CN112152758A - Navigation communication method and device - Google Patents
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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
- H04L1/0045—Arrangements at the receiver end
- H04L1/0054—Maximum-likelihood or sequential decoding, e.g. Viterbi, Fano, ZJ algorithms
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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
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- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
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- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
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Abstract
The application provides a navigation communication method and a navigation communication device, wherein the method comprises the following steps: combining a Viterbi algorithm, respectively performing first bit difference decomposition and second bit difference demodulation on a first signal to be demodulated to obtain a first demodulation result and a second demodulation result; checking the first demodulation result and the second demodulation result respectively by using check codes; selecting the demodulation result which passes the verification in the first demodulation result and the second demodulation result as a final demodulation result; and carrying out communication according to the final demodulation result. Compared with the prior art, the technical scheme provided by the application optimizes the receiving performance of the signal processing equipment under low signal-to-noise ratio and high frequency offset by adopting a coherent Viterbi demodulation algorithm and combining the first bit difference demodulation and the second bit difference demodulation.
Description
Technical Field
The present application relates to the field of wireless communication technologies, and in particular, to a navigation communication method and apparatus.
Background
In the prior art, a conventional demodulation method usually adopts GMSK demodulation and frequency discrimination or differential demodulation, and although such an incoherent demodulation method is simple in design, the reception performance under low signal-to-noise ratio and high frequency offset is poor, and the receiver is very sensitive to noise, so that the receiver sensitivity is not high. In view of this, as the navigation demand in the fields of automatic ship identification systems and the like increases, providing a new navigation communication method becomes an urgent technical problem to be solved.
Disclosure of Invention
In view of this, embodiments of the present application are directed to providing a navigation communication method and apparatus, so as to solve the problem in the prior art that the demodulation effect is not ideal.
In a first aspect, an embodiment of the present application provides a navigation communication method, where the method includes: combining a Viterbi algorithm, respectively performing first bit difference decomposition and second bit difference demodulation on a first signal to be demodulated to obtain a first demodulation result and a second demodulation result; checking the first demodulation result and the second demodulation result respectively by using check codes; selecting the demodulation result which passes the verification in the first demodulation result and the second demodulation result as a final demodulation result; and carrying out communication according to the final demodulation result.
In one embodiment of the present application, the first bit differential demodulation includes 1 bit differential demodulation, and the second bit differential demodulation includes 2 bit differential demodulation.
In an embodiment of the present application, performing a first bit difference demodulation and a second bit difference demodulation on a first signal to be demodulated, respectively, in combination with a viterbi algorithm, to obtain a first demodulation result and a second demodulation result, including: determining a first survivor path and a second survivor path based on the first bit difference demodulation and the second bit difference demodulation; and obtaining a first demodulation result and a second demodulation result based on the first survivor path and the second survivor path backtracking demodulation.
In an embodiment of the present application, before performing first bit difference demodulation and second bit difference demodulation on a first signal to be demodulated respectively by combining with a viterbi algorithm to obtain a first demodulation result and a second demodulation result, the method further includes: acquiring a first low intermediate frequency digital signal based on the first intermediate frequency signal; acquiring a first baseband signal based on the first low intermediate frequency digital signal; based on the first baseband signal, a first signal to be demodulated is acquired.
In one embodiment of the present application, acquiring a first signal to be demodulated based on a first baseband signal includes: and calculating the first baseband signal by using the fixed pilot frequency to obtain a first signal to be demodulated.
In an embodiment of the present application, before acquiring the first low intermediate frequency digital signal based on the first intermediate frequency signal, the method further includes: based on the received first high frequency signal, a first intermediate frequency signal is obtained.
In one embodiment of the present application, the communication according to the final demodulation result includes: determining a communication event corresponding to the second demodulation result based on the communication protocol in the protocol stack; and executing the operation corresponding to the communication event according to the determined communication event.
