Improved optical orthogonal frequency-division multiplexing performance using non-linear signal compression in intensity modulation and direct detection transmission systems incorporating parameter-relaxed digital-to-analogue converters/analogue-to-digita

Adaptively modulated optical orthogonal frequency-division multiplexing (AMOOFDM) using non-linear signal compression (NSC) (AMOOFDM-NSC) is proposed and numerically explored, for the first time, in intensity modulation and direct detection (IMDD) single-mode fibre transmission systems for cost-sensitive optical access networks. AMOOFDM-NSC utilises a simple cosine operation to compress digital electrical OFDM signals prior to performing digital-to-analogue conversion and optical intensity modulation in the transmitter. Compared with conventional AMOOFDM, AMOOFDM-NSC can not only significantly lower requirements on minimum quantisation bits and sampling rates of digital-to-analogue/analogue-to-digital convertors, but also simultaneously doubles the signal transmission capacity for quantisation bits of <; 4. In addition, AMOOFDM-NSC also shows excellent system flexibility and has good performance robustness to variations in system characteristics. AMOOFDM-NSC may have great potential for providing a cost-effective technical solution for practical implementations in cost-sensitive access networks.