Poly Phase Network OFDM/OQAM for Optical Communication System

Orthogonal frequency division multiplexing offset quadrature amplitude modulation (OFDM/OQAM) could provide high spectral efficiency with the eliminating of cyclic prefixed (CP) inserted in conventional OFDM systems. For optical OFDM/OQAM, real filed orthogonal condition guaranteed by the using of the filter bank could combat the inter symbol interference (ISI) induced by chromatic dispersion (CD) and polarization mode dispersion (PMD). However, the constructing of the filter bank is more comprehensive than conventional OFDM modulation. For this approach, the complexities induced by the filtering of the information symbols with the prototype filter brought constraints to the implementation of the optical OFDM/OQAM systems. In this paper, we introduced poly phase network (PPN) OFDM/OQAM to optical communication systems for the first time. With the using of the PPN OFDM/OQAM, the generating of the odd and the even OFDM/OQAM blocks could be performed separately. The convolution approach could be replaced by the multiplication of the PPN OFDM/OQAM symbols with the prototype filter. With the using of the PPN method, the computational complexities of the transmitter and the receiver for optical OFDM/OQAM system could be decreased significantly. As shown in the Montel Carlo simulation results, PPN OFDM/OQAM employing the prototype filter with promising time-frequency-Iocalization (TFL) property provided promising transmission performance for optical communication systems.