The raw trajectories contain large amounts of redundant data that bring challenges to storage, transmission and processing. Trajectory compression algorithms can reduce the number of positioning points while minimizing the loss of information. This paper proposes a heading maintaining oriented trajectory compression algorithm, which takes into account both position information and direction information. By setting an angle threshold, the algorithm can achieve a more accurate approximation of trajectories than traditional position-preserving trajectory compression algorithms. The experimental results show that the algorithm can ensure certain effect on the direction information and is more flexible.

No abstract

With the increasingly severe wireless communication confrontation, the traditional conventional frequency hopping (CFH) system has poor performance in anti-follower jamming, so a new dual frequency hopping mode is proposed from the perspective of frequency hopping principle. Firstly, the communication model and anti-jamming principle of the dual sequence frequency hopping (DSFH) system are introduced. Secondly, the typical follower jamming model and its parameters in communication are summarized, and the anti-follower jamming performance of different parameters of the system under follower jamming is analyzed. Finally, the CFH and DSFH system are compared. Bit error rate performance under different parameter conditions. The results show that under the AWGN channel, the anti-follower jamming performance of the DSFH system is better than that of CFH, and the value of the bit error rate is lower than that of CFH.