CN107017965A - A kind of permanent envelope code modulating method of high-order applied to Unmanned Aerial Vehicle Data Link - Google Patents
A kind of permanent envelope code modulating method of high-order applied to Unmanned Aerial Vehicle Data Link Download PDFInfo
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- CN107017965A CN107017965A CN201710035667.9A CN201710035667A CN107017965A CN 107017965 A CN107017965 A CN 107017965A CN 201710035667 A CN201710035667 A CN 201710035667A CN 107017965 A CN107017965 A CN 107017965A
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- code
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- permanent envelope
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- unmanned aerial
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- 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
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- 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
- H04L1/0041—Arrangements at the transmitter end
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/18—Phase-modulated carrier systems, i.e. using phase-shift keying
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/18—Phase-modulated carrier systems, i.e. using phase-shift keying
- H04L27/20—Modulator circuits; Transmitter circuits
Abstract
The present invention relates to a kind of permanent envelope code modulating method of high-order applied to Unmanned Aerial Vehicle Data Link, belong to communication technical field.The present invention meets the check matrix H of permanent envelope constrained by constructing, and according to the relation of check matrix and generator matrix, calculating obtains generator matrix G；The code element u for needing to transmit is multiplied with generator matrix G, transmitted codewords c can be obtained；Transmitted codewords c is subjected to serioparallel exchange, Q is sent into2PSK modulators are modulated.Prior art is contrasted, the present invention can design the excellent LDPC code of error-correcting performance under the conditions of permanent envelope constrained is met, and code length is longer, and performance can be more excellent；The transmission requirement of the big data quantity under Unmanned Aerial Vehicle Data Link environment is disclosure satisfy that, there is higher band efficiency；Meet the reliable data transmission under the relatively low environment of signal to noise ratio.
Description
Technical field
The present invention relates to a kind of permanent envelope code modulating method of high-order applied to Unmanned Aerial Vehicle Data Link, belong to the communication technology
Field.
Background technology
With the continuous improvement of remote sensing technology, unmanned plane turns into study hotspot in recent years.As shown in figure 1, Unmanned Aerial Vehicle Data
Chain is the key for realizing information transfer between unmanned aerial vehicle onboard data terminal and ground control's control station, and it is a two-way communication
Link.Wherein up-link prevailing transmission earth station to unmanned plane telecommand；Downlink prevailing transmission unmanned plane is extremely
Remote measurement view data, track and localization data and the unmanned plane state parameter at face station etc., more be applied to battlefield remote real-time monitoring and
In terms of remote measurement.Downlink transmission data amount will be significantly larger than up-link, under Military Application background, to its data transfer
Real-time and reliability it is also proposed higher requirement.In addition, when unmanned plane works at a distance, to ensure image transmitting matter
Amount, it is desirable to which Airborne Terminal improves the power utilization of power amplifier as much as possible.Therefore, for Unmanned Aerial Vehicle Data catenary system, enter
Efficiently, reliably transmission data are particularly important row in downlink.
Unmanned Aerial Vehicle Data Link frequency spectrum resource is limited, and downlink needs the data volume of real-time Transmission larger, therefore research high frequency
The modulation-demodulation technique of spectrum utilization rate has particularly important meaning.In order to efficiently utilize band resource, it is necessary to consider high contrast
Scheme Q processed2PSK.The characteristics of program is using Data Profile pulse and transmission carrier wave pairwise orthogonal, creates a space-time
Signal so that its band efficiency is orthogonal phase modulation (Quadrature Phase Shift Keying, QPSK) and minimum
2 times of frequency shift keying (Minimum Shift Keying, MSK) both common modulation, are binary phase shift keying (Binary
Phase Shift Keying, BPSK) 4 times.
On the other hand, unmanned plane, to ensure image transmitting quality in downlink, is needed when remote, long endurance works
The power utilization of transmitting terminal power amplifier is improved as far as possible.Constant enveloped modulation is a Main Means for improving power amplifier utilization rate.
