It proposes the structure of second-order HMM(HMM2) on condition that observation noise is not independent of the Markov chain,and obtain the Baum-Welch algorithm of the model on condition that multiple observations is not independent.

• 给出了在观测噪声和马尔可夫链不相互独立条件下二阶隐马尔可夫模型(second-or-der HMM:HMM2)的结构,获得了在多观测序列不相互独立的情况下HMM2的Baum-Welech学习算法。