利用耦合映像格子恢复信号初值是信号处理研究中一个重要的问题.耦合映像格子具有混沌系统的初值敏感性,当初值受到噪声污染时将会影响到系统对其的恢复.提出了一种由多个一维耦合映像格子系统并列耦合而成的多重耦合映像格子系统,通过将多个一维系统耦合,使因受到噪声干扰而趋向于指数分离的混沌轨道相互靠近,以达到抑制噪声的目的.数值仿真表明,该系统具有较强的抗噪声能力和较高的鲁棒性.在耦合系数选取适当的情况下,即使初始信号受到噪声干扰,该多重耦合系统仍然能够很好地恢复信号初值的统计特性,且对单个初值的恢复情况及与初始信号的相关度等性能都远优于单一的一维系统.
To recover the initial signals from coupled map lattices (CML) is of great importance in signal processing. But like all chaotic systems, CML is highly sensitive to noise. It is hard for CML to recover the initial signals that have been corrupted by noise. A muhi-CML system, which couples many one-dimensional CMI.s paratactically together, is proposed in this paper. Through the coupled one-dimensional CML, the chaotic trajectories, which tend to be exponentially separated in noisy environment, become closer, so the noise influence is restrained. The numerical results verified the robustness and noiserestraining property of the multi-CML system. Given the proper selection of coupling parameters, even in the environment that initial signals are noise-corrupted, compared with single one-dimensional CML, the multi-CML system not only can recover the statistical property of initial conditions well, but also performs well in recovery of single initial signal with a high correlation.