Design of a high speed OFDM modem system for powerline communications

This paper proposes a high speed OFDM modem architecture for powerline communications. The proposed modem using symmetric communication is designed to be compatible with the HomePlug standard. The HomePlug standard adopts from DC to 25 MHz frequency bandwidth, 128 subcarriers for OFDM transmission, and BPSK, DBPSK, and DQPSK modulations for each subcarrier. In particular, this paper proposes algorithms and the associated architectures for the signal detection, AGC and frame synchronization. The AGC and frame synchronization algorithms are based on the symbol power ratio and the sliding cross-correlation of preamble, respectively. The frame is then synchronized with a position of the minimum correlation value. In addition, an area-efficient integrate-and-dump architecture for frame synchronization is proposed. The proposed architectures have been validated using SPW™ and implemented with Verilog-XL. We show that the BER performance of the proposed modem under an AWGN channel is similar to the theoretical one.