scholarly journals Study on Spectrum Allocation and Optimization of Wireless Communication Networks Based on SFOA

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Yu Zhang ◽  
Jianying Li
Keyword(s):  
Communication Network ◽  
Wireless Communication ◽  
Signal To Noise Ratio ◽  
Spectrum Allocation ◽  
The Other ◽  
Signal To Noise ◽  
Wireless Communication Network ◽  
Maximum Value ◽  
Noise Ratio ◽  
Stability And Accuracy

Wireless communication network spectrum is a limited resource. With the rapid increase of mobile communication services in recent years, traditional spectrum allocation methods are only based on a fixed spectrum allocation strategy, which often results in uneven and wasteful resource allocation. Therefore, spectrum allocation and the optimization problem need to be solved urgently. The application of semantic mobile computing in the Internet of Things and the research of emerging bionic models provide new ideas for this problem. In order to solve the problem of spectrum optimization and allocation, this paper proposes an optimization algorithm that simulates fisherman fishing to reasonably arrange the allocation and optimization of wireless network spectrum. This paper selects SFOA and the other two algorithms, designs experimental functions to perform calculations separately, obtains relevant data indicators, and uses comparative analysis to analyze. The analysis shows that in terms of performance, the success rate of SFOA is higher than that of PSO, and the success rate of the two function calculations has reached 100%. In the signal-to-noise ratio analysis, when the signal-to-noise ratio is -4 dB, the throughput of GPSO reaches the maximum value of 0.17, the throughput of PSO reaches the maximum value of 0.56, and the throughput of SFOA reaches 1, which shows that SFOA is adopted. The stability and accuracy of the algorithm are higher than the other two algorithms, and in the case of high signal-to-noise ratio, the advantages of the SFOA algorithm are also more obvious. This shows that the use of this algorithm will be very helpful for spectrum allocation and optimization. Because SFOA has high stability and accuracy, through reasonable adjustment and improvement, it can make good use of spectrum allocation and optimization. Chinese wireless communication network and the development of Internet of Things technology are of great significance.

scholarly journals Geometric Approach to Analytic Marginalisation of the Likelihood Ratio for Continuous Gravitational Wave Searches

Universe ◽  
2021 ◽  
Vol 7 (6) ◽  
pp. 174
Author(s):  
Karl Wette
Keyword(s):  
Gravitational Wave ◽  
Likelihood Ratio ◽  
Signal To Noise Ratio ◽  
Geometric Approach ◽  
The Other ◽  
Efficient Computation ◽  
Likelihood Ratios ◽  
Signal To Noise ◽  
Noise Ratio ◽  
Optimal Signal

The likelihood ratio for a continuous gravitational wave signal is viewed geometrically as a function of the orientation of two vectors; one representing the optimal signal-to-noise ratio, and the other representing the maximised likelihood ratio or F-statistic. Analytic marginalisation over the angle between the vectors yields a marginalised likelihood ratio, which is a function of the F-statistic. Further analytic marginalisation over the optimal signal-to-noise ratio is explored using different choices of prior. Monte-Carlo simulations show that the marginalised likelihood ratios had identical detection power to the F-statistic. This approach demonstrates a route to viewing the F-statistic in a Bayesian context, while retaining the advantages of its efficient computation.

Adaptive MMSE Multiuser Detection in MIMO OFDM Wireless Communication System

2011 ◽  
Vol 367 ◽  
pp. 233-240 ◽  
Author(s):  
T. Eneh ◽  
P. Rapajic ◽  
K. Anang ◽  
Bello Lawal
Keyword(s):  
Signal Processing ◽  
Wireless Communication ◽  
Multiuser Detection ◽  
Communication Systems ◽  
Power Transmission ◽  
Signal To Noise Ratio ◽  
Mobile Station ◽  
Signal To Noise ◽  
Mimo Ofdm ◽  
Noise Ratio

The combination of MIMO signal processing with OFDM is a solution to achieving high data rates for next generation wireless communication systems operating in frequency selective fading environments. To realize the extension of the MIMO with OFDM, a number of changes are required in the baseband signal processing. The developed adaptive Multiuser Detection in MIMO OFDM(AMUD) scheme performs better compared to non adaptive MIMO OFDM, at low Signal to noise ratio (SNR), it shows good performance in computational complexity, bit error rate (BER) and capacity. Simulation results show that the developed algorithm sum rate capacity is very close to MIMO theoretical upper bound (21.5 bits/s/Hz at signal to noise ratio of 20dB) which strongly indicate it’s applicability to the uplink channel where power transmission at the mobile station is a constraint. The BER performance of the developed scheme shows that, as the number of antenna increases, the 8 x 8 AMUD provides a 2dB gain compared to known non adaptive MIMO OFDMO at low SNR.

