光相位调制器和光强度调制器产生40GHz光载OFDM毫米波信号的传输性能比较  

Performance Comparison of 40 GHz Optical Millimeter Wave with OFDM Signal Generated by an Optical Phase Modulator and an Optical Intensity Modulator

作　　者：夏敏敏[1] 董泽[1] 曹子峥[1] 张益民[1] 陈林[1] 

机构地区：[1]湖南大学计算机与通信学院微纳光电器件及应用教育部重点实验室,湖南长沙410082

出　　处：《光学学报》2010年第6期1586-1591,共6页Acta Optica Sinica

基　　金：国家863计划(2007AA01Z263;2009AA01Z222);教育部光通信和光波技术重点实验室(北京邮电大学)开放基金资助课题

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40GHz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20GHz的射频(RF)正弦波信号与2.5Gb/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50kmSSMF传输后,其功率代价分别为小于0.5dB和大于1dB。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。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.

关 键 词：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 

分 类 号：TN929.9[电子电信—通信与信息系统]