UNDERWATER ACOUSTIC VOICE COMMUNICATIONS USING DIGITAL TECHNIQUES
Tahun : 1997Pengarang : Hayri Sari
Penerbit : Hayri Sari
Ket : An underwater acoustic voice communications system can provide a vital communication link between divers and surface supervisors. There are numerous situations in which a communication system is essential. In the event of an emergency, a diver\'s life may depend on fast and effective action at the surface. The design and implementation of a digital underwater acoustic voice communication system using a digital signal processor (DSP) is described. The use of a DSP enables the adoption of computationally complex speech signal processing algorithms and the transmission and reception of digital data through an underwater acoustic channel. The system is capable of operating in both transmitting and receiving modes by using a mode selection scheme. During the transmission mode, by using linear predictive coding (LPC), the speech signal is compressed whilst transmitting the compressed data in digital pulse position modulation (DPPM) format at a transmission rate of 2400 bps. At the receiver, a maximum energy detection technique is employed to identify the pulse position, enabling correct data decoding which in turn allows the speech signal to be reconstructed.
Ketegori : DIGITAL TECHNIQUE
