CN114422033B - Optical fiber isolation communication method and system for onboard power supply of tethered unmanned aerial vehicle - Google Patents
Optical fiber isolation communication method and system for onboard power supply of tethered unmanned aerial vehicle Download PDFInfo
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Abstract
The invention provides a tethered unmanned aerial vehicle airborne power optical fiber isolation communication method and system, wherein the method comprises the following steps: the method comprises the steps of inputting original serial signal data, converting the original serial signal data into parallel data and sending out N discrete complex time domain signals; performing pilot frequency insertion; converting the parallel data into serial data and into an optical signal; then converted into parallel electric signals to obtain N discrete complex frequency domain signals X k Calculating N discrete complex frequency domain signals X k Corresponding received pilot time interval R of (1) k Determining a transfer function H for a transmitter to transfer frequency domain signals to a receiver k Superimposed frequency domain signal complex transfer function
For N discrete complex frequency domain signals X k Performing discrete Fourier transform to remove cyclic prefix inserted by pilot frequency to obtain received discrete complex frequency domain signal Y k,i The method comprises the steps of carrying out a first treatment on the surface of the And carrying out channel equalization to obtain restored original serial signal data. The invention has the advantages of high transmission speed, high isolation, strong anti-interference performance and good transient response.
Description
Technical Field
The invention belongs to the technical field of unmanned aerial vehicle power supplies, and particularly relates to a tethered unmanned aerial vehicle onboard power supply optical fiber isolation communication method.
Background
At present, with the wide application of unmanned aerial vehicles, the demands of various fields on unmanned aerial vehicles are increasing. And for certain fields, there is a long-time leaving operation demand, and the tethered unmanned aerial vehicle is generated. The tethered unmanned aerial vehicle is a multi-rotor unmanned aerial vehicle, and the existing tethered unmanned aerial vehicle is powered in a ground cable mode so as to solve the requirement of long-time reserved operation. The airborne power supply is used as unmanned aerial vehicle power supply equipment, noise interference needs to be well restrained in electromagnetic compatibility, and strict electrical isolation performance is achieved in input and output loops. The input end and the output end of the signal control loop have good real-time communication function, so that the stable closed-loop adjustment performance of the power loop can be realized. Whereas conventional signal isolation transmission generally employs optical coupling isolation and magnetic isolation, both of these isolation methods have their own drawbacks. The input and the output of the optical coupler have no direct electrical correlation, and have a certain isolation effect, but due to the inherent current transmission characteristic, the linearity and the precision of the optical coupler are poor when the optical coupler is used for transmitting analog signals, the response speed is low when the optical coupler is used for transmitting digital signals, and high-speed precise isolation transmission cannot be realized; the magnetic isolation circuit can only transmit alternating current signals, has low transmission rate and poor anti-interference performance, and cannot realize high-speed real-time isolation transmission.
Therefore, the isolation method for realizing high isolation performance and strong anti-interference capability has important application value for unmanned aerial vehicle power supply.
The airborne power supply belongs to a direct-current power supply, voltage and current detection signals, power supply temperature monitoring and fan control signals and power supply overvoltage and undervoltage protection control signals at input and output ends are weak, noise and environment interference are extremely easy to occur, if proper electrical isolation does not occur in the transmission process, measurement and control signals can be interfered, normal operation of a control circuit is affected, and even damage to the detection and control circuit is caused, so that flight safety of an unmanned aerial vehicle is affected. Whether each monitoring signal and control signal can be transmitted rapidly in real time or not determines the performance of the whole power supply. Therefore, the power supply design ensures both rapid signal transmission and a transmission circuit with electrically isolated input and output terminals, and is a key for realizing good control of the power supply.
Disclosure of Invention
Aiming at the defects, the invention provides the tethered unmanned aerial vehicle onboard power supply optical fiber isolation communication method which can ensure that the transmitted data can be correctly restored at the receiving end, can effectively inhibit noise accumulation and improve the signal anti-interference capability.
