Novel Layer-2 transmission strategies for 5G systems

在本项目中，与通信第1层和第2层之间的交互相关的主要问题之一 系统将得到解决。特别是，与混合ARQ(HARQ)和自适应调制相关的新策略 和编码(AMC)将被设计和分析。 支持公司InterDigital希望弥补这两个基本要素的主要弱点 由于缺乏信息交流而导致的现代通信系统的机制 关于信道的状态和解码器的状态。而AMC的目的是调整变速器 对于时变信道的参数，HARQ是一个处理残留误差而不是 充分利用在重传过程中获得的CSI。几乎没有需要调整的参数， HARQ非常健壮，但对提高吞吐量帮助很小。因此，虽然AMC和HARQ有 对现代无线通信系统的成功做出了重大贡献，在目前的形式下，它们 尚未准备好满足5G系统的低延迟(1ms)、高可靠性(99.999)和 尤其是频谱效率的提高。 因此，为了解决交叉指的这种需求，新的传输策略利用了以前的结果 理论研究将为实际的编码和调制提供建议。这些新战略将针对 传输场景类似于4G中使用的场景，以及5G系统预期的其他场景。利用 I)可变长度(或可变带宽)传输、ii)多分组传输和iii)适配的思想 基于在整个HARQ周期中积累的解码器状态信息，传输策略 AMC和HARQ联合利用CSI和丰富的信令反馈来提高网络吞吐量 将提出并分析基于HARQ的传输。

In this project, one of the major issues related to the interaction between Layer 1 and Layer 2 of communication systems will be addressed. In particular, new strategies relating hybrid ARQ (HARQ) and adaptive modulation and coding (AMC) will be designed and analyzed. The supporting company, InterDigital, wants to remedy the major weakness of these two fundamental mechanisms of modern communication systems which is caused by a lack of exchange of information regarding the state of the channel and the state of the decoder. While AMC is meant to adjust the transmission parameters to the time-varying channel, HARQ is a "safety net" which deals with residual errors and does not take advantage of the CSI acquired during the retransmissions. Having practically no parameters to adjust, HARQ is very robust but helps very little to improve the throughput. Therefore, while AMC and HARQ have significantly contributed to the success of modern wireless communication systems, in their current form they are not ready to meet 5G systems requirements of lower latency (< 1ms), high reliability (99.999%) and particularly, the improved spectral efficiency. Thus, to address this need of Interdigital, new transmission strategies exploiting the results of previous theoretical studied will be proposed for practical codes and modulations. These new strategies will target transmission scenarios similar to those used in 4G and others that are expected for 5G systems. Exploiting the ideas of i) variable-length (or variable-bandwidth) transmission ii) multi-packet transmission and iii) adaptation based on the decoder state information accumulated throughout the HARQ cycle, transmission strategies where AMC and HARQ exploit jointly the CSI and rich signaling feedback to improve the throughput of the HARQ-based transmissions will be proposed and analyzed.