research fields

Since the establishment of DOCOMO Beijing Communications Laboratories Co., Ltd., we have focused on the future of wireless system research and standardization. Based on wireless networks with Internet services as the direction, we assume a vital role in the development on the latest applications and innovative business models. We have been working with the 3GPP from Rel. 8 to Rel. 14 (until 2016) developing radio transmission technologies, system control technologies, and applications for value added services.

The Wireless System Research and Standardization Division (WSRS) currently consists of the Advanced Wireless System Group, Enhanced TDD Group, High Frequency Radio Access Group, Multiple Access and Radio Transmission Group, and Platform Development Department. Our main target is to improve the capacity of traditional mobile broadband communication networks and extend new wireless communication services such as IoT and V2X.

From a traditional mobile broadband communication service perspective, we are dedicated to studying technologies that will enhance the capacity of mobile communication systems from three aspects: spectrum efficiency, spectrum extension, and network densification. The technologies that will enhance spectrum efficiency include new air interface development, 3D/massive MIMO, and non-orthogonal multiple access technologies. A new cellular concept that we are developing for cost/energy-efficient dense deployments will improve the network densification aspect. Spectrum extension can be achieved by effectively using high frequency bands. In order to satisfy the variable requirements for the 5G network, we focus on research on massive machine type communications, and ultra-reliable and low latency communications that will be very important to new types of wireless communication services such as smart city, V2X, and IoT.

The main research focuses in this area include new radio (NR), millimeter wave (mmWave), CoMP, small cell enhancement, carrier aggregation/dual connectivity, unlicensed spectrum transmission technology (LAA), MIMO enhancement, non-orthogonal multi-access (NOMA), V2X and machine type communications (MTC) research and standardization. Meanwhile, we are participating in the enhancement of DOCOMO’s commercial networks. We provide technical analysis and support for commercial networks, and contribute to improving the quality of DOCOMO’s commercial network.

Regarding the key technologies for 5G, we focus on massive MIMO technology in TDD systems, dynamic TDD, and flexible/full duplex technologies.  We also commit to key physical layer technologies for high frequency band channel measurement and channel modeling, new radio air interface designs, and multi-antenna systems. As one of the key technologies for 5G, NOMA not only improves the performance in cellular networks (eMBB scenario), but also satisfies the requirements for massive connection, low latency, and high reliability application scenarios. To verify the performance improvement from new technologies, computation simulation results are necessary. The Platform Development Department oversees the development and maintenance of system-level and link-level simulation platforms. Our sustainable platform development supports our standardization contributions, pre-commercial performance evaluations, IPR submissions, and academic publications. At the same time, we support the development of commercial service models and new services such as mobile network big data and natural language processing.