CN107370710A - A kind of lifting airscrew blocks high order modulation signal compensation method - Google Patents

A kind of lifting airscrew blocks high order modulation signal compensation method Download PDF

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CN107370710A
CN107370710A CN201710651009.2A CN201710651009A CN107370710A CN 107370710 A CN107370710 A CN 107370710A CN 201710651009 A CN201710651009 A CN 201710651009A CN 107370710 A CN107370710 A CN 107370710A
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msub
signal
blocks
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CN107370710B (en
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李�浩
何春
戴彬彬
朱立东
王剑
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University of Electronic Science and Technology of China
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/32—Carrier systems characterised by combinations of two or more of the types covered by groups H04L27/02, H04L27/10, H04L27/18 or H04L27/26
    • H04L27/34—Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
    • H04L27/38—Demodulator circuits; Receiver circuits
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/14—Relay systems
    • H04B7/15—Active relay systems
    • H04B7/185—Space-based or airborne stations; Stations for satellite systems
    • H04B7/18502—Airborne stations
    • H04B7/18506—Communications with or from aircraft, i.e. aeronautical mobile service
    • H04B7/18508—Communications with or from aircraft, i.e. aeronautical mobile service with satellite system used as relay, i.e. aeronautical mobile satellite service
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
    • H04L1/0056—Systems characterized by the type of code used
    • H04L1/0061—Error detection codes
    • H04L1/0063—Single parity check
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
    • H04L1/0056—Systems characterized by the type of code used
    • H04L1/0071—Use of interleaving
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/32—Carrier systems characterised by combinations of two or more of the types covered by groups H04L27/02, H04L27/10, H04L27/18 or H04L27/26
    • H04L27/34—Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
    • H04L27/38—Demodulator circuits; Receiver circuits
    • H04L27/3809—Amplitude regulation arrangements

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Physics & Mathematics (AREA)
  • Astronomy & Astrophysics (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • General Physics & Mathematics (AREA)
  • Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
  • Radio Transmission System (AREA)

Abstract

The present invention relates to the technical field of satellite communication that the anti-rotor of helicopter blocks, and in particular to a kind of lifting airscrew blocks high order modulation signal compensation method.The method of the present invention is directed to high-order modulating, the higher order signal blocked to lifting airscrew carries out energy compensating, can solve in helicopter satellite communication, because rotor blocks the influence of fading to signal amplitude, directly utilize and block the problem of signal can reduce error performance.Using the method for the present invention, shield portions data constellation figure can be improved；Identical when blocking utilization rate, signal transmission error code performance is more preferable；When reaching same performance, it is higher to block utilization rate.The method is realized simple, need to only use simple multiplication and division computing and to compare operation i.e. achievable.The application scenarios of the high-order modulating of different rank can be met by snr threshold corresponding to setting and compensated peak threshold value, such as the MQAM signals such as 16QAM, 32QAM, 64QAM（M>4）Effectively there is larger use range, realize the characteristics of simple.

Description

A kind of lifting airscrew blocks high order modulation signal compensation method
Technical field
The present invention relates to the technical field of satellite communication that the anti-rotor of helicopter blocks, and in particular to a kind of lifting airscrew hides Keep off high order modulation signal compensation method.
Background technology
Satellite communication has that communication distance is remote, relative cost is low, coverage is big, message capacity is big, not by geographical conditions Limitation and natural calamity influence the features such as；And in aircraft, helicopter have can low-altitude low-speed flight, to landing condition It is required that it is low, there is the series of advantages such as larger flexibility；Above-mentioned advantage based on helicopter and satellite communication, both are combined Afterwards, can be in medical aid, disaster relief lifesaving, emergency resuce, geological prospecting, the scenes such as fire extinguishing of protecting a forest using the helicopter of satellite communication It is used widely.
