matlab

   仿真程序：首先需要用一个随机发生器产生（0.1）内的均匀随机数，然后再将该序列映射到对应的幅度电平｛Am｝。然后将这个范围再分成4个相等的区间，这些子区间分别对应于4个信号比特的符号00，01，10，11。检测器观察到r=Am+n，并且计算r和4种可能传输的信号幅度之间的距离，它的输出Bm就是相应于最小距离的信号电平。Bm与真正的的传输信号幅度比较，差错计数器用来对检测器产生的差错计数。(Simulation program: first need to use a random generator (0.1) the uniform random number, then the sequence is mapped to the corresponding amplitude level {Am}. Then this range has been divided into four equal intervals, these sub-intervals corresponding to four signal bits of the symbol 00,01,10,11. Detector observed r = Am+ n, and calculate r and 4 possible transmission distance between the signal amplitude, its output corresponding to the minimum distance Bm is the signal level. Bm and the real rate of transmission of the signal comparison, error detection counter is used to generate the error count.)