oscillator afterwards and follow the tracks of described r " _i(k) with r " _q(k) phase place of useful signal in the two paths of signals makes the frequency of described useful signal consistent with the local signal frequency, output r " ' _i(k) with r " ' _q(k) two paths of signals.

5. the monitoring device of a kind of satellite repeater interference signal according to claim 1 is characterized in that: described local signal is the signal that local baseband signal obtains after scrambling, RS coding, convolutional interleave, convolutional encoding, constellation mapping, over-sampling and base band moulding respectively.

6. the monitoring device of a kind of satellite repeater interference signal according to claim 1 is characterized in that: the interference signal of described output respectively through matched filtering, extract, separate that constellation mapping, Viterbi decoding, deconvolution interweave, RS encodes and descrambling obtains required baseband interference signal.

7. the monitoring method of a satellite repeater interference signal is characterized in that comprising the steps:

(1) adjust initial moment of input signal, the initial moment that makes useful signal in the input signal and the ERROR CONTROL in the initial moment of local signal are in a sampling period;

(2) in the further accurate initial moment of adjusting input signal, make the initial moment of useful signal in the input signal consistent with the initial moment of local signal;

(3) frequency of adjustment input signal makes the frequency of useful signal in the input signal consistent with the frequency of local signal;

(4) amplitude of adjustment input signal makes the amplitude of useful signal in the input signal consistent with the amplitude of local signal;

(5) will subtract each other the output interference signal through adjusted input signal of above-mentioned (1)-(4) step and local signal.

8. the monitoring method of a kind of satellite repeater interference signal according to claim 7 is characterized in that: described local signal is the signal that local baseband signal obtains after scrambling, RS coding, convolutional interleave, convolutional encoding, constellation mapping, over-sampling and base band moulding.

9. the monitoring method of a kind of satellite repeater interference signal according to claim 7 is characterized in that: the interference signal of described output through matched filtering, extract, separate that constellation mapping, Viterbi decoding, deconvolution interweave, RS encodes and descrambling obtains required baseband interference signal.

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