Crosstalk noise analysis in ring-based optical networks-on-chip

Abstract

Optical networks-on-chip, ONoCs, has been proposed for ultra-high bandwidth and low latency. Different ONoCs are constructed by the microresonators. One of the drawbacks of these microresonators is that they suffer from intrinsic crosstalk noise and power loss, resulting in the reduction of Signal-to-Noise Ratio (SNR) which causes system performance degradation at the network level. Among the different topologies of ONoCs, ring-based networks-on-chip has been introduced because it utilizes on-chip crossbars providing the on-chip bandwidth. These on-chip crossbars can improve the network latency when the electrical-optical/optical-electrical converters are placed only at the end of the ring. With this characteristic, the on-chip crossbars may suffer from a large amount of crosstalk noise accumulated from the first to the last cluster. Hence, in this thesis, we systematically study the worst-case crosstalk noise and SNR in ring-based ONoCs. For the first time, we formally propose the analytical models at the device level for a DWDM ONoC and utilize a bottom-up approach to analyze the crosstalk noise as well as the SNR of a ring-based ONoC at the network level. Finally, we apply these analyses to simulate the quantitative results of the worst-case power loss, crosstalk noise, and SNR in two different ring-based ONoCs, which are Corona and SUOR the Sectioned Undirectional Optical Ring. The thesis focuses more on the results of Corona ONoC. We also provide comparison of the worst-case SNR and signal power loss among Corona, mesh-based and folded-torus-based ONoCs, all of which consist of the same number of cores. The quantitative results demonstrate the damaging impact of crosstalk noise and power loss in Corona: the worst-case SNR is 14.0 dB in the network, while the worst-case power loss is substantially high, -69.3 dB, in the data channel. Regarding the control arbitration, the worstcase SNR in Corona is noticeably high at -139.26dB. Meanwhile, the worst-case results of SUOR shows that this network provides a competitive signal power loss, at -15.5dB, while keeping the worst-case SNR high, at 11.8dB, compared to Corona and other ONoCs.

Date of Award	2014
Original language	English
Awarding Institution	The Hong Kong University of Science and Technology