Iterative turbo beamforming for OFDM based hybrid terrestrial-satellite mobile system

In the context of orthogonal frequency division multiplexing (OFDM)-based systems, pilot-based beamforming (BF) exhibits a high degree of sensitivity to the pilot sub-carriers. Increasing the number of reference pilots significantly improves BF performance as well as system performance. However, this increase comes at the cost of data throughput, which inevitably shrinks due to transmission of additional pilots. Hence an approach where reference signals available to the BF process can be increased without transmitting additional pilots can exhibit superior system performance without compromising throughput. Thus, the authors present a novel three-stage iterative turbo beamforming (ITBF) algorithm for an OFDM-based hybrid terrestrial-satellite mobile system, which utilises both pilots and data to perform interference mitigation. Data sub-carriers are utilised as virtual reference signals in the BF process. Results show that when compared to non-iterative conventional BF, the proposed ITBF exhibits bit error rate gain of up to 2.5 dB with only one iteration

EFFECT OF PLANT GROWTH REGULATORS ON GROWTH AND ESSENTIAL OIL CONTENT IN PALMAROSA (CYMBOPOGON MARTINII)

 Objective: The aim was to examine the responses viz., herbage yield, essential oil content and oil composition to varying levels of gibberellic acid(GA3), kinetin and indole acetic acid (IAA) in Palmarosa (Cymbopogon martinii).Methods: Essential oils were obtained by hydro-distillation using a Clevenger-type apparatus and oils composition was analyzed by gaschromatography-mass spectrometry. Nitrate reductase (NR) activity was evaluated by in-vivo assay. Protein content was evaluated by Lowry method.Chlorophyll was estimated by Arnon method.Results: Plant growth was improved by GA3 significantly, and the increase was maximum at 100 ppm concentration in plant height, leaf area, tillernumber and herbage yield. Chlorophyll content, protein content, NR activity and oil content increased in the plants due to GA3 treatment comparedto untreated plants, and the increase was maximum at 100 ppm concentration. Effect of IAA and kinetin was similar to GA3 but maximum effect wasobserved at 50 ppm concentration. Geraniol content of the essential oil of Palmarosa increased due to GA3 and kinetin treatment while percentage ofgeranyl acetate decreased.Conclusion: On a comparative basis, among the three promotional hormones, GA3 was most effective in stimulating growth, essential oil content, leafarea, tiller number and metabolic parameters (protein content, chlorophyll content and NR activity).Keywords: Cymbopogon martinii, Essential oils, Plant growth regulators, Oil compositon.Â

Chromosomal abnormalities as a cause of recurrent abortions: a hospital experience

Objective: To analyze the chromosomal abnormalities in couples with history of recurrent abortions. Design: Retrospective study. Setting: Cytogenetic section, Department of Pathology at the Aga Khan University Hospital. Karachi, Pakistan. Patients: Three hundred couples with history of recurrent abortions. Main outcome measure: Structural chromosomal abnormalities in carrier couples. Results: G-banded chromosomes were analyzed from both partners of 300 couples who had had two or more spontaneous abortions. Sixteen (5.3%) couples showed a chromosomal aberration in one of the partners. Seven translocations, 5 inversions, 2 deletions and 2 sex chromosomal abnormalities were identified. There was an increase in structural aberations, which was not significantly different from that reported worldwide. a primary tool in the evaluation of couples with repetitive. Conclusion:Chromosomal analysis is advocated as fetal wastag

Threats Advancement in Primary User Emulation Attack and Spectrum Sensing Data Falsification (SSDF) Attack in Cognitive Radio Network (CRN) for 5G Wireless Network Environment

Primary User Emulation (PUE) attack and Spectrum Sensing Data Falsification (SSDF) attack on Data Fusion Centre and attack on Common Control Channel (CCC) is a serious security problems and need to be addressed in cognitive radio network environment. We are reviewing the recent advances of threats for the future 5th Generation (5G) wireless radio network from these attacks. Several existing security schemes have been proposed and discussed to overcome these attacks. We propose new security scheme that able to mitigate the attacks and provide security solutions. This scheme intended to mitigate the threats from the attacks in CRN and improve the future 5G network security

Productivity and economic evaluation of Willow (Salix alba L.) based silvopastoral agroforestry system in Kashmir valley

Performance of two fodder crops namely, sorghum (Sorghum vulgare L.) and maize (Zea mays L.) was investigated with Willow (Salix alba L.) to evaluate productivity and economics of the silvopastoral agroforestry system in Kashmir valley. The experiment was laid out by planting two year old willows at 2.0m × 2.0m spacing and dividing the main plot into sub-plots of size 8m × 2m each with 5 replications in randomized block design (RDB). The intercrops of sorghum and maize were maintained at 20cm × 10 cm spacing and supplied with recommended doses of fertilizers. The economics of the willow plantation intercropped with fodder crops was compared with sole willow farming by the benefit-cost ratio and net present worth. The study revealed the differential behaviour of Salix alba regarding growth parameters (height, diameter and girth) by different intercrops and various fodder intercrops with respect to yield, above ground biomass, dry matter production and soil nutrient status (pH, organic carbon, available nitrogen, phosphorus and potassium). The willow based silvopastoral system was estimated to have benefit-cost ratio of 2.71 with maize and 2.68 with sorghum, while as sole crop the willows accrued a benefit-cost ratio of 2.66. The study is useful in discovering growth of willows, productivity of fodder crops and soil nutrient status under various silvopastoral agroforestry systems for maximizing economic gains. The findings envisaged evidences in favour of adopting willow based silvopastoral agroforestry instead of sole tree farming and the knowledge of interactions will be helpful in proper management of the system for sustained multiple productions