A Survey of 6G Wireless Communications: Emerging Technologies

While fifth-generation (5G) communications are being rolled out around the world, sixth-generation (6G) communications have attracted much attention from both the industry and the academia. Compared with 5G, 6G will have a wider frequency band, higher transmission rate, spectrum efficiency, greater connection capacity, shorter delay, wider coverage and stronger anti-interference capability, so as to meet the various network requirements for industries. In this paper, we present a survey of potential essential technologies in 6G. In particular, we will introduce index modulation, artificial intelligence, intelligent surfaces, and terahertz communications technologies in detail, while giving a brief introduction to other potential technologies, including visible light communications, blockchain-enabled wireless network, advanced duplex, holographic radio and network in box.