%A HU Mei-xia, LIU Yi, LU Man-hong, ZHANG Zhao-wei, LI Yong-zhao %T Searching range prediction based on Doppler frequency shift estimation method in direct spread spectrum systems %0 Journal Article %D 2014 %J Journal of Jilin University(Engineering and Technology Edition) %R 10.13229/j.cnki.jdxbgxb201406046 %P 1838-1842 %V 44 %N 6 %U {http://xuebao.jlu.edu.cn/gxb/CN/abstract/article_12619.shtml} %8 2014-11-01 %X To improve the unreliable Doppler frequency estimation under the condition of extremely low SNR and high dynamic state, a searching range prediction method was proposed based on Doppler frequency shift estimation used in spread spectrum systems. Using Doppler frequency variation limitation over adjacent two received signals, the proposed method narrows the searching range of the later estimations from the previous estimation results, thus, enhancing the estimation reliability. Simulation results show that this proposed method can effectively increase the Doppler detection reliability.