A low-complexity direction of arrival (DoA) estimation approach based on transmissive intelligent surfaces (TISs) is proposed for single-target scenarios. The proposed DoA estimator is composed of one TIS with pre-designed phase shifts and two receive antennas. The signal from the target transmits through the TIS before being captured by the two antennas, and the DoA of the target is estimated solely based on the ratio of power received at the two antennas. An optimization method is proposed to design the phase shifts of the TIS and the relative positions of the two antennas with two primary objectives: (1) enhancing DoA estimation accuracy, and (2) guaranteeing an analytical expression of the estimated DoA derived from the power ratio. To be specific, the power ratio is approximated using a limited number of Fourier series coefficients, so that the optimization problem is formulated as a small set of quadratic programming problems aimed at optimizing these Fourier series coefficients. Simulation results validate the effectiveness of the proposed TIS-based DoA estimator and the optimization method. The method demonstrates comparable or even lower root mean squared error (RMSE) of DoA estimation in comparison to classic approaches. Unlike classic approaches that rely on complex-valued received signals, the proposed method offers reduced hardware complexity, relying solely on power measurements. Additionally, it involves reduced computational complexity compared to classic approaches including the multiple signal classification (MUSIC) algorithm and the discrete Fourier transform (DFT)-based DoA estimation method.
Low-Complexity DoA Estimation using Transmissive Intelligent Surfaces
2024-10-07
1993817 byte
Conference paper
Electronic Resource
English