Chapter 18: Massive MIMO

Learning Objectives

• Define channel hardening and prove that the normalised channel gain concentrates around its mean as the number of antennas grows
• Explain favourable propagation and prove asymptotic orthogonality of user channels under i.i.d. Rayleigh fading
• Derive achievable uplink and downlink rates with MR, ZF, and MMSE processing using the use-and-then-forget bound
• Analyse pilot contamination as the fundamental bottleneck of multi-cell massive MIMO and quantify the resulting rate ceiling
• Formulate and solve the max-min fairness power control problem for massive MIMO with matched-filter processing
• Compare cell-free massive MIMO with co-located deployments in terms of coverage uniformity and 95%-likely per-user rate
• Evaluate the energy efficiency of massive MIMO systems and determine the optimal number of antennas that maximises bits per joule