A novel adaptive signal subspace transformation for direction-of-arrival (DOA) estimation of wideband sources in the near-field is proposed in this paper. The method is composed of two transformations: signal subspace focusing (SSF) and far-field transformation (FFT). SSF aligns the signal subspaces for different frequencies in the bandwidth of the sources based on focusing matrices. FFT transforms the near-field steering vector to be the far-field steering vector with same direction-of-arrival (DOA) allocation. By the way, we simplify the location estimation of wideband sources in the near-field to be narrowband sources in the far field. The proposed method can track the DOAs and ranges of near-field wideband sources, simultaneously. Simulation results and water-tank experiments confirm the feasibility and efficiency of the proposed adaptive DOA estimation method in underwater environments.
"SIGNAL SUBSPACE TRANSFORMATION FOR DIRECTION-OF-ARRIVAL ESTIMATION OF WIDEBAND SOURCES IN NEAR FIELD,"
Journal of Marine Science and Technology: Vol. 18:
6, Article 7.
Available at: https://jmstt.ntou.edu.tw/journal/vol18/iss6/7