阅读说明：本技术 一种多体制水声通信网络的信号兼容方法 (Signal compatibility method of multi-body underwater acoustic communication network ) 是由 谢哲 张宏滔 戴志春 朱小辉 王桢铎 于 2021-06-29 设计创作，主要内容包括：本发明公开一种多体制水声通信网络的信号兼容方法。其方法为：节点A和B均能利用多种通信体制传输信息,首先A发送控制帧信号RTS至B,B利用RTS感知信道特征并结合先验信息,选择最优通信体制,将选择结果传回A；然后A发送信息至B,B解码信息,根据结果更新通信体制解码性能数据库,如果解码正确,告知A：信息传输正确,过程结束,如果解码不正确,选择最优通信体制,将选择结果通过ACK传回A,并告知A：信息传输错误,重新开始下一回合RTS->CTS->数据->ACK的交互过程,直至传输正确或到达预设最大交互次数N。本发明通过实时感知信道并结合历史数据来实现多种通信体制的兼容和优选,提高了水声通信网络的环境适配和任务自适应能力。(The invention discloses a signal compatibility method of a multi-body underwater acoustic communication network. The method comprises the following steps: the method comprises the following steps that a node A and a node B can transmit information by utilizing various communication systems, firstly, the node A sends a control frame signal RTS to the node B, the node B utilizes the RTS to sense channel characteristics and combines prior information to select an optimal communication system, and a selection result is transmitted back to the node A; then A sends information to B, B decodes the information, upgrade the decoding performance database of the communication system according to the result, if decode correctly, tell A: and (3) the information transmission is correct, the process is finished, if the decoding is incorrect, the optimal communication system is selected, the selection result is returned to A through ACK, and the A is informed: and if the information is transmitted incorrectly, restarting the interactive process of next round RTS- > CTS- > data- > ACK until the information is transmitted correctly or the preset maximum interactive times N are reached. The invention realizes the compatibility and optimization of various communication systems by sensing the channel in real time and combining historical data, and improves the environment adaptation and task self-adaptation capability of the underwater acoustic communication network.)

1. A signal compatibility method of a multi-body underwater acoustic communication network is characterized in that: the method comprises the following steps that a node A and a node B can transmit information by utilizing various communication systems, wherein the node A needs to transmit the information to the node B, firstly, the node A sends a control frame signal RTS to the node B, the node B selects an optimal communication system by utilizing RTS to sense channel characteristics and combining prior information, and a selection result is transmitted back to the node A through a control frame signal CTS; then A sends information to B with the communication system recommended by B, B decodes the information, updates the communication system decoding performance database according to the result, if the decoding is correct, informs A through a control frame signal ACK: and (3) the information transmission is correct, the process is finished, if the decoding is incorrect, the channel characteristics are sensed again by using the received information, the optimal communication system is selected, the selection result is returned to A through ACK, and the A is informed: and if the information is transmitted incorrectly, restarting the interactive process of RTS- > CTS- > data- > ACK until the information is transmitted correctly or the preset maximum interactive times N are reached.

2. The signal compatibility method of the multi-body hydroacoustic communication network according to claim 1, characterized in that: the transmission of control frame signals RTS, CTS and ACK adopts a steady communication system K, the initial states A and B all receive signals by the communication system K, the node B has a communication system decoding performance database which is mainly used for recording the communication system of B and the communication accuracy of each communication system, and the method specifically comprises the following steps:

