时变混合共轭梯度盲提取算法

A Conjugate Gradient Algorithm of Time-varying Mixtures for Blind Source Extraction

  • 摘要: 针对传统独立分量分析(ICA)方法对时变信道跟踪能力较差的问题,提出了一种时变混合共轭梯度盲提取算法。该算法有效利用了各源信号的时序结构差异,仅利用其二阶统计量解决了具有不同功率谱密度的信号的分离,而无须估计信号的概率密度和计算高阶累积量,减少了运算的复杂度并可用于杂系信号混合的盲分离问题;同时,算法利用仅具有一个全局最优解的凸代价函数,采用计算简单并具有较好数值表现的自适应共轭梯度算法进行迭代,获得了更快的收敛速度和更好的稳定性能。仿真结果表明,该算法与传统ICA算法相比,具有对时变系统更好的跟踪能力。

     

    Abstract: Aiming at the problem of poor tracking abilities of traditional independent component analysis (ICA) methods for time-varying channels, a conjugate gradient algorithm was proposed for blind source extraction of time-varying mixtures. The algorithm made effective use of the temporal structure difference among the source signals, and the sources with different power spectral density could be separated by the use of second-order statistics. Thus, there was no necessity to estimate the probability density of source signals or calculate their high-order statistics, in which way, the calculation complexity was decreased and the hybrid signals might also be separated. Meanwhile, the algorithm took advantage of the convex cost function with only one global extreme point, and an adaptive conjugate gradient algorithm which was both easy and effective was used as the iteration algorithm. As a result, a faster convergence speed and a better stable ability were achieved. The simulation results indicate that, the proposed algorithm has better tracking ability for time-varying system than the traditional ICA ones

     

/

返回文章
返回