Research On Remote Control Link Oriented Covert Communication

In recent years,with the development of the UAV technology,it has played an indispensable role in both military and civilian fields.Therefore,studying the covert communication of the UAV remote control link has significant practical significance.The signal of the UAV remote control link is the control command information issued by the ground station,but due to the openness of the wireless channel,the remote control information is easily intercepted,resulting in significant risks such as information leakage and UAV loss of control.Therefore,this article focuses on the requirements of the UAV remote control link communication,starting from the perspective of orthogonal transformation and precoding matrix,and conducts in-depth research on new covert communication algorithms based on remote control links.While ensuring signal covert transmission,it also has anti-interference capability.This paper draws on the characteristics and advantages of traditional remote control link communication,proposes an equivalent spread spectrum technology based on matrix precoding algorithm and a sparse signal transmission technology,which can broaden the signal spectrum,reduce the signal power spectral density,and realize signal information hiding by using the weighted combination method of matrix operation.On these grounds,the generalized chirp-like(GCL)polyphase sequences and chaotic system are applied to the equivalent spread spectrum technology to obtain the chaotic GCL covert communication precoding algorithm.The algorithm first uses the sparse matrix to send sparse signals,and then uses the Chebyshev chaotic map to dynamically form multiple groups of chaotic GCL matrices to improve the concealment of the signal,and realize the equivalent spread spectrum by controlling the determine-column relationship of the chaotic GCL matrix.The simulation shows that using the chaotic GCL covert communication precoding algorithm has better anti-interference ability with the improvement of the equivalent spread spectrum ratio,and the signal is similar to the noise form and has certain concealment.Considering the complexity of the above algorithm implementation,this paper proposes a low complexity and remote control link compliant covert communication algorithm based on the original signal sparse transmission and matrix operation spread spectrum scheme.This algorithm combines a four-dimensional hyperchaotic system to generate a pseudo random chaotic perfect Gaussian integer sequence with up to 16 non zero complex numbers.Considering the characteristics of the sequence,it can also generate spread spectrum matrices with unequal rows and columns.The above algorithm can achieve signal concealment and anti-interference.Provide corresponding receiving models and algorithms based on the characteristics of the algorithm.Simulation shows that the above algorithms not only reduce complexity,but also have certain antiinterference and concealment capabilities.