Research On Combined Algorithm Of Acquisition And Anti-jamming Based On SFT

In GNSS-based communication, signal rapid capture and anti-jamming technology hasbecome the focus of the study on satellite receivers under the environment of high dynamicand complex electromagnetic interference. Direct sequence spread spectrum system (DSSS)has been widely used in satellite navigation. However, there still exist problems in theresearches of parallel pseudo-code capture algorithm and anti-jamming algorithm intransform domain, such as high complexity and large amount of computation, which reallyconstraints the application of satellite systems in military communication and navigation.This thesis makes a study on the rapid capture and anti-jamming method of DSSSsignals that received by navigational satellites. Considering that these two algorithms arehighly overlapping, the correlation peaks after de-spreading are really sparse, and the sparseFourier transform (SFT) has very low complexity, this thesis carries out a SFT basedcombined algorithm of DSSS acquisition and anti-jamming after a solid foundation oftheoretical researching. On one hand, a new idea is proposed by combining the twoprocesses of acquisition and anti-jamming in frequency domain to decrease the originalsignal processing complexity to a half. On the other hand, in order to further reduce thecomplexity of this combined algorithm, the SFT technology is applied to the parallel rapidpseudo-code capture algorithm to simplify the IFFT process in the combined method. Boththeoretical derivations and simulations demonstrate that, the SFT based combinedalgorithm of acquisition and anti-jamming can not only work well under strong interferenceand high dynamic situations but also largely reduce the computing complexity with only avery slight loss of acquisition performance.