(1) in the first round, firstly, a sends control frame signals RTS to B, the RTS does not carry a recommended communication system, then B receives the RTS, the RTS senses channel characteristics, an optimal communication system X is selected, X is returned to A through a control frame signal CTS, then B sets itself to be received in an X communication system, then A sends information DATA to B in the communication system X, and finally B decodes DATA, if decoding is correct, the communication success rate of X in a communication system decoding performance database is updated to be R ═ M +1)/(L +1), M is the number of times of DATA transmission correct for X in the previous round, L is the number of times of DATA transmission correct for X in the previous round, and then B sends control frame signals ACK to A to inform A: the information DATA is correctly transmitted, all the processes are finished, if the decoding is incorrect, the communication success rate of X in the communication system decoding performance database is updated to be R/(L +1), then B uses the DATA to sense the channel characteristics again, selects the optimal communication system X1, transmits X1 back to A through ACK, and informs A: when the information DATA is wrong in transmission, the next round of transmission is restarted, and after the ACK is sent, the B sets the B to receive the information in a K communication system;

(2) the second round, firstly, a sends a control frame signal RTS to B, wherein the RTS carries a recommended communication system X1, then B receives the RTS, and by using RTS to sense channel characteristics, it calculates that the recommended communication system is X2, if X1 is the same as X2, X2 is selected as the optimal communication system, let X be X2, if X1 is not the same as X2, if X1 and X2 both belong to the communication system decoding performance database, the communication success rates of the two are compared, the communication system with high power is selected as the optimal communication system, let X be (the communication success rate is high in X1 and X2), if X1 belongs to the communication system decoding performance database, X2 does not belong to the communication system decoding performance database, let X be X2, if X2 belongs to the communication system decoding performance database, X1 does not belong to the communication system decoding performance database, let X be X1, if X1 and X2 both belong to the communication performance database, after X is X2, B selects the optimal communication system X, X is transmitted back to A through a control frame signal CTS, then B sets itself to be received in the X communication system, then A transmits information DATA to B in the communication system X, finally B decodes DATA, if the decoding is correct, the communication success rate of X in the communication system decoding performance database is updated to R (M +1)/(L +1), then B transmits a control frame signal ACK to A, and A is informed: the information DATA is correctly transmitted, all the processes are finished, if the decoding is incorrect, the communication success rate of X in the communication system decoding performance database is updated to be R/(L +1), then B uses the DATA to sense the channel characteristics again, selects the optimal communication system X1, transmits X1 back to A through ACK, and informs A: when the information DATA is wrong in transmission, the next round of transmission is restarted, and after the ACK is sent, the B sets the B to receive the information in a K communication system;

(3) the third to N-1 th rounds are the same as the second round;

(4) in the Nth round, A sends control frame signals RTS to B, the RTS carries a recommended communication system X1, B receives the RTS, K is directly selected as an optimal communication system, the control frame signals CTS are transmitted back to A, B sets the information to be received in a K communication system, A sends information DATA to B in the communication system K, B decodes the DATA, the communication success rate of K is updated, the decoding result is informed to A through ACK, and all processes are finished.

Technical Field

The invention relates to an underwater acoustic communication technology, in particular to a signal compatibility method of a multi-body underwater acoustic communication network.

Background

The underwater acoustic communication network is more and more widely applied to marine scientific research and resource development, and can realize auxiliary navigation on an underwater vehicle through multi-node combined positioning; the remote control of the underwater operation equipment can be realized through multi-node multi-hop relay; tasks such as large-scale ocean perception and monitoring can be achieved through multi-node networking information interaction. Each application service needs a specific communication system for support, for example, underwater assisted navigation needs high-speed information interaction between nodes to ensure the real-time performance of navigation, so that the nodes need to select a communication system with high communication rate; remote control requires long-distance error-free information transmission, so that a node needs to select a communication system with strong anti-interference capability; the large-range ocean perception and monitoring requires that the nodes select a communication system with both communication rate and anti-interference capability. Therefore, a single communication system cannot meet various application requirements of the underwater acoustic communication network.

On the other hand, the underwater acoustic channel is a time-space-frequency variable channel, the channel environment is complex and variable, and the main influence on the communication comprises: 1. intersymbol interference caused by multipath effects of the underwater acoustic channel; 2. energy loss, frequency offset and phase offset due to uneven seawater media; 3. marine environmental noise and the like, and each communication system has the advantages and short boards of coping with channel influence factors, so that the single communication system cannot meet the adaptability requirement of the underwater acoustic communication network on the variable marine environment.

