A DHT-based Multicarrier Modulation System with Pairwise ML Detection

This paper proposes a complex-valued discrete multicarrier modulation (MCM) system based on the real-valued discrete Hartley transform (DHT) and its inverse (IDHT). Unlike conventional discrete Fourier transform (DFT), DHT can not diagonalize the multipath fading channel due to its inherent properties, which results in the mutual interference between subcarriers in the same mirror-symmetrical pair.We explore the interference pattern in order to seek an optimal solution to utilize the channel diversity for the purpose of enhancing system bit error performance (BEP). It is shown that the optimal channel diversity gain can be achieved via a pairwise maximum likelihood (ML) detection, taking into account not only the subcarrier’s own channel quality but also the channel state of its mirror-symmetrical peer. Performance analysis indicates that DHT-based MCM mitigates the fast fading effect by averaging the channel power gain on the mirror-symmetrical subcarriers. Simulation results show that the proposed system has a substantial improvement in BEP over conventional DFT-Based MCM