Application And Research Of Variable Structure Control In Sonar Array Attitude Stabilization System

In order to achieve high data rates on the severely band-limited underwater acoustic(UWA) channels, bandwidth-efficient modulation techniques must be employed, together with some sophisticated signal processing algorithms, such as adaptive equalization technique for the intersymbol interference caused by channel multipath propagation.To attain reliable high data rate transmission over UWA channels, phase-coherent technology and adaptive equalization technology are selected as major research issue. The main content in this paper are as follows:1.A11 kinds of linear and nonlinear adaptive equalization and typical arithmetic are studied elaborately. And their performances are compared by simulation. The realization of phase-coherent modulation is studied, especially the carrier recovery. In order to improve the system performance, we consider a receiver which performs optimal phase synchronization and channel equalization jointly.2. A UWA communication system is designed, lake experiments are also conducted with several equalization methods being employed. One key of the techniques in underwater acoustic communication-synchronization technique is studied. 3. Finish demonstrating, designing and realizing an underwater voicecommunication system. Code, modulation, equalization and demodulation are realized in real-time.