Currently, the mainstream communication systems of underwater acoustic communication include Direct Sequence Spread Spectrum (DSSS), Orthogonal Frequency Division Multiplexing (OFDM), Multiple Frequency Shift Keying (MFSK), Multiple Phase Shift Keying (MPSK), and the like. The DSSS system carries information on a long code sequence, has advantages in anti-interference and anti-multipath performance, has the defect of low communication rate and is mainly used for long-distance information transmission; the OFDM system carries information on a plurality of subcarrier phases which are transmitted in parallel, the communication rate can be very high, and the defect is that the signal peak-to-average ratio is high, so that the OFDM system is mainly used for short-distance high-speed communication; the MFSK system carries information on a plurality of subcarrier energies, and the communication rate and the transmission reliability are between those of the DSSS system and the OFDM system; the MPSK system carries information on a phase of a single carrier, has a low signal peak-to-average ratio and a high communication rate, but is limited in performance by complex intersymbol interference caused by an underwater acoustic time-varying multipath channel, and is generally suitable for an environment with a good channel condition. The underwater acoustic communication systems have respective advantages in the aspects of communication capacity, reliability, concealment and the like, and have strong complementarity.

Therefore, in the face of increasing application service requirements and complex and variable marine environments, the problem that the traditional underwater acoustic communication network with a single communication system is weak in environment adaptation and multi-task support capability exists, multi-system communication is an effective method for improving the underwater acoustic communication environment adaptation and multi-task support capability, and how to complete multi-system compatibility and optimization among nodes is a problem to be solved urgently.

Disclosure of Invention

The invention aims to provide a signal compatibility method of a multi-system underwater acoustic communication network, aiming at solving the problem that an optimal communication system cannot be selected in a self-adaptive manner among multi-system nodes according to marine environment change and a steady communication link is established.

The object of the present invention is achieved by the following technical means. A method for compatible signals of a multi-body water making acoustic communication network is characterized in that nodes A and B can transmit information by using multiple communication systems, the A needs to transmit the information to the B, firstly, the A sends control frame signals RTS to the B, the B selects an optimal communication system by using RTS to sense channel characteristics and combining prior information, and a selection result is transmitted back to the A by using a control frame signal CTS; then A sends information to B with the communication system recommended by B, B decodes the information, updates the communication system decoding performance database according to the result, if the decoding is correct, informs A through a control frame signal ACK: and (3) the information transmission is correct, the process is finished, if the decoding is incorrect, the channel characteristics are sensed again by using the received information, the optimal communication system is selected, the selection result is returned to A through ACK, and the A is informed: and if the information is transmitted incorrectly, restarting the interactive process of next round RTS- > CTS- > data- > ACK until the information is transmitted correctly or the preset maximum interactive times N are reached. The method realizes the compatibility and optimization of various communication systems by sensing the channel in real time and combining historical data, and improves the environment adaptation and task self-adaptation capability of the underwater acoustic communication network.

The transmission of control frame signals RTS, CTS and ACK all adopt a steady communication system K, the initial states A and B all receive signals in the communication system K, the node B is provided with a communication system decoding performance database which is mainly used for recording the communication system of B and the communication accuracy of each communication system, and the specific communication process is as follows:

