Abstract: In view of the fact that traditional Logistic-Map as well as the modified Logistic-Map only have one surjective parametera,a new chaotic map function was designed,which broadens the range of surjective parameter so as to improve the ergodic property of the chaotic sequence.Based on the coherent chaos shift-keying modulation,a new satellite covert communication system with chaotic spread spectrum was installed.The randomness correlationbalance property of the referred chaotic sequence and the error rate of the covert communication system were analyzed.The simulation results show that the referred chaotic is better than the traditional Logistic chaotic in ergodic property and balance property.The bit error rate of original service receiver is not changed when the power ratio of original service signal to spread spectrum modulated signal is greater than 20dB.The bit error rate of covert communication receiver is below 10－3 when the spread spectrum factor is 80 and the SNR(Signal to Noise Ratio) is greater than 6dB.The proposed system can meet the covert communication requirements.

Key words: Satellite covert communication,Chaotic,Spread spectrum