Mobile information systems have been facing the challenges of continuously increasing demand for high data rates and mobility required by new wireless applications. 4G/LTE wireless networks now enable high-speed mobile web videos, IP telephony, video gaming, mobile high-definition (HD) TV, video conferencing, and even mobile 3D TV. Because of the convenience and freedom afforded by high-performance video-optimized mobile devices, wireless video traffic is exploding. Indeed, the wireless telecommunication industry is facing a watershed ``moment'' where foreseeable capacity may soon fail to meet demand. The current trend of annual doubling of wireless data traffic is expected to continue. Given accelerating sales of tablet computers, which can consume several times as much spectrum as smart phones, these trends are likely to continue. Research on 5G wireless communications have started and developed rapidly. It is expected that 5G wireless infrastructure will be deployed beyond 2020. However, enabling technologies for 5G mobile information systems such as massive MIMO, new modulation, and waveform design are still in their infancy. More efforts from this community are truly needed to get 5G mobile systems to its full fruition.

The goal of the special issue is to disseminate the most recent results in enabling technologies for 5G mobile systems. Researchers and practitioners working in this area are expected to take this opportunity to discuss and express their views on the current trends, challenges, and state of the art solutions addressing various issues in 5G technologies for mobile systems. Review papers on this topic are also welcome.

Potential topics include, but are not limited to:

• Massive MIMO for 5G mobile information system
• Modulation and waveform design for 5G mobile system
• 5G mobile communications channel modeling
• Protocol design and resource allocation for 5G mobile system
• 5G cellular networks for mobile systems
• Millimeter wave communications for 5G mobile systems
• 5G coexistence with other mobile systems
• Measurement and testing of 5G mobile systems