The invention provides the following technical scheme: an optical fiber isolation communication method for an onboard power supply of a tethered unmanned aerial vehicle comprises the following steps:
s1: original serial signal data input, converting into parallel data and transmitting N discrete complex time domain signals x n ；
S2: for N discrete complex time domain signals x n Pilot insertion is performed periodically in each discrete complex time domain signal x n Pilot time interval P transmitted on subcarriers of (a) k ；
S3: converting the parallel data into serial differential digital electric signal data, converting the differential digital electric signal data into analog electric signal data, and converting the analog electric signal data into optical signals which are used as the optical signals sent by a transmitter;
s4: after receiving the optical signal sent by the transmitter in the step S3, converting the optical signal into an electric signal, converting the electric signal into serial differential digital electric signal data, demodulating the serial differential digital electric signal data into parallel electric signals, and obtaining N discrete complex frequency domain signals X k Calculating N discrete complex frequency domain signals X k Corresponding received pilot time interval R of (1) k Determining a transfer function H for a transmitter to transfer frequency domain signals to a receiver k And further calculates a complex transfer function of the superimposed frequency domain signal formed by superimposing the frequency domain signals transferred by the transmitter and the receiver
For N discrete complex frequency domain signals X k Performing discrete Fourier transform to remove cyclic prefix of pilot frequency insertion to obtain kth subcarrier X coded to ith pilot frequency time interval in M pilot frequency time intervals k,i On a received discrete complex frequency domain signal Y k,i ；
S5: channel equalization is carried out to obtain received frequency domain complex data d' which is equalization coded on each subcarrier k,i To obtain the restored original serial signal data,and the tethered unmanned aerial vehicle airborne power supply optical fiber isolation communication is completed.
Further, in the step S2, a pilot time interval P k At a known amplitude A k And phase theta k Periodically transmit on each subcarrier:
k represents the kth subcarrier, k=1, 2,3, …, N s 。
Further, the N discrete complex time domain signals x input in the step S4 n Adopts Hermite symmetry to arrange, and further obtains a discrete complex frequency domain signal X k The calculation formula is as follows:
wherein,,
further, the pilot time interval R is received in the step S4 k The method comprises the following steps:
wherein B is k And phi k Representing the amplitude and phase, W, of the sub-carriers received by the receiver, respectively k Is the noise component of the kth subcarrier after the receiver fourier transform FFT, k representing the kth subcarrier.
Further, the S4 step transmitter and receiver transfer frequency domain signal transfer function H k The calculation formula is as follows:
wherein A is k And theta k Kth subcarriers of a signal transmitted by a known transmitter, respectivelyAmplitude and phase, B k And phi k Respectively representing the kth subcarrier amplitude and phase of the signal received by the receiver, R k For receiving pilot time intervals.
Further, the step S4 calculates a complex transfer function of the superimposed frequency domain signal formed by superimposing the frequency domain signals transferred by the transmitter and the receiver
The following are provided:
wherein,,
pilot time interval for the transmitted superimposed frequency domain signal, < >>
For the pilot time interval of the received superimposed frequency domain signal, i is the i-th pilot time interval, i=1, 2, …, M, P C Is the constant power of the receiver.
Further, the fourier transform of the step S4 includes the steps of:
s401: for the kth subcarrier X coded to the ith pilot time interval in M pilot time intervals k,i Identifying the k+iN superimposed therewith s Sub-carriers
Complex conjugate value +.>
S402: the complex conjugate value calculated by the step S401
Determining the average pilot time interval total number N by adopting a preset integer C s The received scattered signals in the M pilot time intervals are obtained, and the received scattered complex frequency domain signals Y in the M pilot time intervals are encoded on the kth subcarrier of the ith pilot time interval k,i ：
Further, the step S5 includes the steps of:
s501: for the received discrete complex frequency domain signal Y encoded on the kth subcarrier of the ith pilot time interval in the M pilot time intervals obtained in the step S4 k,i Calculating a received discrete complex frequency domain correction signal d 'encoded on a kth subcarrier of an ith pilot time interval over M pilot time intervals' k,i ：
Wherein G is k,i And theta k,i The amplitude and phase of the encoded data on the kth subcarrier, gamma (t) =, encoded to the ith pilot time interval, respectively; t (T) b Is the pilot time interval period, f k Is the frequency of the kth subcarrier;
s502: the S4 step is utilized to calculate the complex transfer function of the obtained superposition frequency domain signal
Calculating to obtain received frequency domain complex data d' which is equilibrium coded on each subcarrier k,i ：
The invention also provides a tethered unmanned aerial vehicle airborne power supply optical fiber isolation communication system adopting the method, which comprises an optical fiber transmitter serving as a control end and an optical fiber receiver serving as a monitoring end; the optical fiber transmitter comprises a data access port for accessing serial data, a transmitter FPGA coding module, a transmitter SERDES module serving as a parallel/serial data converter, a digital-to-analog converter and an electromechanical/optical converter; the optical fiber receiver comprises a receiver serial data receiving port for outputting the restored original serial signal data, a receiver FPGA coding module, a receiver SERDES module used as a parallel/serial data converter, an analog-to-digital converter and a receiver optical/point converter; the receiver optical/electrical converter receives the optical signal converted by the electromechanical/optical converter.
