Analysis And Optimization Of Crosstalk Performance Based On Gaussian Structure Optical Networks-on-Chip

In recent years,in order to meet the increasing computing performance requirements and the desire for multi-task simultaneous processing,the operating frequency and integration density of on-chip transistors have been increasing,and Multiprocessor systems-on-chip(MPSoCs)has become the mainstream trend in on-chip design.Traditional electrical interconnected network(Electrical networks-on-chip,ENoCs)cannot meet the needs of MPSoCs for continuous development due to problems such as high crosstalk,high latency,low bandwidth,and high energy consumption.Optical networkson-chip(ONoCs)replaces the electrical connection as a new interconnection method for multi-processing cores on the chip.It can realize arbitration control through the electrical interconnection layer and realize data transmission through the optical interconnection layer,which can effectively solve the power consumption,delay and bandwidth limitation faced by ENoCs and meet the development requirements of new applications.In an ONoCs-based communication system,on chip network as a communication infrastructure arms to complete data exchange of different IP cores.The topology of the chip determines the efficiency with which the network can efficiently distribute information.In addition to having a significant impact on network bandwidth,latency,fault tolerance,and power consumption,network topology also plays an important role in the design of the ONoCs architecture,such as router fabric design and application mapping.When choosing the suitable network topology for the ONoCs architecture,one of the main goals is to improve network performance by choosing a network topology with better static characteristics such as node degree,diameter,and average hop distance.At the same time,it is also necessary to consider the influence of physical constraints such as line density and router structure complexity.Several topologies have been proposed for ONoCs so far,such as Mesh,Torus,Fat-Tree,etc.Mesh and Torus networks are common choices because their network diameters are relatively short,node degrees are low,and IP cores are easier to lay out.Compared with Mesh or Torus,Gaussian network has significant topological advantages in terms of network diameter and average hopping,and can accommodate more nodes,with less communication delay,while maintaining a regular grid-like structure,thus becoming an suitable topology candidate for ONoCs architecture.However,due to the large number of optical components such as waveguide crossovers and microring resonators in the ONoCs architecture,when optical signals pass through these devices,the inherent characteristics of the physical materials of the optical devices cause optical signals to inevitably encounter crosstalk noise and power loss.Although the impact of device level is very small,as the network scale increases,crosstalk noise continues to accumulate in the optical signal,which will lead to severe degradation of network performance,resulting in signal attenuation and even distortion,thus limiting the networks scalability.Therefore,applying the topology advantages of Gaussian networks to the architecture design of ONoCs,it is very important to analyze the impact of power loss and crosstalk noise on network performance in the network.In this paper,a complete analysis model of power loss and crosstalk noise is proposed for GaussianBased ONoCs.An optimization method for improving the signal-to-noise ratio of optical link is proposed based on the characteristics of Gaussian network topology.The main research contents are as follows:1.The definition,expression,topology and advantages of the Gaussian network are described.2.The physical structure and principle of the silicon-based waveguide and resonant microring that constitute the ONoCs communication system are introduced.A model of several basic optical switching elements(BOSEs)consisting of silicon-based waveguides and micro-rings is proposed.And the calculation of the outgoing optical power and crosstalk noise of each port of BOSEs under different operating conditions is given.The formula lays the foundation for the analysis of the network layer.3.Based on the established BOSEs analysis model,an all-pass five-port optical router model for Gaussian on-chip optical network is proposed.The switch mechanism and Gaussian routing algorithm used in optical networks are introduced.An analysis model of power loss and crosstalk characteristics of the optical router level is established and illustrated.4.The calculation model of power loss,crosstalk noise accumulation,optical signalto-noise ratio(OSNR)and bit error rate(BER)of optical signals transmitted from source node to destination node in the network is analyzed.5.The Cygnus and Crossbar optical routers were used in the numerical simulation to verify the feasibility of the proposed analysis model,and the worst path and maximum network size in the Guassian on-chip optical network were obtained.The simulation results show that with the expansion of the network,the OSNR of the network drops sharply.In order to make the Gaussian on-chip network more usable,we propose an optimization method to improve the network performance,that is,to select the optimal path according to the location distribution of the two communication IP cores,this method can effectively avoid the worst case.Finally,the network model is built based on the Optisystem simulation software to facilitate a more intuitive analysis of network transmission performance.