CN1038702A - Spread spectrum aircraft guidance system - Google Patents
Spread spectrum aircraft guidance system Download PDFInfo
- Publication number
- CN1038702A CN1038702A CN 89103321 CN89103321A CN1038702A CN 1038702 A CN1038702 A CN 1038702A CN 89103321 CN89103321 CN 89103321 CN 89103321 A CN89103321 A CN 89103321A CN 1038702 A CN1038702 A CN 1038702A
- Authority
- CN
- China
- Prior art keywords
- signal
- guidance system
- aircraft
- statement
- noise code
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Landscapes
- Radar Systems Or Details Thereof (AREA)
Abstract
Spread spectrum aircraft guidance system comprises steady arm transmitter installation and glide slope indicator transmitter installation, and they all launch the fixed beam signal of continuous wave.The signal information that provides aircraft to depart from final circle of the former emission, the signal of latter's emission provide depart from the landing glide course line or under information.They are by the modulation of the different pseudo noise sign indicating number in the cluster orthogonal sign indicating number, with the frequency spread on broadband with launching beam.Receiver on the aircraft can narrow down on frequency spectrum simultaneously and the steady arm of demodulate reception and the signal of glide slope, determining its amplitude, and therefrom produces and measures aircraft is off-line.
Description
The present invention relates to an aircraft guidance system, the landing of a spread spectrum aircraft landing specifically guidance system, it has a pair of with respect to the pinpoint transmitter of runway, is used to launch fixing beam signal, and this signal is subjected to launching on broadband after the counterfeit noise modulated; This system also comprises an airborne receiver, be used for receiving and demodulation spread spectrum signal, and the beam signal after the comparison demodulation departs from measuring of the desired line of flight to amplitude thereby provide about aircraft.
Known have a multiple aircraft landing landing guidance system, comprises instrument landing system (ILS) and microwave landing system (MLS).As the permanent installation on airport, the ILS station generally is subjected to the too big restriction of its antenna size.The height at the frequency ratio ILS station that MLS uses at the station, thereby used antenna ratio ILS station is much smaller.But the MLS station is very expensive, and generally is immovable.
It is to work under the frequency of X-band that one landing landing guidance system is arranged, and its antenna is very little, thereby system is movably.This known system comprises, at least two energy are at aircraft and the runway centerline antenna to the left and right bundle equal strength wave beam that sends overlapping on time, and at least two energy send the antenna of the equal strength wave beam of overlapping when the glide-path theta alignment in aircraft and the landing course line of landing.One microwave switch (or other similar devices) is sequentially received each antenna with an X-band signal, sends guidance beam with impulse form, and wave beam is by discerning with respect to the time of occurrence of the identification code pulse train before the guidance beam pulse.Contained receiver receives and handles the guidance beam pulse on the machine, to determine departing from of aircraft and desired landing course line.Although it is fine that this system works under non-rugged surroundings, be subject to disturb and signal intercept.Moreover, have only this system of finite population (40 magnitude) to work simultaneously.
The present invention has overcome the many shortcomings in original aircraft guidance system.This aircraft landing landing guidance system adopts fixing beam signal, and signal is paired with respect to the landing course line that lands, and by counterfeit noise modulated.Like this, when when emission signal spread on broadband, thereby improved the antijamming capability of system, and can reduce the possibility that is blocked.
Aircraft landing landing system among the present invention comprises a transmitter, and it sends a plurality of continuous waves, is the paired fixed beam signal of the landing line of flight that lands relatively, so that orientation and elevation information to be provided.Each fixed beam signal is all by different counterfeit noise code modulation, and to be created in transmitting of spread on the broadband, the counterfeit noise code of wherein each plays the particular beam after the identification modulation.One receiver (aircraft is contained) comprises that one follows the tracks of the annular correlator of incoherent delay synchronous code, it is synchronous with the noise code of received signal to be used for one of a plurality of counterfeit noise code that receiver is produced, the signal that receives with identification and demodulation (or narrowing down on frequency spectrum).This narrow spectrum signal is added to the square ring demodulator then, with amplitude and the therefrom information extraction of determining each narrow spectrum signal.One data guidances handle and show control to by the beam signal of demodulation to comparing, depart from the indication of desired landing landing course line so that aircraft to be provided.
