本文是计算光纤链路中的误码率的。所考虑的链路中光源是一个激光器或发光二极管,传输介质是光纤。光纤中传输的光脉冲,因色散等原因而引起码间干扰。接收部分是一个雪崩二极管(APD)和一个滤波器。APD管简化为一个P-N结跟随一个随机倍增器。在计算过程中,将各因素引起的电子数随机变量的特征函数相乘,而概率密度用傅里叶级数展开。最后算出对应于不同码间干扰量的最差误码率和平均误码率与输入光功率的函数关系。 This article is to calculate the bit error rate in the fiber link. The light source in the link under consideration is a laser or light emitting diode and the transmission medium is optical fiber. Optical pulses transmitted in the optical fiber, due to dispersion and other causes intersymbol interference. The receive section is an avalanche diode (APD) and a filter. The APD tube is reduced to a P-N junction followed by a random multiplier. In the process of calculation, we multiply the eigenfunction of random number of electrons caused by various factors, and the probability density is expanded by Fourier series. Finally, the worst error rate and the average error rate corresponding to different inter-code interference quantities are calculated as a function of input optical power.