NEC, today announced that it has completed joint verification trials with NTT DOCOMO using Massive Multiple Input Multiple Output (MIMO), a core technology for 5G base stations. The trials were conducted in central Tokyo and Kanagawa Prefecture, and used NEC's massive-element Active Antenna System (AAS) supporting the low-SHF band.
The trials employed the low-SHF band-compatible AAS in the base station for both outdoor environments, where radio waves are reflected or diffracted due to buildings, utility poles, vehicles and people, and indoor environments, which also include many obstacles, such as columns and walls. NEC's AAS adopts fully-digitized antenna beam control technology, which improves the precision of beam forming. While transmitting beams to the target mobile handsets, it is capable of forming beams that counteract interfering signals using the multi-path. It can also form beams that improve communication quality by efficiently combining the multi-path of its own signals with the direct waves. The features of NEC's AAS enable concurrent communication with several handsets, even though they are close to each other, while maintaining high communication quality.
In the trials, NEC said it proved that use of the AAS can result in improved capacity and quality of communication between a base station and handsets, while confirming that spectral efficiency was reliably maintained at a level roughly eight times higher than that achieved by LTE in indoor environments.
Nozomu Watanabe, General Manager, Mobile Radio Access Network Division
NEC research into core technologies for 5G, including the massive-element AAS and antenna beam control, will contribute to the successful roll-out of 5G in the near future. Among the high frequency bands, we are working especially hard to put the low-SHF band into practical use, since it is expected to enter into commercial use around 2020.