Further, the FPGA encoding module encodes and converts the parallel data of 8B into parallel data of 10B.
The beneficial effects of the invention are as follows:
1. the invention aims at the problem of transmission performance of the traditional scheme, and the scheme combines digitization and optical fiber isolation, adopts SERDES technology, converts low-speed parallel signals into high-speed serial signals, performs optical fiber signal isolation transmission, can complete point-to-point high-speed two-wire serial communication, demodulates serial signals into low-speed parallel signals at a receiving end (monitoring end), and realizes bidirectional real-time high-speed transmission of high-low-voltage side signals.
2. The invention can ensure that the transmitted data can be correctly recovered at the receiving end, can effectively inhibit noise accumulation and improve the anti-interference capability of signals.
3. The method adopts 8B/10B coding to process parallel data, and converts the parallel data into serial data to be sent out. And the receiving end converts the received serial data into parallel data and then decodes the parallel data to obtain effective parallel data, thereby completing high-speed signal transmission.
4. The invention converts low-speed parallel data into high-speed serial differential data at a transmitting end by arranging SERDES modules in a transmitter and a receiver, and also restores the high-speed serial data into low-speed parallel data at a receiving end. Serial data does not have an independent clock line, and a clock is embedded in a data stream, so that the problem of signal clock offset for limiting the data transmission rate is effectively solved; the high-speed serial differential data has strong noise resistance and interference resistance in transmission, the SERDES implementation adopts a double-edge (DDR) working mode, and the area speed-changing strategy is utilized to reduce the proportion of high-frequency circuits in the circuit, so that the power supply noise is reduced.
5. The method provided by the invention has the advantages of high transmission speed, high isolation, strong anti-interference performance and good transient response.
Drawings
The invention will be described in more detail hereinafter on the basis of embodiments and with reference to the accompanying drawings. Wherein:
FIG. 1 is a schematic flow chart of a method for optical fiber isolation communication of a tethered unmanned aerial vehicle on-board power supply;
fig. 2 is a schematic diagram of a parallel data encoding flow provided by the present invention.
Fig. 3 is a schematic structural diagram of a tethered unmanned aerial vehicle on-board power supply optical fiber isolation communication method.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Example 1
As shown in fig. 1, a flowchart of a method for optical fiber isolation communication of a power supply on board a tethered unmanned aerial vehicle according to the present embodiment is provided, where the method provided in the present embodiment includes the following steps:
s1: the original serial signal data is input to a transmitter, the transmitter receives the serial signal data and converts the serial signal data into parallel data, and the parallel data is processed by a transmitter FPGA control module and then sends N discrete complex time domain signals x n ；
S2: the transmitter FPGA module is used for transmitting N discrete complex time domain signals x n Pilot insertion is performed periodically at each discrete locationComplex time domain signal x n Pilot time interval P transmitted on subcarriers of (a) k ；
S3: for the pilot frequency inserted data, a parallel/serial data converter (a transmitter SERDES module) of the transmitter converts low-speed parallel data into high-speed serial differential digital electric signal data, the differential digital electric signal data is converted into analog electric signal data through a digital-to-analog converter, and the analog electric signal data is converted into an optical signal through an electric/optical converter to be used as an optical signal sent by the transmitter;
s4: after receiving the optical signal sent by the transmitter in the step S3, the receiver converts the optical signal into an electrical signal through an optical/electrical converter pair, then converts the electrical signal into high-speed serial differential digital electrical signal data through an analog-to-digital converter, and a parallel/serial data converter (a receiver SERDES module) of the receiver demodulates the high-speed serial differential digital electrical signal data into low-speed parallel electrical signals to obtain N discrete complex frequency domain signals X k The FPGA module of the receiver calculates N discrete complex frequency domain signals X k Corresponding received pilot time interval R of (1) k Determining a transfer function H for a transmitter to transfer frequency domain signals to a receiver k And further calculates a complex transfer function of the superimposed frequency domain signal formed by superimposing the frequency domain signals transferred by the transmitter and the receiver
The frequency domain signal is superimposed as the kth subcarrier and the kth+iN s The superposition frequency domain signal formed by the subcarriers, i is the ith pilot time interval, i=1, 2, …, M; for N discrete complex frequency domain signals X k Performing discrete Fourier transform to remove cyclic prefix of pilot frequency insertion to obtain kth subcarrier X coded to ith pilot frequency time interval in M pilot frequency time intervals k,i On a received discrete complex frequency domain signal Y k,i ；
S5: channel equalization is performed to obtain received frequency domain complex data d' which is equalization coded onto each (kth) subcarrier k,i And obtaining restored original serial signal data, and completing the optical fiber isolation communication of the onboard power supply of the tethered unmanned aerial vehicle.
