Adaptively modulated optical fiber link in IM-DD Systems

Adaptive modulation is introduced in the field of optical OFDM to motivate the current research carried out in infrared wireless technologies. The proposed all optical OFDM system is described in Section II. Section IV presents the IM/DD systems for the cost effective solution of the optical OFDM system design considerations that should be followed to calculate the system’s parameters. Here optical orthogonal frequency division multiplexing systems using direct detection (DD) individually are also described which are suitable for cost-effective applications. A scheme based on discrete Hartley transform (DHT) is proposed and compared to standard Optical OFDM implementation. Both asymmetrically clipped (AC) and DC biased solutions are given in this paper for intensity-modulated DD systems. We show that AC is a power efficient technique that can be implemented without Hermitian symmetry constraint. For the purpose of getting same performance level the FFT-based Optical OFDM is achieved.