Performance Evaluation of CMFB Transmultiplexer for Broadband Power Line Communications under Narrowband Interference

Power lines are one of the most attractive communication media for access and/or in-home networks. The regulations on power line communication (PLC) may be eased in Japan and we could utilize a frequency band from 2 to 30 MHz in the future. However, this frequency band often suffers from narrowband interference caused by amplitude modulated (AM) broadcasting and/or amateur ham radio. The narrowband interference level may be much higher than the background noise if the interference source is close enough. Therefore, modulation and coding over power line channels are required to have immunity to narrowband interference. Multicarrier modulation (MCM) is expected as one of modulation methods which are robust to narrowband interference. In this paper, we investigate two MCMs, one is OFDM (Orthogonal Frequency Division Multiplexing) with windowing whose window type is a raised cosine window and the other is CMFB (Cosine-Modulated Filter Bank) based transmultiplexer, under narrowband interference environments. We compare the performances of these two MCMs over narrowband noise channels by computer simulations. As these results, we show that CMFB transmultiplexer has a better performance than OFDM with windowing under narrowband noise environments.