一种面向112 Gb/s PAM4接收机的自适应均衡设计方案  

An Adaptive Equalization Design Scheme for112 Gb/s PAM4 Receivers

作　　者：刘雪娜 李振松[1,2] 闻豪 缪旻[1,2] LIU Xuena;LI Zhensong;WEN Hao;MIAO Min(Key Laboratory of Information and Communication Systems,Ministry of Information Industry,Beijing Information Science and Technology University,Beijing 100101,China;Key Laboratory of the Ministry of Education for Optoelectronic Measurement Technology and Instrument,Beijing Information Science and Technology University,Beijing 100101,China)

机构地区：[1]北京信息科技大学信息与通信系统信息产业部重点实验室,北京100101 [2]北京信息科技大学光电测试技术及仪器教育部重点实验室,北京100101

出　　处：《电讯技术》2024年第6期960-966,共7页Telecommunication Engineering

基　　金：国家自然科学基金资助项目(62074017)。

摘　　要：提出了一种适用于超短距离(Very Short Reach,VSR)信道、面向112 Gb/s PAM4(Pulse Amplitude Modulation 4)接收机的自适应均衡设计方案。在该方案中,接收机前端利用3个连续时间线性均衡器(Continuous Time Linear Equalizer,CTLE)对信号分别在高频、中频和低频进行补偿,可变增益放大器(Variable Gain Amplifier,VGA)和饱和放大器(Saturation Amplifier,SatAmp)则用于对信号幅值的缩放。除了3个数据采样器外,引入4个辅助采样器用于进一步改善阈值自适应算法性能。同时,采用符号最小均方算法,利用接收端数据采样器和辅助采样器之间的偏移推动辅助参考电压收敛到信号星座电平,从而确保PAM4接收信号的眼图在垂直方向上3个眼睛具有相等的间隔和恒定的信噪比(Signal-to-Noise Ratio,SNR)。仿真结果表明,所提出的112 Gb/s PAM4接收机能够在损耗为15 dB的信道上实现小于10~(-12)的误码率,并且具有良好的眼图性能,其最差眼高为75 mV,眼宽为0.34 UI(Unit Interval),与传统方案相比具有显著的性能提升。An adaptive equalization design scheme for very short reach(VSR)channels and 112 Gb/s Pulse Amplitude Modulation 4(PAM4)receivers is proposed.In this scheme,three continuous time linear equalizers(CTLE)at the front end of receiver are used to compensate the high-frequency,mid-frequency and low-frequency signals respectively,and the variable gain amplifier(VGA)and saturation amplifier(SatAmp)are used to scale the signal amplitude.In addition to the three data samplers,four auxiliary samplers are introduced to further improve the performance of the threshold adaptive algorithm.At the same time,the sign-sign least mean squares algorithm uses the offset between the data sampler and the auxiliary sampler at the receiver side to drive the auxiliary reference voltage to converge to the signal constellation level,thus ensuring that the eye diagram of the PAM4 received signal has equal spacing and a constant signal-to-noise ratio(SNR)for the three eyes in the vertical direction.The simulation results show that the proposed 112 Gb/s PAM4 receiver achieves a bit error rate of less than 10-12 on a channel with a loss of 15 dB and has a good eye diagram effect,that is to say,the worst eye height and eye width are 75 mV and 0.34 UI(Unit Interval).Significant performance improvements over traditional solutions are demonstrated.

关 键 词：PAM4接收机 判决反馈均衡器 超短距离信道 连续时间线性均衡器 自适应算法 

分 类 号：TN911.5[电子电信—通信与信息系统]