Guided scrambling is an example of multimode coding technique, which belongs to line code. This technique uses scrambling polynomials to form selection sets, by using proper selection criteria, the codeword with least contribution to DC (direct current) content will be chosen for transmitting. This paper designs this kind of GS (guided scrambling) line code which is suitable to be transmitted in long-distance UTP channel. According to the requirement of the real channel, this technique optimizes the design parameters, such as augmenting bits, scrambling polynomials, bit rate and selection criteria, to achieve the high bit rate of 64/67. The simulation experiment shows that this scheme is efficient in suppression of low frequency, and its PSD characteristics meet the requirement of transmission in long-distance UTP channel.
Comparison between nonlinear and linear spectrographic techniques for the complete characterization of high bit-rate pulses used in optical communications