But with the development of technology, the requirement in various application scenarios to real-time high quality communication improves constantly, so The satellite communication for forcing helicopter to use needs higher traffic rate；The side of common raising helicopter satellite communication speed Method is to use high-order modulating, and its real time high-speed rate communication that can meet to a certain extent in helicopter satellite communication will Ask；But high-order modulating, which still suffers from some problems, to be needed to solve；Specifically, in helicopter satellite communication, communication antenna with Signal transmission between satellite is easily blocked by lifting airscrew, is periodically declined so that helicopter satellite communication signals receive Influence.It is a kind of effective ways that confrontation rotor blocks to block gap communication using rotor, but actually by rotor in this mode The signal blocked is just wasted.
Lifting airscrew, which blocks, to be caused to decay to the amplitude of signal, but can't change the polarity and phase of signal, because The phase modulated signal of the low orders such as this QPSK can't influence the correctness of demodulation because of amplitude fading after being blocked by rotor；And After more amplitude high order modulation signal amplitudes such as 16QAM, 32QAM are affected, constellation point may deviate script correct decoding area Domain, as shown in Figure 7a, so as to cause mistake, direct utilization can bring serious error code to influence.Therefore in order to realize finite bandwidth High rate communication scheme, using shield portions higher order signal when, to high order modulation signal carry out corresponding to signal amplitude compensate Just seem very necessary；In the prior art, signal is compensated usually using AGC (automatic growth control), by transmission signal Amplitude Compensation to desired value, this for etc. amplitude phase modulated signal it is effective, such as QPSK signals；But for 16QAM etc. several The higher order signal of degree, AGC also can compensate the signal of different amplitudes originally except meeting is to the signal compensation of shield portions To target amplitude so that correctly constellation point deviates originally for part, so as to bring extra mistake.Such as Fig. 5 a, Fig. 5 b institute Show, circle Re is 16QAM signal averaging amplitudes in the planisphereFor the circle of radius, AGC can make the radius be respectivelyWith Circle on constellation point centered on the origin of coordinates, to circle Re near compensate, directly result in the mistake of this part constellation point By mistake；Therefore AGC is not particularly suited for the compensation of higher order signal in helicopter communication, it is necessary to be communicated using other technologies to helicopter The middle higher order signal blocked by rotor compensates.
The content of the invention
In overcoming prior art helicopter to communicate, the communication between satellite communication antena and satellite Signal is easily blocked by the lifting airscrew in rotation, a kind of the problem of causing signal of communication utilization rate not high, there is provided communication efficiency Higher, communication efficiency is preferably used for the method for compensating signal of helicopter satellite communication.
In order to realize foregoing invention purpose, the invention provides following technical scheme：
A kind of lifting airscrew blocks high order modulation signal compensation method, including：
A：According to the signal received, with reference to lifting airscrew occlusion state, rotor occlusion state is parameterized, obtained straight Rise machine rotor and block curve h (t)；
B：The lifting airscrew obtained according to processing blocks curve h (t), and the inverted rotor that is calculated blocks signal primary Compensation model curve
C：It is different according to Signal-to-Noise, top processing is cut to compensated curve function, the peak of the compensated curve of matching is set Value, obtains final penalty function c (t)；The purpose of the peak value of compensated curve is set to be to suppress the relatively low part signal of signal to noise ratio Compensation；
D：The signal s (t) received is multiplied with final penalty function c (t), the signal r (t) after being compensated.Specifically , the signal s (t) received is multiplied with penalty function c (t) by the corresponding time, i.e., actually signal s (t) each moment Value (penalty coefficient) of the value with penalty function c (t) in the moment is multiplied, the signal r (t) after being compensated.
Further, in the step A, obtain lifting airscrew using equation below and block curve h (t)：
Wherein, when 0≤t≤T, S are that rotor blocks completely, the ratio of signal amplitude average value and original signal, value are blocked Scope is 0 ＜ S≤1, t1,t2,t3,t4Respectively block the time started, block completely the time started, block completely the end time, Block the end time, t1,t2,t3,t4Meet 0≤t1≤t2≤t3≤t4≤ T, T are that lifting airscrew blocks the cycle.
