介绍了一种基于参考的预均衡(RPE)技术，该技术基于自相干混频技术，可实现自相干零差检测系统中传递函数精确定性信息的测量，并且可对传输信号进行预加重处理。RPE技术可以对所有电和光的线性损失进行预补偿，电和光的线性损失包括调制器和功率放大器引起的带宽限制，以及光学前置滤波器造成的高频分量损失。RPE校准性能很大程度上取决于发射机与接收机的激光器线宽。研究了自相干零差检测系统中几种常见激光源的RPE校准性能，提出了一种能够获得传递函数精确定性信息的相位纠正算法。利用几种典型激光源，在波分复用带宽限制为25 GHz、速率为32 Gbit/s的偏振复用正交相移键控相干光通信系统中证实了该算法的可行性。

A reference-based pre-equalization (RPE) technology is introduced. The technology, which is based on the self-coherent mixing frequency technology, can measure the accurate qualitative information of transfer function in self-coherent homodyne detection system and pre-emphasize the transmission signal. The RPE technology can pre-compensate all electrical and optical linear loss, including the bandwidth limitation of modulator and power amplifier and the high-frequency component loss caused by optical pre-filter. The calibration performance of RPE strongly depends on the laser linewidth of both the transmitter and the receiver. We investigate the RPE calibration performances of several laser sources which are universal in self-coherent homodyne detection system, and develop a phase correction algorithm to obtain accurate qualitative information of the transfer function. The feasibility of the algorithm is verified when we use several types of laser sources in coherent optical communication system with polarization-multiplexed quadrature phase shift keying. The wavelength division multiplexing bandwidth limitation is 25 GHz and the rate is 32 Gbit/s.