论文部分内容阅读
虽然OFDM调制技术在射频领域中已得到了广泛的研究,但在无线光领域中的研究才刚开始。由于FSO-OFDM系统中采用马赫-曾德尔(MZM)调制器进行电光转换,该调制器的转移特性曲线为余弦函数,存在很大的非线性问题,因此,FSO-OFDM系统比射频OFDM系统对PAPR更加敏感。为了降低系统PAPR,重点研究了基于Golay互补序列和Reed-Muller码的编码类降低PAPR的算法,对输入的二进制序列进行编码,产生Golay互补序列作为传输码字,来降低系统PAPR,并通过MonteCarlo方法对其进行了仿真验证,结果表明该算法在QPSK系统中可以将峰值功率控制在3 dB以下,在QAM系统中峰值功率可以降低至4.5 dB。
Although OFDM modulation technology has been extensively studied in the field of radio frequency, research in the field of wireless light has just begun. Due to the electro-optical conversion by the Mach-Zehnder (MZM) modulator in the FSO-OFDM system, the transfer characteristic curve of the modulator is a cosine function, which presents a serious nonlinear problem. Therefore, the FSO-OFDM system is more efficient than the RF OFDM system PAPR is more sensitive. In order to reduce the PAPR of the system, we focus on the PAPR reduction algorithm based on the Golay complementary sequence and the Reed-Muller code, reduce the PAPR of the system by encoding the input binary sequence and generating the Golay complementary sequence as the transmission codeword, The simulation results show that this algorithm can control the peak power below 3 dB in QPSK system and reduce the peak power to 4.5 dB in QAM system.