International audienceThe popularity of OFDM, or more precisely CP-OFDM, which is indeed totally justified by its intrinsic properties, makes difficult the breakthrough of other modulation techniques. In the case of PLC networks, windowed OFDM was the retained modulation in the HPAV specification, the current standard implemented in most of the recent in-home PLC systems. But another modulation, named OFDM/OQAM, has been recently presented as a viable alternative to the classical OFDM. Now, the results of our comparisons between the two modulations schemes, done in terms of capacity and throughput, aim at showing that the baseband version of OFDM/OQAM, named in short Hermitian Symmetric OQAM (HS-OQAM), is a serious candidate to efficiently improve data rates in PLC networks

No abstract

No abstract

A well-known allocation technique, called bitloading, results in the creation of tone maps which define, for each subcarrier on a particular transmission path, the appropriate constellation that has to be applied based on a link quality criterion. If this technique allows to efficiently optimize point-to-point transmissions in the network, it poses several challenges when transmitting the same information to multiple stations, i.e. Multicast/Broadcast data streams. In this paper, an efficient algorithm that smartly merges similar tone maps is presented, in order to better handle Multicast/Broadcast data streams. The demonstration of its efficiency will be made placing ourselves in the context of power line communications networks following the HPAV specification. However, our merging principle itself remains applicable to any system associating multicarrier modulations and bit-loading algorithms, as it could be in an indoor wireless environment.Index Terms-Cross-layer optimization, orthogonal frequency division multiplexing (OFDM), bit-loading, broadcast/multicast transmissions, power line communications (PLC).