A Simple way to Estimate the Signal-To-Noise Ratio and to Save Energy

2013 ◽  
Vol 724-725 ◽  
pp. 937-940
Author(s):  
Wen Zhuo Li
Keyword(s):  
Wireless Communication ◽  
Bit Error Rate ◽  
Error Rate ◽  
Law Of Large Numbers ◽  
Signal To Noise Ratio ◽  
Signal To Noise ◽  
Large Numbers ◽  
Noise Ratio ◽  
Save Energy

No one can deny the significance of wireless communication in our life, but there is always noise that can lead to some mistakes in transmitting signal. Facing the noise, we should realize that we cannot eliminate completely. Therefore, we should estimate the signal-to-noise ratio so that we can balance the Bit Error Rate and the power, which can save more energy. Here is a simple way to estimate the signal-to-noise ratio based on Bernoulli's Law of Large Numbers.

scholarly journals Bayesian algorithm to estimate position and activity of an orphan gamma source utilizing multiple detectors in a mobile gamma spectrometry system

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245440
Author(s):  
Antanas Bukartas ◽  
Jonas Wallin ◽  
Robert Finck ◽  
Christopher Rääf
Keyword(s):  
Gamma Spectrometry ◽  
Signal To Noise Ratio ◽  
Measurement Data ◽  
Regulatory Control ◽  
Signal To Noise ◽  
Bayesian Algorithm ◽  
Gamma Source ◽  
Noise Ratio ◽  
Stability And Accuracy ◽  
Multiple Detectors

To avoid harm to the public and the environment, lost ionizing radiation sources must be found and brought back under the regulatory control as soon as possible. Usually, mobile gamma spectrometry systems are used in such search missions. It is possible to estimate the position and activity of point gamma sources by performing Bayesian inference on the measurement data. The aim of this study was to theoretically investigate the improvements in the Bayesian estimations of the position and activity of a point gamma source due to introduction of data from multiple detectors with angular variations of efficiency. Three detector combinations were tested—a single 123% HPGe detector, single 4l NaI (Tl) detector and a 123% HPGe with 2x4l NaI (Tl) detector combination—with and without angular efficiency variations for each combination resulting in six different variants of the Bayesian algorithm. It was found that introduction of angular efficiency variations of the detectors did improve the accuracy of activity estimation slightly, while introduction of data from additional detectors lowered the signal-to-noise ratio threshold of the system significantly, increasing the stability and accuracy of the estimated source position and activity, for a given signal-to-noise ratio.

scholarly journals Development, Validation, and Application of HPLC Method for Quantification of Antihyperuricemic Compounds from Lippia nodiflora in Rat Plasma

2019 ◽  
Vol 6 (01) ◽  
pp. e28-e35
Author(s):  
Lee-Chuen Cheng ◽  
Vikneswaran Murugaiyah ◽  
Kit-Lam Chan
Keyword(s):  
Limit Of Detection ◽  
Peak Plasma ◽  
Signal To Noise Ratio ◽  
Rat Plasma ◽  
Hplc Method ◽  
The Body ◽  
The Other ◽  
Aqueous Acetic Acid ◽  
Signal To Noise ◽  
Noise Ratio

AbstractAn HPLC method for simultaneous determination of arenarioside (1 ), verbascoside (2), 6-hydroxyluteolin (3), 6-hydroxyluteolin-7-O-glycoside (4), and nodifloretin (5) from Lippia nodiflora in rat plasma was developed and validated. The optimal chromatographic separation was achieved with a gradient mobile phase comprising 0.1% aqueous acetic acid and acetonitrile. The limit of detection was 78.1 ng/mL for 3 and 39.1 ng/mL for the other compounds (signal-to-noise ratio=3), whereas the limit of quantification was 312.5 ng/mL for 3 and 156.3 ng/mL for the other compounds (signal-to-noise ratio=12). The recovery values of compounds 1–5 ranged from 89.37–100.92%. Their accuracy values were between 96.48 and 105.81%, while their corresponding precision values were in the range of 0.75–9.06% for both intraday and inter-day analysis. The method was then applied in the first pharmacokinetic study of 1–5. Following intravenous administration, 1–5 were eliminated slowly from the body with a mean clearance value of 0.11, 0.13, 0.30, 0.09, and 0.23 L/kg h, respectively. Meanwhile, their peak plasma concentration upon oral administration was 8.97, 1.07, 1.06, 0.65, and 0.38 µg/mL, respectively. Compound 3 (5.97%) exhibited the highest absolute oral bioavailability value, followed by 1 (5.22%), 4 (3.13%), 2 (2.10%), and 5 (0.93%).

