On the Achievable Spectral Efficiency of Spatial Modulation Aided Downlink Non-Orthogonal Multiple Access

In this paper, a novel spatial modulation aided non-orthogonal multiple access (SM-NOMA) system is proposed. We use mutual information (MI) to characterize the achievable spectral efficiency (SE) of the proposed SM-NOMA system. Due to the finite-alphabet space-domain inputs employed by SM, the expression of the corresponding MI lacks a closed-form formulation. Hence, a lower bound is proposed to quantify the MI of the SM-NOMA system. Furthermore, its asymptotic property is also theoretically investigated in both low and high signal-to-noise ratio (SNR) regions. The SE performance and its analysis of our proposed SM-NOMA system are confirmed by simulation results.Comment: 4 pages, 2 figures, accepted by IEEE Communications Letter

Performance Enhancement of Downlink NOMA by Combination with GSSK

In non-orthogonal multiple access (NOMA), cell-edge users experience significantly low spectral density because only some part of the total transmit power is allocated. This leads to low spectral efficiency for the paired users in NOMA. To overcome this problem, we propose an integration of NOMA and generalized space shift keying (GSSK), called NOMA-GSSK, to improve the spectral efficiency by exploiting the spatial domain. Spectral and energy efficiency, bit error rate (BER), and computational complexity of the proposed system were analyzed and compared to those of multiple-input multiple-output NOMA (MIMO-NOMA). It is shown that NOMA-GSSK outperforms MIMO-NOMA

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 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 artificial intelligence, intelligent surfaces, terahertz communications technologies in detail, while giving a brief introduction to other potential technologies, including visible light communications, Blockchain-enabled wireless network, advanced duplex and holographic radio.Comment: This paper appears in the Proceedings of Future of Information andCommunication Conference (FICC) 202