Adaptive Suppression Algorithm of Narrowband Interference for OFDM-based Power Line Communications

Narrowband interference (NBI) in power line is the major impediments of application for OFDM-based power line communication. Receiver synchronization error is the biggest problem for narrowband interference on the power line communication system. Therefore, this thesis is based on OFDM power line communication system, studies the narrowband interference influence on power line communication system synchronization, and adopts a time domain suppression method based on adaptive block least mean square (DBLMS) filter to eliminate the narrowband interference of OFDM-based power line communication system in time domain. It is generally known that the characteristic of narrowband interference is not easy to change. We firstly detect the narrowband interference frequency point, then use time domain interference suppression scheme to process received signals at the receiver before system synchronization, and then remove narrowband interference effects on power line communication system. The simulation results show that, compared with frequency domain suppression method, time domain suppression scheme can effectively improve the bit error rate (BER) performance, and further improve the reliability of the OFDM-based power line communication system.