Chapter 5: Coded Caching with Multi-Antenna Transmitters

Learning Objectives

• Formulate the cache-aided multi-antenna Gaussian broadcast channel as delivery of general message sets
• State and prove the key CommIT result: $\mathrm{DoF} = t + L$ where $t = KM/N$ and $L$ is the number of transmit antennas
• Understand why the caching and spatial multiplexing gains add rather than multiply
• Construct the Lampiris-Caire scheme: partition $K$ users into $\binom{K}{t+L}$ delivery groups of size $t+L$
• Analyze the finite-SNR rate behavior including pre-log corrections
• Relate the multi-antenna scheme to interference alignment and index coding with side information