Effective Configurable Suppression of Narrow Frequency Bands in Multi-Carrier Modulation Transmission

For regulation requirements and compatibility with other systems a PLC system often has to leave out small frequency bands within a broad frequency range. Conventional methods used therefor either show little flexibility, are expensive or only produce low attenuation. This paper introduces a new method using Nyquist windowing at the transmitter and cyclic extension at the receiver which results in the transmission of wavelets and yields attenuation of carriers even in narrow side-bands which are far beyond those reached by normal zeroing of carriers. By additional evaluation of the Nyquist window also at the receiver full orthogonality of the sub-carriers is obtained even without use of a guard interval at the transmitter.