In a second aspect, an embodiment of the present application provides a navigation communication apparatus, including: the acquisition module is used for respectively carrying out first bit difference decomposition and second bit difference demodulation on a first signal to be demodulated by combining a Viterbi algorithm to acquire a first demodulation result and a second demodulation result; the checking module is used for respectively checking the first demodulation result and the second demodulation result by using the checking code; the selection module is used for selecting the demodulation result which passes the verification in the first demodulation result and the second demodulation result as a final demodulation result; and the execution module is used for carrying out communication according to the final demodulation result.
In a third aspect, an embodiment of the present application provides a computer-readable storage medium, where the storage medium stores a computer program, and the computer program is configured to execute the navigation communication method according to the first aspect.
In a fourth aspect, an embodiment of the present application provides an electronic device, including: a processor; a memory for storing processor executable instructions, wherein the processor is configured to perform the navigation communication method of the first aspect.
The embodiment of the application provides a navigation communication method and a navigation communication device, and the receiving performance of receiving equipment under low signal-to-noise ratio and high frequency offset is optimized by adopting a coherent Viterbi demodulation algorithm and combining differential demodulation of a first bit and a second bit.
Drawings
Fig. 1 is a flowchart illustrating a navigation communication method according to an embodiment of the present application.
Fig. 2 is a flowchart illustrating a demodulation method of a navigation communication method according to an embodiment of the present application.
Fig. 3 is a flowchart illustrating a navigation communication method according to another embodiment of the present application.
Fig. 4 is a flowchart illustrating a navigation communication method according to another embodiment of the present application.
Fig. 5 is a flowchart illustrating a GUI interface application control flow of a navigation communication method according to an embodiment of the present application.
Fig. 6 is a schematic structural diagram of a navigation communication device according to an embodiment of the present application.
Fig. 7 is a block diagram illustrating an electronic device for navigating a communication method according to an embodiment of the present application.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
Fig. 1 is a flowchart illustrating a navigation communication method according to an embodiment of the present application. The method of fig. 1 is performed by a computing device. As shown in fig. 1, the navigation communication method includes the following.
110: and combining a Viterbi algorithm to respectively carry out first bit difference decomposition and second bit difference demodulation on the first signal to be demodulated to obtain a first demodulation result and a second demodulation result.
Specifically, the first signal to be demodulated may include a signal to be demodulated, a frequency offset estimation value, and a modulation index estimation value. The content of the first signal to be demodulated is not particularly limited in the embodiments of the present application.
The manner of performing the first bit difference demodulation and the second bit difference demodulation on the first signal to be demodulated may be performed simultaneously, that is, the first bit difference demodulation process and the second bit difference demodulation process are two parallel processes performed simultaneously (for example, see fig. 2).
In an example, the first bit differential demodulation and the second bit differential demodulation are adjacent different bit differential demodulation. For example, the first bit differential demodulation may be 1 bit differential demodulation, and the second bit differential demodulation may be 2 bit differential demodulation; or the first bit differential demodulation may be 2-bit differential demodulation and the second bit differential demodulation may be 3-bit differential demodulation.
It should be understood that although the first bit difference demodulation and the second bit difference demodulation are set in the embodiment of the present application, in the practical application process, only 1-bit difference demodulation or 2-bit difference demodulation may be performed alone, 1-bit and 2-bit joint difference demodulation may be performed, and 2-bit and 3-bit joint difference demodulation may be performed, and the embodiment of the present application does not specifically limit the bit difference demodulation algorithm. The selection can be flexibly performed according to actual situations, for example, although the eye diagram decision distance is enlarged by the 2 and 3 bit joint differential demodulation compared with the 1 and 2 bit joint differential demodulation, the multi-bit differential symbol can generate continuous misjudgment when the signal-to-noise ratio is low, and the 1 and 2 bit joint differential demodulation is preferable.
120: and respectively checking the first demodulation result and the second demodulation result by using the check codes.
In particular, the check code may be a cyclic Redundancy code, such as a cyclic Redundancy code crc (cyclic Redundancy code). The check code may also be a hamming check code. The check code may also be a parity check code, such as an odd check or an even check, and the check code is not specifically limited in the embodiment of the present application.
Preferably, the cyclic redundancy code CRC is selected for checking in the embodiment of the present application. Not only all odd number dislocation can be detected, but also all double bit dislocation can be detected, and all burst errors which are smaller than or equal to the length of the check bit can be detected.
