Automated organization, multi-RAT and multi-layer heterogeneous networks, those are what are being requested in mobile of 2020, what will be the 5G era - the first meaningful unified wideband mobile communication system.
A recent systematic overview discussed progress on 5G research and highlighted the network architecture and techniques which could be employed in the future 5G systems.
4G LTE systems, supporting up to 100Mbps data rate, at least in laboratories, have been globally deployed and are offering several multimedia services such as HD video, but with the mobile internet and internet of things (IoT), current 4G systems may not satisfy the explosive growth of mobile data, massive device connection, and a variety of emerging services and application scenarios. It is assumed that 5G systems would offer maximum 1Gbps user experienced data rate, tens of Gbps peak data rate, tens of Tbps/km2 traffic volume density, millisecond level of end-to-end latency and support 500+km/h mobility. 5G would permeate every corner of our life and build a truly user-centralized information eco-system. The world's major developed countries and regions have already launched the 5G research projects in order to seize the leadership of the coming 5G era.
The new paper presents an overview of potential network architecture and highlights several promising techniques which could be employed in the future 5G systems by deeply analyzing 5G requirements and current research. These techniques include non-orthogonal multiple access (NOMA), massive multiple input and multiple output (MIMO), cooperative communications and network coding, full duplex (FD), device-to-device (D2D) communications, millimeter wave communications, automated network organization, cognitive radio (CR), and green communications etc. The state-of-art and implementation issue of these techniques are also addressed.
"The quest to improve the spectral efficiency has been regarded as the most important but yet challenging task in the design of future wireless communication systems," the authors wrote in the paper. It seems that NOMA, Massive MIMO, full-duplex, and D2D communications etc. would be the sharp weapons.
Global wireless communications would suffer from the "Spectrum crisis" and radio spectrum resource has gradually become the bottleneck of development of broadband wireless communications. There are two main ways to overcome this problem: one is to develop the rich millimeter wave frequency spectrum, the other is to fully utilize current spectrum resource by the cognitive radio technique.
Citation: MA Zheng, ZHANG ZhengQuan, DING ZhiGuo, FAN PingZhi, LI HengChao. Key techniques for 5G wireless communications: network architecture, physical layer, and MAC layer perspectives. SCIENCE CHINA Information Sciences, 2015, 58(4): 041301(20)