The input/output end voltage and current monitoring signals, the power supply temperature monitoring signals, the undervoltage overvoltage protection signals and the like are converted into a digital signal through A/D to be one-path parallel data, the coded parallel data are converted into serial data at a transmitting end through SERDES, and then the serial data are modulated into optical signals through a photoelectric converter and transmitted to a control side low-voltage end through optical fibers. The photoelectric converter at the control chip end restores the received optical signal into an electric signal, then the electric signal is converted into parallel data by SERDES, and the parallel data is received and processed by the control end after decoding. Likewise, the control signal of the control terminal can be reversely transmitted in the same manner. Thereby achieving point-to-point bi-directional high-speed transmission communication.
In order to determine CTF at subcarrier frequency, in the step S2, a pilot time interval P k At a known amplitude A k And phase theta k Periodically transmit on each subcarrier:
k represents the kth subcarrier, k=1, 2,3, …, N s 。
S4N discrete complex time domain signals x input in step n Arranged with hermite symmetry to encode N discrete complex time domain signals x n Is applied to
Positive frequency units and applying complex conjugates to the corresponding +.>
A negative frequency unit to obtain a discrete complex frequency domain signal X k The calculation formula is as follows:
wherein,,
time interval R of pilot frequency reception in S4 step k The method comprises the following steps:
wherein B is k And phi k Representing the amplitude and phase, W, of the sub-carriers received by the receiver, respectively k Is the noise component of the kth subcarrier after the receiver fourier transform FFT, k representing the kth subcarrier.
S4 step transfer function H of transmitter and receiver transferring frequency domain signal k The calculation formula is as follows:
wherein A is k And theta k The k-th subcarrier amplitude and phase of the transmitted signal of the known transmitter, B k And phi k Respectively representing the kth subcarrier amplitude and phase of the signal received by the receiver, R k For receiving pilot time intervals.
S4, calculating a superimposed frequency domain signal complex transfer function formed by superimposing the frequency domain signals transferred by the transmitter and the receiver
The following are provided:
wherein,,
pilot time interval for the transmitted superimposed frequency domain signal, < >>
For the pilot time interval of the received superimposed frequency domain signal, i is the i-th pilot time interval, i=1, 2, …, M, P C For constant power of the receiver, the second equal sign post represents the accessThe receiver will have constant power P C Pilot subcarriers formed by the M pilot time intervals are allocated.