And only Q2When PSK modulation output signals have permanent envelope trait, Airborne Terminal could use B power amplifier；And Heng Bao
When can avoid passing through nonlinear channel amplitude-phase conversion effect occurs for network signal, it is to avoid introduce phase noise.Had research to
Construction Q is gone out2The constraints of PSK modulation output signals perseverance envelope, but the model is to sacrifice certain band utilization
Rate is that cost exchanges permanent envelope trait for.This is for the unmanned plane environment that frequency spectrum resource is limited, it is clear that be inapplicable.
Under modern electronic warfare environment, unmanned plane is worked in the electromagnetic environment of complexity.Anti-Jamming Technique is to ensure that communication
Link is rapid, accurate, secrecy, unimpeded key technology.Channel coding is a kind of conventional Anti-Jamming Technique, and it is in information code
A number of redundancy symbol is added, makes code word that there is error-detection error-correction ability, reliability of communication system can be improved.Low-density parity
Check code (Low-Density Parity Check Code, LDPC) is a kind of Error Correction of Coding mode of performance close to shannon limit,
There is higher coding gain compared with the conventional encoders such as convolutional code code scheme under the same terms.The randomness of LDPC check matrix causes
Itself there is the performance of anti-burst error, without introducing interleaver, the time delay that may be brought is reduced.These features make LDPC
Code has huge application prospect in the poor radio communication of channel condition.
Traditional LDPC check matrix design is main using the distribution of density evolution theory degree of certainty, complete using PEG algorithms
Into construction process.However, the check matrix designed by this way is unsatisfactory for above-mentioned condition.In order that Q2PSK modulators it is defeated
Going out signal has permanent envelope trait, and it is still 4 times of BPSK modulation, this hair that the band efficiency now improved by modulator is caused again
It is bright to propose a kind of LDPC codings and Q2The structure of PSK modulating cascades is ensureing that communication can as downlink transmitting terminal model
The high order modulation of permanent envelope is realized while by property, it has good applicability in Unmanned Aerial Vehicle Data downlink.
Structure of the invention by constructing LDPC check matrixes, makes LDPC encode output and meets Q2The constraints of the permanent envelope of PSK modulation.
The content of the invention
It is an object of the invention to provide a kind of permanent envelope code modulating method of high-order applied to Unmanned Aerial Vehicle Data Link, lead to
The structure of optimization LDPC check matrix is crossed, construction meets Q2The LDPC check matrix of PSK constant enveloped modulations constraint, so that real
Existing Q2PSK constant enveloped modulation, meets the data transfer demands of Unmanned Aerial Vehicle Data Link.
The purpose of the present invention is achieved through the following technical solutions：
A kind of permanent envelope code modulating method of high-order applied to Unmanned Aerial Vehicle Data Link, its step is as follows：
Step one, the check matrix H structure for meeting permanent envelope constrained is constructed by procedure below：
Wherein n is the code word size after encoding and the multiple for being 4, and H needs the condition met to be then to be divided into left and right two
Part, i.e. H=[A B], and B matrixes should meet reversible condition；HrandomIt is a random sparse matrix, En/4×nIt is one
Often row has 4 continuous 1, often shows the matrix of 11, is represented by and (can carry out column permutation)
If in order to which the check matrix (different from the Hc=0 of general significance, herein Hc=b) with general significance is united,
Augmentation check matrix H can also be constructedextend=[b H], wherein b=(1,1 ..., 1,0 ... 0)T, i.e., preceding n/4 positions value
For 1, remaining value is 0.
Step 2, by the above-mentioned check matrix H for meeting constraints, according to the relation of check matrix and generator matrix, meter
Calculation obtains generator matrix G；
Step 3, it would be desirable to which the code element u of transmission is multiplied with generator matrix G, can obtain transmitted codewords c；
Step 4, serioparallel exchange is carried out by transmitted codewords c, sends into Q2PSK modulators are modulated.
It is to complete a kind of permanent envelope coded modulation side of high-order applied to Unmanned Aerial Vehicle Data Link by aforementioned four step
Method.
