Researches On Wideband Vector-Sensor Array Beamforming And Adaptive Correlator

Wideband vector-sensor array beamforming technology and adaptive correlator technology are discussed and investigated in this dissertation.In the first part, the conventional beamforming, incoherent minimum variance beamforming and spatially resampled coherent signal subspace based wideband optimal beamforming for acoustic vector-sensor array are examined, based on the mathematical model of acoustic pressure array and vector-sensor array. Furthermore, wideband steered minimum variance beamforming for acoustic vector-sensor is proposed, and the relationship between steered matrix of acoustic vector-sensor array and that of acoustic pressure-sensor array is indicated. According to the computer simulation, these beamforming methods are contrastively analyzed. Vector-sensor array's advantageous performances of realizing unambiguous direction finding in the whole space and allowing the uniform interelement spacing to exceed the Nyquist halfwavelength upper limit are analysed. The resolutation abilities for uncorrelated and correlated signal sources of these methods are compared. The bearing estimating performance is simulated and analysed. Finally, the validity and solidity of these algorithms are testified by the sea trial datas with real application scenario.Underwater acoustic channel is a coherent multi-path channel in which replica correlator can not make use of the energy of signals from multi-path. As an improvement, adaptive correlator estimates the system function of the multi-path channel by an adaptive canceller in real-time, and generate a reference waveform which matches the arrived echo by convolving the transmitted signal with the impulse response of the medium. So that it can synthesize the energy of signals from multi-path and enhance the performance of replica correlator. Computer simulation and experiment results validate its good performance.