通信系统中扰码的实现，采用Matlab的S函数-Communication System Scramble the realization of Matlab function S

matlab环境下的窃听信道建模，包括crc校验编码，三种（QPSK,16QAM,64QAM）不同的调制方式仿真，加入扰码增强抗窃听能力。-Matlab environment eavesdropping channel modeling, including the CRC check code, three kinds of (QPSK, 16 qam and 64 qam) different modulation mode simulation, join the scrambler e