Design and Implementation of Key Technologies of Carrier Synchronization in Wireless Communication System

2014 ◽  
Vol 602-605 ◽  
pp. 3329-3332
Author(s):  
Guo Qing Dang ◽  
Xiao Yan Cheng
Keyword(s):  
Wireless Communication ◽  
Communication System ◽  
Signal To Noise Ratio ◽  
Low Complexity ◽  
Carrier Synchronization ◽  
Signal To Noise ◽  
Wireless Communication System ◽  
Low Snr ◽  
Noise Ratio ◽  
The One

Noise multiple and user interference are the two important influencing factors that carrier synchronization technology in the wireless communication system faces. On the one hand, the phase locked loop and data aided carrier synchronization device is faced with poor estimation precision and slow convergence speed. On the other hand frequency offset and channel estimation problem need to be solved in multi-input multi-output (MIMO) communication system collaboration under the condition of dry low signal to noise ratio. So research of carrier synchronization algorithm of low complexity, high precision in view of the low SNR and multi-user communication system is becoming an important issue. 1. Carrier synchronization technology in wireless communication system of low signal-to-noise ratio and multiuser

Determination of the Best Emulsion for the Microscopy of Crystals

1981 ◽  
Vol 39 ◽  
pp. 32-33
Author(s):  
David A. Grano ◽  
Kenneth H. Downing
Keyword(s):  
Spatial Frequency ◽  
Information Transfer ◽  
Signal To Noise Ratio ◽  
Experimental Situation ◽  
Photographic Emulsion ◽  
Modulation Transfer ◽  
Signal To Noise ◽  
Frequency Space ◽  
Noise Ratio

The retrieval of high-resolution information from images of biological crystals depends, in part, on the use of the correct photographic emulsion. We have been investigating the information transfer properties of twelve emulsions with a view toward 1) characterizing the emulsions by a few, measurable quantities, and 2) identifying the “best” emulsion of those we have studied for use in any given experimental situation. Because our interests lie in the examination of crystalline specimens, we've chosen to evaluate an emulsion's signal-to-noise ratio (SNR) as a function of spatial frequency and use this as our critereon for determining the best emulsion.The signal-to-noise ratio in frequency space depends on several factors. First, the signal depends on the speed of the emulsion and its modulation transfer function (MTF). By procedures outlined in, MTF's have been found for all the emulsions tested and can be fit by an analytic expression 1/(1+(S/S0)2). Figure 1 shows the experimental data and fitted curve for an emulsion with a better than average MTF. A single parameter, the spatial frequency at which the transfer falls to 50% (S0), characterizes this curve.

Experiments in Bright-Field Imaging with Hollow-Cone Illumination

1981 ◽  
Vol 39 ◽  
pp. 226-227
Author(s):  
W. Kunath ◽  
K. Weiss ◽  
E. Zeitler
Keyword(s):  
Signal To Noise Ratio ◽  
Carbon Support ◽  
Electronic System ◽  
Optic Axis ◽  
Hollow Cone ◽  
Signal To Noise ◽  
Bright Field ◽  
Noise Ratio ◽  
Single Field ◽  
Field Imaging

Bright-field images taken with axial illumination show spurious high contrast patterns which obscure details smaller than 15 ° Hollow-cone illumination (HCI), however, reduces this disturbing granulation by statistical superposition and thus improves the signal-to-noise ratio. In this presentation we report on experiments aimed at selecting the proper amount of tilt and defocus for improvement of the signal-to-noise ratio by means of direct observation of the electron images on a TV monitor.Hollow-cone illumination is implemented in our microscope (single field condenser objective, Cs = .5 mm) by an electronic system which rotates the tilted beam about the optic axis. At low rates of revolution (one turn per second or so) a circular motion of the usual granulation in the image of a carbon support film can be observed on the TV monitor. The size of the granular structures and the radius of their orbits depend on both the conical tilt and defocus.

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