The power-density spectra of some nB(n + 1) B block coded signals

In many cases, there arises the problem of adapting the power-density spectrum of a binary signal to a transmission channel or of adding redundancy. In such cases, a utilization of the considered block codes can be useful. For these applications, n binary symbols are combined in a block and converted with the aid of a code table. The current paper presents a summary of a technical report provided by Morgenstern (1985), who considers the code relations for 1B2B, 3B4B, and 5B6B block codes. The spectral power densities of signals coded according to these relations are derived, taking into account an arbitrary pulse shape and rectangular pulses. It is pointed out that the 5B6B block code is employed in connection with optical fiber transmissions.