An underwater acoustic communication method combining time-anti-space-time block coding and adaptive equalization

Abstract

The invention relates to the field of underwater acoustic communication, in particular to an underwater acoustic communication method combining time-anti-space-time group coding and adaptive equalization. Design the corresponding time-anti-space-time block coding based on the traditional orthogonal space-time block coding principle; use the time-anti-space-time block coding to divide the symbol sequence transmitted on multiple sub-carriers into several sub-sequences; The encoded subsequence is filtered and multi-tone modulated, and multiple modulated signals are transmitted from different transmitting array elements; based on the principle of time-anti-space-time packet decoding, the estimated channel response and its time-inverse form are used to construct a decoding matrix, and the Filter the multi-tone demodulated signal for decoding processing; use the estimated channel response to calculate the range of symbols affected by multi-channel in the combined channel after decoding, select the length of the adaptive equalizer based on this standard, and analyze the decoded symbols. The sequence is equalized. The invention reduces the hardware and computational complexity of the receiving end, and achieves good suppression of ISI in the FMT underwater acoustic communication.

Description

technical field [0001] The invention relates to the field of underwater acoustic communication, in particular to an underwater acoustic communication method combining time-anti-space-time group coding and adaptive equalization. Background technique [0002] There is a serious multi-path effect in the underwater acoustic channel. When the communication bandwidth is very wide, if the multi-carrier modulation technology is used, the range of symbols affected by the multi-path effect will reach tens or even hundreds of symbols, which will greatly increase. Complexity of Inter-Symbol Interference (ISI) suppression at the receiver. Therefore, in high-speed broadband underwater acoustic communication, multi-carrier modulation technology is usually used. Orthogonal Frequency Division Multiplexing (OFDM) is the most commonly used multi-carrier technology in underwater acoustic communication. It divides the communication frequency band into multiple sub-carriers with the same bandwid...

AI Technical Summary

Problems solved by technology

Although the above technologies can effectively suppress inter-symbol interference, the use of receive diversity will increase the hardware and computational complexity of the receiving end, increase the power consumption of the receiving system, and is not conducive to the miniaturization and low power consumption of underwater communication nodes

Time-reverse-space-time block coding (TR-STBC) technology is a space diversity technology suitable for frequency selective fading channels. This technology can use transmit diversity instead of receive diversity to provide high diversity gain. In addition, the matched filter in the decoding process The processing can also effectively compress the amplitude and range of ISI, which is beneficial to reduce the hardware and computational complexity of the receiving end; the patent application number is CN201510477828.0, a multi-input multi-output passive time-anti-water acoustic communication based on orthogonal space-time coding method, although this technology uses 1 / 2 code rate space-time block coding to improve the ISI suppression performance of passive underwater acoustic communication, but this technology only involves single-carrier underwater acoustic communication

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