A massive-MIMO base station uses an antenna array to form narrow directional beams via phase-shifted signals, concentrating energy toward each user instead of broadcasting uniformly.
SINR ≈ P·G(θ)/(N0 + I)
Shannon: C = B·log2(1+SINR)
- Active users — number of simultaneously served beams; more users share the same time-frequency resource, lowering per-user throughput.
- Beam steering speed — how fast beams re-point to track moving users (beam management overhead).
- Network load — background traffic competing for resource blocks, raising latency and interference.
- Frequency band — mmWave gives huge bandwidth but shorter range/narrower beams; sub-6 GHz trades capacity for wider coverage.
Real-world use: 5G Advanced (3GPP Release 18/19) massive-MIMO beamforming powers stadium and urban small-cell deployments to serve dense crowds with low latency.