scholarly journals Efficient DS-UWB MUD Algorithm Using Code Mapping and RVM

2016 ◽  
Vol 2016 ◽  
pp. 1-9
Author(s):  
Pingyan Shi ◽  
Xiaohui Liu ◽  
Xiaofeng Tao ◽  
Jianchao Ji
Keyword(s):  
Multiuser Detection ◽  
Matched Filter ◽  
Feature Space ◽  
Wide Band ◽  
Multiple Access Interference ◽  
Decision Function ◽  
Optimal Decision ◽  
Suppression Mechanism ◽  
Simulation Results ◽  
Ber Performance

A hybrid multiuser detection (MUD) using code mapping and a wrong code recognition based on relevance vector machine (RVM) for direct sequence ultra wide band (DS-UWB) system is developed to cope with the multiple access interference (MAI) and the computational efficiency. A new MAI suppression mechanism is studied in the following steps: firstly, code mapping, an optimal decision function, is constructed and the output candidate code of the matched filter is mapped to a feature space by the function. In the feature space, simulation results show that the error codes caused by MAI and the single user mapped codes can be classified by a threshold which is related to SNR of the receiver. Then, on the base of code mapping, use RVM to distinguish the wrong codes from the right ones and finally correct them. Compared with the traditional MUD approaches, the proposed method can considerably improve the bit error ratio (BER) performance due to its special MAI suppression mechanism. Simulation results also show that the proposed method can approximately achieve the BER performance of optimal multiuser detection (OMD) and the computational complexity approximately equals the matched filter. Moreover, the proposed method is less sensitive to the number of users.

scholarly journals Optimal Decision-Making to Charge Electric Vehicles in Heterogeneous Networks: Stackelberg Game Approach

Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 325 ◽  
Author(s):  
Shijun Chen ◽  
Huwei Chen ◽  
Shanhe Jiang
Keyword(s):  
Electric Vehicles ◽  
Heterogeneous Networks ◽  
Demand Uncertainty ◽  
Stackelberg Game ◽  
Optimal Solution ◽  
Stackelberg Equilibrium ◽  
Optimal Decision ◽  
Charging Station ◽  
Simulation Results ◽  
Grid Operators

Electric vehicles (EVs) are designed to improve the efficiency of energy and prevent the environment from being polluted, when they are widely and reasonably used in the transport system. However, due to the feature of EV’s batteries, the charging problem plays an important role in the application of EVs. Fortunately, with the help of advanced technologies, charging stations powered by smart grid operators (SGOs) can easily and conveniently solve the problems and supply charging service to EV users. In this paper, we consider that EVs will be charged by charging station operators (CSOs) in heterogeneous networks (Hetnet), through which they can exchange the information with each other. Considering the trading relationship among EV users, CSOs, and SGOs, we design their own utility functions in Hetnet, where the demand uncertainty is taken into account. In order to maximize the profits, we formulate this charging problem as a four-stage Stackelberg game, through which the optimal strategy is studied and analyzed. In the Stackelberg game model, we theoretically prove and discuss the existence and uniqueness of the Stackelberg equilibrium (SE). Using the proposed iterative algorithm, the optimal solution can be obtained in the optimization problem. The performance of the strategy is shown in the simulation results. It is shown that the simulation results confirm the efficiency of the model in Hetnet.

Performance of OQAM/GFDM in Spatial Multiplexing MIMO Systems

2020 ◽  
Vol 11 (2) ◽  
pp. 39-57
Author(s):  
Simon Wissam Tarbouche ◽  
Abdel-Nasser Assimi
Keyword(s):  
Interference Cancellation ◽  
Pulse Shaping ◽  
Matched Filter ◽  
Mimo Systems ◽  
Mimo System ◽  
Spatial Multiplexing ◽  
Frequency Division ◽  
Fifth Generation ◽  
Additional Processing ◽  
Simulation Results

