scholarly journals Improving radar performance with constant envelope multi-level chirp

2019 ◽  
Vol 13 (2) ◽  
pp. 100-103
Author(s):  
Farhad Bahadori-Jahromi ◽  
Alireza Hassannejad
Keyword(s):  
Data Transmission ◽  
Additive White Gaussian Noise ◽  
Continuous Phase ◽  
Rician Fading ◽  
Telecommunication System ◽  
New Approach ◽  
Chirp Modulation ◽  
Constant Envelope ◽  
Transmission Period ◽  
Multi Level

M-level Continuous Phase Chirp Modulation is considered for data transmission. In this article, we would like to propose a new approach to transmitting information with the help of multi-level wave guide signaling. The main problem with the classic chirp modulation system is that the final phase of the signal is not equal in each period to the initial phase of the next step, and this discontinuity is present in each data transmission period. The main objective of this paper is to improve the efficiency of chirp modulation, which is recommended for continuous phase multi-level scalar modulation, which results has a significant increase in system performance. In this new approach, for sending the M symbols, we use the M level to send the message. With the help of this idea, we simulate the telecommunication system and examine the probability of its bit error in the presence of additive white Gaussian noise and Rician fading.

scholarly journals New approach for localization and smart data transmission inside underground mine environment

2021 ◽  
Vol 3 (6) ◽  
Author(s):  
Ankita RayChowdhury ◽  
Ankita Pramanik ◽  
Gopal Chandra Roy
Keyword(s):  
Data Transmission ◽  
Signal To Noise Ratio ◽  
Visible Light Communication ◽  
Underground Mine ◽  
Control Room ◽  
Time Data ◽  
New Approach ◽  
Mine Environment ◽  
Surface Control ◽  
Smart Data

AbstractThis paper presents an approach to access real time data from underground mine. Two advance technologies are presented that can improve the adverse environmental effect of underground mine. Visible light communication (VLC) technology is incorporated to estimate the location of miners inside the mine. The distribution of signal to noise ratio (SNR) for VLC system is also studied. In the second part of the paper, long range (LoRa) technology is introduced for transmitting underground information to above the surface control room. This paper also includes details of the LoRa technology, and presents comparison of ranges with existing above the surface technologies.

The Study of Coded CPM Schemes

2012 ◽  
Vol 198-199 ◽  
pp. 1408-1412
Author(s):  
Lin Bo Su ◽  
Jian Hua Chen ◽  
Ying Peng Hu
Keyword(s):  
Fading Channels ◽  
Convolutional Codes ◽  
Continuous Phase ◽  
Coded Modulation ◽  
Superior Performance ◽  
Continuous Phase Modulation ◽  
Codes Over Rings ◽  
Constant Envelope ◽  
Modulation Schemes ◽  
Serially Concatenated

Continuous Phase Modulation (CPM) schemes belong to a class of constant-envelope digital modulation schemes, the constant-envelope nature of the CPM signals makes them robust for the nonlinear and fading channels, and very useful for the satellite and/or the mobile radio channels. Comparing to PSK modulation, CPM modulation can not only provide spectral economy, but also exhibit a “coding gain”. CPM can be decomposed into a Continuous Phase Encoder (CPE) followed by a Memoryless Modulator (MM), this allows many new coded modulation schemes of combination of convolutional encoder and CPM modulator to be possible, such as serially-concatenated CPM (SC-CPM), SC-CPM with Convolutional Codes over Rings, pragmatic CPM (P-CPM), Concatenation of convolutional endocder and extended CE（CCEC）, etc. Some simulations show that these new CPM schemes can offer superior performance.

