一种新的具有信噪比处理增益的前馈型ANC系统设计

对于噪声场中混有有用信号的环境,例如车辆(语音和发动机噪声)和舰艇(目标信号和舰艇自噪声),传统的有源降噪(ANC)系统并不能有效工作。针对这一情况,提出了一种新的结构:将独立成分分析(ICA)技术用于ANC系统参考输入的前置预处理。这种结构使ANC系统能够更加灵活地设置参考传感器的位置;得到的参考输入较之传统ANC系统有着更低的信噪比(SNR)和(与信号的)相关性。因此系统可以有更快的收敛速度、更高的信噪比处理增益和更小的信号失真度;同时具备了选择性地噪声抵消能力。对系统结构作了理论分析,并利用实测数据进行了计算机仿真实验,其结果表明该系统较之传统的ANC系统有着更好的性能。

Novel Design of Feedforward ANC System with SNR Process Gain

In some special applications of active noise cancellation (ANC) system, some useful signals may exist in the noise field, for example, the cases of vehicles (sound signals and engine noises) and ships (target signals and self-noises of ships), where the traditional ANC system doesn't work well. In view of this situation, a novel system structure is proposed in which the reference input of ANC system is pretreated using the technology of independent component analysis (ICA). Benefiting from the new system structure, the location of reference sensors can be more flexible and the signal-to-noise ratio (SNR) and correlation between new reference input and signals are lower compared with those in the traditional ANC system. Consequently, better performance of system is obtained, such as faster convergence speed, higher SNR process gain and lower level of signal distortion. Another important advantage is that the capability of selective noise cancellation is achieved. The theoretical analysis is done and computer simulative experiments are also accomplished using real data. The experiment results show that the proposed scheme is more effective than the traditional ANC system for these especial applications.