Subspace Noise Estimation and Gamma Distribution Based Microphone Array Post-filter Design  

作　　者：CHENG Ning LIU Wenju WANG Lan 

机构地区：[1]Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China [2]The Chinese University of Hong Kong, Shatin, Hong Kong, China [3]National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China

出　　处：《Chinese Journal of Electronics》2011年第2期293-298,共6页电子学报（英文版）

基　　金：This work is supported in part by the National Natural Science Foundation of China （No.90920002, No.60772165, No.90820303 and No.90820011）, Natural Science Foundation of Guangdong Province, China （No.10478922035-X004936） and the National Grand Fundamental Research 973 Program of China （No.2004CB318105）.

摘　　要：This paper presents a novel method to design the microphone array post-filter. The key issue of post-filter is to accurately estimate the noise power spectrum, thus a subspace based noise estimation method is proposed. Furthermore, the Gamma probability density function is used to describe the signal power spectrum distribution and the signal-plus-noise subspace dimension is determined by maximizing the probability density signal to noise ratio. The noise power spectrum can be computed either with the speech or without the speech, using the eigenvalues corresponding to the noise subspace. With the same Gamma distribution assumption, a post-filter estimation method is proposed. Experiments show that the proposed noise estimation performs better than the conventional VAD based method. The post-filter can obtain a significant gain over the comparing methods in terms of quality measures of the enhanced speech.

关 键 词：Microphone array post-filter Gamma distribution Speech enhancement Subspace. 

分 类 号：TN915.1[电子电信—通信与信息系统] TN911.23[电子电信—信息与通信工程]