Simulation of CSS communication system in VLF atmospheric noise

Chirp spread spectrum (CSS) technique has been extensively studied in the application of Ultra-wide band (UWB). Considering the long distance propagation capacity and low intercepted probability of chirp signal, we propose to apply the CSS technique to the very low frequency (VLF) communication system. First, we discuss the CSS system based on fractional Fourier transform (FRFT), including the definition of FRFT and means of modulation and demodulation. Then we introduce an analytic model of VLF atmospheric noise presented by E C. Field [1] and generate atmospheric noise by MATLAB software. Finally, we perform simulation of the CSS communication system in atmospheric noise. The simulation results validate its feasibility.