More particularly, the system among the present invention comprises two emitters, a locating device and a glide slope indicating device.Locating device is launched four equifrequent continuous wave spread spectrum beam signals, and these signals are respectively right wing district wave beam, left sector beam, right precise guidance wave beam and left precise guidance wave beam.The glide slope indicating device is launched three equifrequent continuous wave spread spectrum beam signals, is respectively sector beam, upwards a precise guidance wave beam and a downward precise guidance wave beam.Receiver comprises that one follows the tracks of first annular correlator that postpones synchronous code and the square ring demodulator of handling received fixture signal, and one follows the tracks of second annular correlator that postpones synchronous code and the square ring demodulator of handling the glide slope indicator signal that receives simultaneously.
The counterfeit noise code that is used to modulate fixed beam is one group of mutually orthogonal sign indicating number, and the CDMA connected mode of transmitting channel is provided, to increase the number of the system of working simultaneously.Because the system among the present invention adopts continuous wave to send, rather than sequential pulse sends, then can be high as far as possible integrated, thereby improved the degree of accuracy of calculating based on the guidance of the beam signal amplitude that receives.Moreover, because it is relevant that all steady arm transmitting channels are carrier waves, and sign indicating number clock phase mutually synchronization, in case there is a channel to be switched on synchronously by counterfeit noise code, system just Be Controlled automatically follows the tracks of the signal that receives from other channels of device, and need not to carry out other connection process again.The situation of glide slope indicating device also is like this.
Above-mentioned and other purpose of the present invention, advantage and new feature, and the details situation of given embodiment can be familiar with more fully by following description and accompanying drawing.
Fig. 1 is the runway skeleton view, shows the glide slope of the landing of aircraft landing among the present invention guidance system and the position of steady arm transmitter installation, and the fixed beam that sends of these devices;
Fig. 2 is the block scheme of the transmitter of steady arm shown in Fig. 1;
Fig. 3 is the block scheme of receiver among the present invention;
Block scheme among Fig. 4 shows counterfeit noise code generator used in transmitter of the present invention and the receiver;
Block scheme among Fig. 5 shows the relevant device of annular of the incoherent delay synchronous code of the tracking shown in Fig. 3;
Figure among Fig. 6 a-c shows the related function of channel before and after the correlator among Fig. 5 respectively, and multiple correlation function one in front and one in back;
Fig. 7 is the block scheme of square ring demodulator among the present invention.
Spread spectrum aircraft landing guidance system among the present invention comprises that two transmitter installations, a positioner device 10 and a glide slope indicating device 12(are as shown in Figure 1), be used to guide the aircraft that has the receiver (see figure 3) along relevant with runway 16 center lines 14 and become the scheduled landing airline operation of a glide slope angle.Locating device 10 is positioned at the end of runway 16 center lines 14, launches four wave beams 18,19,20 and 21, so that the right side/left guidance information in the orientation of relative runway centerline 14 to be provided to the aircraft that is landing.Glide slope indicating device 12 is positioned on the runway 16 near the desired earth point, launches three wave beams 22,23 and 24, with on providing with respect to the glide slope angle vertical position to the aircraft that is landing/following guidance information.
Specifically, steady arm wave beam 18 and 19 is paired right and left sector beams, provides the orientation with respect to runway centerline 14 to be+35 ° of coverages with-35 °.Paired glide slope wave beam 22 and 23 is upper and lower precise guidance wave beams, provide approximately ± 10 ° orientation near the glide slope angle+1.5 ° of ratios to-1.5 ° of elevation coverages guide.Glide slope wave beam 24 is sector beams, and the false course protection can be provided in ± 35 ° of bearing ranges.Though steady arm sector beam 18 and 19 and glide slope sector beam 24 accurate not as precise guidance wave beam 20,21,22 and 23, sector beam can provide the navigation signal of angle than broad, enters the position that can obtain accurate guidance beam with vector aircraft.
18, the intensity of 19 and 20,21 each steady arm wave beam of wave beam centering is set like this, promptly through directly receiving the right side/left sector beam signal of equal strength (or amplitude) and the right side of equal strength (or amplitude)/left accurate guidance beam signal along center line 14 to the aircraft of runway 16 landing.And when aircraft during in center line 14-side direction runway 16 landing, right beam signal that aircraft receives or left beam signal intensity can be bigger than the intensity when the runway opposite side.Similarly, on/following glide slope wave beam 22 and 23 each intensity sets like this, promptly along glide slope straight to the aircraft of runway landing can receive equal strength or amplitude on/following accurate guidance beam signal; And to be greater than or less than glide slope angle when runway 16 landing, aircraft receives goes up or that the intensity of accurate guidance beam signal can be than another beam signal down is big.
