Save and Transmit Scheme for Energy Harvesting MIMO Systems with TAS/MRC

In this paper, we propose and analyze a wirelesstransmitter, for multiple-input multiple-output (MIMO) systems,that relies exclusively on energy harvesting. We consider wirelesstransceivers where the transmitter harvests the total requiredenergy from its environment through various sources. We assumethat both transmitter and receiver are equipped with multipleantennas. At the transmitter, a single transmit antenna thatmaximizes the signal-to-noise ratio (SNR) at the receiver isselected for transmission. The remaining antennas are used forenergy harvesting. At the receiver side, maximal-ratio com-bining (MRC) is used. Furthermore, we assume that all theharvested power is used to power the transmitter immediately.The performance of the proposed scheme is analyzed in terms ofoutage probability (OP), symbol error rate (SER) and channelcapacity. The harvested energy comes from random sourcesand is considered as a random variable. Assuming that theharvested power follows a gamma distribution and the MIMOchannel is a Rayleigh flat fading process, we derive a closed-form expressions for the exact cumulative distribution function(CDF) and probability density function (PDF) of the SNR. Basedon this, we analyze the performance of the proposed energyharvesting scheme. The obtained analytical results are validatedby comparing them with the results of Monte-Carlo simulations

The γ-polymorph of AgZnPO4 with an ABW zeolite-type framework topology

The γ-polymorph of the title compound, silver zinc orthophos­phate, was synthesized under hydro­thermal conditions. The structure consists of ZnO4, PO4 and AgO4 units. The coord­ination spheres of ZnII and PV are tetra­hedral, whereas the AgI atom is considerably distorted from a tetra­hedral coordination. Each O atom is linked to each of the three cations. An elliptic eight-membered ring system is formed by corner-sharing of alternating PO4 and ZnO4 tetra­hedra, leading to a framework with an ABW-type zeolite structure. The framework encloses channels running parallel to [100] in which the Ag cations are located, with Ag⋯Ag contacts of 3.099 (3) Å. This short distance results from d 10⋯d 10 inter­actions, which play a substantial role in the crystal packing. The structure of γ-AgZnPO4 is distinct from the two other polymorphs α-AgZnPO4 and β-AgZnPO4, but is isotypic with NaZnPO4-ABW, NaCoPO4-ABW and NH4CoPO4-ABW

Poly[ethyl­enediammonium [tris­[μ3-hydrogenphosphato(2−)]dicadmium] monohydrate]

The title compound, {(C2H10N2)[Cd2(HPO4)3]·H2O}n, was synthesized under hydro­thermal conditions. The structure of this hybrid compound consists of CdO6, CdO5 and PO4 polyhedra arranged so as to build an anionic inorganic layer, namely [Cd2(HPO4)3]2−, parallel to the ab plane. The edge-sharing CdO6 octa­hedra form infinite chains running along the a axis and are linked by CdO5 and PO4 polyhedra. The ethyl­ene­diammonium cation and the water mol­ecule are located between two adjacent inorganic layers and ensure the cohesion of the structure via N—H⋯O and O—H⋯O hydrogen bonds

Performance of Blind Turbo Equalizer in Indoor Channels

In this paper, we consider the transmission of turbo coded symbols in the indoor radio environment. The system isaffected by the intersymbol interference (ISI) caused by the multipath time-delay spread of the transmission medium. To reduce the channel effect, we propose to use a blind turbo equalizer combining channel estimation, equalization and turbo decoding. The equalizer consists of an interference canceller (IC) and a MAP-BCJR decoder. To improve system performances, we redefine the channel reliability factor used by the MAP-BCJR decoding algorithm. We propose a new metric that takes into account the statistics of the signal at the equalizer output. The channel coefficient estimation is performed using a recursive least squares (RLS) algorithm. A blind receiver initializationtechnique is proposed. This technique is based on a soft decisiondirected least mean square algorithm (soft DD-LMS). For the proposed turbo detector, the ISI cancellation, channel estimation and decoding are jointly performed through an iterative process where modules exchange a soft information

Crystal structure of (1S,2R,4R,9S,11S,-12R)-9α-hydroxy-4,8-dimethyl-12-[(thio-morpholin-4-yl)methyl]-3,14-dioxatri-cyclo[9.3.0.02,4]tetradec-7-en-13-one

The authors thank the Unit of Support for Technical and Scientific Research (UATRS, CNRST) for the X-ray measurements.Peer reviewedPublisher PD