130: and selecting the demodulation result which passes the verification in the first demodulation result and the second demodulation result as a final demodulation result.
Specifically, the final demodulation result may be the sequence that can pass the CRC check in the two demodulation results (i.e., the first demodulation result and the second demodulation result) selected as the final demodulation result. The embodiment of the application does not specifically limit the checking process, and can be flexibly set according to the actual situation.
140: and carrying out communication according to the final demodulation result.
In particular, the communication according to the final demodulation result may be performed by a central processing unit.
In one example, the central processing unit includes a GUI interface application (see fig. 5) for presenting information corresponding to the communication event, such as picture information, at the user interface. The central processing unit may be implemented by an ARM device (Advanced RISC Machine). The central processing unit can be developed based on a Linux operating system, or can also be developed based on a Windows operating system, or can also be developed based on a MaxOS operating system. The embodiment of the present application is not particularly limited to this.
It should be understood that the application scenario of the embodiment of the present application may be in the field of meteorology, and in order to effectively solve the disadvantages of low precision, poor anti-interference capability, low sensitivity, and the like of the analog demodulation meteorology fax receiver, an optimal design scheme of a meteorology fax receiving system based on software radio is provided. The application scenario may also be in the field of an Automatic Identification System (AIS) for a ship, and the application field of the navigation communication method is not specifically limited in the embodiment of the present application.
Therefore, the embodiment of the application is favorable for optimizing the traditional differential demodulation algorithm or the analog demodulation method by adopting the coherent demodulation method and the Viterbi algorithm and combining the first bit difference demodulation and the second bit difference demodulation. And meanwhile, the final communication information is presented to the user interface through the GUI interface application program, and the visual property of the communication information is enhanced.
According to an embodiment of the application, the first bit differential demodulation comprises 1 bit differential demodulation and the second bit differential demodulation comprises 2 bit differential demodulation.
Specifically, referring to fig. 2, a first signal to be demodulated, which is calculated by synchronization and frequency offset estimation (e.g., step 210 in fig. 2), is subjected to 1-bit differential demodulation and 2-bit differential demodulation simultaneously, and two demodulation results are output. That is, 1-bit differential demodulation outputs one demodulation result (one of the first demodulation result and the second demodulation result), and 2-bit differential demodulation outputs one demodulation result (the other of the first demodulation result and the second demodulation result).
Therefore, in the embodiment of the application, 1-bit and 2-bit differential demodulation is adopted, and the continuous misjudgment generated by a multi-bit differential code element when the signal-to-noise ratio is low is avoided. In addition, the original bit stream is demodulated by using a Viterbi algorithm in combination with 1-bit and 2-bit differential demodulation on the premise of obtaining accurate synchronization and frequency offset estimation during demodulation. Due to the adoption of a coherent demodulation scheme, the performance is improved by more than 3dB compared with the traditional noncoherent demodulation algorithm.
According to an embodiment of the present application, in combination with a viterbi algorithm, performing first bit difference demodulation and second bit difference demodulation on a first signal to be demodulated, respectively, to obtain a first demodulation result and a second demodulation result, including: determining a first survivor path and a second survivor path based on the first bit difference demodulation and the second bit difference demodulation; and obtaining a first demodulation result and a second demodulation result based on the first survivor path and the second survivor path backtracking demodulation.
Specifically, a first survivor path (or a second survivor path) is determined based on the first bit differential demodulation. A second survivor path (or first survivor path) is determined based on the second bit differential demodulation. The determining order of the first survivor path and the second survivor path may be determined simultaneously, or the first survivor path may be determined first and then the second survivor path may be determined first and then the first survivor path may be determined first.
In one embodiment, the differential demodulation method may adopt a method of combining the differential demodulation and the viterbi algorithm.
For convenience of description, 1-bit and 2-bit differential demodulation is taken as an example, and the demodulation method provided in the embodiment of the present application is described in detail below.
