Asymmetric Stream Allocation and Linear Decodability in MIMO Coded Caching
2026-03-06 • Information Theory
Information Theory
AI summaryⓘ
The authors study how coded caching (CC) can improve multi-antenna wireless systems by turning stored data into useful communication resources. They focus on making sure signals are easy to decode when different users get different amounts of data streams, not just equal shares. The paper introduces a simple rule to ensure this decoding works well for both balanced and unbalanced stream distributions. Using this rule, the authors propose a way to schedule data delivery that allows more flexible allocation of streams, potentially improving system performance compared to previous methods that only used equal sharing.
Coded CachingMIMO (Multi-Input Multi-Output)Degrees of Freedom (DoF)Linear DecodabilityStream AllocationSchedulingBit-level CacheWireless CommunicationSignal DecodingHeuristic Algorithm
Authors
Mohammad NaseriTehrani, MohammadJavad Salehi, Antti Tölli
Abstract
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.