The fourier transform of step S4 comprises the steps of:
s401: for the kth subcarrier X coded to the ith pilot time interval in M pilot time intervals k,i Identifying the k+iN superimposed therewith s Sub-carriers
Complex conjugate value +.>
S402: the complex conjugate value calculated by the step S401
Determining the average pilot time interval total number N by adopting a preset integer C s The received scattered signals in the M pilot time intervals are obtained, and the received scattered complex frequency domain signals Y in the M pilot time intervals are encoded on the kth subcarrier of the ith pilot time interval k,i ：
The step S5 comprises the following steps:
s501: for the received discrete complex frequency domain signal Y encoded on the kth subcarrier of the ith pilot time interval in the M pilot time intervals obtained in the step S4 k,i Calculating a received discrete complex frequency domain correction signal d 'encoded on a kth subcarrier of an ith pilot time interval over M pilot time intervals' k,i ：
Wherein G is k,i And theta k,i The amplitude and phase of the encoded data on the kth subcarrier encoded to the ith pilot time interval,
gamma (t) ensures reception of a discrete complex frequency domain signal d' k,i For a rectangular pulse shaping waveform, ensuring that the ith coded data is zero outside the ith pilot time interval; t (T) b Is the pilot time interval period, f k For the frequency of the kth subcarrier, +.>
f 0 Is a fixed frequency offset;
s502: the S4 step is utilized to calculate the complex transfer function of the obtained superposition frequency domain signal
Calculating received frequency domain complex data d' which is equilibrium coded to each (kth) subcarrier k,i ：
As shown in FIG. 2, the encoding and decoding functions of the data are completed by an FPGA module at the control end, and an 8B/10B encoding and decoding mode is adopted. The 16-bit parallel data is 8B/10B encoded, which can be 8B/10B encoded with two bytes of data per clock cycle. As shown in fig. 2, the non-uniformity signal output from the encoder 1 is input as the non-uniformity signal of the encoder 2. The encoding and the inequality calculation of the two encoders are performed in the same clock cycle. In addition, the data flow control and byte alignment are realized by searching special codes (such as K codes), so that the data recovery work can be assisted in receiving, the transmission errors of the data bits can be found in early stage, and the errors are restrained from continuing to occur. In order to conveniently identify the boundary of the data 10B, the K code is used as a start and end mark of the data, and the receiving end can judge the coding boundary after identifying the K code, so that 8B/10B decoding work can be carried out. By doing so, an 8B/10B codec design is achieved.
Example 2
As shown in fig. 2, the tethered unmanned aerial vehicle on-board power supply optical fiber isolation communication system adopting the method provided in embodiment 1 provided in this embodiment includes an optical fiber transmitter as a control end and an optical fiber receiver as a monitoring end; the optical fiber transmitter comprises a data access port for accessing serial data, a transmitter FPGA coding module, a transmitter SERDES module serving as a parallel/serial data converter, a digital-to-analog converter and an electromechanical/optical converter; the optical fiber receiver comprises a receiver serial data receiving port for outputting the restored original serial signal data, a receiver FPGA coding module, a receiver SERDES module used as a parallel/serial data converter, an analog-to-digital converter and a receiver optical/point converter; the receiver optical/electrical converter receives the optical signal converted by the electromechanical/optical converter.
The FPGA coding module of the transmitter and the FPGA coding module of the receiver code and convert the parallel data of 8B into the parallel data of 10B.
Since a general digital signal is not suitable for direct transmission in an optical fiber, in order to facilitate the optical fiber transmission, it is necessary to encode the digital signal. The 8B/10B coding feature is to ensure DC balance so that the signal does not become DC-detuned when the link times out. Through 8B/10B coding, the transmitted data can be ensured to be correctly restored at a receiving end, noise accumulation can be effectively restrained, and the anti-interference capability of signals is improved. The method adopts 8B/10B coding to process parallel data, and converts the parallel data into serial data to be sent out. And the receiving end converts the received serial data into parallel data and then decodes the parallel data to obtain effective parallel data, thereby completing high-speed signal transmission.
The SERDES converts low-speed parallel data into high-speed serial differential data at a transmitting end, and restores the high-speed serial data into low-speed parallel data at a receiving end. Serial data does not have an independent clock line, and a clock is embedded in a data stream, so that the problem of signal clock offset for limiting the data transmission rate is effectively solved; the high-speed serial differential data has strong noise resistance and interference resistance in transmission, the SERDES implementation adopts a double-edge (DDR) working mode, and the area speed-changing strategy is utilized to reduce the proportion of high-frequency circuits in the circuit, so that the power supply noise is reduced.
The photoelectric conversion circuit finishes the mutual conversion between the electric signal and the optical signal through the optical fiber transmitter and the optical fiber receiver, and realizes the optical transmission of the electric signal. The optical fiber transmitter converts the electric signal into an optical signal for transmission, and the optical fiber receiver restores the received optical signal into the electric signal. In order to improve transmission performance, serial communication is completed by adopting double optical fibers, and an optical fiber transceiver (with transmitting and receiving functions) only performs photoelectric signal conversion, so that the process does not change a coding format, does not perform data processing, is only used for point-to-point data transmission, and thus, the speed is greatly improved.