In one example, in a 1-bit differential demodulation process, the phase difference of 1 symbol time interval of the first signal to be demodulated is recorded as delta phin＝φ(nTb)-φ[(n-1)Tb]It can be concluded that: delta phinSymbol and symbol an-2Are the same as the symbols in (a). The following derivation is made:
in the formula, the time delay is Tb，akTo input symbols, an-1To an-3Symbols in different states. Furthermore, the above derivation also utilizes the symmetry of the q (t) waveform, so that the expression is more concise. Containing symbol a in the middlen-2The other two terms are intersymbol Interference (ISI). Wherein, pi x q (T)b) The unit of (d) can be converted to degrees.
The code element sum delta phi can be made according to the formula obtained after the formula derivationnTable 1 for correspondence (BT ═ 0.4):
table 1
| Status number | an-3 | an-2 | an-1 | Δφn/π | Δφn |
| 1 | -1 | -1 | -1 | -0.5 | -1.7346 |
| 2 | -1 | -1 | 1 | -0.6540 | -1.4577 |
| 3 | -1 | 1 | -1 | 0.3456 | 0.7453 |
| 4 | -1 | 1 | 1 | 0.6535 | 1.4546 |
| 5 | 1 | -1 | -1 | -0.6743 | -1.4314 |
| 6 | 1 | -1 | 1 | -0.4598 | -0.6421 |
| 7 | 1 | 1 | -1 | 0.8678 | 1.1342 |
| 8 | 1 | 1 | 1 | 0.5 | 1.9087 |
In one example, in a 2-bit differential demodulation process, the phase difference of the first signal to be demodulated for 2 symbol time intervals is recorded as delta phin＝φ(nTb)-φ[(n-2)Tb]It can be concluded that: delta phinSymbol and symbol product a ofn-2an-3Are the same as the symbols in (a). The following derivation is made:
in the formula, the time delay is Tb，akTo input symbols, an-1To an-4Symbols in different states. Furthermore, the above derivation also utilizes the symmetry of the q (t) waveform, so that the expression is more concise. Containing the symbol a in the middlen-2And an-3The other two terms are ISI. Wherein, pi x q (T)b) The unit of (d) can be converted to degrees.
The code element sum delta phi can be made according to the formula obtained after the formula derivationnTable 2 for correspondence (BT ═ 0.4):
table 2
1. The 2-bit differential viterbi demodulation algorithm may be a combination of a 1, 2-bit differential demodulation algorithm and a viterbi algorithm. According to the description of the above example, the different symbol sums Δ φnThere is a one-to-one correspondence between them. Thus, different symbol combinations can be viewed as different states. And the branch metric is calculated from the actual calculated delta phinDelta phi from the originalnThe square of the difference between (note: the difference in angle is constrained to [ - π, π [ ], π [)]Within the interval). Finally, Maximum Likelihood Sequence Estimation detection (MLSE) is realized by adopting a viterbi algorithm, so that the path with the minimum path metric is selected as a survivor path (namely a first survivor path and a second survivor path), and then the viterbi algorithm is applied again for retrospective demodulation to obtain a first demodulation result and a second demodulation result. In addition, the embodiment of the present application does not specifically limit the process of performing traceback demodulation by using the viterbi algorithm, and all that is required is to fall within the protection scope of the present application as long as the corresponding demodulation result is obtained by traceback demodulation.
The first survivor path backtracking demodulates to obtain a first demodulation result (or a second demodulation result). The second survivor path backtracking demodulates to obtain a second demodulation result (or the first demodulation result).
Illustratively, the first signal to be demodulated in the above example is a signal to be demodulated included in the first signal to be demodulated.
It should be appreciated that theoretically 2-bit differential demodulation has approximately 2dB (decibel) better noise immunity than 1-bit differential demodulation. The 1-bit differential demodulation has stronger interference resistance because the actually received data may have sudden phase change. Therefore, in order to ensure the accuracy of the demodulation result, a mode of combining 1-bit and 2-bit differential demodulation is adopted, and the group of demodulation results which can pass the CRC check is selected to be output.
Therefore, the embodiment of the application optimizes the traditional demodulation method by demodulating the original bit stream by using the viterbi algorithm and combining 1-bit and 2-bit differential demodulation on the premise of obtaining accurate synchronization and frequency offset estimation.
