A Parallel Combined Spread Spectrum Underwater Acoustic Communication Method with Interleaved Gold Mapping Sequences

Abstract

The invention discloses a parallel combined spread spectrum underwater acoustic communication method of an interleaved Gold mapping sequence. The method comprises the following steps: step 1) selecting r information sequences from a spread spectrum sequence set according to a data-spread spectrum sequence mapping table at a signal transmitting end to perform multichannel interleaving to generate an information mapping sequence, selecting a sequence that is not related to the sequences in the spread spectrum sequence set as a synchronizing sequence, transmitting the synchronizing sequence andthe information mapping sequence into an underwater acoustic channel after performing quadrature modulation; and step 2) demodulating received signals to a complex baseband at a signal receiving end,performing Doppler compensation to obtain a received signal sequence, then obtaining L multichannel parameters by using the operation results of the synchronizing sequence and the received signal sequence, performing de-interleaving and multichannel merging on the received signal sequence by using these parameters, and performing operation to obtain r sequences, respectively performing maximum value calculation judgment on the r sequences by using M paths of correlators to obtain judgment symbols of transmitting sequences, and then obtaining sequence numbers of the transmitted r information sequences.

Description

technical field [0001] The invention relates to the field of underwater acoustic communication, more specifically, relates to a parallel combination spread spectrum underwater acoustic communication method of interleaving Gold mapping sequences. Background technique [0002] Parallel combined spread spectrum communication is a commonly used technology in underwater acoustic communication at present, and it has higher information transmission efficiency than ordinary direct sequence spread spectrum communication (DSSS) and M-ary spread spectrum (M-ray). Parallel combination spread spectrum is in M ​​orthogonal spread spectrum sequences, according to the information data to be transmitted, select r sequences among them, combine and send in parallel, and can transmit at the same time bits of information. In the formula, "[]" means to round x to an integer, It is a combination of r in M. As the number r of the selected sequence increases, the peak-to-average ratio of the tr...

AI Technical Summary

Problems solved by technology

Parallel combined spread spectrum often uses the Gold sequence as the spread spectrum code set, but the sum of the r Gold sequences is likely to have a strong correlation with other unselected sequences in the spread spectrum code set after the symbol majority transformation, forming a false peak , which seriously affects the communication performance of the system

The conventional solution is to select r information sequences from r Gold sequences of different families to avoid the appearance of false peaks, but the number of Gold sequence families is limited, which leads to a limited number of information sequences r

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