The TLK2711 technology adopted by the SERDES module in the transmitter and the receiver is a high-speed serial technology based on SERDES, clock and data are combined together to be transmitted through differential signals, and a clock recovery technology is adopted, so that the anti-interference capability is enhanced, the problem of signal clock offset is solved, and the single-path serial transmission rate is up to 2.5Gbit/s. The TLK2711 is a gigabit high-speed transceiver, is a physical layer interface device, and mainly completes the functions of receiving high-speed serial data into low-speed parallel data and transmitting low-speed parallel data into high-speed serial data, wherein a transmitting interface and a receiving interface of the TLK2711 can be independently used (simplex communication) or simultaneously used (duplex communication), and can be applied to a point-to-point ultrahigh-speed bidirectional transmission system.
The encoded 10-bit parallel data is converted into high-speed data stream by a parallel/serial data converter, and is transmitted to the photoelectric converter at high speed according to 20 times of the speed of a reference clock by pre-emphasis and impedance matching of a transmitter. Similarly, the encoded serial data is received, the interpolator and clock recovery circuit lock the data stream, and the bit rate clock is extracted. The recovered clock is used to re-time the data stream. The serial data is then aligned to the boundary of two 10-bit codewords, 8B/10B decoded, and the data is output on a 16-bit parallel bus synchronized with the extraction clock RXCLK.
The invention adopts an photoelectric receiving-transmitting and converting module AFBR-57R5APZ of an AVAGO company to realize the conversion and transmission of double-line photoelectric signals. AFBR-57R5APZ is a high performance serial optical data exchanger with transmission rates up to 4.25Gb/s, supporting MMF cables (500 m,50 μm) and (300 m,62.5 μm) (@ 1.0625 Gbd), built-in 850nm Vertical Cavity Surface Emitting Lasers (VCSELs). The structural block diagram of the AFBR-57R5APZ is shown in figure 3, and mainly comprises the following steps: the optical fiber interface, the electrical appliance interface, the sending and receiving parts are all four. For the transmitting part, firstly, two paths of differential electric signals are received from TD+ and TD-and are transmitted to a laser transmitter after being modulated and controlled by a laser driving circuit, and finally, the laser transmitter converts the electric signals into optical signals carrying corresponding information and transmits the optical signals to an optical fiber for transmission. In addition, in the driving circuit portion
Further auxiliary circuits are included, which function to ensure the output power of the optical signal; for the receiving part, firstly, optical signals are received from optical fibers, the electric signal information carried by the optical signals is extracted through an optical detector, then the original electric signals are restored through amplification, denoising and other processes, and finally, two paths of differential electric signals are sent out through RD+ and RD-interfaces. RX_LOS is used for detecting a received signal, and outputs a low level when a received optical signal is normal, and outputs a high level when the received optical signal is abnormal. The control and storage circuit is used for completing the functions of device error information diagnosis, fault detection, identification, isolation and the like.
While the invention has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In particular, the technical features mentioned in the respective embodiments may be combined in any manner as long as there is no structural conflict. The present invention is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions falling within the scope of the claims.
Claims (10)
1. The optical fiber isolation communication method for the onboard power supply of the tethered unmanned aerial vehicle is characterized by comprising the following steps of:
s1: original serial signal data input, converting into parallel data and transmitting N discrete complex time domain signals x n ；
S2: for N discrete complex time domain signals x n Pilot insertion is performed periodically in each discrete complex time domain signal x n Pilot time interval P transmitted on subcarriers of (a) k ；
S3: converting the parallel data into serial differential digital electric signal data, converting the differential digital electric signal data into analog electric signal data, and converting the analog electric signal data into optical signals which are used as the optical signals sent by a transmitter;
s4: after receiving the optical signal sent by the transmitter in the step S3, converting the optical signal into an electric signal, converting the electric signal into serial differential digital electric signal data, demodulating the serial differential digital electric signal data into parallel electric signals, and obtaining N discrete complex frequency domain signals X k Calculating N discrete complex frequency domain signals X k Corresponding received pilot time interval R of (1) k Determining a transfer function H for a transmitter to transfer frequency domain signals to a receiver k And further calculates a superimposed frequency domain signal complex transfer function H formed by superimposing the frequency domain signals transferred by the transmitter and the receiver (k+iNs),k The method comprises the steps of carrying out a first treatment on the surface of the For N discrete complex frequency domain signals X k Performing discrete Fourier transform to remove cyclic prefix of pilot frequency insertion to obtain kth subcarrier X coded to ith pilot frequency time interval in M pilot frequency time intervals k,i On a received discrete complex frequency domain signal Y k,i ；
S5: channel equalization is carried out to obtain received frequency domain complex data d' which is equalization coded on each subcarrier k,i And obtaining restored original serial signal data, and completing the optical fiber isolation communication of the onboard power supply of the tethered unmanned aerial vehicle.
