用于高Gb／s光通信系统的新型时钟提取电路

New Clock-Recovery Circuit for Multigigabit/second Optical Communication Systems

新型时钟提取电路省去传统提取电路中的非线性处理电路，从而简化了接收设备。在利用这种电路的光通信系统中，在发送端，时钟脉冲叠加在数字信号上；在接收端，主放电路以后分成两个通路，一通路接有一个Ｎｙｑｕｉｓｔ滤波器，只允许信号脉冲通过，另一路则接有一窄带滤波器，实现时钟信号的提取。为了验证此方案的可实现性，研制出一套１．２４４Ｇｂ／ｓ光通信系统。本文从理论上分析这种光通信接收机的灵敏度与时钟脉冲调制度及时移的关系，并与实验结果相对比。另一方面，还建立了一个简单的公式计算所提取的时钟信号抖动值。

The new clock-recovery circuit eliminate nonlinear circuit in the traditional clock recovery circuit.It siniplifies the receiver set.At the transmission end of the optical communication system using this clock-recovery circuit,the clock is superposed on the data signal.At the receiver end the composite signal is separated into two paths,one for recovering the data signal by using a Nyquist filter to attenuate the clock,and the other for recovering the clock by using a high Q,narrow-band filter.To investigate the realizability of this scheme,we set up a l.244Gb/s optical fiber communication system. In this paper we discribe the theoritical analysis of the relation between the sensitivity of the receiver and the modulation deep,time shift of the clock pulse,and compare them with the experimental results.Additionally,we also form a simple formula to calculate the Jitter of the recovering clock.