Le sens du mot "Theios" chez Platon

The orthogonal frequency division multiplexing (OFDM) modulation is the most popular multicarrier modulation scheme nowadays. The main advantage of OFDM is its simplicity. However, due to the rectangular pulse shaping of the Fast Fourier transform filters, OFDM systems exhibit very high frequency leakage and poor stopband attenuation. In the light of these limitations, the offset-QAM-based filterbank multicarrier (FBMC-OQAM) modulation has recently received increasing attention. Rather than using a rectangular pulse, FBMC-OQAM uses a pulse shape which is more spread out in time, which results in a much better frequency localization. This in turn translates into higher spectral efficiency and much more flexibility for spectrum allocation.
The main objective of this thesis is to investigate the applicability of the FBMCOQAM modulation for next generations of communication systems. More specifically, we focus on two main directions. The first direction studies advanced equalization algorithms for multiple-antenna wireless systems characterized by highly frequency and/or time selective channels. The second direction studies two main linear impairments in optical fiber systems, namely, phase noise and chromatic dispersion.