Fig. 3 is a flowchart illustrating a navigation communication method according to another exemplary embodiment of the present application. FIG. 3 is an example of the embodiment of FIG. 1, and the same parts are not repeated herein, and the differences are mainly described here. As shown in fig. 3, the method includes the following.
310: based on the first intermediate frequency signal, a first low intermediate frequency digital signal is obtained.
Specifically, acquiring the first low intermediate frequency digital signal may be based on analog-to-digital converter (e.g., ADC) bandpass sampling, converting the first intermediate frequency signal to the first low intermediate frequency digital signal. By utilizing ADC band-pass sampling, the intermediate frequency signal is converted into a digital domain, and the data is subjected to band-pass sampling, so that the calculation amount can be reduced, the hardware design is simplified, and the precision requirement can be met.
320: based on the first low intermediate frequency digital signal, a first baseband signal is obtained.
Specifically, after digital down-conversion, filtering and down-sampling of the first low intermediate frequency digital signal, an 8 times oversampled first baseband signal is output.
The structure of the decimation filter may use an integration Comb decimation filter (CIC). The decimation filter structure may also employ an FIR filter. When the sampling rate of the input signal is very high, the structure of the decimation filtering can also adopt a down-conversion scheme of polyphase filtering, and the operation link is arranged after decimation.
330: based on the first baseband signal, a first signal to be demodulated is acquired.
Specifically, the first baseband signal is synchronized and frequency offset estimated, and the first signal to be demodulated is calculated by a correlation algorithm using a fixed pilot (e.g., a 24-bit sequence). For details, reference is made to the following description of the embodiments and will not be repeated herein.
340: and combining a Viterbi algorithm to respectively carry out first bit difference decomposition and second bit difference demodulation on the first signal to be demodulated to obtain a first demodulation result and a second demodulation result.
350: and respectively checking the first demodulation result and the second demodulation result by using the check codes.
360: and selecting the demodulation result which passes the verification in the first demodulation result and the second demodulation result as a final demodulation result.
370: and carrying out communication according to the final demodulation result.
Specifically, the steps 350 to 380 are substantially the same as the steps 110 to 140 in fig. 1, and please refer to the description of the steps 110 to 140 in fig. 1 for details, which are not repeated herein for avoiding repetition.
It should be understood that referring to fig. 2, the input of the digital front end 210 is a first intermediate frequency signal, which is band-pass sampled by an Analog-to-digital converter (ADC) to obtain a first low intermediate frequency digital signal, and after performing digital down-conversion, filtering and down-sampling on the first intermediate frequency digital signal, the first baseband signal which is 8 times over-sampled is output and is sent to a post-stage for processing. The input to the synchronization and frequency offset estimation block 210 is a first baseband signal, and a first demodulated signal is calculated using a fixed pilot. The demodulation modules 230 and 240 input a first signal to be demodulated, the output of which is a demodulation sequence. The demodulation algorithm combines 1-bit differential viterbi demodulation and 2-bit differential viterbi demodulation schemes, and selects one sequence of the two demodulation results which passes CRC check as a final demodulation result.
Therefore, the embodiment of the application improves the precision of data processing by performing bandpass sampling, down-conversion and other processing on the early-stage signal.
According to an embodiment of the present application, acquiring a first signal to be demodulated based on a first baseband signal includes: and calculating the first baseband signal by using the fixed pilot frequency to obtain a first signal to be demodulated.
Specifically, the first baseband signal is synchronized and frequency offset estimated. The synchronization and frequency offset estimation may be performed by setting a fixed bit sequence at the beginning of each frame for synchronization and frequency offset estimation. The fixed pilot may be a 24-bit sequence, which is not specifically limited in this embodiment of the present application.
The first to-be-demodulated signal obtained can be first band-pass sampled by the ADC (step 310 in fig. 3); then, aiming at the waveform of the training sequence, matching the received signal by using a locally stored reference waveform; and finally, capturing a starting point of the signal, and estimating the frequency offset of the signal and the modulation index of the signal.
Therefore, the accuracy of synchronization and frequency offset estimation is improved through the fixed pilot frequency and the related algorithm, and guarantee is provided for subsequently demodulating the original bit stream.
