不同编码方式的频谱特性 a23d10 b1厂aca上5用2 yon n legend 21用O B8Zs HDB3 d: AMI i a Alternate mark inversion SP B8ZS Bipolar with 8 zeros substitution Freque HDB3 ligh-density bipolar--3 zeros NRZ-L NRZL-L= Nonreturn to zero level 1.0 F.NRZI 128 NRZI= Nonreturn to zero inverted R 0.8 aml pseudoternary o d s 1o sungod or 90.6 e wesTener Manchester Differential Mancheste 0.2 0.40.60.81.01.21.4161.8 2.0 Normalized frequency (/R) Figure 5.3 Spectral Density of Various Signal Encoding Schemes7 不同编码方式的频谱特性