Thanks to abundant spectral resource, millimeter wave (mmWave) communications have become an important research area. Though mmWave communications have achieved great progresses in WLAN, it faces huge challenges in realizing wide ultra-high throughput area coverage. The paper provides a comprehensive survey on mmWave channel measurement and modeling, multiple input and multiple output (MIMO) technology and network framework, and proposes a new densely distributed mmWave massive MIMO system by incorporating new technologies such as large-scale cooperative transmission, cloud computing and distributed storage, which is expected to realize ultra-high throughput wide coverage and support middle-high mobility in mmWave communications.