摘要
传统的非高斯噪声信道下数字接收机中的非线性处理器,如:消波器、限幅器、熄灭器等,只是对噪声时域中的较大幅值进行简单处理,没有考虑实际噪声的统计分布特性,对噪声的抑制能力有限;α稳定分布模型虽然能很好地描述大气噪声等非高斯噪声的"重尾"特征,但其概率密度函数除特殊值外无闭式,在实际使用中带来很大不便。首先采用柯西高斯模型,可以对α稳定分布的概率密度函数进行很好的近似;然后通过估计得到的噪声的概率密函数来构建高斯化滤波器,并针对不同α值的对称α稳定(Symmetric alpha stable,SαS)分布非高斯大气噪声模型进行专门的高斯化处理;最后通过仿真对比,得出高斯化滤波器的性能明显优于传统非线性处理方法。
Several nonlinear filters, such as hard limiter, clipper and hold puncher, in tradition- al digital receivers only focus on larger amplitude in time domain and do not consider actual sta- tistical characteristics of noises, a stable distribution is a non-Gaussian model, which can be a- dopted to describe the ＂heavy-tailed＂ noise well. But there is no closed form expression of the probability density function （PDF） of a stable distribution model except for several special val- ues, which is inconvenient to use. Firstly the Cauchy Gaussian model （CGM） with specific ex- pressions of PDF is adopted to approximate a distribution model. Then Gaussianization filter is formulated by estimated PDF according to different value of a. At last simulation results indi- cate that this filter is better than traditional nonlinear filters.
出处
《数据采集与处理》
CSCD
北大核心
2013年第6期784-789,共6页
Journal of Data Acquisition and Processing
关键词
大气噪声
非高斯
Α稳定分布
柯西高斯模型
atmosphere noises
non-Gaussian
（CGM） a stable distribution
Cauchy Gaussian model
