CAJ | 학술논문

相干光正交频分复用(CO-OFDM)系统中的较大峰值平均功率比(PAPR)问题会导致严重的光纤非线性效应。本文提出了一种改进的星座图扩展(ACE)算法，取得了更好的PAPR抑制效果。研究表明，ACE算法与凸集投影法(POCS)相结合可减少计算复杂度，但存在峰值再生现象等问题。为此，本文利用抛物峰值抵消(PPC)算法改善迭代过程中的峰值再生现象，并采用星座映射预修正技术提高了收敛速度。采用改进算法对4QAM、29 Gb/s 的CO-OFDM系统进行了仿真实验，结果表明改进算法使OFDM信号的PAPR降低了4.41 dB，并且具有更快的收敛速度。
상간광정교빈분복용(CO-OFDM)계통중적교대봉치평균공솔비(PAPR)문제회도치엄중적광섬비선성효응。본문제출료일충개진적성좌도확전(ACE)산법，취득료경호적PAPR억제효과。연구표명，ACE산법여철집투영법(POCS)상결합가감소계산복잡도，단존재봉치재생현상등문제。위차，본문이용포물봉치저소(PPC)산법개선질대과정중적봉치재생현상，병채용성좌영사예수정기술제고료수렴속도。채용개진산법대4QAM、29 Gb/s 적CO-OFDM계통진행료방진실험，결과표명개진산법사OFDM신호적PAPR강저료4.41 dB，병차구유경쾌적수렴속도。
The high Peak-to-average Power Ratio (PAPR) problem in the Coherent Optical Orthogonal Frequency-division Multiplexing (CO-OFDM) systems can lead to serious optical fiber nonlinear effects. In order to solve this problem, an improved Active Constellation Extension (ACE) algorithm was proposed, which could obtain better PAPR suppression effect. The traditional ACE algorithm was achieved combined with the projection onto convex sets method (POCS). In the proposed algorithm, Parabolic Peak Cancellation (PPC) algorithm was used to improve the peak regeneration phenomenon in the process of iteration, and the speed of convergence was improved by constellation point pre-adjustment technology. We applied the improved algorithm to a 4-QAM, and 29 Gb/s CO-OFDM system. The simulation results show that the proposed algorithm can effectively reduce the PAPR of OFDM signals by 4.41 dB and have faster convergence speed.