Illustrate in more detail among steady arm emitter 10(Fig. 2) comprise crystal oscillator 26 once overbaking, the clock signal of 19MHz can be provided.The output of oscillator 26 is added on the multiplier 28,490 times of the clock signal frequencys multiplication of 19MHz can be become carrier signal to 9310MHz.This carrier signal is exaggerated the full transmit power level that reaches device after device 30 amplifies, and power loop divider 32 is coupled in its output.The latter provides the signal of constant power respectively to four output channels 34,36,38 and 40, produce left sector beam signal, left accurate guidance beam signal, right accurate guidance beam signal and right wing district beam signal.Specifically, the 9310MHz carrier signal in the passage 34,36,38 and 40 is added to respectively on balanced modulator 42,44,46 and 48, and the counterfeit noise code modulated carrier signal of The latter makes it in each passage spread on broadband.In the example shown, the modulation of carrier wave realizes by the phase-shift keying modulation, but, also can adopt other modulation systems, for example frequency shift keying modulation.
Advance the phase-shift keying (PSK) modulation in each output channel, producing two of carrier signal, be provided with respectively and four output channels, 40,38,36 and 34 corresponding four counterfeit noise code generators 50,52,54 and 56, the 19MHz clock signal of sending from oscillator 26 then is coupled on each generator 50,52,54 and 56, so that clock to be provided.Each counterfeit noise code generator 50,52,54 and 56 all produces identical cluster orthogonal sign indicating number, preferably balance Gold code (detailed description that sees below).Microprocessor 58 is then exported different sign indicating numbers simultaneously by the different starting condition control generators 50,52,54 and 56 in when starting.Output channel 34,36,38 and 40 CDMA connecting mode make antenna 60,62,64 and 66 can both launch the beam signal of continuous wave with same 9310MHz frequency simultaneously in each output channel.Because during guiding each transmitter output channel all in continuous working producing the beam signal of continuous wave, the measurement of carrying out in receiver (below discussion is arranged) is more accurate because the time of signal integration is long.
The 19MHz output of sending from oscillator 26 also is used for to number generator 68 timing watchs.Specifically, the signal of 19MHz is delivered to and oscillator clock signal can be divided on 1/190th, 000 the frequency divider 70, and the 100Hz clock signal of generation is delivered to number generator 68.The latter delivers in totalizer 72,74,76 and 78 each to data with the speed of 100 bps, asks mould 2 Hes, promptly each the output in data and counterfeit noise code generator 50,52,54 and 56 is added up.The mould 2 of data and each counterfeit noise code of sending from totalizer 72,74,76 and 78 and deliver to balanced modulator 48,46,44 and 42 again separately, 9310MHz carrier signal in each output channel 32 is carried out the phase-shift keying (PSK) modulation, with carrier signal spread on broadband.Same data have been comprised from the spread spectrum signal of antenna 60,62,64 and 66 emissions, but by different counterfeit noise code modulation, like this, with the counterfeit noise code of the signal launched effectively identification signal be right or left sector beam signal or right or left accurate guidance beam signal.What provide relevant aircraft landing guidance information is the intensity or the amplitude of the received beam signal of the aircraft of equipment receiver (below discussion is arranged).The data that comprise in transmitting may be relevant with navigation, also may have nothing to do.For example, data can comprise the information of relevant runway 16 length, perhaps comprise the instruction to the aviator, near the information of the ongoing activity perhaps relevant runway.
The drawn positioner device remainder of glide slope indicating device 12 and Fig. 2 is identical, be used power divider be three the tunnel, with each the 9310MHz carrier signal that provides power to equate in three delivery channels.Each delivery channel all is coupled with one of three counterfeit noise code generators, modulo 2 adder and balanced modulators.Given this, glide slope indicating device 12 is not shown specifically.The carrier signal of glide slope indicating device 12 does not have with the carrier signal of steady arm transmitter installation 10 synchronous.This is an advantage, because positioner device 10 and glide slope indicating device 12 common wide aparts require the communication between synchronous two devices of words needs.But, if the common carrier signal wave is arranged, stream oriented device can use this common signal source.
Receiver among the present invention (shown in Figure 3) places on the aircraft, and effect is the landing landing airline aircraft of vector aircraft along desired relative runway 16.The spread spectrum that the receiving antenna 80 of receiver receives 9310MHz transmits, and delivers to low-converter 82.The latter has the local oscillator frequency of 9234MHz, is produced by the crystal oscillator 84 through baking, and intermediate frequency (IF) signal of 76MHz is provided.The frequency of oscillator 84 outputs is selected like this, and promptly the output frequency of low-converter is the multiple of transmitter 19MHz clock signal, with the tracking and the demodulation function of auxiliary receiver.The IF signal of 76MHz is delivered to the bandpass filter 86 that bandwidth is 19MHz.Bandpass filter 86 can improve the signal Processing gain of system, because noise bandwidth has been limited in 19MHz.After bandpass filter 86 was amplified, the IF amplifier 88 of the IF signal of 76MHz through having automatic gain (AGC) amplified.76MHz IF signal after the amplification is delivered to a steady arm correlator and demodulating equipment 90 and a glide slope correlator and demodulating equipment 92 again, and they are worked simultaneously to obtain and to follow the tracks of from the steady arm and the glide slope beam signal of steady arm and glide slope indicator transmitter installation 10 and 12 emissions.
