关键词: 快速频谱融合, 多段正弦信号, 离散时间傅里叶变换（DTFT）快速算法, 降维, 1/3主瓣相关

Abstract: The spectra fusion method for multi-sections sinusoids（called “the fore-fusion method” for short）is an effective way of estimation frequency for the sinusoids in low Signal-to-Noise Ratio（SNR）, which has an important theoretical significance and practical value. In order to meet the high real-time demand in some fields such as radar, sonar and electronic countermeasures, a fast spectra fusion algorithm for multi-section sinusoids is put forward. This proposed algorithm can reduce the calculation and improve the real-time characteristic by the following techniques：design a fast DTFT algorithm, reduce dimensions of the weighted fusion spectrum matrix, and analyse the correlation of the 1/3 main-lodes of the optimization weighted-accumulation spectrum and the accumulation spectrum. The principles of the above techniques are expatiated. Calculation analyses and simulations demonstrate that the proposed algorithm can reduce most calculation of the fore-fusion method with lower little precision, and it works better in very low SNR[(SNR-13 dB)].

Key words: fast spectra fusion, multi-sections sinusoids, fast Discrete Time Fourier Transform（DTFT） algorithm, dimensions reduction, correlation of 1/3 main-lodes