Beneficial effect
Prior art is contrasted, the invention has the characteristics that：
1st, using the code modulating method that provides of the present invention, it disclosure satisfy that big data quantity under Unmanned Aerial Vehicle Data Link environment
Transmission requirement, there is higher band efficiency；
2nd, the code modulating method provided using the present invention, disclosure satisfy that the data under the relatively low environment of signal to noise ratio are reliable
Transmission；
3rd, the code modulating method provided using the present invention, can be on the premise of permanent envelope constrained condition be met, design
Go out the excellent LDPC code of error-correcting performance, and code length is longer, performance can be more excellent.
Brief description of the drawings
Fig. 1 is application environment --- the basic composition structure chart of Unmanned Aerial Vehicle Data Link of the present invention；
Fig. 2 is the CE-Q for being included serioparallel exchange step2PSK modulator structure schematic diagrames；
Fig. 3 is the Q for being included serioparallel exchange step2PSK modulator structure schematic diagrames；
Fig. 4 is the LDPC codings+Q of the present invention2PSK modulator models；
Fig. 5 is the traffic model of the specific embodiment of the invention one；
Fig. 6 is the traffic model of the specific embodiment of the invention two；
Fig. 7 be the present invention check matrix building method under different code length LDPC code BER Simulation result figure；
Fig. 8 is the permanent envelope code modulating method of high-order and LDPC+CE-Q of the present invention2PSK performance comparison figure.
Embodiment
The preferred embodiment of the present invention is described further with reference to Figure of description and embodiment.
Existing CE-Q2PSK modulator structures and Q2As shown in Figure 2,3, compare in figure to see PSK modulator structures
Go out, CE-Q2PSK is in order to meet the condition of permanent envelope, to being handled all the way among four road signals, equivalent to becoming three
Road signal, from analysis, this way sacrifices 1/4 band efficiency.The present invention realizes to solve this problem
The reliable and effective transmission of Unmanned Aerial Vehicle Data Link under low signal-to-noise ratio, by the constraint of permanent envelope on LDPC codings, passes through structure
The check matrix for meeting permanent envelope requirement is made, LDPC codings are carried out, then the code word after coding is sent into Q2PSK modulators are adjusted
System, realizes the high order modulation under permanent envelope requirement.LDPC codings+the Q of the present invention2PSK modulator models are as shown in Figure 4.
Illustrated below by two embodiments applied to the permanent envelope coded modulation side of the high-order of Unmanned Aerial Vehicle Data Link
The process of method.
Embodiment 1
Step one, construction meets Q2The LDPC check matrix of the permanent envelope constrained condition of PSK modulation.
Assuming that code word is c=(c after coding1,c2,...cn)T, code length be n and be 4 multiple, to meet the pact of permanent envelope
Beam, then the code word after four road Signal codings need meet
c4k+1+c4k+2+c4k+3+c4k+4=1 k=0,1 ..., n/4-1 (3)
Construct following check matrix
Wherein n is the code word size after encoding and the multiple for being 4, and the condition that H needs are met is then：It is divided into left and right two
Part, i.e. H=[A B], B matrixes should meet reversible condition.HrandomIt is a random sparse matrix, En/4×nIt is one every
Row has 4 continuous 1, often shows the matrix of 11, is represented by and (can carry out column permutation)：
It is different with general verification relation Hc=0, Hc=b herein, wherein b=(1,1 ..., 1,0 ... 0)T, i.e., preceding n/
4 position values are 1, and remaining value is 0.
Step 2, by the above-mentioned check matrix H for meeting constraints, according to generator matrix G and the relation of check matrix H
(formula 4), can try to achieve generator matrix G.
HGT=0 (4)
Step 3, it would be desirable to which the code element u of transmission is multiplied with generator matrix G, can obtain transmitted codewords c.
Assuming that needing the information word transmitted to be u, encoded according to c'=uG, separately there is code word known to oneMeetIt
After makeThe code word of this verification relation of Hc=b can be obtained meeting.Receiving terminal obtains c after successfully decoded, availableRecover raw information.Therefore cataloged procedure is equivalent to result after the quasi-cyclic LDPC code of standard coding and adds a fixation
Code wordProcess.During using this coded system, communication system block diagram is provided by Fig. 5.
Step 4, serioparallel exchange is carried out by transmitted codewords c, sends into Q2PSK modulators are modulated.