Generalized frequency division multiplexing (GFDM) is a prominent candidate to be used by the mobile Fifth Generation (5G) physical layer. Nevertheless, the integration of GFDM with Spatial Multiplexing (SM) MIMO system is essential to fulfill the data rate requirements. SM detection of MIMO-GFDM becomes a more challenging topic because of ICI and ISI due to the non-orthogonal nature of GFDM, along with IAI. In this article, the authors propose a system that combines the Offset-Quadrature Amplitude Modulation (OQAM) with GFDM to mitigate self-induced interference, by using a simple Matched Filter (MF) detector and minimum additional processing at the receiver. Simulation results show a considerable achieved improvement in BER by the proposed OQAM/GFDM compared to QAM/GFDM when using MMSE-based Ordered Successive Interference Cancellation (OSIC) detector. Furthermore, this system is unaffected by the roll-off factor variations of used pulse-shaping filters.

Ultra-wideband elliptical patch antenna for microwave imaging of wood

2019 ◽  
Vol 11 (9) ◽  
pp. 948-966 ◽  
Author(s):  
Tale Saeidi ◽  
Idris Ismail ◽  
Wong Peng Wen ◽  
Adam R. H. Alhawari
Keyword(s):  
Low Frequency ◽  
Wide Band ◽  
Microwave Imaging ◽  
Ultra Wideband ◽  
Uniform Illumination ◽  
Elliptical Shape ◽  
Measurement Results ◽  
Simulation Results ◽  
Strip Loading ◽  
Good Agreement

AbstractThis paper presents the design of an elliptical shape ultra-wide band antenna for imaging of wood. The antenna is constructed comprising an elliptical shape of patch loaded by a stub to resonate at lower bands, strip loading at the back, and chamfered ground. Despite having miniaturized dimensions of 20 mm × 20 mm, the proposed antenna shows better results compared to recent studies. The simulation results depict a good ultra-wide bandwidth from 2.68 to 16 GHz, and 18.2–20 GHz. Besides, the proposed antenna has two low-frequency bands at 0.89–0.92 and 1.52–1.62 GHz, maximum gain of 5.48 dB, and maximum directivity of 6.9 dBi. The measurement outcomes are performed in air, plywood, and high-density wood and show a good agreement with the simulated results done using electromagnetic simulator CST. In addition to that, the measurement results of S-parameters, transmitted and received signals show a good agreement with the simulated results. Besides, the measured results illustrate a good isolation and uniform illumination among arrays as well as the received signals' shapes do not change in different environments, but only the amplitude. Hence, the proposed antenna seems to be adequate for microwave imaging of wood.

Improved Amplify-and-Forward Cooperative Scheme for Satellite Communication Systems

2012 ◽  
Vol 198-199 ◽  
pp. 1707-1711
Author(s):  
Min Jia ◽  
Xue Mai Gu ◽  
Qun Wu
Keyword(s):  
Communication Systems ◽  
Satellite Communication ◽  
Cooperative Diversity ◽  
System Capacity ◽  
Wireless Communication Systems ◽  
Conventional System ◽  
Amplify And Forward ◽  
Cooperative Scheme ◽  
Simulation Results ◽  
Ber Performance

The technology of Amplify-and-forward cooperative diversity is popular for the cooperative communication system. And it can be applied when a communication terminal can’t communicate with other communication terminal directly. Moreover, this kind of scheme has been studied by the researchers for the application of terrestrial wireless communication systems. The conventional system presents that the power are equally distributed among all nodes. However, this algorithm can not be applied to satellites communication systems directly. Therefore, an improved Amplify-and-Forward cooperative scheme is presented in this paper, and the simulation results show that it can obtain the larger system capacity and better BER performance.

A Min-Sum Algorithm Suitable for Hardware Implementation Based on LDPC Codes

2011 ◽  
Vol 271-273 ◽  
pp. 458-463
Author(s):  
Rui Ping Chen ◽  
Zhong Xun Wang ◽  
Xin Qiao Yu
Keyword(s):  
Hardware Implementation ◽  
Ldpc Codes ◽  
Low Complexity ◽  
Scaling Factor ◽  
Computation Complexity ◽  
Decoding Complexity ◽  
Decoding Algorithms ◽  
Hardware Resource ◽  
Simulation Results ◽  
Ber Performance

