【作者】 蒋国军；

【导师】 刘国枝；

【作者基本信息】 哈尔滨工程大学 ， 船舶与海洋工程， 2005， 硕士

【摘要】 作为强背景干扰下工作的被动定位声纳系统，其第一要务是要高可靠地完成信号的检测。被动信号检测的最佳检测器是能量检测器，但是能量检测器往往因为背景干扰的起伏和信噪比的劣化导致检测性能的下降。 双谱检测由于具有很好的高斯干扰抑制能力，在瞬态信号检测方面具有能量检测不具有的优势，将双谱检测和能量检测结合构成的联合检测系统利用了水声信号中的二阶、三阶统计信息，增加了所利用的信息量，且能在更大程度上适应复杂水声环境变化，改善和提高水声信号的检测性能。 本文通过对高斯平稳随机过程和爆炸波瞬态信号的双谱特性分析，有效利用双谱特性差别进行瞬态信号检测。与能量检测器相比，双谱检测器具有更好的抗高斯噪声能力，试验仿真结果证明了这一点。 为了进一步提高瞬态信号检测性能，我们构建了双谱检测和能量检测相结合的联合检测系统，试验仿真结果表明，两者的结合具有更好的抗噪声能力和信号检测能力。更多还原

【Abstract】 For passive sonar system operating in the background of strong interference, the most important task is to fulfill signal detection with high reliability. The optimum detector for passive detection is energy detector. Yet energy detector usually deteriorates due to fluctuation of background interference and a decrease in SNR.Bispectrum detection features a good capability in depressing Gaussian interferences, so it outperforms energy detector in the case of instantaneous signal detection. By incorporating bispectrum detection and energy detection method, a coalition detection system can be developed, which can obtain more information by making use of the second and third order statistics of underwater acoustic signals, and can adapt to a broader extent to complicated underwater acoustic environments, thus greatly improving underwater acoustic signal detection performances.In this paper stationary Gaussian random processes as well as bispectrums of instantaneous explosive wave signals are analyzed, and the differences between bispectrums are efficiently used for instantaneous signal detection. As compared with energy detector, bispectrum detector can depress Gaussian noise much better, which is proved via test simulation. In order to further increase instantaneous signal detection performances, we have constructed a coalition detection system upon bispectrum detection and energy detection. Test simulation results show that the incorporation of bispectrum detection and energy detection can bring out a much better capability in noise reduction and signal detection.更多还原