Steady arm correlator and detuner 90 comprise that one follows the tracks of the annular correlator 94 of incoherent delay synchronous code, its effect be by with the specific counterfeit noise code of a channel synchronously to obtain one of steady arm delivery channel 60,62,64 or 66.It realizes that by seeking to be correlated with in the counterfeit noise code of input IF signal and the generation of this machine wherein the signal generation rate of the counterfeit noise code generator of this machine changes a little, makes it to run into the IF signal of input.In case the counterfeit noise code that this machine produces and the IF Signal Matching of input are followed the tracks of the annular correlator of incoherent delay synchronous code and are just exported the signal that a frequency spectrum narrows down, and deliver to square ring demodulator 98.Square ring demodulator 98 is finished carrier synchronization, carrying out the relevant amplitude detection of IF signal, and extracts data from signal.
The annular correlator 96 and the detuner 92 of the incoherent delay synchronous code of tracking of glide slope indication correlator are identical with the working method of correlator 94, with by specific counterfeit noise code reaches one of three delivery channels of glide slope indicator synchronously with it.After realizing synchronously, glide slope beam signal frequency spectrum narrows down and is added on the square ring demodulator 100; The latter is identical with the working method of detuner 98, promptly realizes carrier synchronization, to detect glide slope beam signal amplitude and to extract data.
Deliver to automatic gain control from the expression of detuner 98 and 100 outputs through the signal of the beam signal amplitude of synchronous and tracking, the latter controls the gain of IF amplifier 88 under the mode transfer formula, make gain by desired signal but not disturb and to set, in the channel acquisition process, one obtain/follow the tracks of/obtain the gain of controller 108 again, with auxiliary acquisition process by automatic gain controller 105 control amplifiers 88.
From square ring demodulator 98 and 100 output expression steady arm beam signals and the signal of glide slope beam signal amplitude also deliver to comparer 106, with reference voltage V
TRelatively.Comparer 106 is used for determining when that correlator 94 and 96 realizes synchronously, and realize one indicator signal of back output synchronously to obtain/follow the tracks of/obtain controller 108 again.The counterfeit noise code generator of this machine of correlator 94 and 96 sent into relevant with a glide slope delivery channel with a steady arm delivery channel respectively original state vector respectively by controller 108, and in correlator 94 and 96 further control code generator Phase advance, determine to have finished synchronously until comparer 106.In case steady arm correlator 94 has obtained a steady arm delivery channel, just need not repeat acquisition process, relevant because the steady arm delivery channel is a carrier wave, and the sign indicating number clock is the phase mutually synchronization.Obtain/follow the tracks of/obtain again controller 108 and only will be input to the counterfeit noise code generator 94 of correlator 94, and correlator will be from this signal of motion tracking next steady arm transmitter delivery channel proper state vector.Similarly, in case a glide slope delivery channel is acquired, second and third glide slope delivery channel then is acquired pack into the counterfeit noise generator of correlator 96 of proper state vector by controller 108.
Data and amplitude information from steady arm and glide slope indication correlator and decoupling zero apparatus 90 and 92 are sent to data guidance processing and display controller 102.The latter is for two paired beam signals, and for example right and left accurate guidance beam signal is made response, and to determine the relative position of aircraft to desired landing landing course line, promptly aircraft is in right side, the left side of runway centerline 14 or faces.This is relatively realized by the paired beam signal amplitude of carrying out with wherein storage by controller 102.If one amplitude of a pair of beam signal is bigger than another, just controller 102 can be determined the desired line of flight that aircraft has departed from so, promptly in the right side or the left side of runway centerline, perhaps on the glide slope angle or under.In a single day controller 102 has determined the relative position of aircraft to the desired landing landing line of flight, just controls display 104 and demonstrates aircraft aligning or off-line situation.Similarly, the data output of controller 102 decoding steady arms and glide slope modem device 90 and 92 and control display 104 demonstrate adequate information.Data guidances is handled and is shown that control 102 can be a microprocessor control, obtains/follows the tracks of/obtain the part that the microprocessor of controller 108 controls again or separate with it as formation.Have, display can be used in the conventional ILS system again, perhaps has the CRT of the complex figure of describing guidance information and data.
