Distributed Massive MIMO in Cellular Networks: Impact of Imperfect Hardware and Number of Oscillators

Distributed massive multiple-input multiple-output (MIMO) combines the array gain of coherent MIMO processing with the proximity gains of distributed antenna setups. In this paper, we analyze how transceiver hardware impairments affect the downlink with maximum ratio transmission. We derive closed-form spectral efficiencies expressions and study their asymptotic behavior as the number of the antennas increases. We prove a scaling law on the hardware quality, which reveals that massive MIMO is resilient to additive distortions, while multiplicative phase noise is a limiting factor. It is also better to have separate oscillators at each antenna than one per BS.

Why do national court judges refer to human rights treaties?: A comparative international law analysis of CEDAW

An analysis was conducted of 325 national judicial decisions across 55 jurisdictions, in which CEDAW was referred to in the reported decision. Despite predictions to the contrary based on previous scholarship, significant variations between courts in their interpretation of CEDAW occurred relatively infrequently, courts referred relatively seldom to interpretations of CEDAW by other national courts, and there was little evidence of transnational dialogic approaches to judging. An analysis of these results suggests that domestic judges invoking CEDAW act primarily as domestic actors who use international law in order to advance domestic goals, rather than acting primarily as agents of the international community in applying CEDAW domestically, or contributing to the transnational shaping of international law to suit national interests. The Article suggests an understanding of the domestic implementation of a human rights treaty as not only law, but a unique kind of law that performs a particular function, in light of its quality as something akin to hard and soft law simultaneously.

Formation of soluble mercury oxide coatings: transformation of elemental mercury in soils

The impact of mercury (Hg) on human and ecological health has been known for decades. Although a treaty signed in 2013 by 147 nations regulates future large-scale mercury emissions, legacy Hg contamination exists worldwide and small scale releases will continue. The fate of elemental mercury, Hg(0), lost to the subsurface and its potential chemical transformation that can lead to changes in speciation and mobility are poorly understood. Here we show that Hg(0) beads interact with soil or manganese oxide solids and x-ray spectroscopic analysis indicates that the soluble mercury coatings are HgO. Dissolution studies show that after reacting with a composite soil, > 20 times more Hg is released into water from the coated beads than from a pure liquid mercury bead. An even larger, > 700 times, release occurs from coated Hg(0) beads that have been reacted with manganese oxide, suggesting that manganese oxides are involved in the transformation of the Hg(0) beads and creation of the soluble mercury coatings. Although the coatings may inhibit Hg(0) evaporation, the high solubility of the coatings can enhance Hg(II) migration away from the Hg(0)-spill site and result in potential changes in mercury speciation in the soil and increased mercury mobility.