摘要
为了使用自动增益控制对接收信号的幅度进行动态压缩,采用统计接收端信号过门限瞬时值次数的方法,判断是否要调整原信号和基于对数或指数信号的变步长调整自动增益控制算法。在对数或指数信号变步长调整中,对数或指数信号之间是可以互相转换的,步长和收敛因子的选取受水声信道特性、信号幅度、噪声种类的影响。该方法已应用于水声信号接收系统,可较好地对输入信号的幅度进行动态压缩,还滤除了部分噪声的影响,达到了设定的期望值。实验结果表明,该方法抑制噪声能力强,跟踪速度快,适合在水声通信系统中应用。
To realize the synchronization and demodulation of frequency band in the receiving end,dynamic compression of received signal amplitude should be carried out through the automatic gain control（AGC）. The method that counts the number of instantaneous threshold,which the receiver signal passes,was used to judge whether the original signals should be adjusted and the AGC algorithm should be adjusted by vari-able step length based on logarithmic or index signals.In logarithmic or index signal variable step length adjustment,logarithmic or index signal can be mutually transformed between each other,and step length and the selection of convergence factor are influenced by the underwater acoustic channel characteristic,the signal amplitude and the noise type.The method was applied in the underwater acoustic signal receiving system,proving good for the dynamic compression of input signal,eliminating a part of the noise effect,and thus achieving the expected results.Experimental results show that the method has advantages of strong ability to resist noise,fast tracking speed,and therefore,it is suitable for underwater acoustic communication system.
出处
《解放军理工大学学报（自然科学版）》
EI
北大核心
2015年第3期213-219,共7页
Journal of PLA University of Science and Technology(Natural Science Edition)
基金
国家自然科学基金资助项目(61471308
61001142)
关键词
水声信号
自动增益控制
过门限次数
underwater acoustic signal
automatic gain control（AGC）
threshold number
