Coded caching (CC) can transform cache memory at network devices into an active communication resource. Prior studies have shown that CC can significantly enhance the achievable Degrees of Freedom (DoF) in multi-input multi-output (MIMO) systems. To fully exploit MIMO-CC gains across all SNR regimes and enable practical linear receivers, flexible scheduling is required. Existing DoF analysis, scheduling, and linear receiver design, however, largely assume symmetric stream allocations across users. This paper extends the authors' recent work on DoF and linear decodability analysis for MIMO-CC systems by deriving a simple criterion, based on per-user stream allocation, that guarantees linear decodability for both symmetric and non-symmetric bit-level CC schemes. Building on this, we propose a heuristic MIMO-CC delivery and scheduling framework that enables asymmetric stream allocation while adhering to linear decodability, thereby expanding the feasibility region of achievable DoF compared to symmetric-constrained designs.

翻译：编码缓存（CC）能够将网络设备中的缓存内存转化为主动通信资源。先前研究表明，CC能够显著提升多输入多输出（MIMO）系统中可实现的自由度（DoF）。为充分挖掘MIMO-CC在所有信噪比（SNR）区间的增益并实现实用的线性接收机，需要灵活的调度机制。然而，现有的DoF分析、调度策略及线性接收机设计大多假设用户间采用对称的流分配方案。本文通过推导一个基于每用户流分配的简洁判据，扩展了作者近期在MIMO-CC系统自由度与线性可译码性分析方面的研究，该判据可同时保证对称与非对称比特级CC方案的线性可译码性。在此基础上，我们提出了一种启发式MIMO-CC传输与调度框架，该框架在遵循线性可译码性的前提下支持非对称流分配，从而相较于对称约束设计方案扩展了可实现自由度的可行域。