使用分层调制在混合单频网络中提供本地内容

基于分层调制的最优多用户调度

Throughput Optimal Multi-user Scheduling via Hierarchical Modulation

我们研究了两个用户同时调度时的网络稳定性问题。其关键思想是通过采用分层调制，同时向经历不同信道条件的多个用户进行传输。对于两个用户的调度问题，我们开发了一个吞吐量优化算法，可以稳定网络，只要这是可能的。此外，我们分析证明，该算法实现了更大的可达速率区域相比，传统的最大权重算法，采用均匀调制和发送一个用户。我们证明了该算法的有效性，在一个现实的仿真环境中使用的参数高数据率协议的码分多址系统。仿真结果表明，该算法能够以较低的时延承载较高的用户流量。

Optimal DVB-S2 spectral efficiency with hierarchical modulation

We study the design of a DVB-S2 system in order to maximise spectral efficiency. This task is usually challenging due to channel variability. The solution adopted in modern satellite communications systems such as DVB-SH and DVB-S2 relies mainly on a time sharing strategy. Recently, we proposed to combine time sharing with hierarchical modulation to increase the transmission rate of broadcast systems. However, the optimal spectral efficiency remained an open question. In this paper, we show that the optimal transmission rate is the solution of a linear programming problem. We also study the pe…

利用分层调制提高DVB-S2频谱效率

DVB-S2 Spectrum Efficiency Improvement with Hierarchical Modulation

我们研究了DVB-S2系统的设计，以最大限度地提高频谱效率。由于信道可变性，此任务通常具有挑战性。诸如DVB-SH和DVB-S2的现代卫星通信系统主要依赖于分时策略来优化频谱效率。最近，我们表明，结合分时分层调制可以提供显着的收益（在频谱效率方面）相比，最好的分时战略。然而，我们以前的设计并没有提高DVB-S2的性能时，所有的接收机经历低或大的信噪比。本文介绍了一种分级QPSK和一种分级32-APSK，并通过一个基于DVB-S2的实际应用表明，分级QPSK在接收机信道条件较差时能提供改善，而32-APSK在接收机信道条件较好时能提高频谱利用率。

面向广播信道分层语义通信的基于深度学习的叠加编码调制

Deep Learning Based Superposition Coded Modulation for Hierarchical Semantic Communications over Broadcast Channels

针对广播信道中不同接收方需恢复相关但分层的语义信息问题，提出DeepSCM，通过特征分层、LMMSE去相关与概率叠加调制提升图像语义广播性能。

基于分层模式索引调制的正交延迟-多普勒分复用调制

Orthogonal Delay-Doppler Division Multiplexing Modulation with Hierarchical Mode-Based Index Modulation

针对OTFS-IM检测复杂度高的问题，提出分层模式索引调制HMIM，结合ODDM构成ODDM-HMIM，在相同SE下BER和复杂度均优于传统IM，还提出适配大帧的低复杂度SIC-MMSE检测器。

用于概率成形编码调制的分层分布匹配

Hierarchical Distribution Matching for Probabilistically Shaped Coded Modulation

本文提出面向概率成形编码调制的HiDM方案，以并行接口和流水线架构高效完成DM/invDM，并在相同invDM后BER下支持更高FEC后BER，代价是略高速率损失与信噪比需求。

Cooperative Hierarchical Caching in 5G Cloud Radio Access Networks (C-RANs)

Over the last few years, Cloud Radio Access Network (C-RAN) has arisen as a transformative architecture for 5G cellular networks that brings the flexibility and agility of cloud computing to wireless communications. At the same time, content caching in wireless networks has become an essential solution to lower the content-access latency and backhaul traffic loading, which translate into user Quality of Experience (QoE) improvement and network cost reduction. In this article, a novel Cooperative Hierarchical Caching (CHC) framework in C-RAN is introduced where contents are jointly cached at th…

Deep Reinforcement Learning for Adaptive Caching in Hierarchical Content Delivery Networks

Caching is envisioned to play a critical role in next-generation content delivery infrastructure, cellular networks, and Internet architectures. By smartly storing the most popular contents at the storage-enabled network entities during off-peak demand instances, caching can benefit both network infrastructure as well as end users, during on-peak periods. In this context, distributing the limited storage capacity across network entities calls for decentralized caching schemes. Many practical caching systems involve a parent caching node connected to multiple leaf nodes to serve user file reque…

Hierarchical Soft Slicing to Meet Multi-Dimensional QoS Demand in Cache-Enabled Vehicular Networks

Vehicular networks are expected to support diverse content applications with multi-dimensional quality of service (QoS) requirements, which cannot be realized by the conventional one-fit-all network management method. In this paper, a service-oriented hierarchical soft slicing framework is proposed for the cache-enabled vehicular networks, where each slice supports one service and the resources are logically isolated but opportunistically reused to exploit the multiplexing gain. The performance of the proposed framework is studied in an analytical way considering two typical on-road content se…

分层编码缓存

Hierarchical Coded Caching

在非高峰时段缓存流行内容是一种减少高峰时段网络负载的策略。最近的工作已经显示出显着的好处，设计这样的缓存策略，不仅在本地提供的内容的一部分，但也提供编码的多播机会，甚至在用户之间有不同的需求。利用这两个增益被证明是近似最佳的高速缓存系统与一个单一的高速缓存层。出于实际情况下，我们认为在这项工作中的分层内容分发网络的两层缓存。我们提出了一个新的缓存方案，结合了两种基本的方法。第一种方法在每个层内提供编码多播机会;第二种方法提供跨多个层的编码多播机会。通过在这两种方法之间取得适当的平衡，我们表明，该方案实现了最佳的通信速率在一个恒定的乘法和加法的差距。我们进一步表明，有没有在两个层中的每一个的速率之间的张力，以上述差距。因此，两个层可以同时以近似最小速率操作。

关于具有离线用户的分层编码缓存

On Hierarchical Coded Caching with Offline Users

针对带离线用户的两层分层网络编码缓存问题，提出分层热插拔放置交付阵列（HHPDA）描述一般情况下的放置与交付阶段，并利用组合t-设计构造了一类HHPDA。

城市车载网络中的主动内容缓存方案

Proactive Content Caching Scheme in Urban Vehicular Networks

针对城市车载网络高动态性挑战，提出边缘计算使能的分层协作缓存框架，通过轨迹与流行度预测及隐私保护，实现自适应资源管理，显著提升命中率并降低延迟。