面向高信道衰减的低功耗112 Gibit/s Duo-binary PAM4 SerDes发射机设计

为了解决串行收发机在强信道衰减下误码过高的问题,采用Duo-binary PAM4编码技术设计了一款低功耗的112 Gibit/s SerDes发射机。通过采用Duo-binary PAM4编码技术,解决了高速PAM4(Pulse Amplitude Modulation-4)信号衰减过大的问题;采用CMOS的1/4速架构的4∶1合路器,降低了发射机的系统功耗;采用阻抗校准电路,提高了Duo-binary PAM4发射机的线性度。该发射机采用CMOS 28 nm工艺设计,0.9 V电压供电。仿真结果表明:该发射机在20.9 dB强信道衰减下,可以工作在112 Gibit/s,功耗为1.9 pJ/bit,且线性度达到88.3%。

Research on Dispersion Compensation of 40 GB/s Optical Duo-Binary Coded Transmission System

A 40 Gb/s high speed optical transmission system is designed, and the different dispersion compensation schemes are adopted to realize the transmission of the optical duo-binary (ODB) signals over 120 km optical fiber. Optical duo-binary signals are generated by using a precoder, two low- pass filters (LPF) and one mach-zehnder modulator (MZM). Through combination of dispersion compensation fiber (DCF) and single mode fiber (SMF) in the transmission link, four different dispersion compensation schemes (pre-compensation, post-compensation and hybrid compensation (pre+ post) and hybrid compensation (post+ pre)) were compared. Analyzing Q factor, BER, eye diagrams and receiver sensitivity in several dispersion compensation schemes, the simulation results are: the cut-off frequency of LPF affects the transmission performance, and the hybrid compensation (post+ pre) scheme is the optimal dispersion compensation method.