Bayesian High Resolution Doa Estimation Method For Performance Analysis And Applied Research

High-resolution multi-source direction estimation is always the key point in array signal processing. The breakthrough of this technique is greatly meaningful in many research fields such as sonar, radar, communication, biomedical engineering, geology and so on. Combined with these applied backgrounds and supported by the National Science Foundation, the Aviation Science Foundation as well as the National Important Pre-research Project, a new high-resolution technique for direction estimation Bayesian high-resolution method is thoroughly studied in this thesis. Based on the previous research of our research group, some new progresses are achieved and more valuable conclusions are drawn. The main research advances can be summarized as follows. 1. The performance of Bayesian high-resolution method is studied comprehensively. First, its angular resolution thresholds under different SNR are analyzed when applied in uniform linear array. The results demonstrate that the highest angular resolution ability of Bayesian method is 1/18 bandwidth of the beam main lobe under high SNR(2OdB) and 1/3 bandwidth under low SNR(-lOdB). The effects on its performance by the factors such as snapshot, number of array sensors and spatial location of sources are investigated and their relations are also quantitatively analyzed. 2.. Bayesian high-resolution method is compared with other typical methods like MUSIC and MLE and the superiority of Bayesian method is revealed. Bayesian method is compared with the other two methods in the aspects like angular resolution ability, performance under low SNR as well as estimation of coherent signals. It is proved that Bayesian high-resolution method possesses better performance than MLE and MUSIC. 3.. Bayesian high-resolution method applied in arc and circular arrays is proposed. In order to meet the practical engineering requirements, the new Bayesian algorithm applied in arc and circular arrays is deduced, which further perfects Bayesian high-resolution direction estimation theory. On the basis of theoretical study, large amount of computer simulation and statistical analysis is conducted to investigate the performance of this method. The research indicates that when applied on arc and circular arrays, Bayesian method possesses outstanding angular resolution ability. It can absolutely distinguish two sources spaced by 1/15 bandwidth under the SNR of 20dB. When SNR is reduced to -10dB, -15dB and -18dB, its angular resolution thresholds are 2/5, 3/5 and 4/5 bandwidth respectively. It is more noticeable that Bayesian method can directly estimate coherent signals without preprocessing and also shows good estimation performance. When SNR is 20dB, its highest angular resolution ability could be 1/15 bandwidth and for SNR of -10dB, it could estimate the two sources which are 1/2 bandwidth apart. So it is no doubt that Bayesian method is a new effective approach to estimation of coherent soUrces when arc and circular arrays are used.