Duobinary coding and modulation technique for optical communication
systems
    1.
    发明授权
    Duobinary coding and modulation technique for optical communication systems 失效
    光通信系统的二进制编码和调制技术

    公开(公告)号:US5892858A

    公开(公告)日:1999-04-06

    申请号:US827419

    申请日:1997-03-27

    摘要: A method for encoding a binary input sequence x(0,1) to obtain a duobinary output sequence y(+1,0,-1) is provided. The duobinary coding technique always provides an output bit y.sub.k =0 when the corresponding bit x.sub.k =0; bits y.sub.k alternatively assume a logical level "+1" and "-1" whenever an input bit x.sub.k-1 =0 changes to x.sub.k =1, and the output bit y.sub.k maintains the logical level "+1" or "-1" whenever the corresponding bit x.sub.k maintains the logical level "1". A coding device for encoding a binary input sequence x(0,1) to a duobinary output sequence y(+1,0,-1) is also provided, comprising a D-type flip-flop for generating a binary switch signal. A first AND circuit receives the input sequence and the switch signal, and provides a first binary sequence a(0,1), while a second AND circuit receives the input sequence and the complement of the switch signal and provides a second binary sequence b(0,1). These first and second binary sequences are applied to a summer to obtain the output sequence y(+1,0,-1). A method for differentially driving a M-Z modulator using a virtual ground level is also provided, which reduces the peak-to-peak drive voltage by a factor of two.

    摘要翻译: 提供了一种用于对二进制输入序列x(0,1)进行编码以获得双二进制输出序列y(+ 1,0,-1)的方法。 当对应的位xk = 0时,双向编码技术总是提供输出位yk = 0; 只要输入位xk-1 = 0改变为xk = 1,位yk或者假设逻辑电平“+1”和“-1”,并且输出位yk每当维持逻辑电平“+1”或“-1” 对应的位xk保持逻辑电平“1”。 还提供了用于将二进制输入序列x(0,1)编码到二进制输出序列y(+ 1,0,-1)的编码装置,包括用于产生二进制开关信号的D型触发器。 第一AND电路接收输入序列和开关信号,并提供第一二进制序列a(0,1),而第二AND电路接收输入序列和开关信号的补码,并提供第二二进制序列b( 0,1)。 将这些第一和第二二进制序列应用于加法器以获得输出序列y(+ 1,0,-1)。 还提供了一种用于使用虚拟接地电平差分驱动M-Z调制器的方法,其将峰 - 峰驱动电压降低了二倍。