Fig. 4 is a flowchart illustrating a navigation communication method according to another exemplary embodiment of the present application. FIG. 4 is an example of the embodiment of FIG. 3, and the same parts are not repeated herein, and the differences are mainly described here. As shown in fig. 4, the method includes the following.
410: based on the received first high frequency signal, a first intermediate frequency signal is obtained.
Specifically, the first high frequency signal may be a Very High Frequency (VHF) signal received through a VHF antenna.
In one example, a super-heterodyne architecture is employed to acquire the first intermediate frequency signal.
A typical application of the super-heterodyne architecture may be a super-heterodyne receiver. A first high-frequency signal received from an antenna (e.g., a VHF antenna) is amplified by a high-frequency amplifier (i.e., a tuned amplifier), and is added to a mixer together with a signal generated by a local oscillator to be converted, so as to obtain a first intermediate-frequency signal.
420: acquiring a first low intermediate frequency digital signal based on the first intermediate frequency signal
430: based on the first low intermediate frequency digital signal, a first baseband signal is obtained.
440: based on the first baseband signal, a first signal to be demodulated is acquired.
450: and combining a Viterbi algorithm to respectively carry out first bit difference decomposition and second bit difference demodulation on the first signal to be demodulated to obtain a first demodulation result and a second demodulation result.
460: and respectively checking the first demodulation result and the second demodulation result by using the check codes.
470: and selecting the demodulation result which passes the verification in the first demodulation result and the second demodulation result as a final demodulation result.
480: and carrying out communication according to the final demodulation result.
Specifically, the steps 420 to 480 are substantially the same as the steps 310 to 370 in fig. 3, and please refer to the description of the steps 310 to 370 in fig. 3 for details, which are not repeated herein for avoiding repetition.
Therefore, the superheterodyne digital intermediate frequency demodulation method is combined with the digital intermediate frequency demodulation scheme by adopting the superheterodyne structure. The advantages of high sensitivity and good selectivity of the superheterodyne structure are reserved.
According to an embodiment of the present application, the communication according to the final demodulation result includes: determining a communication event corresponding to the second demodulation result based on the communication protocol in the protocol stack; and executing the operation corresponding to the communication event according to the determined communication event.
Specifically, the protocol stack may include at least one customized data communication protocol, and the number of the communication protocol schemes may be 3, 4, or 5, which is not specifically limited in this embodiment of the present application. The communication protocol may be an AIS communication protocol, such as a formation communication and area broadcast protocol. The embodiment of the present application does not limit the specific content of the communication protocol.
In an example, the operation corresponding to executing the communication event may specifically refer to fig. 5, and is controlled by a gui (graphical User interface) interface application. The gui (graphical User interface) interface application is used for waiting for an event to occur, in a continuously scanning state, detecting whether an output type event exists may include a change display event, a print required event, and a store required event, and an input type event may include an input event and a UART (Universal Asynchronous Receiver/Transmitter) communication event.
If a change Display event is detected, a Display drive, such as an LCD drive (Liquid Crystal Display), LCM drive (Liquid Composite moving), or OLED drive (Organic Light-Emitting Diode), is invoked. If a print-required event is detected, a print driver, such as a USB print driver, is invoked. If the event needing to be stored is detected, a storage drive, such as an SD (Secure Digital) drive, an OM (Read-Only Memory) drive or a RAM (Random Access Memory) drive, is called, so that received voice, characters, navigation data and the like are recorded into the Memory, the storage and retrieval of communication data are realized, and historical data are managed.
If the input event is detected, the input event processing module is entered, whether the input event is an event triggered by a keyboard or a remote controller is judged, if the input event is the keyboard, a keyboard driver is called to acquire a key value and return the key value to the input event processing module, if the input event is the remote controller, the remote controller driver is called to acquire the key value and return the key value to the input event processing module, and finally the key value is sent to the GUI interface application program by the input event processing module. If the UART communication event is detected, the method enters a communication module of the FPGA to analyze the frame format transmitted by the FPGA, and judges whether the frame format is text, voice, navigation data or control information, if the frame format is the data information, the frame format is converted by a data processing module and the data is sent to a GUI interface application program, and if the frame format is the control information, the frame format is analyzed by a command analysis processing module and a control signal is sent to the GUI interface application program.
