通信系统中常用的多进制数字相位调制的源代码 并结合ofdm系统 加入了相应的保护前缀（cp）和导频序列 应用于有关ofdm的信道估计等系统-Communication systems commonly used in multi-band digital phase modulation of the source code and combine OFDM system by adding a prefix corresponding protection (cp) and the pilot