According to the present invention, owing to utilized the channel CDMA connecting mode of cluster orthogonal sign indicating number, each delivery channel of one or more spread spectrum aircraft landing systems all can be worked simultaneously, with the same frequency emission continuous wave beam signal of 9310MHz.Adopted balance Gold code in most preferred embodiment, the Gold sign indicating number is to be formed by the cluster that the nodulo-2 addition of paired preferred maximum length sequence produces equal length.Whole members of cluster sign indicating number are at local auto-correlation peak and peak, mutual pass is all had identical boundary.Balance Gold code is meant that the number of " 1 " Duos 1 just than the number of " 0 ".Balance Gold code has than the superior spectral property of non-equilibrium sign indicating number, is best therefore.
The counterfeit noise code generator that produces balance Gold code is shown among Fig. 4, and it is suitable for steady arm and glide slope indicator emitter 10 and 12, and in the glide slope correlator and modem device 90 and 92 of steady arm and receiver.Counterfeit noise code generator comprises two 11 grades linear feedback shift register 110 and 112, and its output on online 114 and 116 is sent on the modulo 2 adder 118, produces balance Gold code on online 120.The generator polynomial expression of shift register 110 is:
f（X）＝1+X
2+X
3+X
4+X
6+X
7+X
9+X
10+X
11，
The the 2nd, 3,4,6,7,9,10 and 11 grade of mould 2 summed result that item is a totalizer 122 wherein, its output is fed back to the input of shift register 110.The generator polynomial expression of shift register 112 is:
G（X）＝1+X
2+X
11
Wherein the 2nd and 11 grade of mould 2 summations that item is a totalizer 124, its output is fed back to the input of shift register 112.The starting condition of shift register 112 be except that the 11st grade all the level all comprise one 0 and the 11st grade comprise one 1.And being the 11st grade, unique starting condition of shift register 110 comprises one 0.Because 1 to 10 grade of shift register 110 can have 2
10Or 1024 kinds may be made up, so the counterfeit noise generator of Fig. 4 can produce 1024 different balance Gold codes.The counterfeit noise generator of Fig. 4 can be used in as many as 1024/7 or 146 systems of working simultaneously, each system's emission 7 beam signal (4 steady arms and 3 glide slope beam signals), wherein each beam signal has the different balance Gold code that interrelates with it.Concerning the system with more carry digits, the system that can work simultaneously also can be more, and use short shift register can realize fewer purpose work system simultaneously.
Following the tracks of the annular correlator 94 and the 96(details of incoherent delay synchronous code sees shown in Figure 5) comprise preceding channel 130, one back channels 132, and a working time channel 134, be added with IF signal output respectively from the 76MHz of IF amplifier 88.76MHz IF signal in the forward and backward channel 130 and 132 is respectively by the counterfeit noise code modulation in the front and back of a counterfeit noise code generator 138 of machine.Specifically, the output of counterfeit noise code generator 138 is coupled on the shift register 139, its (n-1) level output 140 is added to-low-pass filter 142 of 9.5MHz on, counterfeit noise code before a balanced modulator 144 provides one, the 76NHz IF signal before being used for modulating in 146 of channel 130.The n level of shift register 139 output 146 is sent to-low-pass filter 148 of 9.5MHz, produce the counterfeit noise code in a back, and deliver to a balanced modulator 150, be used for modulating the 76MHz IF signal of back channel 132.
The back counterfeit noise code that is added to modulator 150 is identical with the preceding counterfeit noise code that is added to modulator 144, but has postponed a substrate width in time.This point can be found out by the back channel related function shown in the preceding channel related function shown in Fig. 6 a and Figure 66.The width of each triangle peaks all is 2Tc, and Tc is the width of yard substrate here, and the height that each peak leaves the peak dot level relatively is 2 to the counterfeit noise code that Fig. 4 generator produces
11=66.2dB.The effect of correlator 94 and 96 delay locked loop 151 is that correlator channel output in the past deducts back correlator channel output, to produce the function of functions with trace point 136 as shown in Figure 6.