Decoding algorithms with strong practical value not only have good decoding performance, but also have the computation complexity as low as possible. For this purpose, the paper points out the modified min-sum decoding algorithm(M-MSA). On the condition of no increasing in the decoding complexity, it makes the error-correcting performance improved by adding the appropriate scaling factor based on the min-sum algorithm(MSA), and it is very suitable for hardware implementation. Simulation results show that this algorithm has good BER performance, low complexity and low hardware resource utilization, and it would be well applied in the future.

scholarly journals 5G UFMC Scheme Performance with Different Numerologies

Electronics ◽  
2021 ◽  
Vol 10 (16) ◽  
pp. 1915
Author(s):  
Lambros Sakkas ◽  
Eleftherios Stergiou ◽  
Georgios Tsoumanis ◽  
Constantinos T. Angelis
Keyword(s):  
Mobile Communications ◽  
Bit Error Rate ◽  
Communication Systems ◽  
Modulation Scheme ◽  
Fifth Generation ◽  
Data Rates ◽  
The World ◽  
Simulation Results ◽  
5G Systems ◽  
Ber Performance

5G is the latest mobile communications standard that is spreading fast across the world. Recently defined requirements for 5G systems have led to higher applications’ requirements regarding data rates, lower requirements for latency, and higher efficiency regarding the spectrum usage. Universal Filtered Multi-Carrier (UFMC) is one new candidate modulation scheme for emergent Fifth Generation (5G) communication systems. This paper focuses on Universal Filtered Multi-Carrier (UFMC) design aspects in terms of Bit Error Rate (BER) performance in relation to the filter length used in subband filtering. Simulation results show that BER and CCDF performance varies for different filter lengths and modulation schemes. The main achievement of this work is that the results show that different Dolph–Chebyshev FIR filter lengths do not affect the BER performance both for the 64 and 256 QAM.

An Effective Scheme of M-Ary Spread Spectrum System Based on Orthogonal Spread Spectrum and CPSK

2013 ◽  
Vol 765-767 ◽  
pp. 2696-2700
Author(s):  
Yue Xuan Liu ◽  
Shu Jian Liang ◽  
Yue Huai Ma ◽  
Song Xian Gong
Keyword(s):  
Monte Carlo Simulation ◽  
Bit Error Rate ◽  
Spread Spectrum ◽  
Bandwidth Efficiency ◽  
Transform Domain ◽  
Communication Scheme ◽  
System Synchronization ◽  
Orthogonal Spread ◽  
Simulation Results ◽  
Ber Performance

A hybrid M-ary spread spectrum (SS) communication scheme which combined with orthogonal SS and CPSK technique is proposed. Based on dual orthogonal SS, every SS code is treated as original code to adopt CPSK modulation, the unattached synchronous code is chosen to achieve system synchronization. At the receiver, A circular correlator based on transform domain processing is employed to de-spread the received signals. Compared with M-ary SS and CPSK, the proposed scheme is able to obtain higher bandwidth efficiency, stronger anti-intercept capability, and better synchronous performance. The Monte-Carlo simulation results demonstrate that the proposed scheme can achieve better synchronous and bit error rate (BER) performance under additional white gauss noise channel models.

scholarly journals Efficient TTI for 3G Multimedia Applications

2007 ◽  
Vol 2007 ◽  
pp. 1-7 ◽  
Author(s):  
Costas Chaikalis
Keyword(s):  
Computational Complexity ◽  
Bit Error Rate ◽  
Fading Channel ◽  
Rayleigh Fading ◽  
Turbo Coding ◽  
Operating Environments ◽  
Data Rates ◽  
Simulation Results ◽  
Flat Rayleigh Fading ◽  
Ber Performance

Time transmission interval (TTI) or outer block interleaving is an important task for the implementation of UMTS turbo coding in flat Rayleigh fading environment. An efficient TTI choice can save computational complexity. However, different multimedia scenarios are investigated using the maximum UMTS frame length, and simulation results are presented for the four possible outer block interleaver configurations in the case of flat Rayleigh fading channel. It is shown that different operating environments require an appropriate TTI in terms of bit error rate (BER) performance for the following data rates: 28.8 kbps, 64 kbps, 144 kbps, 384 kbps, and 2 Mbps.

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