Meet the code word c=(c of certain rule by code construction1,c2,...cn)T, then obtain after serioparallel exchange four
Road parallel signal streamWith ForThe set of composition.By gained
Four road parallel signal feeding Q2PSK modulators are modulated, and modulator block diagram is as shown in Figure 3.Four road parallel signal streamsWithA i.e. in corresponding diagram 31(t)、a2(t)、a3(t)、a4(t), the road signals of Jiang Zhe tetra- are respectively fed to ht1(t) and
ht2(t) the originator formed filter group of this pair of pairwise orthogonals, by filtered four road signal respectively with two-way carrier wave cI(t) and
cQ(t) it is multiplied, obtains four tunnel modulated signal s1(t)、s2(t)、s3(t)、s4(t), the tunnel modulated signals of Jiang Zhe tetra- are added i.e. available
Final modulated signal
The high-order coded modulation process of the present invention leaves it at that, gained modulated signalFor Unmanned Aerial Vehicle Data Link
Data transfer.
Embodiment 2
Step one, construction meets Q2The LDPC check matrix of the permanent envelope constrained condition of PSK modulation.
Assuming that code word is c=(c after coding1,c2,...cn)T, code length be n and be 4 multiple, to meet the pact of permanent envelope
Beam, then the code word after four road Signal codings need meet
c4k+1+c4k+2+c4k+3+c4k+4=1 k=0,1 ..., n/4-1 (3)
Construct following check matrix
Wherein n is the code word size after encoding and the multiple for being 4, and the condition that H needs are met is then：It is divided into left and right two
Part, i.e. H=[A B], B matrixes should meet reversible condition.HrandomIt is a random sparse matrix, En/4×nIt is one every
Row has 4 continuous 1, often shows the matrix of 11, is represented by and (can carry out column permutation)：
It is different with general verification relation Hc=0, Hc=b herein, wherein b=(1,1 ..., 1,0 ... 0)T, i.e., preceding n/
4 position values are 1, and remaining value is 0.In order to which the check matrix with general significance is united, augmentation check matrix is constructed
Hextend=[b H], so as to meet HextendC=0.
Step 2, by the above-mentioned augmented matrix H for meeting constraintsextend, according to generator matrix G and the pass of check matrix H
It is (formula 4), corresponding G can be tried to achieveextend。
HGT=0 (4)
Step 3, it would be desirable to the code element u and generator matrix G of transmissionextendIt is multiplied, transmitted codewords c can be obtained.
Assuming that field to be encoded is u, u is takenextend=(1, uT)T, the G calculated using step 2extend, calculate cextend T
=uextend TGextend, then have Hextendcextend=0, wherein cextend=(1, cT)T.Only need to transmit c in communication process.
The input of receiving terminal ldpc decoder is r, and 1 bit information is added before r before decoding obtains rextend, utilize HextendDecoding.
During using this encoding and decoding algorithm, communication system block diagram is as shown in Figure 6.
Step 4, serioparallel exchange is carried out by code word c to be transmitted, sends into Q2PSK modulators are modulated.
Meet the code word c=(c of certain rule by code construction1,c2,...cn)T, then obtain after serioparallel exchange four
Road parallel signal streamWith ForThe set of composition.By gained
Four road parallel signal feeding Q2PSK modulators are modulated, and modulator block diagram is as shown in Figure 3.Four road parallel signal streamsWithA i.e. in corresponding diagram 31(t)、a2(t)、a3(t)、a4(t), the road signals of Jiang Zhe tetra- are respectively fed to ht1(t) and
ht2(t) the originator formed filter group of this pair of pairwise orthogonals, by filtered four road signal respectively with two-way carrier wave cI(t) and
cQ(t) it is multiplied, obtains four tunnel modulated signal s1(t)、s2(t)、s3(t)、s4(t), the tunnel modulated signals of Jiang Zhe tetra- are added i.e. available
Final modulated signal
The high-order coded modulation process of the present invention leaves it at that, gained modulated signalFor Unmanned Aerial Vehicle Data Link
Data transfer.
