Power Efficiency Improvement in CE-OFDM System With 0 dB IBO for Transmission over PLC Network

Orthogonal frequency division multiplexing (OFDM) OFDM has been adopted for high speeddata transmission of multimedia traffic such as HomePlug A/V and Mobile WiMax. However,OFDM also has a drawback of a high PAPR (peak-to-average-power-ratio). Due to this highPAPR amplifier usually does not act in dynamic range. One potential solution for reducing thepeak-to-average power ratio (PAPR) in an OFDM system is to utilize a constant envelopeOFDM (CE-OFDM) system. Furthermore, by utilizing continuous phase modulation (CPM) ina CE-OFDM system, the PAPR can be effectively reduced to 0 dB, allowing for the signal tobe amplified with a power efficient non-linear power amplifier with Input Back-Off (IBO) of 0dB. This paper describes a CE-OFDM based modem for Power Line Communications (PLC)over the low voltage distribution network. Relying on a preliminary characterization of a PLCnetwork, a complete description of the modem is given. Also CE-OFDM is compared withconventional OFDM under HomePlug 1.0 in the presence of power amplifier nonlinearities,considering different values of IBO.