Application Of Coding Technology In Passive Optical Interconnection Data Center

With the increasing network traffic,the data center service scale of the Internet industry is becoming larger and larger,and its requirements for bandwidth and power consumption are becoming higher and higher.The scale and power consumption of electrical interconnection data center are limited by components,its cost has been high,and the rate is close to the upper limit of electrical bandwidth.In order to reduce the cost of data center,it is a good choice to apply optical fiber to data center.The bandwidth that optical interconnection can provide is unmatched by electrical interconnection.Thanks to the rapid development of optical devices,optical interconnection scheme has strong advantages in energy consumption and flexibility.At the same time,the high-speed propagation of light makes the optical interconnection have very low time delay and improves the communication efficiency.In the optical interconnection data center,in order to ensure the normal communication between different servers,wavelength division multiplexing is used to provide sufficient channel bandwidth,that is,one server uses one wavelength channel,but this way makes the wavelength channel consumed a lot and the channel utilization is not high.When the scale of the data center in the future is expanded,the limited number of channels is the bottleneck to improve the scale of optical interconnection data center.How to make full use of each wavelength channel is an urgent problem to be solved in the data center.With the development of 5G and other industries,data synchronization in data centers has become more and more important.Data synchronization between data centers has been studied a lot,but data synchronization in data centers is rarely heard.Considering the increasing traffic demand of the data center,PAM4 is applied to the data center to provide the rate and bandwidth that NRZ cannot provide.In the future high-speed data center,how to reduce the number of wavelength division multiplexing required for internal communication in the high-speed data center to improve the channel utilization is another problem in the data center.This article proposes three solutions to three different problems in the data center.Firstly,a passive optical interconnect scheme using NRZ and Manchester coded signals combined with polarization multiplexing is proposed to reduce the wavelength channel usage of wavelength division multiplexing in the data center rack and improve the channel utilization.Firstly,the principle of polarization multiplexing and the superposition and demodulation of two coded signals are introduced.Secondly,the server transceiver structure of the scheme and the overall scheme of the system are introduced.Finally,the feasibility of the scheme is verified by simulation experiments.Secondly,a fast synchronization method widely used in data center is studied.This method uses XOR operation to encode and partially decode the data,and realizes data demodulation through recovery matrix.In this article,a specific case and error control coding theory are used to describe and analyze the method in the binary domain,and the synchronization efficiency and feasibility of the method are summarized.Finally,the rate is increasing in the future,to cut down the number of wavelengths used in the rack of optical interconnect data center and improve the utilization rate of channel,a scheme of full duplex communication using physical layer network coding is proposed in the coupler-based rack using PAM4 for data transmission,in this article,simulation experiments are carried out under different rates and different transmission power,and the advantages of this scheme are summarized.