Low-Subpacketization MIMO Coded Caching with Flexible Stream Allocation

2026-05-31

AI Summary

This work addresses the impracticality of coded caching in multi-antenna wireless networks due to excessive subpacketization. To overcome this challenge, the authors propose a low-complexity MIMO coded caching scheme that leverages virtual broadcast channel decomposition and shared cache modeling. The design explicitly controls spatial multiplexing gains under linear solvability constraints and, for the first time, jointly optimizes flexible stream allocation with low subpacketization at the receivers. Theoretical analysis demonstrates that the proposed method reduces subpacketization overhead by several orders of magnitude while asymptotically achieving the known optimal degrees of freedom. Numerical experiments further confirm that the scheme significantly enhances system throughput at practical signal-to-noise ratios.

Abstract

Subpacketization remains a major obstacle to the practical deployment of coded caching (CC) in multi-antenna wireless networks. In this paper, we propose a low-complexity multiple-input multiple-output (MIMO) CC scheme that enables flexible delivery rate adaptation while substantially reducing subpacketization requirements. The proposed design builds on a virtual decomposition of the broadcast channel and extends the shared-cache model to multi-antenna receivers, enabling adaptive selection of feasible user and stream configurations and thereby providing explicit control over the spatial multiplexing gain under linear decodability constraints. Analytical results show that the proposed framework can asymptotically approach the best-known achievable degrees of freedom (DoF) under linear decodability constraints while requiring orders-of-magnitude lower subpacketization than existing schemes. Numerical evaluations further demonstrate that this flexibility yields notable throughput improvements at practical signal-to-noise ratios.

Problem

• subpacketization
• coded caching
• MIMO
• multi-antenna networks
• practical deployment

Innovation

• low-subpacketization
• MIMO coded caching
• flexible stream allocation
• spatial multiplexing gain
• linear decodability