Further, in the step C, snr threshold SNR is setthreshold=0dB, obtain and the threshold value SNRthresholdThe compensated peak threshold value G of corresponding compensated curvethreshold, GthresholdWith snr threshold SNRthresholdSet Determined according to following relation, SNR0+20log10h(t0)=SNRthreshold, Gthreshold=g (t0), wherein SNR0For currently without screening The signal to noise ratio of signal during gear transmission.To primary compensation model curve g (t), if g (tx) ＞ Gthreshold, make g (tx)=Gthreshold, Utilize formulaObtain final penalty function c (t)；Because block Process is really the process that Signal-to-Noise reduces, if Signal-to-Noise is too low, directly can excessively be put using function g (t) compensation Big noise, in order to suppress this partial noise, threshold value SNR is setthreshold=0dB, only to signal to noise ratio snr ＞ SNRthresholdPortion Divide and compensated according to g (t), signal to noise ratio snr≤SNRthresholdPart signal press SNRthresholdProcessing.
Compared with prior art, beneficial effects of the present invention：The method of the present invention is directed to high-order modulating, to helicopter The higher order signal that rotor blocks carries out energy compensating, can solve in helicopter satellite communication, because rotor is blocked to signal width The influence of fading of degree, directly utilize and block the problem of signal can reduce error performance.Using the method for the present invention, screening can be improved Stopper divided data planisphere；Identical when blocking utilization rate, signal transmission error code performance is more preferable；When reaching same performance, profit is blocked It is higher with rate.Method is realized simple, need to only use simple multiplication and division computing and to compare operation i.e. achievable.By corresponding to setting SNRthresholdAnd GthresholdThe application scenarios of the high-order modulating of different rank can be met, such as 16QAM, 32QAM, The MQAM signals such as 64QAM (M>4) effectively there is larger use range, realize the characteristics of simple.
Brief description of the drawings：
Fig. 1 compensation method signals provided by the invention move towards figure；
Fig. 2 blocks illustraton of model for what the present invention parameterized；
Fig. 3 blocks model for present invention basis and compensation model figure is calculated；
Fig. 4 is the present invention is compared to cut the final compensation model figure that top handles to obtain according to noise；
Fig. 5 a, Fig. 5 b are respectively the specific embodiment of 16QAM signal constellation (in digital modulation) figures before and after AGC compensation；
Fig. 6 is that shield portions higher order signal compensates precompensation example schematic block diagram；
Planisphere contrasts before and after the compensation of shield portions higher order signal when Fig. 7 a, Fig. 7 b are respectively noiseless；
Planisphere contrasts before and after the compensation of shield portions higher order signal when Fig. 8 a, Fig. 8 b are respectively SNR=20dB；
Fig. 9 is transmitted without time diversity Transmission system example block diagram to be applied to 64QAM signals in the present invention；
Figure 10 is to carry out data slit without time diversity Transmission system in Fig. 9 to send schematic diagram；
Figure 11 a are to transmit error bit ability figure without time diversity 64QAM without time diversity Transmission system in Fig. 9；
Figure 11 b are without time diversity Transmission system errored bit figure in Fig. 9；
It is applied to 64QAM signal transmission time diversity transmission exemplary system block diagrams in Figure 12 present invention；
Figure 13 is that time diversity Transmission system Data duplication sends schematic diagram in Figure 12；
Figure 14 is time diversity Transmission system error bit ability figure in Figure 12.
Embodiment
Below in conjunction with the accompanying drawings and specific embodiment the present invention is described in further detail.But this should not be interpreted as to this The scope for inventing above-mentioned theme is only limitted to following embodiment, all to belong to the present invention based on the technology that present invention is realized Scope.
The present invention utilizes the method based on lifting airscrew occlusion prediction, obtains lifting airscrew occlusion state, by ginseng It is used to calculate preliminary compensation model function after numberization, penalty function is carried out further according to signal to noise ratio to cut top optimization processing, obtained most Whole penalty function, then by penalty function it is corresponding with reception signal multiplication be compensated after signal.It is specifically described below.
