A block zero-padding method based on DCFT for L1 parameter estimations in weak signal and high dynamic environments

Abstract

Weak L1 signal acquisition in a high dynamic environment primarily faces a challenge: the integration peak is negatively 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.

Keywords

Threshold detection / Discrete chirp-Fourier transform / Block zero-padding / High dynamic / Weak L1 signal acquisition

References

[1] Aceros-Moreno, C.A., Rodriguez, D., 2005. Fast discrete chirp Fourier transforms for radar signal detection systems using cluster computer implementations. Proc. 48th Midwest Symp. on Circuits and Systems, p.1047―1050. [

[2] Belega, D., Dallet, D., 2008. Frequency estimation via weighted multipoint interpolated DFT. IET Sci. Meas. Technol., 2(1): 1―8. [

[3] Dai, L., Wang, Z., Wang, J., , 2010. Joint code acquisition and Doppler frequency shift estimation for GPS signals. Proc. IEEE 72nd Vehicular Technology Conf., p.1―5. [

[4] Fan, B., Zhang, K., Qin, Y., , 2013. Discrete chirp-Fourier transform-based acquisition algorithm for weak Global Positioning System L5 signals in high dynamic environments. IET Radar Sonar Navig., 7(7): 736―746. [

[5] Fu, H., Kam, P.Y., 2007. MAP/ML estimation of the frequency and phase of a single sinusoid in noise. IEEE Trans. Signal Process., 55(3): 834―845. [

[6] Geiger, B.C., Vogel, C., 2013. Influence of Doppler bin width on GPS acquisition probabilities. IEEE Trans. Aerosp. Electron. Syst., 49(4): 2570―2584. [

[7] Geiger, B.C., Vogel, C., Soudan, M., 2012. Comparison between ratio detection and threshold comparison for GNSS acquisition. IEEE Trans. Aerosp. Electron. Syst., 48(2): 1772―1779. [

[8] Huang, P., Pi, Y., Progri, I., 2013. GPS signal detection under multiplicative and additive noise. J. Navig., 66(4): 479―500. [

[9] Kay, S., 1989. A fast and accurate single frequency estimator. IEEE Trans. Acoust. Speech Signal Process., 37(12): 1987―1990. [

[10] Li, X., Guo, W., 2013. Efficient differential coherent accumulation algorithm for weak GPS signal bit synchronization. IEEE Commun. Lett., 17(5): 936―939. [

[11] Li, X., Guo, W., Xie, X., 2011. A GPS bit synchronization method for high-dynamic and weak signal. J. Electron. Inform. Technol., 33(10): 2521―2525(in Chinese). [

[12] Shanmugam, S.K., Nielsen, J., Lachapelle, G., 2007. Enhanced differential detection scheme for weak GPS signal acquisition. Proc. Int. Technical Meeting of the Satellite Division of the Institute of Navigation, p.1―14.

[13] Spangenberg, S.M., Scott, I., McLaughlin, S., , 2000. An FFT-based approach for fast acquisition in spread spectrum communication systems. Wirel. Pers. Commun., 13(1-2): 27―55. [

[14] Su, Y.T., Wu, R.C., 2000. Frequency acquisition and tracking in high dynamic environments. IEEE Trans. Veh. Technol., 49(6): 2419―2429. [

[15] Yang, C., Han, S., 2001. Block-accumulating coherent integration over extended interval (BACIX) for weak GPS signal acquisition. Proc. 19th Int. Technical Meeting of the Satellite Division of the Institute of Navigation, p.2427―2440.

[16] Yang, C., Nguyen, T., Blasch, E., , 2008. Post-correlation semi-coherent integration for high-dynamic and weak GPS signal acquisition. Proc. IEEE/ION Position, Location and Navigation Symp., p.1341―1349. [