非线性相位噪声对DQPSK调制系统性能影响研究

Effect of nonlinear phase noise on performance of DQPSK modulation system

摘要: 为了研究非线性相位噪声对差分正交相移键控（DQPSK）调制系统性能的影响，在理论推导非线性相位噪声数学模型的基础上，通过固定接收端信噪比不变，仿真分析了40Gb/s速率时DQPSK调制系统误码率随输入信噪比的变化情况。结果表明：与二进制差分相移键控（DPSK）调制相比，DQPSK调制对非线性相位噪声的影响更为敏感，当非线性效应较大时，非线性相位噪声将使系统误码率显著增大，严重影响系统通信质量。因此，当采用DQPSK调制时，必须考虑非线性相位噪声对系统性能的影响。

Abstract: In order to study the effect of nonlinear phase noise on the performance of DQPSK modulation system, based on the analysis of mathematical model of nonlinear phase noise, the property of bit error rate (BER) varying with the change of signal to noise ratio at transmitter was simulated in a 40 Gb/s DQPSK modulation system by keeping the signal to noise ratio at transmitter invariable. Compared with DPSK modulation, DQPSK modulation is much more sensitive to the effect of nonlinear phase noise, and the BER will obviously increase when the nonlinearity is big enough, by which communication quality of the system will be seriously influenced. As a result, the effect of nonlinear phase noise on the system must be taken into consideration when DQPSK modulation is used.