As shown in figure 1, the present embodiment, which provides a kind of lifting airscrew, blocks high order modulation signal compensation method, including：
Step 100：According to the signal received, with reference to lifting airscrew occlusion state, rotor occlusion state is parameterized, Obtain lifting airscrew and block curve h (t)；Specifically, obtaining lifting airscrew using equation below blocks curve h (t)：
Wherein, when 0≤t≤T, S are that rotor blocks completely, the ratio of signal amplitude average value and original signal, value are blocked Scope is 0 ＜ S≤1, t1,t2,t3,t4Respectively block the time started, block completely the time started, block completely the end time, Block the end time, t1,t2,t3,t4Meet 0≤t1≤t2≤t3≤t4≤ T, T are that lifting airscrew blocks the cycle, typically should Cycle T is as shown in Figure 2.
S200：Curve h (t) is blocked according to the lifting airscrew that processing obtains, the inverted rotor that is calculated blocks signal Primary compensation model curveThis is because, block signal s (t)=x (t) h (t), wherein x (t) For originally transmitted signal, due to thermal compensation signal rc(t)=s (t) g (t), in order that thermal compensation signal reverts to original signal, i.e. rc(t) =x (t), then it can try to achieve penalty functionIt is specific as shown in Figure 3.
S300：Snr threshold SNR is setthreshold=0dB, obtain and threshold value SNRthresholdCorresponding compensated curve Compensated peak threshold value Gthreshold, GthresholdWith snr threshold SNRthresholdSet and determined according to following relation, SNR0+ 20log10h(t0)=SNRthreshold, Gthreshold=g (t0), wherein SNR0For current unobstructed transmission when signal signal to noise ratio. To primary compensation model curve g (t), if g (tx) ＞ Gthreshold, make g (tx)=Gthreshold, utilize formulaObtain final penalty function c (t)；Because block process reality It is the process that Signal-to-Noise reduces, if Signal-to-Noise is too low, directly can excessively amplifies noise using function g (t) compensation, be Suppress this partial noise, threshold value SNR is setthreshold=0dB, only to signal to noise ratio snr ＞ SNRthresholdPart according to g (t) compensate, signal to noise ratio snr≤SNRthresholdPart signal press SNRthresholdProcessing.It is specific as shown in Figure 4.
S400：The signal s (t) received is multiplied with final penalty function c (t), the signal r (t) after being compensated.Tool Body, the signal s (t) received is multiplied with penalty function c (t) by the corresponding time, i.e., actually signal s (t) each moment Value (penalty coefficient) of the value with penalty function c (t) in the moment be multiplied, the signal r (t) after being compensated.
The present invention is further described with reference to a specific example.
Example one：Influence of the compensation method to constellation point：
Example one uses emulation platform as MATLAB R2014a, used to block model as shown in Fig. 2 shielding rate 20%, shielding rate is to block the time to account for the ratio for blocking the cycle, i.e. (t4-t1)/T, blocks decline and blocks the rise time and respectively account for screening The 40% of time is kept off, blocking the time completely accounts for and block the 20% of the time, and signal energy decays to 20dB when blocking completely, unobstructed When signal energy decay to 0dB, block model curve block decline and rising be linear course.
Example one uses 64QAM modulated signals, by blocking model treatment, the higher order signal after being blocked, by adding The receiving terminal helicopter emulated of making an uproar blocks higher order signal.Penalty function c (t) is calculated according to calculation formula, to receiving Signal compensates, and example schematic block diagram is as shown in Figure 6.Noise-free case and signal to noise ratio snr=20dB situations are drawn respectively, are hidden Stopper divides high order modulation signal compensation front and rear planisphere, as shown in Fig. 7 a, Fig. 7 b and Fig. 8 a, Fig. 8 b.
Be respectively the front and rear planisphere of noise-free case compensation as shown in Fig. 7 a, Fig. 7 b, high order modulation signal amplitude due to Block and decay, signal constellation point offsets to the origin of coordinates and deviate from the constellation point region of script, is directly believed using this part Number it can then cause mistake.And signal can be compensated well for back to the constellation point region of script well using compensation method is blocked.