When synchronous, keep synchronous by trace point 136 work at the multiple correlation function by ring 151 with the counterfeit noise code of spread 76MHz IF signal for the counterfeit noise code that produces when this machine.Specifically, when the counterfeit noise code of any and 76MHz IF signal in the front or rear counterfeit noise code during a substrate width inter-sync, balanced modulator 144,150 can be exported a sharp-pointed relevant peaks, deliver to the bandpass filter 152 and 154 of 8KHz respectively from this relevant peaks of balanced modulator 144,150 output, constitute rearmounted correlator IF bandwidth.Narrow-band pass filter is very important to the signal Processing gain that obtains desired system, should be too narrow to be large enough to hold any frequency displacement that may occur and to get final product.Envelope detector 156 and 158 are delivered in wave filter 152 and 154 output respectively, and the paraphase and the non-inverting input terminal of an operational amplifier 160 delivered in the latter's output more respectively.Amplifier 160 deducts the back channel signal in the channel signal in the past, and the output voltage that is produced adds to a tracking loop mode filter 162, and the latter constitutes a low-pass filter.A voltage-controlled oscillator 164 is delivered in the output of wave filter 162, and the latter is provided with the clock repetition rate of counterfeit noise code generator 138.Change the output of voltage-controlled oscillator 164 according to the difference signal of amplifier 160 output, just can hold the variation that occurs in Doppler shift and transmitting oscillator 26 outputs.
After receiver is opened, obtain/follow the tracks of/obtain again controller 108 the original state vector is sent into counterfeit noise code generator 138, and make it in half substrate width of every section quiet hour Td end stepping, realized synchronously until aforementioned comparer 106 definite its.The original state vector one of can the corresponding counterfeit noise code that is for example produced by positioner device or glide slope indicating device code generator.Quiet hour, Td selected like this, and is promptly long to allowing square ring demodulator 98 and the 100 acquisition frequency spectrums signal that narrows down.After occurring synchronously, the counterfeit noise code of time domain that is added on the balanced modulator 166 is just accurately mated with the counterfeit noise code that is used for spread input IF signal.The time domain sign indicating number that is added on the modulator 166 is postponed to be obtained after half substrate width by a delayer 168 by the output of (n-1) of shift register 140 level.It promptly is the time domain sign indicating number that a low-pass filter 170 its outputs of back are delivered in the output of delayer 168.With the counterfeit noise code of time domain after synchronous and after importing the IF signal multiplication, the counterfeit noise code that is used for spread input IF signal just has been removed with balanced demodulator 166.Data with counterfeit noise code exclusive-OR in steady arm/glide slope indicator emitter are retained on the carrier wave, so time domain correlator channel 134 is to have two frequency spectrums that advance the phase-shift keying (PSK) data-modulated IF signal that narrows down from the output of 8KHz bandpass filter 172.
Deliver to square ring demodulator shown in Figure 7 98,100 from the frequency spectrum of annular correlator 94,96 output of the following the tracks of incoherent delay synchronous code signal that narrows down.Specifically, the 76MHz IF signal that frequency spectrum narrows down is sent to frequency multiplier 174, the also available squaring circuit representative of the latter.Frequency multiplier 174 produces in order to finish the carrier signal of relevant amplitude detection.Because the signal of phase-shift keying (PSK) modulation has suppressed carrier, frequency multiplication or square process in, signal will remove all phase-shift keying (PSK)s modulation, and produce the carrier wave of a doubled frequency.It should be noted that,, will produce a DC component if replace frequency multiplier 174 with squaring circuit.The latter need remove with the way of unsteady flow coupling or the way of high-pass filtering.
The 152MHz signal of frequency multiplier 174 outputs is sent to the input end of phaselocked loop 176, and phaselocked loop comprises a balanced mixer 178, and its output is coupled to voltage-controlled oscillator 182 by a loop filter 180.When phaselocked loop 176 is lockable, its energy sustaining voltage, control generator 182 is locked into the signal of 152MHz.Because the carrier signal that phaselocked loop produces has 90 ° of phase differential with the phaselocked loop input signal on phase place, so need one 90 ° phase compensation.This compensation is realized that by 90 ° of phase shifters 184 its output produces relevant AM modulation with the 152MHz output multiplication of balanced mixer 186 with frequency multiplier.The output of balanced mixer 186 is sent to a low-pass filter 188, and the amplitude of received signal is represented in the latter's output.The data guidance is handled and display controller 102 utilizes this signal of representing amplitude generation one to depart from the indication of the desired line of flight about aircraft.
The output of phaselocked loop 176 also is sent to a frequency-halving circuit; To reproduce the carrier signal of a frequency domain.The output of frequency divider 190 is sent to a balanced mixer 192, the latter is the frequency spectrum of frequency domain carrier signal and the input IF signal multiplication that narrows down, to recover the data that phase-shift keying (PSK) has been modulated.The output of balanced mixer 192 is sent to-low-pass filter 194 of 150Hz, produce data with the speed of 100 of per seconds, deliver to that the data guidance is handled and display controller 102 in.Can see that in the restore data, amplitude also can be determined simultaneously the 76MHz IF signal that narrows down from frequency spectrum, because these processes are quadratures.This point is different with original system, is that data pulse replaces control pulse in the original system, and they are constantly processed in difference respectively.
