这里面有两个程序，两个都是采用4QAM调制。不过个人觉得第一个更容易懂，因为写的很有条理。我改的那个程序就是根据这个来的。

不过在这里面有个问题就是信道系数只能是由高到低，大家可以试试，改成[0.227 0.46 0.688 0.46 0.227]这个是老师给我的仿真中常用的信道系数，这个成为归一化信道，就是系数平方和为1.

第二个程序没有涉及到信道系数，但是这个程序当中，在128个子载波中，前后有32个空载波，这个在OFDM中也是经常用的，这样可以降低误码率。

-And there are two programs, two are based on 4QAM modulation. But personally feel that the first is easier, because the writing is organized. I changed that procedure is based on the past. However, there is a problem in that there is only channel coefficients from high to low, we can try and change into [0.227 0.46 0.688 0.46 0.227] This is the teacher gave me the simulation channel coefficient commonly used, this became normalized channel, is coefficient of the square and is 1. The second program is not related to channel coefficients, but this program which, in the 128 sub-carriers, the before and after the 32 air carriers, the in OFDM is also often used, which can reduce the error rate.