Signal to noise ratio snr=front and rear planisphere of 20dB situations compensation, the noisy height after blocking as shown in Fig. 8 a, Fig. 8 b Contrast signal constellation point is concentrated mainly on the intermediate region centered on the origin of coordinates, directly utilizes and also results in mistake, After blocking compensation, it can be seen that constellation point is compensated well for go back to original constellation point region.Contrast is it can be found that block Compensation can largely reduce signal constellation point mistake caused by blocking deviation script region.
Example two：Compensation method is to the influence without time diversity Transmission system performance
Model is identical with example one for the emulation platform of example two and blocking of using, and builds anti-helicopter as shown in Figure 9 Rotor blocks no time diversity Transmission system, and receiving terminal is set to blocking signal compensation and uncompensated two kinds of processing schemes respectively, Final result is contrasted, verifies the effect that application method of the present invention is brought.
Transmitting terminal randomly generates 60480bits binary data, then carries out piecemeal LDPC codings to binary data, LDPC code lengths are 2016, code check 1/2；Data after being encoded to LDPC are interleaved processing；Data after intertexture are carried out 64QAM symbols map, and mapping uses Gray code mode；Situation is blocked according to lifting airscrew and blocks utilization rate to enter in the ranks Gap is sent, as shown in Figure 10；Transmission signal successively blocks module and Gaussian noise resume module by rotor, simulates actual transmissions Channel；Receiving terminal receives signal and is divided into two-way：Penalty function c (t) is calculated according to calculation formula in the first via, and signal is entered Row compensation, then to the soft demodulation of 64QAM corresponding to signal progress after compensation, deinterleave, LDPC decoding base band data processing, the second tunnel Without blocking compensation, directly progress and first via identical subsequent treatment, errored bit counts (a), errored bit in fig.9 respectively Count the bit error rate after bit error rate and LDPC decodings after the statistics 64QAM demodulation of (b) two positions, respectively corresponding diagram 11a and Figure 11 b；Facilities respectively：(1) 50%, which blocks utilization rate, compensation, and (2) 50% to block utilization rate uncompensated, and (3) 20% hide It is uncompensated to keep off utilization rate, influence of the contrast verification compensation method to signal transmission performance.Utilization rate is wherein blocked to be defined as blocking The ratio of the data length that part utilizes and shield portions total length of data, as shown in Figure 10, that is, blocks utilization rate β=2Td/ (t4-t1)。
It is to transmit error bit ability figure without time diversity 64QAM signals under Gaussian channel as shown in fig. 11a.SNR ＜ 5.5dB When, because noise is larger, compensation method does not have much affect to the error bit ability of signal；During SNR ＞ 5.5dB, comparison diagram 11a It can be found that during unobstructed compensation, 20% slightly inferior properties when blocking utilization rate are made an uproar in pure Gauss for middle curve 2, curve 3 and curve 4 Acoustic channel situation, 50% transmission performance when blocking utilization rate further decline, i.e. signal blocks utilization rate is higher, and signal transmission misses Bit performance loss is bigger；Curve 1 and curve 2 are found in comparison diagram 11a, and 50%, which blocks utilization rate, compensation situation transmission performance It is substantially better than 50% and blocks the uncompensated situation (BER of utilization rate<When 0.05, performance difference 1dB), illustrate that compensation side is blocked in use Method, the performance loss that brings when improving signal blocks utilization rate can be made up to a certain degree, i.e., it is identical when blocking utilization rate, block The transmission performance of compensation is more preferable；Curve 1 and curve 3 are found in comparison diagram 11a, and 50%, which blocks utilization rate, compensation situation performance ratio 20% to block the uncompensated situation error performance of utilization rate close, when illustrating to reach identical traffic performance, has and blocks blocking for compensation Utilization rate is higher.
It is without time diversity Transmission system error bit ability figure under Gaussian channel as shown in figure 11b.During without time diversity, warp After crossing deinterleaving LDPC decodings, the curve of three kinds of situations in comparison diagram 11b, analyzed with reference to result above, block compensation method pair Still have without time diversity Transmission system to draw a conclusion：Compensation method is blocked using the present invention, identical when blocking utilization rate, system Error performance is more preferable；When reaching identical systems error performance, it is higher to block utilization rate.Figure 11 b can enter in example three with Figure 14 One step comparative illustration.