Spectral spreading aircraft landing guiding systems processed among the present invention has not only reduced the possibility that the signal launched from locator and glide slope device indicating is blocked, but also improved anti-interference ability, come compared with original system, system is difficult for being disturbed, and can work under the intensive environment of signal. Have again, because the output channel has adopted can work the simultaneously number of system of CDMA connecting mode greatly to increase, increase to 146 such systems (this number is decided by the length of the shift register that system adopts). The direct spectral spreading technology of counterfeit noise among the present invention can be decomposed easily, to seek more protection. After the sensitiveness of system was compressed to multichannel, guiding accuracy can further improve.
Claims (19)
1, an aircraft guidance system is characterized in that it comprises:
Launch the emitter of at least two paired continuous wave signals of the relative line of flight with fixed beam, described emitter comprises with the different pseudo noise sign indicating number modulates in the described signal each, to be created in the device of the modulation signal of spread on the broadband;
The contained guidance device that is used for vector aircraft along described line of flight flight on the aircraft, described guidance device comprise that being used to receive the described signal beam of being modulated also uses each the received device that is subjected to modulation signal of counterfeit noise code demodulation that interrelates with it;
Be used for determining each described device of being modulated signal amplitude; And
Be used for the more described signal amplitude of being modulated to determine the device of the situation that departs from the described line of flight.
2, the aircraft guidance system of statement in the claim 1, the wherein said signal frequency of being sent by emitter is identical, and described counterfeit noise code is mutually orthogonal;
3, the aircraft guidance system of statement in the claim 1, wherein said signal frequency of being launched by emitter is identical, and described counterfeit noise code is the Gold sign indicating number.
4, the aircraft guidance system of statement in the claim 3, wherein said counterfeit noise code is a balance Gold code.
5, the aircraft guidance system of statement in the claim 1, wherein said modulating device comprises a plurality of counterfeit noise code generators, each all interrelates with a different beams, described counterfeit noise code generator produces the sign indicating number of same cluster constantly in difference, like this, described modulating device can be modulated each wave beam with the different sign indicating numbers of same cluster sign indicating number.
6, the aircraft guidance system of statement in the claim 1, wherein said emitter is included in the device of four fixed beams of the orientation emission continuous wave form of relative runway centerline, wherein two wave beams are represented the sector beam in runway right side and left side, in addition the accurate guidance beam in two representative runway right sides and left side.
7, the aircraft guidance system of statement in the claim 6, wherein said emitter comprises the device with No. four power dividers that can produce four same frequency carrier signals, and modulates described four carrier signals to produce the device of four orientation wave beams respectively with different counterfeit noise code signals.
8, the aircraft guidance system of statement further comprises a number generator in the claim 7; Produce the device of four mutually orthogonal counterfeit noise code simultaneously and with each described counterfeit noise code of described data exclusive-OR to produce the device of described different pseudo noise coded signal.
9, the aircraft guidance system of statement in the claim 7, wherein said modulating device comprises and is used for the device that phase-shift keying (PSK) is modulated each described carrier signal.
10, the aircraft guidance system of statement in the claim 1, wherein said transmitter is included in the interior device with three continuous wave forms emission fixed beams of elevation coverage of the glide slope angle of a relative line of flight, one of wave beam is represented the glide slope sector, in addition two upper and lower accurate guidance beams of the described glide slope angle of representative.
11, the aircraft guidance system of statement in the claim 6, wherein said emitter comprises the device of the three-way power divider with the carrier signal that can produce three same frequencys, and modulates described three carrier signals to produce the device of described three glide slope wave beams respectively with different counterfeit noise code signals.
12, the aircraft guidance system of statement in the claim 11, wherein said modulating device comprises and is used for the device that phase-shift keying (PSK) is modulated each described carrier signal.
13, the aircraft guidance system of statement also further comprises a number generator in the claim 11, be used for producing simultaneously the device of three mutually orthogonal counterfeit noise code, reach with each described counterfeit noise code of described data exclusive-OR to produce the device of described different pseudo noise coded signal.
14, the aircraft guidance system of statement in the claim 1, amplitude wherein determines that device comprises a square ring demodulator.
15, the aircraft guidance system of statement in the claim 1, wherein said modulating device comprises a number generator, be used for each is treated that modulation signal produces the device of different pseudo noise sign indicating number, and with each described counterfeit noise code of described data exclusive-OR think the modulation of described signal provide different counterfeit noise code with.
