Cost effective all-optical fractional OFDM receiver using an arrayed waveguide grating

Experimental emulation of nonlinear distortion suppression by FrOFDM subcarriers

“…The signal performing FrFT of -p at the transmitter can be received by performing FrFT of p at the receiver. FrFT can be implemented using passive optical components such as wavelength selective switches (WSS) and arrayed waveguide gratings [23]. In OFDM, PAPR becomes high when many subcarriers are in phase, as shown in Fig.…”

“…In other words, flexible control of the CP-insertion effect and PAPR reduction, in accordance with the transmission conditions, is important. A fractional Fourier transform (FrFT)-based multiplexing scheme, fractional OFDM (FrOFDM), using an intermediate domain in the time-frequency plane exhibits considerable flexibility in the axis of multiplexing and a medium characteristic between OFDM and N-OTDM [19][20][21][22][23][24][25]. Therefore, FrOFDM can improve the signal quality or extend fiber span via PAPR reduction [25][26][27] and reduce the required performance of receivers through CP insertion [24], which allows flexible selection of the transmission scheme.…”

Power efficient optical serial-to-parallel conversion using fractional OFDM-based linear technique

“…Our proposed Fr-OFDM based serial-to-parallel conversion is expected to incorporate both benefits of previous serial-to-parallel conversion techniques; the densest serial and parallel features of N-OTDM and OFDM as well as power efficiency of a linear technique. where t is time, f is frequency, T is the symbol duration, and p is the fractional parameter (p ¼ 1 for standard FT), N is the total number of subcarriers, respectively [8,12,14]. While a conventional Fourier Transform performs a =2 rotation in the time-frequency plane, the FrFT makes a rotation of an intermediate angle p=2.…”

“…1). A WSS can work as Fr-OFDM based Tx and Rx as well as arrayed waveguide grating (AWG) based optical filters [14]. It not only generates the sinc-shaped pulses, but it also multiplexes and properly delays the streams, without using any delay synchronization, splitter and coupler, as in conventional approaches.…”