Optimization of Optical Modulator for LTE RoF in Nonlinear Fiber Propagation

IEEE Photonics Technology Letters (Impact Factor: 2.18). 04/2012; 24(7):617-619. DOI: 10.1109/LPT.2012.2185927

ABSTRACT This letter proposes an optimized launch power for the direct detection of optical orthogonal frequency-division multiplexing (DD-OOFDM) for radio-over-flber (RoF). The aim is to optimize the physical layer connectivity for the third generation partnership program-long-term evolution employing RoF technologies. We also analytically derive an expression for the distributed-feedback laser, laser-induced positive frequency chirping, incorporating the phenomena that induce phase distortion at the receiver, and explicitly explain the transient chirp of DD-OOFDM. Results show that transmission at the optimized launch power of -4 dBm improves the system power efficiency of 16-quadrature amplitude modulation (QAM) DD-OOFDM by ~20% and ~37%, 64-QAM DD-OOFDM by ~21% and ~35% compared to launch powers in the linear and nonlinear regions, respectively.

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