文章简单介绍了光差分正交相移键控(DQPSK)调制格式的调制和解调方式,对光DQPSK的预编码也进行了必要的说明。使用软件Matlab构建了光DQPSK背靠背系统,得到了不同的DQPSK调制的频谱图和眼图,并对仿真结果进行了验证,就NRZ—DQPSK和RZ33DQPSK的差异进行了比较。
The modulation and demodulation methods of the optical Differential Quadrature Phase-Shift Key(DQPSK) are briefly introduced, including a necessary illustration of its precoding. Its back to back system is established by using Matlab, the optical power spectra and eye diagrams in different DQPSK modulations obtained and their simulation results verified Finally, NRZ-DQPSK is compare with RZ33-DQPSK.