A Comparison of CP-OFDM, PCC-OFDM and UFMC for 5G Uplink Communications

Polynomial-cancellation-coded orthogonal frequency division multiplexing (PCC-OFDM) is a form of OFDM that has waveforms which are very well localized in both the time and frequency domains and so it is ideally suited for use in the 5G network. This paper analyzes the performance of PCC-OFDM in the uplink of a multiuser system using orthogonal frequency division multiple access (OFDMA) and compares it with conventional cyclic prefix OFDM (CP-OFDM), and universal filtered multicarrier (UFMC). PCC-OFDM is shown to be much less sensitive than either CP-OFDM or UFMC to time and frequency offsets. For a given constellation size, PCC-OFDM in additive white Gaussian noise (AWGN) requires 3dB lower signal-to-noise ratio (SNR) for a given bit-error-rate, and the SNR advantage of PCC-OFDM increases rapidly when there are timing and/or frequency offsets. For PCC-OFDM no frequency guard band is required between different OFDMA users. PCC-OFDM is completely compatible with CP-OFDM and adds negligible complexity and latency, as it uses a simple mapping of data onto pairs of subcarriers at the transmitter, and a simple weighting-and-adding of pairs of subcarriers at the receiver. The weighting and adding step, which has been omitted in some of the literature, is shown to contribute substantially to the SNR advantage of PCC-OFDM. A disadvantage of PCC-OFDM (without overlapping) is the potential reduction in spectral efficiency because subcarriers are modulated in pairs, but this reduction is more than regained because no guard band or cyclic prefix is required and because, for a given channel, larger constellations can be used

Figurations of the Spiritual Squalid in Allen Ginsberg's Indian Journals: Transformation of India in Post-War Beat and American Imagination

This article explores the impact that India had on Beat imagination with specific emphasis on Ginsberg's under-studied Indian Journals, written during his travels in India in 1962-63, and published in 1970. The earlier American literary view of India was dominated by the notion of the spiritual East, and was evoked in the high prose of Emerson and Whitman. In the new context and historical time of post-war counterculture, India came to constitute a different kind of repertoire: 1) the trope of physical travel (unlike the earlier literary forebears who had never actually visited India) and its sense of encounter with the un-transcendable physical 'dirt' of India; 2) India as a new realm of the sexual (in contrast with the more traditional dominant trend of India as 'ascetic spiritual') and the intertwining of the sexual and spiritual; and 3) Experimenting with drugs to explore the spaces between pilgrimage and tourism wherein India as a whole and in itself offers alternate states of bodily being. Moving away from conventional postcolonial notions of 'representation' in modes that might still be seen as quasi-Orientalist, I read the Ginsberg's text as creating a new kind of literary and aesthetic density, mixing genres of travelogue, diary, poetry, confession, doodle, photography. Further, in contrast to the entirely uni-directional notions of Orientalist representation, I argue that this encounter re-defined Beat notions of space, sexuality, and alternate consciousness

Economics of Wastewater Treatment and Recycling: An Investigation of Conceptual Issues

In the context of continuous droughts, the search for alternative water sources and increasing environmental restrictions on discharge of treated wastewater into natural water bodies, treated wastewater recycling offers a potential solution. In this paper the methods needed to assess the questions - to what extent treated wastewater can complement the existing water sources in different sectors and at what cost - are discussed? It was concluded that a comparative Benefit Cost Analysis of different combinations of uses and treatment levels would be a critical component in the development of a decision support tool which could be used by urban planners and water authorities. It was also found that community acceptance of recycled water, distribution of costs and benefits of recycling and its broader impact on regional development are issues that need to be considered, along with the economics of wastewater recycling.Wastewater, recycling, water quality, pricing, allocation, urban design, Resource /Energy Economics and Policy,

Zebrafish as a model to study the neuroendocrine system and toxicity of endocrine disruptors

Zebrafish is a popular vertebrate model system to study development and perform genetic analysis. It offers numerous advantages such as small size, short generation time, high fecundity, rapid and ex utero development of embryos and optically transparent embryos. Zebrafish is genetically closely related to humans and share high similarity in developmental processes, physiology and behavior. In addition, recent advances in forward and reverse genetics coupled with the availability of a large number of mutants makes zebrafish a useful model for genetic analysis of development. Furthermore, the above mentioned advantages offered by this model organism will be a valuable resource for toxicologists not only to assess toxicity of endocrine disrupting chemicals (EDCs) but also to dissect the mechanisms of toxicity of EDCs. The development and function of the neuroendocrine system in zebrafish is to a great extent similar to other vertebrates. Thus, in an aim to understand the development of the neuroendocrine stress axis we have characterized the expression of corticotropin-releasing hormone (crh) in the embryonic brain of zebrafish. Transcripts of crh were detected in a broad range of adult tissues and also during embryonic and larval stages. Whole-mount in situ hybridization analysis revealed distribution of crh transcripts in various regions of the developing brain including telencephalon, preoptic area, hypothalamus, posterior tuberculum, thalamus, epiphysis, midbrain tegmentum, hindbrain and retina. Expression of crh in the preoptic area and in extra-hypothalamic regions is consistent with its roles as a hypophysiotropin and a neuromodulator. Estrogen receptors are ligand activated transcription factors involved in regulating the neuroendocrine axis of reproduction. We have analyzed the mRNA levels of the esr genes in the absence and presence of exogenous ligands. The three esr genes, esr1 (ERalpha), esr2b (ERbeta1) and esr2a (ERbeta2) were expressed in all adult tissues tested in the absence of exogenous ligands. Expressions of esr1 and esr2a were altered in the liver, brain, testis and intestine following ligand treatment (17β- estradiol (E2) or diethylstilbestrol (DES) or 4-nonylphenol, (4-NP)). During embryogenesis, only esr1 and esr2b were predominantly expressed and both were regulated by ligands. Our results demonstrate that the esr genes in zebrafish are regulated in a sex- and tissue specific manner and that 4-NP, a well-known endocrine disruptor possess both agonist and antagonist properties in adult tissues. We further extended our study to assess the toxic effects of 4-NP on developing embryos and larvae of zebrafish. A sub-lethal dose of 4-NP not only perturbed the neuroendocrine axis but also induced distortions/kinks and herniations in the notochord. The differentiation of the notochordal cells and the formation of the perinotochordal basement membrane were disrupted by 4-NP. Early disturbances induced by 4-NP in the notochord resulted in deformaties in the vertebral column at late larval stages. The notochord phenotype was accompanied by impaired swimming pattern. Repeated electrical stimulation of the larval muscles of 4-NP treated embryos showed impairment in the relaxation between stimuli which might be a possible reason for the defective swimming observed in 4-NP treated embryos

Inertial Oscillations of Pinned Dislocations

Dislocation pinning plays a vital role in the plastic behaviour of a crystalline solid. Here we report the first observation of the damped oscillations of a mobile dislocation after it gets pinned at an obstacle in the presence of a constant static shear load. These oscillations are found to be inertial, instead of forced as obtained in the studies of internal friction of solid. The rate of damping enables us to determine the effective mass of the dislocation. Nevertheless, the observed relation between the oscillation frequency and the link length is found to be anomalous, when compared with the theoretical results in the framework of Koehler's vibrating string model. We assign this anomaly to the improper boundary conditions employed in the treatment. Finally, we propose that the inertial oscillations may offer a plausible explanation of the electromagnetic emissions during material deformation and seismic activities.Comment: 28 pages, 4 figure