A Space-Time Channel Multiplexing Method for Multistatic Sonar

Abstract

The invention relates to the field of processing of a sonar signal, and particularly relates to a multi-base sonar space-time channel multiplexing method. The method comprises the following steps of obtaining a space-time code signal modulated in a pseudo random way; distributing independent and mutually orthogonal space-time code groups for transmitting terminals of a multi-base system; encoding the transmitting address and transmitting time of each transmitting signal; copying the related detection on the received signal, and distinguishing whether the detection signal of the corresponding transmitting terminal is contained in the received signal; extracting a time code, and using the space-time signal code of the corresponding base to carry out maximum likelihood decoding; and obtaining the information of the transmitting address and the transmitting time of the detection signal, namely the space-time information. The method has the advantages that the correlation between code elements of the space-time code is reduced, the high-efficiency multiplexing of the multi-base sonar space-time channel is realized by the accurate evaluation of the space-time information of any received signal, the time of the multi-base sonar system is improved, and the utilization rate of frequency bands is improved.

Description

technical field [0001] The invention relates to the field of sonar signal processing, in particular to a multi-base sonar space-time channel multiplexing method. Background technique [0002] Multi-base sonar is a sonar system with spatially separated transceiver devices. Single or multiple sound sources emit sound waves, and single or multiple receivers receive the scattered echoes of the target. By measuring the reflection direction and time delay of the target echo, the multi-base sonar Direction and ranging, and then solve the target position through the positional relationship between the transceiver equipment and the sonar positioning equation. According to the number of sending and receiving devices, multi-base sonar can be divided into several types: one sending and multiple receiving, multiple sending and one receiving, and multiple sending and multiple receiving. Multi-base sonar combines the working characteristics of active and passive sonar, and has the advanta...

AI Technical Summary

Problems solved by technology

In the European patent "Method for the multistatic detection and locating of a mobile craft through the use of digital broadcasting transmitters", it is proposed that each transmitter of the multi-base station adopts signals of different carrier frequencies in order to distinguish them at the receiver. However, for multi-base For sonar systems, the frequency band resources are limited, so that this method can only be applied in the case of a small number of transmitters. At the same time, the patent also involves how to distinguish detection signals from different transmission times

In the application of multi-mode and multi-base sonar, the composition of the received signal at the receiving end at a certain moment is very complex, including direct waves and target echoes from different transmitting ends in space and at different transmitting times in time. If the space-time information of the received signal cannot be obtained, the ranging and direction finding of the target cannot be realized, let alone the positioning optimization algorithm.

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