NEW APPROACH TO MULTI-LEVEL PROCESSOR SCHEDULING

2010 ◽  
Vol 19 (03) ◽  
pp. 335-346 ◽  
Author(s):  
SAMANEH HOSSEINI SEMNANI ◽  
KAMRAN ZAMANIFAR
Keyword(s):  
Fitness Function ◽  
Systems Design ◽  
Heuristic Function ◽  
Problem Space ◽  
New Approach ◽  
Processor Scheduling ◽  
Quantum Time ◽  
Multi Level ◽  
Evaluation Parameters

The problem of finding the best quantum time in multi-level processor scheduling is addressed in this paper. Processor scheduling is one of the most important issues in operating systems design. Different schedulers are introduced to solve this problem. In one scheduling approach, processes are placed in different queues according to their properties, and the processor allocates time to each queue iteratively. One of the most important parameters of a processor's efficiency in this approach is the amount of time slices associated to each processor queue. In this paper, an ant colony optimization (ACO) algorithm is presented to solve the problem of finding appropriate time slices to assign to each processor queue. In this technique, each ant tries to find an appropriate scheduling. Ant algorithm searches the problem space to find the best scheduling. The quality of each ant's solution is evaluated using a new fitness function. This fitness function is designed according to the evaluation parameters of each processor queue and also according to the queue theory's relations. Also a heuristic function is presented which prompts ant to select better solutions. Computational tests are presented and the comparisons made with genetic algorithm (GA) and particle swarm optimization (PSO) algorithms which try to solve same problem. The results show the efficiency of this algorithm.

Performance Analysis Of Non-Orthogonal Multiple Access Technique Using Simulink

2021 ◽  
Vol 9 (7) ◽  
pp. 921-928
Keyword(s):  
Multiple Access ◽  
Additive White Gaussian Noise ◽  
Multipath Fading ◽  
Rician Fading ◽  
Similar Data ◽  
Cell Edge ◽  
Novel Technology ◽  
Cell Coverage ◽  
Power Domain ◽  
Rician Fading Channel

Non orthogonal multiple access (NOMA) is a novel technology for transmission of the data with similar data-rate for users both at the cell center and the at cell edge. Due to its good cell coverage and large transmission bandwidth enables reliable communication for users located at the cell edge. The signals for the users are transmitted through entire spatial bandwidth by multiplexing in the power domain. This work presents the Simulink implementation of non-orthogonal multiple access over additive white Gaussian noise channel, Rayleigh and Rician fading channel. The NOMA Transmitter and the receiver blocks with SIC are implemented for two user and three user environments. Multipath fading environment was providing using parameter settings available in theblocks. Performance of the models implemented are analyzed with respect to Bit error rate (BER) v/s Eb/Noplots comparing using various modulation schemes over various channels. The results are tabulated and analyzed.

scholarly journals Water-in-Water Emulsion as a New Approach to Produce Mesalamine-Loaded Xylan-Based Microparticles

2019 ◽  
Vol 9 (17) ◽  
pp. 3519
Author(s):  
Bartolomeu S. Souza ◽  
Henrique R. Marcelino ◽  
Francisco Alexandrino ◽  
Silvana C. C. Urtiga ◽  
Karen C. H. Silva ◽  
...  
Keyword(s):  
Small Molecules ◽  
Drug Loading ◽  
Continuous Phase ◽  
Clinical Use ◽  
Water Emulsion ◽  
New Approach ◽  
Emulsion Method ◽  
Discontinuous Phase ◽  
Rapid Diffusion ◽  
Full Factorial

The water-in-water emulsion method has been reported as a technique able to prepare microparticles without using harmful solvents. However, there are few reports showing the encapsulation of small molecules into microparticles produced within this technique. The probable reason relays on the rapid diffusion of these molecules from the discontinuous phase to the continuous phase. In the present study, xylan microparticles containing mesalamine were produced and the doubled crosslinking approach, used to promote higher encapsulation rates, was disclosed. To achieve this goal, a 23 full factorial design was carried out. The results revealed that all formulations presented spherical-shaped microparticles. However, at specific conditions, only few formulations reached up to 50% of drug loading. In addition, the new xylan-based microparticles formulation retained almost 40% of its drug content after 12 h of a dissolution assay likely due to the degree of crosslinking. Thus, the doubled crosslinking approach used was effective on the encapsulation of mesalamine and may pave the way to successfully produce other polysaccharide-based carriers for clinical use.

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