Improving DOA estimation of LFM signals based on ESPRIT method

Direction of arrival estimation (DOA) of nonstationary signals with sensor arrays is an essential task in radar, sonar, acoustics, biomedical and multimedia applications. In order to improve the angle measurement precision of one of the most popular nonstationary signals (LFM signals) with a low computational complexity, a direction of arrival estimation algorithm (DOA) named, short time Fourier transform multi-step knowledge aided iterative estimation of signal parameters via rotational invariance techniques (STFT-MS-KAI-ESPRIT) is proposed in this paper. Firstly, we present an algorithm for the estimation of chirp rate and carrier frequency .Next, the STFT of the array element’s output is calculated and the signals are transformed to the time-frequency domain. Then the spatial time-frequency distribution (STFD) matrix is used and the signal subspace can also be obtained using Eigen value decomposition (EVD). The simulation results show that the proposed algorithm reduces the computational complexity compared with the traditional algorithms and it can be employed in low signal to noise ratio (SNR) scenarios.

کلیدواژه ها:

Chirp rate ، Direction of arrival estimation ، Linear Frequency modulation ، short time Fourier transform..