Adaptive cyclostationary filtering for DGPS interference cancellation

In this work it is introduced a scheme to reduce the effects of a differential GPS signal when acting as interference in narrowband powerline communications systems. The novelty is the use of specific cyclostationary characteristics of the interfering signal for its cancellation. A robust detection method (the forward consecutive mean excision algorithm) is used to define if the interfering signal is present. As a second step, when the interference is detected, two alternatives are considered: simple subcarrier notching, on one side or, adaptive frequency shift filtering. The latter alternative uses the known parameters of the interference signal, i.e., differential GPS, in particular its cyclostationarity. We compare results and demonstrate that adaptive frequency shift filtering outperforms subcarrier notching, especially when the interferer power is high.