LS码在水声扩频中的应用及估计

水声多径干扰限制了水声直接扩频通信系统的进一步应用，选取性能更好的扩频序列可以提高水声扩频系统的抗干扰性能。在讨论了LS码特性的基础上，提出了将LS码应用于水声直接扩频通信中，并分析了LS码应用的优势。通过多径瑞利水声信道模型仿真，验证了LS码水声扩频通信的良好性能。利用了二次谱和奇异值分解的方法对LS码水声直扩信号的扩频序列进行了估计。仿真结果表明，该方法在信噪比为-11dB时还能准确的估计出LS码。

Application and Estimation of LS Code in Underwater Acoustic Spread-spectrum Communication

The further application of underwater acoustic spread-spectrum communication system is limited by multipath interference, so the choice of spread spectrum sequences with better performances can im- prove the anti-jamming performances of underwater acoustic spread spectrum system. Based on discussion of LS code properties, LS codes is proposed for underwater acoustic spread- spectrum communication , and the superiority of its application also analyzed in this paper. Simulation on rayleigh channel model of un- derwater acoustic indicates good performances of the spread-spectrum communication based on LS code. With power- spectrum processing and singular value decomposition, the spread spectrum sequence of un- derwater acoustic spread-spectrum signal based on LS code is estimated. The simulation results shows that with this method,the LS code can be estimated correctly in the condition of SNR =- 11 dB.