Example three：Influence of the compensation method to time diversity Transmission system performance：
Model is identical with example one for the emulation platform of example three and blocking of using, and builds anti-helicopter as shown in figure 12 Rotor blocks time diversity Transmission system, is set respectively in receiving terminal to blocking signal compensation and uncompensated two kinds of processing schemes, Final result is contrasted, verifies the effect that application method of the present invention is brought.
Transmitting terminal randomly generates 60480bits binary data, then carries out piecemeal LDPC codings to binary data, LDPC code lengths are 2016, code check 1/2；Data after being encoded to LDPC are interleaved processing；Data after intertexture are carried out 64QAM symbols map, and mapping uses Gray code mode；Symbol after mapping presses 80% repetitive rate according to rotor circumstance of occlusion Time diversity processing is carried out, as shown in figure 13, is blocked with resisting lifting airscrew, ensures normal communication；Transmission signal is successively Module and Gaussian noise resume module are blocked by rotor, simulates actual transmission channel；Receiving terminal receives signal and is divided into two-way： Penalty function c (t) is calculated according to calculation formula in the first via, and signal is compensated, then carries out subsequent recombination, and 64QAM is soft Demodulation, deinterleave, LDPC decodings processing, finally count bit error rate, the second tunnel is directly carried out and first without blocking compensation Road identical subsequent treatment；Facilities respectively：(1) 50%, which blocks utilization rate, compensation, and (2) 50% to block utilization rate of no help Repay, (3) 20% block that utilization rate is uncompensated, influence of the contrast verification compensation method to signal transmission performance.
System error bit ability figure is as shown in figure 14, by it was found that, during SNR ＜ 5dB, because noise is larger, compensation Method does not have much affect to the error bit ability of signal；During SNR ＞ 5dB, correlation curve 1 and 2 finds that blocking utilization rate is In the case of 50%, BER ＜ 10-3When have and block error bit ability well about 0.2dB of the compensation than unobstructed compensation, i.e., it is identical to block profit During with rate, there is the transmission performance for blocking compensation more preferable；Correlation curve 1 and 3 finds that 50%, which blocks utilization rate, the mistake for blocking compensation Error bit ability when bit performance blocks utilization rate unobstructed compensation with 20% is close, it can be seen that when reaching same performance, There is the shield portions signal utilization rate for blocking compensation higher than unobstructed compensation, when reaching same performance in example three, block The utilization rate of compensation is higher than the utilization of unobstructed compensation by about 30%.Analyzed with reference to result above, block compensation method to the time point Collect Transmission system, still have to draw a conclusion：Identical when blocking utilization rate using blocking compensation, system error performance is more preferable；Reach phase During homologous ray performance, it is higher to block utilization rate.
Curve 1 and curve 3 in comparison diagram 11b and Figure 14 find, during no time diversity, 20% to block utilization rate uncompensated Situation performance blocks utilization rate better than 50% compensation situation, and during having time diversity, both performances are almost consistent, and this is due to 50% block utilization rate situation blocked than 20% the merging gain of utilization rate situation it is bigger caused by.Comparison diagram 11b and Figure 14, knot The contrast for closing different situations spectrum efficiency in table one finds that time diversity system ratio is more excellent without time diversity system error performance, It is higher without time diversity system channel spectrum efficiency, and the compensation method of blocking of the present invention has notable effect in two systems Fruit.The present invention's blocks that compensation method is not only effective to 64QAM signals, equally has to the high-order modulating of other more amplitudes Effect.
Table one
The embodiment of the present invention is described in detail above in conjunction with accompanying drawing, but the present invention is not restricted to Embodiment is stated, in the case of the spirit and scope of claims hereof are not departed from, those skilled in the art can make Go out various modifications or remodeling.