Therefore, the communication event is combined with the GUI application program, the communication event is presented on the user interface, and the visual effect of presentation of the communication event is enhanced.
Fig. 6 is a schematic structural diagram of a navigation communication device according to an embodiment of the present application. The navigation communication device includes: an acquisition module 610, a verification module 620, a selection module 630, and an execution module 640.
An obtaining module 610, configured to perform first bit difference demodulation and second bit difference demodulation on the first signal to be demodulated, respectively, in combination with a viterbi algorithm, and obtain a first demodulation result and a second demodulation result; a checking module 620, configured to perform check code checking on the first demodulation result and the second demodulation result respectively; a selecting module 630, configured to select a demodulation result that passes the verification from the first demodulation result and the second demodulation result as a final demodulation result; and an executing module 640, configured to perform communication according to the final demodulation result.
The embodiment of the application provides a navigation communication method and a navigation communication device, and a coherent demodulation method and a Viterbi algorithm are adopted, and at least one bit differential demodulation is combined, so that the receiving performance of communication equipment is improved, and the traditional differential demodulation algorithm or analog demodulation method is optimized.
According to an embodiment of the application, the first bit differential demodulation comprises 1 bit differential demodulation and the second bit differential demodulation comprises 2 bit differential demodulation.
According to an embodiment of the present application, in combination with a viterbi algorithm, performing first bit difference demodulation and second bit difference demodulation on a first signal to be demodulated, respectively, to obtain a first demodulation result and a second demodulation result, including: determining a first survivor path and a second survivor path based on the first bit difference demodulation and the second bit difference demodulation; and obtaining a first demodulation result and a second demodulation result based on the first survivor path and the second survivor path backtracking demodulation.
According to an embodiment of the present application, before performing first bit difference demodulation and second bit difference demodulation on a first signal to be demodulated respectively by combining a viterbi algorithm, the method further includes: acquiring a first low intermediate frequency digital signal based on the first intermediate frequency signal; acquiring a first baseband signal based on the first low intermediate frequency digital signal; based on the first baseband signal, a first signal to be demodulated is acquired.
According to an embodiment of the present application, acquiring a first signal to be demodulated based on a first baseband signal includes: and calculating the first baseband signal by using the fixed pilot frequency to obtain a first signal to be demodulated.
According to an embodiment of the present application, acquiring a first signal to be demodulated based on a first baseband signal includes: and calculating the first baseband signal by using the fixed pilot frequency to obtain a first signal to be demodulated.
According to an embodiment of the present application, before acquiring the first low intermediate frequency digital signal based on the first intermediate frequency signal, the method further includes: based on the received first high frequency signal, a first intermediate frequency signal is obtained.
According to an embodiment of the present application, the communication according to the final demodulation result includes: determining a communication event corresponding to the second demodulation result based on the communication protocol in the protocol stack; and executing the operation corresponding to the communication event according to the determined communication event.
It should be understood that, for specific working processes and functions of the obtaining module 610, the verifying module 620, the selecting module 630 and the executing module 640 in the foregoing embodiments, reference may be made to the description in the navigation communication method provided in the foregoing embodiments of fig. 1 and fig. 4, and in order to avoid repetition, details are not described here again.
Fig. 7 is a block diagram of an electronic device 700 for navigating a communication method according to an exemplary embodiment of the invention.
Referring to fig. 7, electronic device 700 includes a processing component 710 that further includes one or more processors, and memory resources, represented by memory 720, for storing instructions, such as applications, that are executable by processing component 710. The application programs stored in memory 720 may include one or more modules that each correspond to a set of instructions. Further, the processing component 710 is configured to execute instructions to perform the navigation communication method described above.
The electronic device 700 may also include a power supply component configured to perform power management of the electronic device 700, a wired or wireless network interface configured to connect the electronic device 700 to a network, and an input-output (I/O) interface. The electronic device 700 may be operated based on an operating system, such as a real-time operating system, e.g., μ C/OS-II, stored in the memory 720.
