说明：  信道容量C的迭代算法 函数说明： [CC,Paa]=ChannelCap(P,k) 为信道容量函数 变量说明： P：输入的正向转移概率矩阵，k：迭代计算精度 CC：最佳信道容量，Paa：最佳输入概率矩阵 Pa：初始输入概率矩阵，Pba：正向转移概率矩阵 Pb：输出概率矩阵，Pab：反向转移概率矩阵 C：初始信道容量， r：输入符号数，s：输出符号数
(Channel capacity C of the iterative algorithm function Description: [CC Paa] = ChannelCap (P, k) for the channel capacity functions variable Description: P: input forward transfer probability matrix k: iterative calculation precision CC: best channel capacity, Paa: optimal input probability matrix Pa: initial input probability matrix, Pba: positive transition probability matrix Pb: output probability matrix, Pab: reverse transition probability matrix C: the capacity of the initial channel, r: the number of input symbols, s: the number of output symbols )