2. The tethered unmanned aerial vehicle on-board power fiber isolation communication method of claim 1, wherein in step S2, pilot time interval P k At a known amplitude A k And phase theta k Periodically transmit on each subcarrier:
k represents the kth subcarrier, k=1, 2,3, …, N s 。
3. The tethered unmanned aerial vehicle on-board power supply optical fiber isolation communication method according to claim 1, wherein the N discrete complex time domain signals x input in the step S4 n Adopts Hermite symmetry to arrange, and further obtains a discrete complex frequency domain signal X k The calculation formula is as follows:
wherein,,
4. the tethered unmanned aerial vehicle on-board power fiber isolation communication method of claim 1, wherein the pilot time interval R is received in step S4 k The method comprises the following steps:
wherein B is k And phi k Representing the amplitude and phase, W, of the sub-carriers received by the receiver, respectively k Is the noise component of the kth subcarrier after the receiver fourier transform FFT, k representing the kth subcarrier.
5. The tethered unmanned aerial vehicle on-board power fiber isolation communication method of claim 1, wherein the S4 step is a transfer function H for a transmitter and a receiver to transfer frequency domain signals k The calculation formula is as follows:
wherein A is k And theta k The k-th subcarrier amplitude and phase of the transmitted signal of the known transmitter, B k And phi k Respectively representing the kth subcarrier amplitude and phase of the signal received by the receiver, R k For receiving pilot time intervals.
6. The method for isolated communication of power supply fiber of tethered unmanned aerial vehicle according to claim 1, wherein the step S4 calculates a complex transfer function of the superimposed frequency domain signal formed by superimposing the signals of the transmission frequency domain of the transmitter and the receiver
The following are provided:
wherein,,
pilot time interval for the transmitted superimposed frequency domain signal, < >>
For the pilot time interval of the received superimposed frequency domain signal, i is the i-th pilot time interval, i=1, 2, …, M, P C Is the constant power of the receiver.
7. The tethered unmanned aerial vehicle on-board power fiber isolation communication method of claim 1, wherein the fourier transform of step S4 comprises the steps of:
s401: for the kth subcarrier X coded to the ith pilot time interval in M pilot time intervals k,i Identifying the k+iN superimposed therewith s Sub-carriers
Complex conjugate value +.>
S402: the complex conjugate value calculated by the step S401
Determining the average pilot time interval total number N by adopting a preset integer C s The received scattered signals in the M pilot time intervals are obtained, and the received scattered complex frequency domain signals Y in the M pilot time intervals are encoded on the kth subcarrier of the ith pilot time interval k,i ：
8. The tethered unmanned aerial vehicle on-board power fiber isolation communication method of claim 1, wherein the step S5 comprises the steps of:
s501: for the received discrete complex frequency domain signal Y encoded on the kth subcarrier of the ith pilot time interval in the M pilot time intervals obtained in the step S4 k,i Calculating a received discrete complex frequency domain correction signal d 'encoded on a kth subcarrier of an ith pilot time interval over M pilot time intervals' k,i ：
Wherein G is k,i And theta k,i Respectively, are coded to the ith guideAmplitude and phase of encoded data on the kth subcarrier of the frequency time interval, γ (t) =; t (T) b Is the pilot time interval period, f k Is the frequency of the kth subcarrier;
s502: the S4 step is utilized to calculate the complex transfer function of the obtained superposition frequency domain signal
Calculating to obtain received frequency domain complex data d' which is equilibrium coded on each subcarrier k,i ：
9. A tethered unmanned aerial vehicle on-board power fiber isolation communication system employing the method according to any of claims 1-8, wherein the system comprises a fiber transmitter as a control end and a fiber receiver as a monitoring end; the optical fiber transmitter comprises a data access port for accessing serial data, a transmitter FPGA coding module, a transmitter SERDES module serving as a parallel/serial data converter, a digital-to-analog converter and an electromechanical/optical converter; the optical fiber receiver comprises a receiver serial data receiving port for outputting the restored original serial signal data, a receiver FPGA coding module, a receiver SERDES module used as a parallel/serial data converter, an analog-to-digital converter and a receiver optical/point converter; the receiver optical/electrical converter receives the optical signal converted by the electromechanical/optical converter.
