Diversity Technique for OFDM Systems: Enhanced Time-Frequency Multiplexing (eTFM)

Nowadays, orthogonal frequency division multiplexing (OFDM) systems are widely used for many different purposes, such as wireless broadcasting systems as digital video broadcasting-second generation terrestrial (DVB-T2), mobile networks as fourth generation long term evolution, or even specifications as the already approved by the DVB project, DVB-next generation for handhelds. The two first standards use state-of-the-art technologies that have currently made them two of the most cutting edge communication systems. In this paper, we propose a new diversity technique applicable to OFDM systems that improves the overall system performance. This technique will be evaluated in the frame of the DVB-T2 standard and compared to one of its most innovative diversity technologies: the rotated constellations (RC). Applying the proposed technique a performance improvement up to about 1 dB can be obtained when compared to the same system using RC. However, as RC, the proposed technique introduces a complexity increase in the detecting process.