基于置乱矩阵的短参差分混沌键控系统

Short-reference differential chaos shift keying system based on scrambling matrix

短参差分混沌键控(short reference differential chaos shift keying,SR-DCSK)有效提升了系统的传输速率,但也导致安全性能大幅度降低。针对该问题,提出了基于置乱矩阵的SR-DCSK(SR-DCSK based on scrambling matrix,SMSR-DCSK)系统。基于前向移位矩阵设计了一种结构简单并且具有正交性的置乱矩阵。该置乱矩阵能够打乱混沌序列的顺序,从而降低混沌参考信号与信息信号之间的相关性。采用高斯近似法推导了在加性高斯白噪声信道中的系统误比特率(bit error rate,BER)公式,并依此进行了最优化性能参数的求解。仿真结果表明,推导的BER公式能够准确衡量系统BER性能。相对于SR-DCSK系统,SMSR-DCSK系统在安全性和BER性能方面均有明显提升,并且具有实现复杂度低的优点。

The short reference differential chaos shift keying (SR-DCSK) can effectively improve the transmission rate of the system, but the security performance is greatly reduced. To solve this problem, an SR-DCSK system based on scrambling matrix is proposed. Based on the forward shift matrix, a simple and orthogonal scrambling matrix is designed, which can disrupt the sequence of chaotic sequences and reduce the correlation between chaotic reference signals and information signals. Adopting the Gaussian approximation method, the bit error rate (BER) formula of system is derived in the additive Gaussian white noise channel, and the optimal performance parameters are solved accordingly. The simulation results show that the derived BER formula can accurately measure the BER performance of the system. Compared with the SR-DCSK system , the SMSR-DCSK system has a significant improvement in security and BER performance, and has the advantage of low implementation complexity.