一种基于滤波器组设计的多频带组合信号增强方法

A multi-band combined signal enhancement method based on filter bank design

针对低信噪比情况下未知多频带组合信号增强及其检测问题,提出了一种基于滤波器组设计的多频带组合信号增强方法。首先,依据耳蜗时频分解原理设计伽马通滤波器组,对传感器采集数据进行分频带处理;然后,根据信号与背景噪声在强度和稳定性上的差异性,对各频带数据进行方差归一化处理,建立判决统计量;最后,依据判决统计量对各频带数据进行判决处理,实现对多频带组合信号增强。数值仿真结果表明,在仿真条件下,该方法能够将数据中未知多频带组合信号信噪比提高6 dB以上,在信号频带未知情况下实现了对多频带组合信号的增强,提升了能量累积检测方法对未知多频带组合信号的检测效果。

For enhancement and detection of unknown multi-band combined signal under low signal-to-noise ratio, a multi-band combined signal enhancement method based on filter bank design is proposed. Firstly, according to the time-frequency decomposition principle of cochlear, a Gammatone filter bank is designed to divide the data collected by sensor into different frequency bands. Then, according to the differences of intensity and stability between signal and background noise, the normalized variance processing of the data in each frequency band is carried out to establish the decision statistics, by which, the data in different frequency bands are weighted, so that the multi-band combined signal can be enhanced without searching single filter band. The numerical simulation results show that, under the simulation conditions, the signal-to-noise ratio of the unknown multi-band combined signal is increased by more than 6 dB. When the signal frequency band is unknown, this method can enhance the multi-band combined signal and improve the detection effect of the energy accumulation method on unknown multi-band combined signal.