Study On Compression Of Voice Signal In Mine Wireless Communication

With the gradual improvement in the degree of modernization of coal mines, the traditional wired communication has been unable to fully meet the needs of modern mine voice communication. Mine wireless communication technology have mine wired communication incomparable advantages in strengthening the capacity of the mine production management, improve efficiency and increase the mine accident rescue capability and so on. Wireless voice communication technology is used in the mine becomes imperative.Aiming at the problems existed in mine wireless transmission channel, such as great transmission loss, short distance, narrow transmission channel, great noise jamming, limited transmissibility and low speech signal SNR (Signal to Noise Ratio), grasp the characteristics of the speech signal the mine, analyze noise and interference characteristics of underground transmission channel for the wireless transmission of voice compression mine design has very important significance. Through analyzes the characteristics of mine wireless communication speech signal, physical interference, electromagnetic interference and the impact on the signal transmission channel, based on the speech compression, this paper proposes a model for mine wireless voice signal compression. Due to the special nature of the mine environment, reduce redundancy by establishing psychoacoustic model has a little effect on compression of voice signal in mine wireless communication. Based on voice compression technology, through analyzing the pulse code modulation, delta modulation and adaptive delta modulation which belongs to waveform coding techniques, proposed a model for mine wireless voice signal compression. In this paper, the filter mainly played role in filtering the noise which is outside voice bandwidth and make the signal smoother. Filtering characteristics of modern popular categories filter paper was also analyzed, and in which select the second-order Butterworth filter design as the subject.The compression scheme model was simulated with Systemview, a real time communication system dynamic simulation software, to verify the feasibility of the scheme. The test results show that, from the anti-noise performance, call clarity, coding rate, algorithm complexity degree angle and other aspects point of view, compression scheme can meet the design requirements when the speech signal frequency is within the range of800-3000Hz and the sampling frequency is4-6times of the speech signal with maximum frequency. The Study of this topic provides a theoretical support for the compression of voice signal in mine wireless communication, which is feasible and practical.