this paper demonstrates performance comparison between two Ultra-wideband (UWB) pulse shapes in the IEEE802.15.3a channel model using different RAKE Receiver types in presence of Multiple-User-Interference (MUI). System models used in this paper are based on both Direct-Sequence (DS) and Time-Hopping (TH) as spreading techniques for the UWB Pulses. UWB System presented in this paper studied in the presence of MUI and Gaussian-Noise using RAKE Receiver with different number of RAKE Fingers. The analysis and simulation has been run using two types of narrow (Sub-nanoseconds) UWB Pulse Shapes with same power; first- the second derivative of UWB Gaussian pulse ( Gaussian Doublet), and second- the 6th derivative of UWB Gaussian pulse which is the Main Case-study concerns this paper. The analysis and results show and clarify that both; the used UWB pulse-shape and also the number of RAKE fingers has an obvious impact on the SNR and consequently the BER performance in the IEEE802.15.3a channel model. Finally, the paper conclude that the proposed 6th derivative UWB pulse is more suitable for both; fulfilling the FCC power regulation requirements, and BER performance in MUI environment since increasing derivative order consequently increases the peak emission frequency but decreases signal Bandwidth.
Index Terms: Bit-Error-Rate (BER), Direct-Sequence (DS), Federal-Communication-Commission (FCC), Multiple-User-Interference (MUI), Signal-to Noise-Ratio (SNR), Time-Hopping (TH), Ultra-Wideband (UWB), Power-Spectral-Density (PSD), Channel Model (CM).
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Abstract: The aim of the study was to determine the toxicity of ammonia in the blood of freshwater fish Cyprinus carpio. Changes in the haemoglobin content of fish Cyprinus carpio exposed to sublethal concentration of ammonia for 35 days were presented in Table 4 and figure. 3. During the above exposure period a biphasic trend was observed in the present study. The hemoglobin was decreased from 7th, 14th, 21st, 28th, and 35th days showing a percent decrease of -15.948, -11.809, -13.483, -12.621, -10.204. However, hemoglobin was declined showing a minimum percent decrease of -10.204 at the end of the treatment period (35th day) and a maximum percent decrease of -15.948 at the end of 7th day.
Key words: Ammonia, Cyprinus carpio, Hemoglobin..
Abstract: The paper deals with the design of remote control system based on Short Message Service (SMS) for displaying publicity on Liquid Crystal Display (LCD's). The control center is supplied with Global System for Mobile communications (GSM) for SMS transmission and reception. The GSM receiver is connected to a microcontroller which decodes the messages and accordingly sends commands. The microcontroller issues orders to display advertisements as required by the message. The control system includes two separate units; the control center and the control unit. Therefore there are two operating environments. The control center operates indoors whereas the control unit operates outdoors .The indoors electronic devices are within the temperature and humidity limits for proper operation of the hardware. The outdoor units must be fully enclosed and protected from the climate changes for the safety of the hardware
Key words:microcontroller, LCD, GSM, SMS, publicity, Control center, Control unit.
Abstract: Prosopis cineraria and prosopis glandulosa torryana wildly growing trees in Thar Desert Pakistan exude gum in appreciable quantities. The climatic conditions of desert catalyze gum exudation from trees and may affect their quality characteristics. No research work has been carried out to characterize these valuable gums and evaluate their potential for commercial exploitation. In the present study 135 samples (16kg) of P.glandulosa gum and 87 samples (9kg) of P.cineraria gum were collected and studied for their physicochemical properties. P. cineraria gum was sorted in three classes as amber, light yellow having dull luster and transparent golden yellow shades. P.glandulosa gum samples were sorted as dark brown and light brown samples. Among the physicochemical characteristics studied, moisture content of all classes of gums varied between 8-14%, ash 3-9%, protein 10 -21%, insoluble matter 0.8 - 1.9%, and the tannin content of transparent golden yellow samples of p.cineraria gum as 0.3-0.6%. The tannin content p. glandulosa was found to be fairly high making it unsuitable substitute of gum for food applications. All the samples were found to be dextrorotary and showed lower pH values. The intrinsic viscosity of gum samples ranged between 10.6-13.6 ml/g and the values were used to calculate viscosity average molecular weight of gum samples. All the samples were found to be rich in amino acid content having Hydroxyproline between 300-380, tyrosine 270-326, aspartic acid 170-210, and serine 170-195 residues per 10000 residues. Cationic composition of ash of gum samples revealed calcium magnesium sodium and potassium as major cations whereas no presence of toxic metals lead cadmium and mercury was detected. Comparative assessment of data indicated that P.cineraria gum was of better quality as compared to that of P. glandulosa and that the application of classification procedure has marked effect on gum quality and potential to make p. cineraria gum as suitable substitute of gum arabic.
Key words: Chemical characterization, Prosopis gum, prosopis glandulosa, prosopis cineraria
Abstract: Multipath propagation is a fact of life in any terrestrial radio scenario. While the direct or line of sight path is normally the main wanted signal, a radar receiver will receive many signals resulting from the signal taking a large number of different paths. These paths may be the result of reflections from buildings, mountains or other reflective surfaces including water, etc. that may be adjacent to the main path. Additionally other effects such as ionosphere reflections give rise to multipath propagation as does tropospheric ducting .The multipath propagation resulting from the variety of signal paths can give rise to interference in a variety of ways including distortion of the signal, loss of data and multipath fading. This paper deals with the processing of the received signals in the radar receiver in order to minimize the effects of the multipath signals. The line-of-sight (LOS) echo is considered the main signal to represent the target.
Key words:Radar , multipath propagation , fading , line of sight path , target
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