(1) in the first round, firstly, a sends control frame signals RTS to B, the RTS does not carry a recommended communication system, then B receives the RTS, the RTS senses channel characteristics, an optimal communication system X is selected, X is returned to A through a control frame signal CTS, then B sets itself to be received in an X communication system, then A sends information DATA to B in the communication system X, and finally B decodes DATA, if decoding is correct, the communication success rate of X in a communication system decoding performance database is updated to be R ═ M +1)/(L +1), M is the number of times of DATA transmission correct for X in the previous round, L is the number of times of DATA transmission correct for X in the previous round, and then B sends control frame signals ACK to A to inform A: the information DATA is correctly transmitted, all the processes are finished, if the decoding is incorrect, the communication success rate of X in the communication system decoding performance database is updated to be R/(L +1), then B uses the DATA to sense the channel characteristics again, selects the optimal communication system X1, transmits X1 back to A through ACK, and informs A: when the information DATA is wrong in transmission, the next round of transmission is restarted, and after the ACK is sent, the B sets the B to receive the information in a K communication system;

(2) the second round, firstly, a sends a control frame signal RTS to B, wherein the RTS carries a recommended communication system X1, then B receives the RTS, and by using RTS to sense channel characteristics, it calculates that the recommended communication system is X2, if X1 is the same as X2, X2 is selected as the optimal communication system, let X be X2, if X1 is not the same as X2, if X1 and X2 both belong to the communication system decoding performance database, the communication success rates of the two are compared, the communication system with high power is selected as the optimal communication system, let X be (the communication success rate is high in X1 and X2), if X1 belongs to the communication system decoding performance database, X2 does not belong to the communication system decoding performance database, let X be X2, if X2 belongs to the communication system decoding performance database, X1 does not belong to the communication system decoding performance database, let X be X1, if X1 and X2 both belong to the communication performance database, after X is X2, B selects the optimal communication system X, X is transmitted back to A through a control frame signal CTS, then B sets itself to be received in the X communication system, then A transmits information DATA to B in the communication system X, finally B decodes DATA, if the decoding is correct, the communication success rate of X in the communication system decoding performance database is updated to R (M +1)/(L +1), then B transmits a control frame signal ACK to A, and A is informed: the information DATA is correctly transmitted, all the processes are finished, if the decoding is incorrect, the communication success rate of X in the communication system decoding performance database is updated to be R/(L +1), then B uses the DATA to sense the channel characteristics again, selects the optimal communication system X1, transmits X1 back to A through ACK, and informs A: when the information DATA is wrong in transmission, the next round of transmission is restarted, and after the ACK is sent, the B sets the B to receive the information in a K communication system;

(3) the third to N-1 th rounds are the same as the second round;

(4) in the Nth round, A sends control frame signals RTS to B, the RTS carries a recommended communication system X1, B receives the RTS, K is directly selected as an optimal communication system, the control frame signals CTS are transmitted back to A, B sets the information to be received in a K communication system, A sends information DATA to B in the communication system K, B decodes the DATA, the communication success rate of K is updated, the decoding result is informed to A through ACK, and all processes are finished.

The invention has the beneficial effects that:

1. the invention can lead the multi-system nodes to select the optimal communication system for steady communication under the complicated and changeable underwater acoustic channels.

2. The invention is beneficial to the multi-system underwater acoustic communication network to meet diversified application requirements.

Drawings

Fig. 1 is a diagram of a process of signal compatible communication of a multi-body underwater acoustic communication network.

Detailed Description

The invention will be described in detail with reference to the following figures and examples:

in this embodiment, the node a needs to transmit the DATA information to the node B, and a maximum of 4 transmission rounds are preset, where each round includes: a sends control frame signals RTS to B, B replies control frame signals CTS to A, A sends DATA to B, and B replies control frame signals ACK to A. The communication center frequency is 4.5kHz, the bandwidth is 3kHz, the sampling rate is 64kHz, A and B are compatible with four communication systems, namely direct sequence spread spectrum (later replaced by DSSS), multi-frequency shift keying (later replaced by MFSK), multi-phase shift keying (later replaced by MPSK) and orthogonal frequency division multiplexing (later replaced by OFDM). DSSS communication system is adopted for transmission of control frame signals RTS, CTS and ACK, and initial states of A and B are as follows: receiving by a communication system DSSS; .