16, the aircraft guidance system of statement further comprises simultaneously and determines that with described amplitude device is from the described device that is extracted data the restituted signal in the claim 15.
17, the aircraft guidance system of statement in the claim 15, wherein said amplitude determines that device comprises a square ring demodulator, is used for determining simultaneously also therefrom to be extracted data by the amplitude of restituted signal.
18, the aircraft guidance system of statement in the claim 1, wherein said receiving trap comprises an AGC (automatic gain control) system, it determines that to described amplitude device responds, and adjusts the gain of described receiving trap according to the amplitude of described restituted signal.
19, the aircraft guidance system of statement further comprises the device that is used to produce the data-signal that is coupled with described modulating device in the claim 1, modulates described continuous wave signal with this data-signal.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US19528388A | 1988-05-17 | 1988-05-17 | |
| US195283 | 1988-05-17 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1038702A true CN1038702A (en) | 1990-01-10 |
Family
ID=22720794
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 89103321 Pending CN1038702A (en) | 1988-05-17 | 1989-05-17 | Spread spectrum aircraft guidance system |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN1038702A (en) |
| IL (1) | IL90141A0 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101101216B (en) * | 2006-07-05 | 2010-05-12 | 中国农业大学 | Navigation path identification method for cotton field medicament-spraying machine |
| WO2018077113A1 (en) * | 2016-10-28 | 2018-05-03 | 深圳市道通智能航空技术有限公司 | Method and apparatus for determining return direction, unmanned aerial vehicle, and computer readable storage medium |
| CN108725819A (en) * | 2017-04-14 | 2018-11-02 | 刘明成 | Coordinate type aircraft carrier ship-board aircraft landing airmanship |
-
1989
- 1989-05-01 IL IL90141A patent/IL90141A0/en unknown
- 1989-05-17 CN CN 89103321 patent/CN1038702A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101101216B (en) * | 2006-07-05 | 2010-05-12 | 中国农业大学 | Navigation path identification method for cotton field medicament-spraying machine |
| WO2018077113A1 (en) * | 2016-10-28 | 2018-05-03 | 深圳市道通智能航空技术有限公司 | Method and apparatus for determining return direction, unmanned aerial vehicle, and computer readable storage medium |
| CN108725819A (en) * | 2017-04-14 | 2018-11-02 | 刘明成 | Coordinate type aircraft carrier ship-board aircraft landing airmanship |
Also Published As
| Publication number | Publication date |
|---|---|
| IL90141A0 (en) | 1989-12-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4041391A (en) | Pseudo noise code and data transmission method and apparatus | |
| US6094162A (en) | Low-power satellite-based geopositioning system | |
| US6492945B2 (en) | Instantaneous radiopositioning using signals of opportunity | |
| US4346384A (en) | Remote object position and orientation locator | |
| GB2222922A (en) | Vehicle location system | |
| US6922166B2 (en) | System and method for distance measurement by inphase and quadrature signals in a radio system | |
| US4665404A (en) | High frequency spread spectrum positioning system and method therefor | |
| US4328548A (en) | Locator for source of electromagnetic radiation having unknown structure or orientation | |
| AU712975B2 (en) | GPS translator with spread spectrum pilot | |
| US4423419A (en) | Pulsed, pseudo random position fixing radio navigation method and system and the like | |
| EP0679906A1 (en) | Apparatus for measuring physical quantities related to relative movement between two objects | |
| CN112666517A (en) | Small unmanned aerial vehicle signal positioning system and method based on time difference measurement | |
| US6040801A (en) | Low duty cycle navigation system | |
| US3263231A (en) | Quantized hyperbolic navigation and communication system | |
| CN1038702A (en) | Spread spectrum aircraft guidance system | |
| US4325068A (en) | Loran-C signal processor | |
| US4367542A (en) | Phase shifting of waveforms | |
| CN211293246U (en) | Micro-deformation remote measuring system based on wireless synchronization technology | |
| GB2267623A (en) | Radio frequency ranging apparatus | |
| WO1985002023A1 (en) | High frequency spread spectrum positioning system and method therefor | |
| RU2030755C1 (en) | Radio-navigation system | |
| CN115598601A (en) | Frequency hopping signal receiving device and receiving method thereof | |
| US4047177A (en) | Doppler scanning guidance system receiver | |
| Fernandes et al. | Acquisition and Tracking of S-Band Signals of Navigation with Indian Constellation (NavIC) | |
| Dubose et al. | VHF navigation experiment |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C01 | Deemed withdrawal of patent application (patent law 1993) | ||
| WD01 | Invention patent application deemed withdrawn after publication |