10. The tethered unmanned aerial vehicle on-board power fiber isolation communication system of claim 9, wherein the FPGA encoding module encodes and converts 8B parallel data to 10B parallel data.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101300758A (en) * | 2005-09-02 | 2008-11-05 | 莫纳什大学 | Methods and apparatus for optical transmission of digital signals |
| CN103621031A (en) * | 2011-04-06 | 2014-03-05 | 班戈大学 | Symbol alignment in high speed optical orthogonal frequency division multiplexing transmission systems |
| WO2015188381A1 (en) * | 2014-06-13 | 2015-12-17 | 华为技术有限公司 | Modulation method, apparatus, and device for orthogonal frequency division multiplexing optical signal |
| CN107395282A (en) * | 2017-07-20 | 2017-11-24 | 浙江工业大学 | Phase noise compensation method of time domain unscented Kalman filtering large-linewidth CO-OFDM system |
| CN107800481A (en) * | 2017-09-11 | 2018-03-13 | 中国电子科技集团公司第四十研究所 | A kind of high-speed digitization Fiber isolation transmitting device and method |
| CN108632189A (en) * | 2017-03-22 | 2018-10-09 | 展讯通信（上海）有限公司 | Sending method, device and the user equipment of upstream data |
| CN109004984A (en) * | 2018-07-18 | 2018-12-14 | 武汉邮电科学研究院有限公司 | Communication means, system and method for signal multiplexing, device between time-frequency domain |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8718160B2 (en) * | 2011-09-16 | 2014-05-06 | Beijing University Of Posts And Telecommunications | Multi-carrrier optical communication method and system based on DAPSK |
| US10998980B2 (en) * | 2018-03-27 | 2021-05-04 | Florida Institute of Technology, Inc. | System for achieving multiple bits per symbol in optical communications systems by combining spatial domain multiplexing and pulse amplitude modulation |
-
2021
- 2021-12-30 CN CN202111648142.5A patent/CN114422033B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101300758A (en) * | 2005-09-02 | 2008-11-05 | 莫纳什大学 | Methods and apparatus for optical transmission of digital signals |
| CN103621031A (en) * | 2011-04-06 | 2014-03-05 | 班戈大学 | Symbol alignment in high speed optical orthogonal frequency division multiplexing transmission systems |
| WO2015188381A1 (en) * | 2014-06-13 | 2015-12-17 | 华为技术有限公司 | Modulation method, apparatus, and device for orthogonal frequency division multiplexing optical signal |
| CN106464631A (en) * | 2014-06-13 | 2017-02-22 | 华为技术有限公司 | Modulation method, apparatus, and device for orthogonal frequency division multiplexing optical signal |
| CN108632189A (en) * | 2017-03-22 | 2018-10-09 | 展讯通信（上海）有限公司 | Sending method, device and the user equipment of upstream data |
| CN107395282A (en) * | 2017-07-20 | 2017-11-24 | 浙江工业大学 | Phase noise compensation method of time domain unscented Kalman filtering large-linewidth CO-OFDM system |
| CN107800481A (en) * | 2017-09-11 | 2018-03-13 | 中国电子科技集团公司第四十研究所 | A kind of high-speed digitization Fiber isolation transmitting device and method |
| CN109004984A (en) * | 2018-07-18 | 2018-12-14 | 武汉邮电科学研究院有限公司 | Communication means, system and method for signal multiplexing, device between time-frequency domain |
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