Wireless Network-on-Chip (WNoC) is a promising concept which provides a solution to overcome the scalability issues in prevailing networks-in-package for many-core processors. However, the electromagnetic propagation inside the chip package leads to energy reverberation, resulting in Inter-Symbol Interference (ISI) with high delay spreads. Time Reversal (TR) is a technique that benefits the unique time-invariant channel with rich multipath effects to focus the energy to the desired transceiver. TR mitigates both ISI and co-channel interference, hence providing parallel communications in both space and time. Thus, TR is a versatile candidate to improve the aggregate bandwidth of wireless on-chip networks provided that a Medium Access Control (MAC) is used to efficiently share the wireless medium. In this paper, we explore a simple yet resilient TR-based MAC protocol (TR-MAC) design for WNoC. We propose to manage multiple parallel transmissions with simultaneous spatial channels in the same time slot with TR precoding and focused energy detection at the transceiver. Our results show that TR-MAC can be employed in massive computing architectures with improved latency and throughput while matching with the stringent requirements of the physical layer.

翻译：无线片上网络是一种前景广阔的概念，为解决多核处理器中现有封装内网络的可扩展性问题提供了方案。然而，芯片封装内部的电磁传播会导致能量混响，从而产生具有高延迟扩展的码间干扰。时间反转是一种利用具有丰富多径效应的独特时不变信道特性、将能量聚焦至目标收发器的技术。该技术能同时抑制码间干扰和同信道干扰，从而在空间和时间维度上实现并行通信。因此，若配合介质访问控制协议以高效共享无线介质，时间反转技术有望成为提升无线片上网络聚合带宽的通用解决方案。本文针对无线片上网络探索了一种简洁且鲁棒的时间反转介质访问控制协议设计。我们提出通过时间反转预编码与收发器端的聚焦能量检测，在相同时隙内利用同步空间信道管理多路并行传输。实验结果表明，该协议可应用于大规模计算架构，在满足物理层严苛要求的同时，显著改善传输延迟与吞吐量性能。