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Mobile WiMAX Physical Layer Optimization and Performance Analysis Towards Sustainability and Ubiquity 1

2nd International Conference on Information Systems Design and Intelligent Applications (INDIA)

作者： Saha, Sajal Chakraborty, Angana Mukhopadhyay, Asish K. Bhattacharjee, Anup Kumar Narula Inst Technol Kolkata 700109 India Indian Inst Engn Sci & Technol Howrah 711103 India SR Grp Inst Jhansi Uttar Pradesh India Natl Inst Technol Durgapur India

ISBN: (数字)9788132222507

ISBN: (纸本)9788132222507;9788132222491

Mobile WiMAX is emerging as a means for low cost reliable wireless broadband connection compared to traditional DSL cable. The system requirement of next generation mobile WiMAX is supposed to be based on IEEE 802.16 m which is still in letter ballot stage. This paper attempts to make in depth performance evaluation of Mobile WiMAX under various PHY parameters such as modulation and coding schemes (MCS), cyclic prefixes and different path-loss models. Moreover it also present an optimized adaptive modulation scheme that senses the SNR and adaptively switches to required MCS towards achieving the desired level of Quality of Service (QoS) and link stability. Simulation results show that dynamic adaptation of modulation and coding scheme based channel conditions can offer enhanced throughput, load, reduced delay, SNR and BER.

关键词： Wimax Path-loss modulation and coding Load Throughput

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Multi-entity Bayesian network for the handling of uncertainties in SATCOM Links 8

Multi-entity Bayesian network for the handling of uncertaint...

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Conference on Sensors and Systems for Space Applications

作者： Tian, Xin Chen, Genshe Martin, Todd Chang, K. C. Tien Nguyen Khanh Pham Blasch, Erik Intelligent Fus Technol Inc Germantown MD 20876 USA George Mason Univ Fairfax VA 22030 USA Catholic Univ Amer Washington DC 20064 USA Air Force Res Lab Space Vehicles Directorate Kirtland AFB NM 87117 USA Air Force Res Lab Informat Directorate Rome NY 13441 USA

ISBN: (纸本)9781628415858

Accurate prediction of satellite communications (SATCOM) data link loss is critical for SATCOM systems to effectively achieve required Quality of Service (QoS) and link availability. A major challenge is to account for various sources of uncertainties (such as atmospheric loss, rain loss, depolarization loss, pointing offset loss, etc.,) and their impacts on the aggregated link loss. This paper investigates the use of Bayesian Network (BN) for acquiring accurate SATCOM link loss estimation and link budget analysis over various modulation and coding schemes. Based on the proposed BN models, a SATCOM Bayesian Network Analysis toolbox has been developed to support link budget analysis and decision making for robust SATCOM applications.

关键词： SATCOM Cognitive Radio uncertainties Multi-Entity Bayesian Network (MEBN) link budget analysis waveform selection modulation and coding

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Simplified LLR calculation for DVB-S2 LDPC decoder 4

Simplified LLR calculation for DVB-S2 LDPC decoder

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IEEE Int Conference Commun Networks Satellite

作者： Olivatto, Vanessa B. Lopes, Renato R. de Lima, Eduardo R. Eldorado Res Inst Dept Hardware Design Campinas SP Brazil Univ Estadual Campinas Sch Elect & Comp Engn Campinas SP Brazil

ISBN: (纸本)9781467382496

The computation of the Log-Likelihood Ratio (LLR) at the channel output may impose great demand of memory and hardware area, especially for high-order modulations. This paper introduces a new approach for the approximation of the LLR in AWGN channels based on the splitting of the original constellation into smaller sectors. Each new sector has a less complex configuration in which it is possible to take into account only two symbols besides the received one. The proposed solution is applied for the 8-PSK and 16-APSK constellations adopted in the Digital Video for Satellite Second Generation standard (DVB-S2).

关键词： Log-likelihood ratio (LLR) LDPC Codes DVB-S2 Soft Demapper modulation and coding Communication Theory

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An adaptive cross-layer optimization scheme for light compressed High-definition Video Transmission Based on 60 GHz system

An adaptive cross-layer optimization scheme for light compre...

