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61.
ABSTRACT

Quantum-dot cellular automata (QCA) is an emerging nanotechnology and a possible alternative solution to the limitation of complementary metal oxide semiconductor (CMOS) technology. One of the most attractive fields in QCA is the implementation of configurable digital systems. This article presents a novel multifunctional gate called the modified-majority voter (MMV). The proposed gate works on the explicit interaction of the cell characteristic property for the implementation of digital circuits. This prominent feature of the proposed gate reduces the maximum hardware cost and implements highly efficient QCA structures. To verify the functionality of the proposed gate, some physical proofs, truth table and computational simulation results are performed. These results assured the validity of the existence of the proposed gate. It also dissipates less energy which has been calculated under three separate tunnelling energy levels using the QCAPro tool. To prove the effectiveness of the proposed MMV gate, several optimal irreversible arithmetic circuits such as three-input XOR, half-adder and full-adder are proposed. The modular layouts are verified with the freely available QCADesigner tool version 2.0.3.  相似文献   
62.
One hybrid ARQ for broadcasting or multicasting in wireless erasure channel   总被引:1,自引:0,他引:1  
In this paper, we introduce a new hybrid ARQ technique for broadcasting or multicasting in erasure channel. The system is tested according to the objective criteria—quantity of information sent by the source, loses, and number of negative acknowledgments (NACKs) sent by the receiver nodes (end nodes). We compare our proposed method with automatic repeat request (ARQ), hybrid ARQ II (HARQ II), and also with a forward error correction (FEC) transmission technique based on Reed Solomon code (RS). The main focus of the presented HARQ is to reduce the quantity of redundant information sent by the source as well as the number of NACKs sent by the receivers, maintaining the condition that all the information is being recovered successfully by the receivers.  相似文献   
63.
Ahmad  Bilal  Jian  Wang  Enam  Rabia Noor  Abbas  Ali 《Wireless Personal Communications》2021,118(2):1055-1073

As per the most recent literature, Orthogonal Frequency Division Multiplexing (OFDM), a multi access technique, is considered most suitable for the 3G, 4G and 5G techniques in high speed wireless communication. What made OFDM most popular is its ability to deliver high bandwidth efficiency and superior data rate. Besides it, high value of peak to average power ratio (PAPR) and Inter Carrier Interference (ICI) are the challenges to tackle down via appropriate mitigation scheme. As a research contribution in the present work, an improved self-cancellation (SC) technique is designed and simulated through Simulink to mitigate the effect of ICI. This novel proposed technique (Improved SC) is designed over discrete wavelet transform (DWT) based OFDM and compared with conventional SC scheme over different channel conditions i.e. AWGN and Rayleigh fading environments. It is found that proposed DWT-OFDM with Improved SC scheme outperforms conventional SC technique significantly, under both AWGN and Rayleigh channel conditions. Further, in order to justify the novelty in the research contribution, a Split-DWT based Simulink model for Improved SC scheme is investigated to analyse the BER performance. This Split-DWT based Simulink model presented here foretells the future research potential in wavelet hybridization of OFDM to side-line ICI effects more efficiently.

  相似文献   
64.
Semiconductors - Thin films of AlN:Tm are deposited on a Si(111) and Si(100) substrates and optical fiber by rf magnetron sputtering method. 200–400 nm thick films are deposited at various...  相似文献   
65.
A CMOS distributed amplifier (DA) with low-power and flat and high power gain (S21) is presented. In order to decrease noise figure (NF) an RL terminating network used for the gate transmission line instead of single resistance. Besides, a flat and high S21 is achieved by using the proposed cascade gain cell consist of a cascode-stage with bandwidth extension capacitor. In the high-gain mode, under operation condition of V dd  = 1.2 V and the overall current consumption of 7.8 mA, simulation result shown that the DA consumed 9.4 mW and achieved a flat and high S21 of 20.5 ± 0.5 dB with an average NF of 6.5 dB over the 11 GHz band of interest, one of the best reported flat gain performances for a CMOS UWB DA. In the low-gain mode, the DA achieved average S21 of 15.5 ± 0.25 dB and an average NF of 6.6 dB with low power consumption (PDC) of 3.6 mW, the lowest PDC ever reported for a CMOS DA or LNA with an average gain better than 10 dB.  相似文献   
66.
Abdalrazik  Ahmad  Gomaa  Ahmed  Kishk  Ahmed A. 《Wireless Networks》2022,28(8):3779-3786
Wireless Networks - This paper proposes a quadruple band stacked oval patch antenna with sunlight-shaped slots supporting L1/L2/L5 GNSS bands and the 2.3 Ghz WiMAX band. The antenna produces...  相似文献   
67.
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69.
The optical properties of ZnO/Ag/ZnO (ZAZ) multilayer structures were numerically modeled and calculated by a FDTD method. Such tri-layers were also manufactured using an ion beam sputtering plant. A good agreement is obtained between modelizations and realizations. The impact of the oxide thicknesses on the optical properties of the ZAZ structures were experimentally and numerically investigated, and allow us to adjust the spectral position of the transmission maximum. The transmission of these structures is optimized up to around 74%, on the whole absorption spectral range of the photoactive P3HT:PCBM bulk heterojunction. The best electrode design is glass/ZnO (30 nm)/Ag (14 nm)/ZnO (30 nm), which presents a sheet resistance of 7 Ω/□. The optimized ZAZ structure was successfully integrated in an organic solar cell as anode. A photovoltaic efficiency of 2.58% is obtained and is compared to an organic solar cell integrating a traditional ITO anode with an efficiency of 2.99%. Numerical calculations of the intrinsic absorption inside each layer of the organic solar cells are performed. Alternative ITO-free electrodes for organic solar cells are demonstrated.  相似文献   
70.
Namal  Suneth  Ahmad  Ijaz  Saud  Saad  Jokinen  Markku  Gurtov  Andrei 《Wireless Networks》2016,22(2):663-677
Wireless Networks - The static conventional network architecture is ill-suited to the growing management complexity and highly dynamic wireless network topologies. Software Defined Radio systems...  相似文献   
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