2-D DOA Estimation of LFM Signals based on Sparse Representation in Fractional Fourier Domain

For the problem of two dimensional direction of arrival (2-D DOA) estimation of Liner Frequency Modulated (LFM) signals, a novel 2-D DOA estimation method is proposed based on sparse representation in fractional Fourier domain. First, utilizing the energy-concentrated characteristic of fractional Fourier transform for LFM signals, the redundant dictionaries based on the space angles are established in fractional Fourier domain. Then the space angles can be estimated by sparse recovery algorithm respectively. Finally, the azimuth and elevation angles are calculated through the estimated space angles. The proposed method has a better estimation precision, high-resolution performance and lower SNR threshold without multidimensional search process. The validity of the proposed method is verified by theoretic analysis and simulation results.