在程序中，任意产生一个mimo的信道矩阵，分别使用注水法和等增益算法求出信道容量。结果得到子信道的功率分配，进行作图。(A channel matrix of MIMO is generated randomly, and the channel capacity is calculated by water filling algorithm and equal gain algorithm respectively.　Power allocation of subchannels is obtained and plotted.)