Weak L1 signal acquisition in a high dynamic environment primarily faces a challenge： the integration peak is neg- atively influenced by the possible bit sign reversal every 20 ms and the frequency error. The block a...Weak L1 signal acquisition in a high dynamic environment primarily faces a challenge： the integration peak is neg- atively influenced by the possible bit sign reversal every 20 ms and the frequency error. The block accumulating semi-coherent integration of correlations （BASIC） is a state-of-the-art method, but calculating the inter-block conjugate products restricts BASIC in a low signal-to-noise ratio （SNR） acquisition. We propose a block zero-padding method based on a discrete chirp-Fourier transform （DCFT） for parameter estimations in weak signal and high dynamic environments. Compared with the conventional receiver architecture that uses closed-loop acquisition and tracking, it is more suitable for open-loop acquisition. The proposed method combines DCFT and block zero-padding. In this way, the post-correlation signal is coherently post-integrated with the bit sequence stripped off, and the high dynamic parameters are precisely estimated using the threshold set based on a false alarm probability. In addition, the detection performance of the proposed method is analyzed. Simulation results show that compared with the BASIC method, the proposed method can precisely detect the high dynamic parameters in lower SNR when the length of the received signal is fixed.展开更多
基金supported by the National Natural Science Foundation of China(Nos.61172138 and 61401340)the Natural Science Basic Research Plan in Shaanxi Province of China(No.2013JQ8040)+4 种基金the Research Fund for the Doctoral Program of Higher Education of China(No.20130203120004)the Open Research Fund of the Academy of Satellite Application(No.2014_CXJJ-DH_12)the Xi’an Science and Technology Plan(No.CXY1350(4))the Fundamental Research Funds for the Central Universities(Nos.201413B,201412B,and JB141303)the Open Fund of Key Laboratory of Precision Navigation and Timing Technology,National Time Service Center,CAS(Nos.2014PNTT01,2014PNTT07,and 2014PNTT08)
文摘Weak L1 signal acquisition in a high dynamic environment primarily faces a challenge： the integration peak is neg- atively influenced by the possible bit sign reversal every 20 ms and the frequency error. The block accumulating semi-coherent integration of correlations （BASIC） is a state-of-the-art method, but calculating the inter-block conjugate products restricts BASIC in a low signal-to-noise ratio （SNR） acquisition. We propose a block zero-padding method based on a discrete chirp-Fourier transform （DCFT） for parameter estimations in weak signal and high dynamic environments. Compared with the conventional receiver architecture that uses closed-loop acquisition and tracking, it is more suitable for open-loop acquisition. The proposed method combines DCFT and block zero-padding. In this way, the post-correlation signal is coherently post-integrated with the bit sequence stripped off, and the high dynamic parameters are precisely estimated using the threshold set based on a false alarm probability. In addition, the detection performance of the proposed method is analyzed. Simulation results show that compared with the BASIC method, the proposed method can precisely detect the high dynamic parameters in lower SNR when the length of the received signal is fixed.
