摘要
传统的有源降噪(ANC)系统的待抵消噪声中不包含有用信号,噪声希望被完全抵消;但在某些特殊的应用场合里,特别是对引入新的声场极度敏感的舰艇环境,待抵消噪声(主要是舰艇自噪声)中包含有目标信号(有用信号),噪声被降低的同时,希望信号被保留,这就是具有信噪比处理增益的有源降噪系统。本文给出了这种系统的物理模型,提出了针对该系统的“信噪比处理增益”和“信号失真度”概念,并进行了数理分析和仿真实验。研究表明:该系统能够降低噪声,但是信号会失真,影响该系统性能的最主要因素是参考输入端信噪比的大小。也就是说,只要合理设计参考噪声的拾取方式,该系统能够用于抵消舰艇自噪声,在获得较高的信噪比处理增益的同时,保持较低的信号失真度。
Noise is always expected to be cancelled completely in a conventional active noise cancellation(ANC)system because it does not contain any useful information in most cases.But in some special applications,particularly,introducing a new sound field in naval ships is an extremely sensitive matter,the main input is composed of noise(the self-noise of ships mostly)and target signals(useful signals).It is hoped to have the highest level of noise reduction while to retain the signal energy to the greatest extent.The system used to realize the above idea is called an ANC system with SNR processing gain.Its physical model is built,the conceptions of“SNR processing gain”and“signal distortion” for the system are defined and introduced,and its mechanical analysis and simulations are done.The classical ANC principle is applied to this system,the noise can be cancelled but the signal will be distorted to some extent,and the result shows that the most important factor that influences the system performance is the SNR of the reference input.In other words,if the way of picking up the reference input is designed appropriately,the system can cancel the self-noise of ships with a higher SNR processing gain and a lower distortion level of signal.
出处
《振动与冲击》
EI
CSCD
北大核心
2007年第7期152-155,163,共5页
Journal of Vibration and Shock
基金
水声技术国防科技重点实验室基金项目资助(51445070101ZS2301)
关键词
声学
舰船辐射噪声抵消
有源降噪
信噪比处理增益
信号失真度
信噪比
acoustics,ship radiation noise cancellation,active noise cancellation(ANC),signal noise ratio(SNR)processing gain,signal distortion,signal noise ratio(SNR)