Claims (3)

1. a kind of lifting airscrew blocks method for compensating signal, it is characterised in that：Including：
A：According to the signal received, with reference to lifting airscrew occlusion state, rotor occlusion state is parameterized, obtains helicopter Rotor blocks curve h (t)；
B：The lifting airscrew obtained according to processing blocks curve h (t), and the inverted rotor that is calculated blocks the primary compensation of signal Model curve0≤t≤T；
C：It is different according to Signal-to-Noise, top processing is cut to compensated curve function, the peak value of the compensated curve of matching is set, obtained Take final penalty function c (t)；
D：The signal s (t) received is multiplied with final penalty function c (t), the signal r (t) after being compensated.
2. lifting airscrew according to claim 1 blocks method for compensating signal, it is characterised in that：In the step A, profit Lifting airscrew, which is obtained, with equation below blocks curve h (t)：
<mrow> <mi>h</mi> <mrow> <mo>(</mo> <mi>t</mi> <mo>)</mo> </mrow> <mo>=</mo> <mfenced open = "{" close = ""> <mtable> <mtr> <mtd> <mrow> <mfrac> <mrow> <mi>S</mi> <mo>-</mo> <mn>1</mn> </mrow> <mrow> <msub> <mi>t</mi> <mn>2</mn> </msub> <mo>-</mo> <msub> <mi>t</mi> <mn>1</mn> </msub> </mrow> </mfrac> <mo>&amp;times;</mo> <mrow> <mo>(</mo> <mi>t</mi> <mo>-</mo> <msub> <mi>t</mi> <mn>1</mn> </msub> <mo>)</mo> </mrow> <mo>+</mo> <mn>1</mn> </mrow> </mtd> <mtd> <mrow> <msub> <mi>t</mi> <mn>1</mn> </msub> <mo>&lt;</mo> <mi>t</mi> <mo>&amp;le;</mo> <msub> <mi>t</mi> <mn>2</mn> </msub> </mrow> </mtd> </mtr> <mtr> <mtd> <mi>S</mi> </mtd> <mtd> <mrow> <msub> <mi>t</mi> <mn>2</mn> </msub> <mo>&lt;</mo> <mi>t</mi> <mo>&amp;le;</mo> <msub> <mi>t</mi> <mn>3</mn> </msub> </mrow> </mtd> </mtr> <mtr> <mtd> <mrow> <mfrac> <mrow> <mn>1</mn> <mo>-</mo> <mi>S</mi> </mrow> <mrow> <msub> <mi>t</mi> <mn>4</mn> </msub> <mo>-</mo> <msub> <mi>t</mi> <mn>3</mn> </msub> </mrow> </mfrac> <mo>&amp;times;</mo> <mrow> <mo>(</mo> <mi>t</mi> <mo>-</mo> <msub> <mi>t</mi> <mn>3</mn> </msub> <mo>)</mo> </mrow> <mo>+</mo> <mi>S</mi> </mrow> </mtd> <mtd> <mrow> <msub> <mi>t</mi> <mn>3</mn> </msub> <mo>&lt;</mo> <mi>t</mi> <mo>&amp;le;</mo> <msub> <mi>t</mi> <mn>4</mn> </msub> </mrow> </mtd> </mtr> <mtr> <mtd> <mn>1</mn> </mtd> <mtd> <mrow> <mi>o</mi> <mi>t</mi> <mi>h</mi> <mi>e</mi> <mi>r</mi> <mi>s</mi> </mrow> </mtd> </mtr> </mtable> </mfenced> <mo>;</mo> </mrow>
Wherein, when 0≤t≤T, S are that rotor blocks completely, the ratio of signal amplitude average value and original signal, span are blocked For 0 ＜ S≤1, t1,t2,t3,t4The time started is respectively blocked, the time started is blocked completely, blocks the end time completely, blocks End time, t1,t2,t3,t4Meet 0≤t1≤t2≤t3≤t4≤ T, T are that lifting airscrew blocks the cycle.
3. lifting airscrew according to claim 2 blocks method for compensating signal, it is characterised in that：In the step C, if Put snr threshold SNRthreshold=0dB, obtain and threshold value SNRthresholdThe compensated peak threshold value of corresponding compensated curve Gthreshold, utilize formula0≤t≤T obtains final penalty function c (t).
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