Novel Wideband DOA Estimation Based on Sparse Bayesian Learning With Dirichlet Process Priors
Novel Wideband DOA Estimation Based on Sparse Bayesian Learning With Dirichlet Process Priors
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DOI：
10.1109/tsp.2015.2481790
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发表时间：
2016-01-15
影响因子：
5.4
通讯作者：
Zhang, Haijian
中科院分区：
文献类型：
--
作者：
Wang, Lu;Zhao, Lifan;Zhang, Haijian
基于联合稀疏性的波达方向(DOA)估计方法由于具有分辨率高、快照数目有限等优点而备受关注。然而，当来自不同方向的信号占用不同的频带时，通常的假设是来自不同方向的信号共享频段是不合适的。为了灵活地处理这种情况，提出了一种新的宽带DOA估计算法，该算法利用角域的稀疏性同时推断带宽占用和估计高分辨率DOA。通过在潜在参数空间上施加Dirichlet过程(DP)先验来利用频带占用。此外，通过两种方案将该方法扩展到处理离网问题。一种是将线性近似应用于真实字典，并通过变分贝叶斯期望最大化(VBEM)以一种综合的方式推断隐藏变量和参数。另一种是分离方案，根据重建的结果通过后搜索过程来精化DOA。由于所提出的方案可以根据子带的基本占用情况自动将子带划分为簇，因此利用一个簇内的测量值可以实现更准确的DOA估计。综合仿真结果表明，所提方案的性能优于其他文献报道的方案。
Direction of arrival (DOA) estimation methods based on joint sparsity are attractive due to their superiority of high resolution with a limited number of snapshots. However, the common assumption that signals from different directions share the spectral band is inappropriate when they occupy different bands. To flexibly deal with this situation, a novel wideband DOA estimation algorithm is proposed to simultaneously infer the band occupation and estimate high-resolution DOAs by leveraging the sparsity in the angular domain. The band occupation is exploited by exerting a Dirichlet process (DP) prior over the latent parametric space. Moreover, the proposed method is extended to deal with the off-grid problem by two schemes. One applies a linear approximation to the true dictionary and infers the hidden variables and parameters by the variational Bayesian expectation-maximization (VBEM) in an integrated manner. The other is the separated scheme where DOA is refined by a postsearching procedure based on the reconstructed results. Since the proposed schemes can automatically partition the sub-bands into clusters according to their underlying occupation, more accurate DOA estimation can be achieved by using the measurements within one cluster. Results of comprehensive simulations demonstrate that the proposed schemes outperform other reported ones.