Application of Dual Microphone Adaptive Echo Cancellation System in the Communication EnvironmentImprovement

• Main Authors: TING-HONG YEH, 葉庭宏
• Other Authors: ZHAO-NAN WANG
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/zzga53

碩士 === 國立臺灣大學 === 工程科學及海洋工程學研究所 === 106 === This paper presents a dual-microphone method based on the Microphone Array theorem, which develops a system that can be applied to a microphone device for communication purposes. The main purpose is to eliminate the ambient noise and the echo of the speaker due to time delay (Come from one''s own way or each other) ,in order to create a more comfortable communication environment. Least Mean Squares filter(LMS filter), Normalized Least Square filter(NLMS filter) and Recursive Least Square filter(RLS filter) are used with deep learning to find the most suitable parameters and algorithm to optimize the anti-noise effect. To compare with a method which is the more intuitive way to eliminate noise, we call it''s ingle microphone method" in this paper. In the anti-noise system, the filter works mainly through two pairs of relevant signals to match, find and eliminate the noise part of the noise, and the greater the correlation between the more accurate, the more accurate to find Out of the noise section. Compared to the single-microphone method, the dual-microphone method is used to compare the two signals because of the same space and the time difference is extremely short, so the correlation is large, can more effectively find the noise and eliminate. The default of the study is the case of remote meetings, during communication, sometimes the both sides speak at the same time. At this point the microphone will receive our voice, as well as the sound of dialogue that comes from the speaker of communication equipment. After the transmission the other party will receive our message and their own echo, both sounds mixed together makes the signal blurred, so the communication cannot proceed smoothly. This article calls this situation as "Double Talk" which cause the communication interference. The dual-microphone device is used to solve such problems. The results of the experiment can be proved that the dual-microphone method has good results in dealing with the call, whether it is single talk or double talk, after the treatment by the dual-microphone system can effectively anti-noise.