基带传输：

欲传送的01比特流 + 码型变换（HDB3码） + 基带成型网络（采用升余弦滚降系统）+ 信道 + 码型反变换 + 01比特流。

-Baseband transmission: To send the 01 bit stream+ code type transformation (HDB3 code)+ base-band forming network (with raised cosine roll-off system)++ code based channel inverse transform+ 01 bit stream.