In recent years, MIMO (multiple-input and multiple-output) technology has been considered for B3G and 4G communication systems. This technology can increase the diversity and/or multiplicity of data transmission. Since millimeter-waves have short wavelengths, a large number of antennas can possibly be implemented at transmitters and receivers. The high directivity and spatial gain provided by massive antennas can overcome the large fading of millimeter-wave transmission. Our research focuses on communication techniques with massive antennas for reliable communications over fast fading millimeter-wave channels.