Fig. 7 is given using above-mentioned building method, and three groups of code lengths of construction are respectively 1024,4096,16384, and code check is
The BER Simulation result of 1/2 LDPC code.As can be seen from Figure, it is more uncoded when using code length for 4096 LDPC code
In the case of coding gain (bit error rate 10-6) reach more than 8dB.And simulation result shows, LDPC code code length is longer, performance meeting
It is more excellent.
Fig. 8 is the permanent envelope code modulating method of high-order and LDPC+CE-Q of the present invention2PSK performance comparison figure.Meng Teka
Lip river simulation result shows that bit error rate is 10-6When, code modulating method of the invention compares LDPC+CE-Q2PSK is poor about
0.82dB.But compared to LDPC+CE-Q2PSK, band efficiency of the invention improves 1/3.It is main in view of downlink
For transmitting video, view data, it is therefore contemplated that the reliability for sacrificing 0.82dB is acceptable (because exchanged higher for
Band efficiency).
Described above is presently preferred embodiments of the present invention, and the present invention should not be limited to the embodiment and accompanying drawing institute is public
The content opened.It is every not depart from the lower equivalent or modification completed of spirit disclosed in this invention, both fall within the model that the present invention is protected
Enclose.
In order to illustrate present disclosure and implementation, this specification gives a specific embodiment.In embodiment
The middle purpose for introducing details is not the scope for limiting claims, and is to aid in understanding the method for the invention.This area
Technical staff should be understood that：Do not departing from the present invention and its spirit and scope of the appended claims, to most preferred embodiment step
Various modifications, change or replacement be all possible.Therefore, the present invention should not be limited to disclosed in most preferred embodiment and accompanying drawing
Content.
Claims (2)
1. the permanent envelope code modulating method of a kind of high-order applied to Unmanned Aerial Vehicle Data Link, it is characterised in that comprise the following steps：
Step one, the check matrix H structure for meeting permanent envelope constrained is constructed by procedure below：
Wherein n is the code word size after encoding and the multiple for being 4, and H needs the condition met to be then to be divided into left and right two
Point, i.e. H=[A B], and B matrixes should meet reversible condition；HrandomIt is a random sparse matrix, En/4×nIt is one every
Row has continuous 41, often shows the matrix of 11；
Step 2, by the above-mentioned check matrix H for meeting constraints, according to the relation of check matrix and generator matrix, is calculated
To generator matrix G；
Step 3, it would be desirable to which the code element u of transmission is multiplied with generator matrix G, can obtain transmitted codewords c；
Step 4, serioparallel exchange is carried out by transmitted codewords c, sends into Q2PSK modulators are modulated.
2. a kind of permanent envelope code modulating method of high-order applied to Unmanned Aerial Vehicle Data Link according to claim 1, it is special
Levy and be：The H uses following augmentation check matrix Hextend=[b H], wherein b=(1,1 ..., 1,0 ... 0)T, i.e., before
N/4 positions value is 1, and remaining value is 0.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101305521A (en) * | 2004-07-27 | 2008-11-12 | Lg电子株式会社 | Method of encoding and decoding using low density parity check code |
| US20100310009A1 (en) * | 2009-06-09 | 2010-12-09 | Ismail Lakkis | Method and apparatus for constant envelope modulation |
| CN105900364A (en) * | 2013-10-01 | 2016-08-24 | 矿业电信学校联盟 | MAP decoding method using expanded point array |
-
2017
- 2017-01-17 CN CN201710035667.9A patent/CN107017965A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101305521A (en) * | 2004-07-27 | 2008-11-12 | Lg电子株式会社 | Method of encoding and decoding using low density parity check code |
| US20100310009A1 (en) * | 2009-06-09 | 2010-12-09 | Ismail Lakkis | Method and apparatus for constant envelope modulation |
| CN105900364A (en) * | 2013-10-01 | 2016-08-24 | 矿业电信学校联盟 | MAP decoding method using expanded point array |
Non-Patent Citations (1)
| Title |
|---|
| 张淑玲: "《基于LDPC编码的CE-OFDM波形性能研究》", 《舰船科学技术》 * |
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Application publication date: 20170804 |