We experimentally and numerically demonstrated the generation of a (3, 1) vector signal by a single Mach-Zehnder modulator (MZM) without pre-coding. The MZM is driven by the (3, 1) modulated signal after photoelectric conversion by the "square law" of a photodetector. Although the phase changes, the corresponding constellation distribution is consistent with that of the regular signal. Our proposed scheme effectively avoids the pre-coding process with a simple architecture. The bit-error-ratio (BER) results indicate that the (3, 1) signal has a better BER performance than the pre-coded quadrature phase shift keying vector signal, and both are below ${3.8}\times {{10}^{ - 3}}$3.8×10-3 after 25 km optical fiber transmission.

中文翻译：

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基于光载波抑制而无需预编码即可生成（3，1）矢量信号。

我们在实验上和数值上证明了没有预编码的单个Mach-Zehnder调制器（MZM）生成的（3，1）矢量信号。通过光电检测器的“平方律”进行光电转换后，由（3，1）调制信号驱动MZM。尽管相位改变，但是相应的星座分布与常规信号的星座分布一致。我们提出的方案有效地避免了具有简单架构的预编码过程。误码率（BER）结果表明（3，1）信号具有比预编码正交相移键控矢量信号更好的BER性能，并且均低于$ {3.8} \倍{{10} ^ {-3}} $ 25×3公里光纤传输后$ 3.8×10-3。