由于千兆无源光网络系统中的上行光信号采用高速突发模式，故对其特性的检测是实现实时光层监测的难点。详细分析了上行光信号的传输特性、帧开销及噪声模型。并在此基础上，设计了一种检测方案，该方案通过高阻抗的前置放大器将信号引出，不影响原系统的正常工作，从而满足了实时检测的需要；通过峰值检波电路将高频突发信号降为低频进行处理，大大降低了检测的难度；在求出信号的平均功率后，利用底层光接收机模块中自带的限幅放大与数字判决功能修正误差。由于该方案对输入信号的信噪比有较大提升，且利用了系统的数字判决功能获取信号的占空比信息，故其实现成本低廉，检测精度理想。实验仿真的结果证明了该方案的可行性。

It is difficult to realize real-time power detection as the upstream signal of gigabit passive optical network(GPON) system is high-speed burst mode. Based on the analysis of the upstream signal transmission characteristics, the frame overhead, and the noise model, a new detection method is presented. This method raises the signal to the original system with pre-through high-impedance amplifier, which does not affect the performance of the original system. High-frequency burst signal will be down converted for processing, through the peak detecting and low-pass filtering. A limiting amplifier and digital decision device of low-level optical receiver module can be used to correct the error after the signal′s average power is obtained. Since the method can improve the signal-to-noise ratio, and make full use of system function to obtain information of the duty ratio, it is low-cost and has high detection accuracy. The experimental result has shown that the method is quite suitable for GPON system upstream signal power detection.