Capacity-Achieving Iterative LMMSE Detection for MIMO-NOMA Systems

This paper considers a iterative Linear Minimum Mean Square Error (LMMSE) detection for the uplink Multiuser Multiple-Input and Multiple-Output (MU-MIMO) systems with Non-Orthogonal Multiple Access (NOMA). The iterative LMMSE detection greatly reduces the system computational complexity by departing the overall processing into many low-complexity distributed calculations. However, it is generally considered to be sub-optimal and achieves relatively poor performance. In this paper, we firstly present the matching conditions and area theorems for the iterative detection of the MIMO-NOMA systems. Based on the proposed matching conditions and area theorems, the achievable rate region of the iterative LMMSE detection is analysed. We prove that by properly design the iterative LMMSE detection, it can achieve (i) the optimal sum capacity of MU-MIMO systems, (ii) all the maximal extreme points in the capacity region of MU-MIMO system, and (iii) the whole capacity region of two-user MIMO systems.Comment: 6pages, 5 figures, accepted by IEEE ICC 2016, 23-27 May 2016, Kuala Lumpur, Malaysi

A Scientometrics Review on Research of Knowledge Sharing in Virtual Communities

The number of literature on knowledge sharing in virtual communities has gained rapid growth during last decade; however, there have been few attempts to map the global research in this domain. In this study, the CiteSpace software package was used to conduct a series of content analyses to identify the state of the field and trends in knowledge sharing in virtual communities, including the distribution of core authors and institutions; high-frequency categories and keywords; highly cited papers and hot topics of research; and trends pertain to co-author analysis, co-word analysis, co-citation analysis, and particularly cluster analysis. We present all research focuses in a scientometric way and arrive at the following findings. First, the most significant developments and progress in knowledge sharing in virtual communities have occurred primarily in China, Taiwan, USA, Malaysia. Second, the existing studies in the field of knowledge sharing in virtual communities focus primarily on Business & Economics, Engineering and Computer Science. Third, five hot knowledge sharing in virtual communities topics were also disclosed, they are: knowledge sharing, virtual communities, trust, behavior, management and network

Heat transport of electron-doped Cobaltates

Within the t-J model, the heat transport of electron-doped cobaltates is studied based on the fermion-spin theory. It is shown that the temperature dependent thermal conductivity is characterized by the low temperature peak located at a finite temperature. The thermal conductivity increases monotonously with increasing temperature at low temperatures T $<$ 0.1$J$, and then decreases with increasing temperature for higher temperatures T $>$ 0.1$J$, in qualitative agreement with experimental result observed from Na$_{x}$CoO$_{2}$ .Comment: 4 pages, 1 fig, corrected typos, accepted for publication in Commun. Theor. Phy