Research On Echo Suppression In Emergency Rescue Communication Application

As the country’s increasing demand for coal resources, coal mining quantity is growing rapidly, so the accidents is increaseing greatly. This pose a serious threat to the miner’s life safety and state property. When a serious accident happened, emergency rescue communications system is used to exchange information between commanders and mine rescue personnel underground. Commander officers can communicate with rescue workers in real time by IP call,and know the situation, so this can improve the rescue efficiency greatly. Due to the underground complex environment, it’s easy to format the echo. This would interfere with the normal calls, it hinders the rescue work greatly.This topic is from the national science and technology support plan that disaster relief communication technology and equipment based on the mine visualization wireless Mesh network. It’s tocarry out the research on rescuing echo suppression issue in mutiple voice call. At present, the adaptive echo suppression technology is one of the main technology to eliminate echo. The adaptive echo cancellation technology is the main technical to eliminate echo recently. In this paper, I will do the such several aspects of research work following based on the theory of adaptive echo cancellation.First, it introduces the basic theory of the adaptive filter and the adaptive algorithm. The improved NLMS algorithm is designed based on adaptive FIR filter, and it has more advantages in terms of convergence speed and steady-state misadjustment.Second, it Introduces the information recorder calls and development environment of the mine emergency rescue system, and gives an idea of how to design adaptive echo cancellation.According to scheme of adaptive echo canceller, it comes true modular, and expounds the implementation of each module algorithm in detail using the C language.At last, it simulates the adaptive algorithm by MATLAB, the simulation results demonstrates the advantages of Adaptive Echo Canceller. The sound file experiment is given to demonstrate that the performance of the adaptive filter for eliminating echo in this paper chieved good effect on inhibition of 6 db attenuation delay within 32 ms echo, and meets the needs of real-time call.