Thorium divanadate dihydrate, Th(V2O7)(H2O)2

The title compound, Th(V2O7)(H2O)2, was synthesized by a hydro­thermal reaction. The crystal structure consists of ThO7(OH2)2 tricapped trigonal prisms that share edges, forming [ThO5(OH2)2]n chains along [010]. The edge-sharing ThO7(OH2)2 polyhedra share one edge and five vertices with the V2O7 divanadate anions having a nearly ecliptic conformation parallel to [001]. This results in an open framework with the water mol­ecules located in channels. O—H⋯O hydrogen bonding between water molecules and framework O atoms is observed. Bond-valence-sum calculations are in good agreement with the chemical formula of the title compound

Performance analysis of NOMA in 5G systems with HPA nonlinearities

LISBOA-01-0145-FEDER-0307095-PTDC/EEITEL/30709/2017 PTDC/EEI-TEL/30588/20 UIDB/50008/2020In this paper, we provide an analytical performance assessment of downlink non-orthogonal multiple access (NOMA) systems over Nakagami-m fading channels in the presence of nonlinear high-power amplifiers (HPAs). By modeling the distortion of the HPA by a nonlinear polynomial model, we evaluate the performance the NOMA scheme in terms of outage probability (OP) and ergodic sum rate. Hence, we derive a new closed-form expression for the exact OP, taking into account the undesirable effects of HPA. Furthermore, to characterize the diversity order of the considered system, the asymptotic OP in the high signal-to-noise (SNR) regime is derived. Moreover, the ergodic sum rate is investigated, resulting in new upper and lower bounds. Our numerical results demonstrate that the performance loss in presence of nonlinear distortions is very substantial at high data rates. In particular, it is proved that in presence of HPA distortion, the ergodic sum rate cannot exceed a determined threshold which limits its performance compared to the ideal hardware case. Monte-Carlo simulations are conducted and their results agree well with the analytical results.publishersversionpublishe

From Structural Linguistics to Theatre Semiotics

لا أحد يجادل في الدور الريادي الذي لعبته حلقة براغ اللسانية خلال الثلاثينيات والأربعينيات من القرن الفارط في تطور الفكر اللساني العالمي، على أن قلّة من الناس يعرفون أن الفضل يرجع إليهم في نشأة سيميائيات الثقافة والفن بعامة، وسيميائيات المسرح على وجه الخصوص. فقد حاولوا نقل العدة المفاهيمية والإجراءات المنهجية التي صيغت لدراسة اللغة الطبيعية إلى دراسة أنظمة رمزية أخرى، محاولين بذلك تحقيق حلم فرديناند دو سوسير بقيام علم شامل للعلامات. هكذا تحاول هذه المقالة أن ترصد هذا الانتقال من اللسانيات البنيوية إلى السيميائيات المسرحية، مسلطة الضوء على شروط ترحيل جملة من المفاهيم الأساسية من المجال اللساني إلى مجال الدراسات المسرحية، وأن تبرز الدور الحاسم الذي لعبه رواد الحلقة في رسم المنحى الذي سيتخذه البحث السيميائي المسرحي بعدهم.Nobody denies the leading role Prague Linguistic Series has played in the development of the international linguistic thinking during the 1930s and 1940s of the last century. Given that, only few people are aware of the fact that the merit of the establishment of cultural semiotics in art generally and in theater semiotics in particular goes back to them. They have tried to transfer the conceptual tools and curriculum procedures, which have been formulated to study Natural Language, other coded study systems, trying in this way to realize the dream of Ferdinand de Saussure, i.e., to come up with a holistic science of signs. This article, thus, tries to pinpoint the transfer from structural linguistics to theater semiotics, shedding light on the conditions of taking a sentence from its basic concept in the linguistic field to the theater semiotic domain. It also tries to demonstrate the pertinent role of the series’ pioneers in tracing the path that theater semiotics research would follo

5,9-Dihy­droxy-9-methyl-3,6-dimethyl­ene-3a,4,5,6,6a,7,8,9,9a,9b-deca­hydro­azuleno[4,5-b]furan-2(3H)-one

The title compound, C15H20O4, was synthesized from 9α-hy­droxy­parthenolide (9α-hy­droxy-4,8-dimethyl-12-methyl­ene-3,14-dioxatricyclo­[9.3.0.02,4]tetra­dec-7-en-13-one), which was isolated from the chloro­form extract of the aerial parts of Anvillea radiata. The seven-membered ring has a chair conformation, while the five-membered rings display twisted conformations. The dihedral angle between the seven-membered ring and the lactone ring is 21.69 (10)°. In the crystal, mol­ecules are linked into chains propagating along the c axis by inter­molecular O—H⋯O hydrogen bonds; an intra­molecular O—H⋯O link also occurs