Time-reversal ESD for Direction of Arrival Estimation over Multipath channels

The fast fading of the signal caused by the multipath effect will cause a large difference in the signal that reaches the receiver at the same time, which seriously affects the effect of the positioning algorithm based on the direction of arrival (DOA). To address this problem, this paper proposes an indoor DOA positioning algorithm based on Time Reversal (TR). This algorithm uses TR technology at the antenna array to focus the wireless signal space-time on the target point to reduce the impact of multipath effects. In addition, it uses Eigenvalue-Subspace Decomposition (ESD) method when analyzing DOA estimates, makes full use of the information of signal subspace and noise subspace to improve the accuracy of DOA estimation. The simulation results show that the positioning algorithm proposed in this paper can improve the positioning accuracy, which is mainly manifested by reducing the lower bound of the system Cramer-Rao and reducing the root mean square error generated during signal estimation.