Signal transmission method based on acoustic orbital angular momentum multiplexing

Abstract

The invention discloses a signal transmission method based on acoustic orbital angular momentum multiplexing. The method comprises the following steps that a plurality of mini loudspeakers form a loudspeaker array, sound waves of acoustic orbital angular momentums of different orders are generated as independent channels, wherein the sound waves of the acoustic orbital angular momentums of the different orders are different channels, and each group of binary data streams formed by 0-1 are encoded on amplitudes and phases of the sound waves of one group of channels as signal sources; and (2) the signal source of an input end transmits a sound wave signal of the signal source to demodulation metasurfaces which are arranged in sequence through a transmission pipe, and the sound wave signal detected by a microphone is arranged at the back of each demodulation metasurface and is the original input data stream. According to the signal transmission method based on acoustic orbital angular momentum multiplexing, the signals can be simultaneously loaded to sound pressure values of vortex fields of different orders to carry out synchronous transmission, and meanwhile, the designed demodulation metasurfaces can be utilized to realize high-efficiency separation and detection of different pieces of information.

Description

technical field [0001] The invention relates to a signal transmission method based on acoustic orbital angular momentum multiplexing, and belongs to the field of acoustic wave signal transmission. Background technique [0002] The ocean is a huge treasure house of various minerals, oil and gas and biological resources. With the development of human civilization, the strategic position of the ocean has become increasingly prominent. All countries are actively developing and utilizing ocean resources and space, and adopt various advanced means to realize the long-distance transmission of underwater communication signals. The further deepening of ocean exploration puts forward higher requirements for the efficient transmission of communication signals under water. In seawater, the attenuation of light waves and radio waves is very serious, and the propagation distance is very limited, which is difficult to meet the needs of human ocean activities. Acoustic waves are currently...

AI Technical Summary

Problems solved by technology

However, since the signal to be transmitted may have aliasing in different time or frequency ranges, the received signal after encoding and decoding will be greatly distorted from the original signal

In addition, using only one degree of freedom of time or frequency as the base vector of codec can only expand the channel capacity in a limited range

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