Chaotic sequence-based packet M element spread spectrum communication method and device

Abstract

The invention provides a chaotic sequence-based packet M element spread spectrum communication method and a device, and the method comprises the following steps: 1) dividing communication coded data to be sent into data blocks consisting of K code elements; 2) leading each data block to obtain and form a combination of a chaotic frequency regulation value sequence and a chaotic phase regulation value sequence according to a certain chaotic mapping relationship; 3) generating a chaotic frequency regulation, phase regulation and spread spectrum signal set through the combinations of the chaoticphase regulation value sequences and the chaotic phase regulation value sequences, overlapping various elements of the set into a group of concurrent chaotic frequency regulation, phase regulation and spread spectrum signals, further adding synchronous signals and then transmitting; and 4) carrying out signal channel equalization and synchronization on the received data, detecting and judging by copy correlation and recovering coded information according to the chaotic mapping relationship. The method can effectively reduce the peak-to-average ratio of communication transmitted signals, lead the mutual interference level among the various concurrent signals to be low, lead the number of the concurrent signals to be large and effectively improve the acoustic communication performance underlow signal noise ratio.

Description

technical field [0001] The invention belongs to the technical field of underwater acoustic communication, in particular, the invention relates to a communication method and device for group M-element spread spectrum communication using chaotic sequences. The invention is mainly used in long-distance underwater acoustic communication. Background technique [0002] In the field of underwater acoustic communication, the communication between 20km and 200km is generally regarded as long-distance communication. Due to the serious propagation attenuation of the underwater acoustic channel, the underwater acoustic communication signal is often misinterpreted due to the low demodulation signal-to-noise ratio after long-distance propagation. The code rate increases, so that normal communication cannot be performed. At present, in order to solve this problem, spread spectrum communication technology is usually used to improve the signal-to-noise ratio of demodulation by obtaining spr...

AI Technical Summary

Problems solved by technology

If the group M-ary spread spectrum communication method is adopted, the communication data rate can reach R = ln C M r / T , Compared with the conventional spread spectrum communication method, the lnC is improved M r times (where r is the number of M spread spectrum codes selected concurrently), and the core premise of using grouped M-ary spread spectrum communication is that the selected concurrent spread spectrum code sequences must be mutually orthogonal. In the patent of Wang Haibin et al. Using the chaotic FM sequence as the spread spectrum coding sequence (Wang Haibin et al., a M-ary spread spectrum communication method, 03156106.3, 2003), although it can obtain better orthogonal performance, but there is a large peak-to-average ratio when superimposed on each other concurrently. Lead to low emission efficiency, so its practicability and confidentiality are subject to certain restrictions

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