(1) In the first round, firstly, a sends control frame signals RTS to B, the RTS does not carry a recommended communication system, then B receives the RTS, the RTS senses channel characteristics, an optimal communication system is selected to be OFDM, the selection result is returned to A through a control frame signal CTS, then B sets itself to be received in the OFDM communication system, A sends information DATA to B through the communication system OFDM, finally B decodes DATA, the decoding result is known to be wrong through a check code, the number of times of accumulating the DATA transmitted through the OFDM in the previous round is 25, the number of times of accumulating the DATA transmitted through the common OFDM in the previous round is 50, therefore, the communication success rate of the OFDM in the communication system decoding performance database is updated to be R/(L +1) and returned to be 25/(50+1) to be 49.0%, then B senses the channel characteristics again through the DATA, the optimal communication system MPSK is selected, MPSK passes through ACK A, and inform A: and if the information DATA is transmitted in error, the next round of transmission is restarted, and after the ACK is sent, the B sets the B to receive the information DATA in the DSSS communication system.

(2) The second round, firstly A sends control frame signal RTS to B, RTS carries recommended communication system MPSK, B receives RTS, uses RTS to sense channel characteristic, calculates recommended communication system OFDM, checks communication system decoding performance database, finds that there is no record of MPSK in communication system decoding performance database, so selects optimum communication system MPSK, sends back selection result to A through control frame signal CTS, B sets itself to be received by MPSK communication system, A sends information DATA to B through communication system MPSK, B decodes DATA, and knows decoding result error through check code, communication system decoding performance database adds MPSK, its communication success rate is updated to R/(L +1) ═ 0/(1) ═ 0%, then B senses channel characteristic again by DATA, selects optimum communication system MFSK, send MFSK back to A via ACK, and inform A: and if the information DATA is transmitted in error, the next round of transmission is restarted, and after the ACK is sent, the B sets the B to receive the information DATA in the DSSS communication system.

(3) The third round, firstly A sends control frame signal RTS to B, RTS carries recommended communication system MFSK, then B receives RTS, using RTS to sense channel characteristic, calculates recommended communication system OFDM, checking communication system decoding performance database to find that communication success rate of MFSK and OFDM is 57.1% and 49.0%, therefore, selects optimal communication system MFSK, sends back selection result to A through control frame signal CTS, then B sets itself to be received by MFSK communication system, A sends information DATA to B through communication system MFSK, finally B decodes DATA, decoding result is wrong through check code, communication success rate of MFSK in communication system decoding performance database is updated to R M/(L + 1): 40/(70+ 1): 56.3%, then B uses DATA to sense channel characteristic again, selects communication system MPSK, MPSK is sent back to A through ACK, and A is informed: and if the information DATA is transmitted in error, the next round of transmission is restarted, and after the ACK is sent, the B sets the B to receive the information DATA in the DSSS communication system.

(4) And in the fourth round, firstly, a sends control frame signals RTS to B, the RTS carries a recommended communication system MPSK, then, B receives the RTS, DSSS is directly selected as an optimal communication system, the control frame signals CTS return to A, then, B sets the DSSS communication system to receive the information, A sends information DATA to B in the communication system DSSS, finally, B decodes the DATA, the decoding result is correct through a check code, the communication success rate of the DSSS in the communication system decoding performance database is updated to be R (M +1)/(L +1) (82+1)/(99+1) ═ 83.0%, the decoding result is informed to A through ACK, then, B sets the DSSS communication system to receive the information, and all the processes are finished.

The method realizes environment self-adaptive steady communication by continuously sensing channel characteristics and simultaneously updating and selecting an optimal communication system for transmitting information by combining prior information, passes theoretical and simulation verification, and is applied to the project of 'multi-body underwater acoustic communication heterogeneous network system technology'.

It should be understood that equivalent substitutions and changes to the technical solution and the inventive concept of the present invention should be made by those skilled in the art to the protection scope of the appended claims.