Comparison of modulation schemes with frequency agility for application in power line communication systems

The typical properties of electrical power distribution networks for communication purposes normally rule out standard modulation schemes such as ASK, PSK or FSK. More sophisticated band-spreading techniques such as frequency hopping (FH), however, significantly enhance overall system robustness. On the other hand, an essential drawback of FH is the need for an increased chip rate to yield the necessary interference suppression. In consequence faster system clocks must be provided, which poses severe loads on the synchronisation devices. An essential aim of this paper is to present and analyse a modified FH scheme being able to guarantee excellent performance concerning robustness, and at the same time calling for only moderate enhancement of system clock speed.