A non-transitory computer readable storage medium having instructions therein, which when executed by a processor of the electronic device 700, enable the electronic device 700 to perform a navigational communication method, comprising: demodulating the first signal to be demodulated with at least one bit difference Viterbi at the same time to obtain at least one demodulation result; checking at least one demodulation result by a check code to obtain a second demodulation result; and sending the second demodulation result to the central processing unit, and executing the communication information corresponding to the second demodulation result.
All the above-mentioned optional technical solutions can be combined arbitrarily to form the optional embodiments of the present invention, and are not described herein again.
Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.
It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.
In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.
The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.
In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.
The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: various media capable of storing program check codes, such as a U disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk.
In the description herein, references to the description of "one embodiment," "some embodiments," "an example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
Furthermore, in the description of the present application, the terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. In addition, in the description of the present application, "a plurality" means two or more unless otherwise specified.
The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modifications, equivalents and the like that are within the spirit and principle of the present application should be included in the scope of the present application.
Claims (10)
1. A navigation communication method of an automatic ship identification system is characterized by comprising the following steps:
combining a Viterbi algorithm, respectively performing first bit difference decomposition and second bit difference demodulation on a first signal to be demodulated to obtain a first demodulation result and a second demodulation result;
checking the first demodulation result and the second demodulation result respectively by using check codes;
selecting a demodulation result passing the verification in the first demodulation result and the second demodulation result as a final demodulation result;
and carrying out communication according to the final demodulation result.
2. The navigation communication method of claim 1, wherein the first bit differential demodulation comprises 1 bit differential demodulation and the second bit differential demodulation comprises 2 bit differential demodulation.
3. The navigation communication method of claim 1, wherein the combining with the viterbi algorithm for performing the first bit difference demodulation and the second bit difference demodulation on the first signal to be demodulated respectively to obtain the first demodulation result and the second demodulation result comprises:
determining a first survivor path and a second survivor path based on the first bit difference demodulation and the second bit difference demodulation;
obtaining the first demodulation result and the second demodulation result based on the first survivor path and the second survivor path backtracking demodulation.
4. The navigation communication method of claim 1, wherein before performing the first bit difference demodulation and the second bit difference demodulation on the first signal to be demodulated respectively by combining with the viterbi algorithm to obtain the first demodulation result and the second demodulation result, the method further comprises:
acquiring a first low intermediate frequency digital signal based on the first intermediate frequency signal;
acquiring a first baseband signal based on the first low intermediate frequency digital signal;
and acquiring the first signal to be demodulated based on the first baseband signal.
5. The navigation communication method according to claim 4, wherein the obtaining the first signal to be demodulated based on the first baseband signal comprises:
and calculating the first baseband signal by using the fixed pilot frequency to obtain a first signal to be demodulated.
6. The navigation communication method according to claim 4, further comprising, before the obtaining the first low intermediate frequency digital signal based on the first intermediate frequency signal:
and acquiring the first intermediate frequency signal based on the received first high frequency signal.
7. The navigation communication method according to claim 1, wherein the communicating according to the final demodulation result comprises:
determining a communication event corresponding to the second demodulation result based on a communication protocol in a protocol stack;
and executing the operation corresponding to the communication event according to the determined communication event.
8. A navigation communication device, comprising:
the acquisition module is used for respectively carrying out first bit difference decomposition and second bit difference demodulation on a first signal to be demodulated by combining a Viterbi algorithm to acquire a first demodulation result and a second demodulation result;
the checking module is used for respectively checking the first demodulation result and the second demodulation result by checking codes;
a selection module, configured to select a demodulation result that passes the verification from the first demodulation result and the second demodulation result as a final demodulation result;
and the execution module is used for carrying out communication according to the final demodulation result.
9. A computer-readable storage medium storing a computer program for executing the navigation communication method according to any one of claims 1 to 6.
10. An electronic device, the electronic device comprising:
a processor;
a memory for storing the processor-executable instructions,
wherein the processor is configured to execute the navigation communication method of any one of the above claims 1 to 6.
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