Orthogonal frequency division multiplexing (OFDM) in optical communications with direct detection for metro networks

The paper addresses OFDM transmission over optical links with low and moderate cost optics which is mandatory in access and in metro applications. Here we address especially direct detection receivers using photo detectors without the need for local lasers at the transmitter side. Thus the transmission becomes nonlinear due to the magnitude squared envelope detection which requires attention when used in dispersive fibre links. We consider several solutions to overcome this problem and we optimize the transceiver design.