Hardware realization of an XPIC system/measurement method and results

A new generation of 64 QAM radio relay systems developed for the transmission of SDH- and PDH- signals has been presented by Geidel et al. (1991). The most advanced version from the technical point of view as well as with respect to cost effectiveness and frequency economy was a system with quadruple carrier transmission, using both frequency and polarization multiplex techniques with cross polarization interference cancellers (XPIC). A more detailed description is given of the modulators and demodulators mentioned in this context, the concepts of which have been slightly modified. Furthermore measurement methods and results are also discussed