Unequal error protection for impulsive noise channels in power line communications

Abstract

Communication over power lines has many application areas including smart grids, where data with different QoS may be transmitted. Power lines suffer from impulsive noise. In this paper, we present a study of power line communications with two and four priority levels of data using hierarchical QAM modulation and space-time block coding in impulsive noise with Bernoulli and Poisson arrivals. Hence, we achieve UEP on both of bit and symbol levels. Approximate closed-form expressions for the error probability are obtained for each priority level for both single carrier and OFDM in SISO and MIMO systems. The simplified expressions are used in a bit loading algorithm to provide UEP for the frequency-selective PLC channel. We conclude that single carrier modulation is preferable in the low SNR regime and OFDM is preferable at the high SNR regime. Finally, we describe three different MIMO architectures for use in PLC systems to allow more control on UEP levels.