ZF and MMSE Detectors Performances of a Massive MIMO System Combined with OFDM and M-QAM Modulation

Wireless Personal Communications - This paper presents a least squares channel estimation (LSCE) in the UpLink transmission for a Massive MIMO systems in 5G wireless communications, combined with...     

Multipolarized Antennas Channel Model of URA Based on SW Massive MIMO Systems in UpLink Transmission

Wireless Personal Communications - Multipolarized Uniform Rectangular Array (mURA) Massive Multiple Input Multiple Output systems (mMIMOs) is a promising technology in 5G wireless communications....     

Performances of OSIC Detector of an UpLink OFDM Massive-MIMO System in Rayleigh and Ricain Fading Channels

A compact rectangular microstrip-fed Ultra Wideband patch antenna with double band notched feature at Wi-Max and WLAN is offered in this paper. The designed antenna is composed of an ordinary rectangular patch antenna with a partially defective ground structure. For achieving dual notch characteristics a ‘U’ and ‘Reversed U’ slots are embedded in the radiating patch. The partial ground plane structure with U shaped slot in the middle is incorporated for achieving additional resonance and bandwidth enhancement. The proposed antenna has a measurement of 20 × 33 × 1.6 mm³. First notch created by U shaped slot at frequency 3.5 GHz is for Wi-Max (from 2.9 to 4.5 GHz) and Second notch which is generated by Reversed U shaped slots at frequency 5.4 GHz is for WLAN (from 5.49 to 6.45 GHz). The antenna covers almost complete range of Ultra Wideband (3.1–10.6 GHz). The Simulation analysis of the proposed antenna is carried out using CST-2011 simulation software. The radiation pattern of the simulated antenna is near Omnidirectional and the Gain of proposed antenna is almost stable over the range of UWB excluding notch bands.

     

MicroRNAs from Extracellular Vesicles Secreted by Bovine Embryos as Early Biomarkers of Developmental Competence

During early development, embryos secrete extracellular vesicles (EVs) that participate in embryo–maternal communication. Among other molecules, EVs carry microRNAs (miRNAs) that interfere with gene expression in target cells; miRNAs participate in embryo–maternal communication. Embryo selection based on secreted miRNAs may have an impact on bovine breeding programs. This research aimed to evaluate the size, concentration, and miRNA content of EVs secreted by bovine embryos with different developmental potential, during the compaction period (days 3.5–5). Individual culture media from in vitro–produced embryos were collected at day 5, while embryos were further cultured and classified at day 7, as G1 (conditioned-culture media by embryos arrested in the 8–16-cells stage) and G2 (conditioned-culture media by embryos that reached blastocyst stages at day 7). Collected nanoparticles from embryo conditioned culture media were cataloged as EVs by their morphology and the presence of classical molecular markers. Size and concentration of EVs from G1 were higher than EVs secreted by G2. We identified 95 miRNAs; bta-miR-103, bta-miR-502a, bta-miR-100, and bta-miR-1 were upregulated in G1, whereas bta-miR-92a, bta-miR-140, bta-miR-2285a, and bta-miR-222 were downregulated. The most significant upregulated pathways were fatty acid biosynthesis and metabolism, lysine degradation, gap junction, and signaling pathways regulating pluripotency of stem cells. The characteristics of EVs secreted by bovine embryos during the compaction period vary according to embryo competence. Embryos that reach the blastocyst stage secrete fewer and smaller vesicles. Furthermore, the loading of specific miRNAs into the EVs depends on embryo developmental competence.     

Encryption Based Strategy to Overcome the Problem of Pilot Contamination Within Multi-cellular Massive MIMO Systems

The problem of inter-cell interferences keeps its site as the most challenging constraint that faces the massive multi-input multi-output (M-MIMO) technology. This constraint, known as the problem of pilot contamination (PC), is a direct result of reusing the same set of orthogonal pilot sequences (OPSs) across several cells, due to the scarcity of available pilot resources, compared to the number of the user equipments (UEs) that must be served, the reuse of the same OPSs within different cells is unavoidable. Accordingly, assigning the available OPSs to the UEs should be managed to address the PC problem. To reach that goal, a new decontaminating strategy is proposed herein, which is referred to as the ENCryption-based decontaminating strategy (ENC). The ENC strategy is based on injecting some recognition pilot symbols within the pilot sequence of the UEs; hence, the base stations become able to distinguish between the desired pilot signals from the undesired ones, therefore, the quality of servicecan be enhanced, furthermore, the proposed ENC strategy is of low computational complexity compared to the existing strategies.

     

Possibility of Silicon Nanocages as Anode Electrodes in Metal-Ion Batteries: Computational Examination

Silicon - Potential of silicon nanocages (Sin, n = 20, 24, 28, 32, 36, 40, 44, 48, 60, 70, 80 and 90) as anodes in batteries are examined. The thermal stability, ionization potentials,...