基于LAS码与混沌的水下LPI波形设计  

Underwater LPI Waveforms Design Based on LAS Code and Chaos

作　　者：洪嘉翔[1] 易红[2] 张娟[1] 张林让[1] 

机构地区：[1]西安电子科技大学雷达信号处理国防科技重点实验室,陕西西安710071 [2]中国船舶重工集团公司第705研究所,陕西西安710072

出　　处：《鱼雷技术》2011年第6期433-437,478,共6页Torpedo Technology

摘　　要：鉴于水下探测对低截获概率(LPI)波形特性的需求,将混沌序列连续化后用以相位调制得到基本波形,然后用大区域同步(LAS)码对其分别作脉内、脉间调制设计出2种新波形,借助其模糊图的零延时切面和零频移切面直观比较了新波形与连续波(CW)、线性调频(LFM)、二进制相移键控(BPSK)、Costas等4种典型水下探测波形的分辨特性,并通过时间分辨常数和频率分辨常数作出量化分析。模糊图的非零频移切面被用以理想背景下各波形的多普勒敏感性比较,并通过Q函数进一步比较了它们的抗混响能力。对比分析表明,新设计的2种波形具有出色的距离分辨率和多普勒容忍性,且在整个实际所需探测速度范围上有很强的抗混响能力。In view of the requirement for low probability of intercept（LPI） waveform characteristics in underwater de-tection,we serialize the chaotic sequences and use it to modulate the signal phase such that the basic waveform is ob-tained.Then the large area synchronized（LAS） codes are introduced for both interpulse and intrapulse modulations to design two new waveforms.Relying on the zero-delayed section and zero-Doppler section of an ambiguity function,we compare the discrimination property of the two new waveforms intuitively with four kinds of typical underwater detec-tion waveforms,i.e.continuous waveform（CW）,linear frequency modulation（LFM） waveform,binary phase shift keying（BPSK） waveform and Costas waveform.Quantification analysis is made by their time resolution constants and frequency resolution constants.In addition,nonzero-Doppler section of an ambiguity function is used to compare their Doppler sensitivity characteristics under the ideal background,followed by a further comparison of reverberation sup-pression capability via the Q function.The results show that two new waveforms have outstanding distance resolution,Doppler tolerance and reverberation suppression capability over whole velocity ranges required by practical use.

关 键 词：自低截获概率 大区域同步(LAS)码 混沌 分辨特性 多普勒敏感性 抗混响性能 

分 类 号：TJ630.34[兵器科学与技术—武器系统与运用工程] TN911.7[电子电信—通信与信息系统]