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15th IEEE International Conference on Communication Technology (ICCT)

作者： Zhang, Wei Liu, Danpu Beijing Univ Posts & Telecommun Beijing Key Lab Network Syst Architecture & Conve Beijing 100876 Peoples R China

ISBN: (纸本)9781479900749

By using 60GHz spectrum in high frequency carrier, IEEE 802.11ad is widely used in the transmission of high-definition videos. In this paper, an adaptive cross-layer optimization scheme is proposed based on IEEE 802.11ad which involves modulation and coding at the physical layer, retransmission policy at the medium access control layer and source coding at the video coding layer. The scheme aims at minimize the video distortion between original video at sending end and reconstructed video at receiver under certain time delay. Simulation results show that the proposed scheme can select a proper combination of parameters at each layer mentioned above for a given SNR and greatly improve the overall performance in minimizing the video distortion.

关键词： IEEE 802.11ad HD video cross-layer optimization source coding modulation and coding retransmission

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Energy-Driven Scheduling for Digital Video Broadcasting - Satellite Second Generation (DVB-S2)

Energy-Driven Scheduling for Digital Video Broadcasting - Sa...

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IEEE 3rd International Conference on Space Science and Communication (IconSpace)

作者： Thian, L. L. Al-Saegh, Ali M. Ramli, K. F. Ibrahim, N. S. Sali, A. Salman, Mustafa Ismael Univ Putra Malaysia Fac Engn Dept Comp & Commun Syst Engn Serdang 43400 Selangor Malaysia

ISBN: (纸本)9781467352338

The continuous growth in wireless data traffic results in the increase in total energy consumption of wireless networks. Therefore, energy-efficient solutions are extremely required to minimize the energy consumption over the entire network. In this paper, an energy-driven scheduling algorithm with optimized throughput, termed as Energy Efficiency Fair (EEF) queuing algorithm, is proposed. Based on energy efficiency of each modulation and coding scheme (MODCOD) available in Digital Video Broadcasting - Satellite Second Generation (DVB-S2), the EEF algorithm improves a scheduling mechanism of a two-step scheduler by selecting frames to be transmitted next according to "energy efficiency" policy developed. The EEF is compared with Round Robin (RR) algorithm, and a gain in energy efficiency of 47% is obtained when different modulation schemes with common code rate are implemented. Furthermore, EEF outperforms RR by 264% concerning the useful transmitted bits when QPSK modulation scheme with different coding rates is used.

关键词： component energy-efficient scheduling modulation and coding spectral efficiency DVB-S2

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Energy-Driven Scheduling for Digital Video Broadcasting - Satellite Second Generation (DVB-S2)

Energy-Driven Scheduling for Digital Video Broadcasting - Sa...

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International Conference on Space Science and Communication

作者： L. L. Thian Ali M. Al-Saegh K. F. Ramli N. S. Ibrahim A. Sali Mustafa Ismael Salman Dept. of Computer and Communication Systems Engineering Faculty of Engineering Universiti Putra Malaysia

ISBN: (纸本)9781467352321

关键词： Component Energy-efficient scheduling modulation and coding Spectral efficiency DVB-S2

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An adaptive cross-layer optimization scheme for light compressed High-definition Video Transmission Based on 60 GHz system

An adaptive cross-layer optimization scheme for light compre...

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2013 15th IEEE International Conference on Communication Technology

作者： Wei Zhang Danpu Liu Beijing University of Posts and Telecommunications Beijing Key Laboratory of Network System Architecture and Convergence

ISBN: (纸本)9781479900763

By using 60GHz spectrum in high frequency carrier,IEEE 802.11ad is widely used in the transmission of high-definition *** this paper,an adaptive cross-layer optimization scheme is proposed based on IEEE 802.11ad which involves modulation and coding at the physical layer,retransmission policy at the medium access control layer and source coding at the video coding *** scheme aims at minimize the video distortion between original video at sending end and reconstructed video at receiver under certain time *** results show that the proposed scheme can select a proper combination of parameters at each layer mentioned above for a given SNR and greatly improve the overall performance in minimizing the video distortion.

