光学学报, 2010, 30 (6): 1586, 网络出版: 2010-06-07
光相位调制器和光强度调制器产生40 GHz光载OFDM毫米波信号的传输性能比较 下载: 757次
Performance Comparison of 40 GHz Optical Millimeter Wave with OFDM Signal Generated by an Optical Phase Modulator and an Optical Intensity Modulator
光纤无线通信 正交频分复用 光毫米波产生 相位调制器 强度调制器 radio-over-fiber orthogonal frequency division multiplexing generation of millimeter wave phase modulator intensity modulator
摘要
实验研究了分别采用光相位调制器和光强度调制器产生40 GHz光载正交频分复用(OFDM)信号的毫米波光纤无线通信(ROF)系统,并比较了二者的传输性能。在中心站,将20 GHz的射频(RF)正弦波信号与2.5 Gb/s的OFDM信号混频后驱动相位调制器或强度调制器进行双边带(DSB)调制,产生的光载OFDM信号的毫米波经标准单模光纤(SSMF)传输到基站。在基站,经光纤布拉格光栅(FBG)滤除中心载波后的光调制信号经光电检测器转换成电调制信号,再与射频信号混频,恢复出基带OFDM信号,而分离出来的中心载波信号可以用于实现波长重用。实验验证了OFDM信号峰值平均(峰均)功率比大小对系统误码率的影响。实验结果显示,在大入纤功率情况下,相位调制和强度调制产生的毫米波光信号经过50 km SSMF传输后,其功率代价分别为小于0.5 dB和大于1 dB。说明光相位调制器产生光载毫米波加载OFDM信号在光纤中的传输性能优于光强度调制器。
Abstract
A 40 GHz radio-over-fiber (ROF) system is investigated experimentally to generate optical millimeter wave with optical orthogonal frequency division multiplexing (OFDM) signal using an optical phase modulator or an optical intensity modulator, and the transmission performances of optical millimeter waves are compared. In the central station, the 2.5 Gb/s OFDM analog data and a 20 GHz radio frequency (RF) clock are mixed to drive an optical phase modulator or an optical intensity modulator to realize the double-sideband (DSB) modulation, generated optical millimeter wave with OFDM signal, transmitted to the base station over standard single-mode fiber(SSMF). In the base station, the optical millimeter wave signals are converted to electrical signals after optical-electrical conversion, and the down-converted OFDM signals are detected after mixed with the local oscillators, and the optical carrier filtered out by a fibber Bragg grating (FBG) can be used to realize wavelength reuse. Effect of different peak-to-average power ratios on bit error rate (BER) is demonstrated experimentally. The results show that under the high optical power, after transmission over 50 km SSMF, the power penalty for the optical millimeter wave generated by an optical phase modulator and an optical intensity modulator are less than 0.5 dB and more than 1 dB, respectively. It demonstrates that the fiber transmission quality of optical millimeter wave with OFDM signal generation using an optical phase modulator is better than an optical intensity modulator.
夏敏敏, 董泽, 曹子峥, 张益民, 陈林. 光相位调制器和光强度调制器产生40 GHz光载OFDM毫米波信号的传输性能比较[J]. 光学学报, 2010, 30(6): 1586. Xia Minmin, Dong Ze, Cao Zizheng, Zhang Yimin, Chen Lin. Performance Comparison of 40 GHz Optical Millimeter Wave with OFDM Signal Generated by an Optical Phase Modulator and an Optical Intensity Modulator[J]. Acta Optica Sinica, 2010, 30(6): 1586.