基于混沌、分形理论的多径衰落分析

本文首次将混沌、分形等非线性理论引入多径衰落的研究,针对现场实测数据分析了它的非线性动力特征.首先通过重构状态空间和关联维数验证了其动力机制的有限维自由度,然后通过计算其Lyapunov指数考察了系统的时空演化特性,最后利用分形机制对多径信号进行了重构.研究结果表明,与传统的随机模型相比,非线性动力模型能更恰当地描述多径衰落的内在物理机制.

Analysis of Multipath Fading Channels Using Chaos and Fractal Theories

This paper applies chaos and fractal theories to the analysis of mulitpath fading in mobile radio communications for the first time,and investigates its nonlinear dynamical system characteristics based on the measured data from field trials.By reconstructing the status space and correlation dimension,we show that the dynamical system of the multipath fading channels has finite degree of freedom and a positive maximum Lyapunov exponent.The chaotic characteristic of the multipath fading is demonstrated and the nonlinear evolution mechanism is observed.Finally,we apply fractal model to the interpolation of multipath signals,yielding reasonably accurate replications.The results indicate that the nonlinear dynamical system could be a more suitable model than the conventional random process for describing multipath fading phenomenon.