关键词： IEEE 802.11ad HD video cross-layer optimization source coding modulation and coding retransmission

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Design of encoders and decoders for code/pulse-position-swapping (C/PPS) based on sonar codes

Design of encoders and decoders for code/pulse-position-swap...

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Conference on Free-Space Laser Communication Technologies XXIV

作者： Mendez, Antonio J. Mendez R&D Associates El Segundo CA 90245 USA

ISBN: (纸本)9780819488893

The time slots of M-ary pulse-position-modulation (PPM) can be replaced by M optical CDMA codes: Code/Pulse-Position- Swapping (C/PPS) or Code-Shift-Keying (CSK). Features of C/PPS are that it: (1) retains the intensity-modulation/ direct-detection (IM/DD) and multiple-bits-per-symbol features of PPM;(2) supports multiple access communications;(3) supports bandwidth-on-demand;(4) supports tailoring quality of service;(5) translates the received symbol to its corresponding bit sequence without using look-up-tables (LUTs));(6) and has a common electronic bandwidth for all data rates. In this paper we describe the design of C/PPS encoders and decoders based on the specific example of 4x4 fast frequency hopping (FFH) sonar codes.

关键词： modulation and coding optical communications pulse-position-modulation (PPM) code division multiple access code-shift-keying multiple access communications intensity-modulation/direct-detection (IM/DD) sonar codes

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A Broadband W-Band Polarization Rotator With Very Low Cross Polarization

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IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS 2011年第3期21卷 127-129页

作者： Pisano, Giampaolo Melhuish, Simon Savini, Giorgio Piccirillo, Lucio Maffei, Bruno Univ Manchester Sch Phys & Astron Manchester M13 9PL Lancs England UCL Dept Phys London WC1E 6BT England

We present a 82-100 GHz circular waveguide polarization rotator based on a broadband rotating half-wave retarder. The device was designed for astrophysics experiments aimed to characterize the polarization of the cosmic microwave background radiation. The device is based on a Pancharatnam recipe used in optics [1] and has a very low intrinsic cross polarization, very flat phase response across the band and very low losses. It can be used in astronomical experiments where very high performance is required but also as a variable polarization source for instrument calibrations. The design was manufactured and then tested using a millimeter-wave vector network analyzer. The average measured RL, IL and cross polarization across a 30% bandwidth were, respectively, -38 dB, -0.27 dB, and -36.5 dB.

关键词： modulation and coding waveguide polarizers

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Architecture, design, and numerical simulation of a code/pulse-position- swapping (CPPS) direct translating receiver

Architecture, design, and numerical simulation of a code/pul...

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Conference on Free-Space Laser Communication Technologies XXIII

作者： Mendez, Antonio J. Hernandez, Vincent J. Bennett, Corey V. Gagliardi, Robert M. Mendez R&D Associates MRDA POB 2756 El Segundo CA 90245 USA Lawrence Livermore Natl Lab El Segundo CA 90245 USA Univ Southern California El Segundo CA 90245 USA

ISBN: (纸本)9780819484604

Code/pulse-position-swapping (CPPS) is a communications scheme that substitutes pulse-position-modulation (PPM) symbols with optical-code-division-access (O-CDMA) codes. CPPS retains the multiple bits per symbol communication of M-ary PPM and the asynchronous multiple access of O-CDMA. Additionally, CPPS has the advantages of granular communications, common electrical bandwidth for all users independent of data rates, compatibility with free-space or guided (fiber and waveguide) communication links, and compatibility with intensity modulation/direct detection. The transmitted symbols (codes) of CPPS are translated from a deserialized bit stream that has been divided into words of length log(2)M. Thus the receivers associate the detected symbol with the original bit sequence by means of an electronically implemented look-up-table (LUT). This paper describes the architecture and design of a direct translating receiver based on map-coding, which uses optical processing to output the transmitted bit sequence without the need for a LUT. Analyses and computations characterize the receiver concept in terms of bit errors (mistranslations).

关键词： modulation and coding pulse-position-modulation (PPM) optical-code-division-multiple-access (O-CDMA) 2D O-CDMA codes wavelength/time matrix codes optical communications planar lightwave circuits (PLCs)

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