ex1.m仿真出删余卷积码和不删余两种情况下的误比特率差异,ex2.m设置不同的回溯长度，比较删余卷积码的误码率 -ex1.m simulation of the punctured convolutional code and do not delete the bit error rate is more than the difference in both cases, ex2.m set different back lengths, the error rate comparis