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Extrinsic Information Transfer Analysis and Design of Block-Based Intermediate Codes

IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2011年第3期60卷 762-770页

作者： Maunder, Robert G. Hanzo, Lajos Univ Southampton Sch Elect & Comp Sci Southampton SO17 1BJ Hants England

Intermediate codes have been shown to facilitate iterative decoding convergence to the maximum-likelihood (ML) error ratio performance in serially concatenated schemes. In this paper, we propose a novel block-based intermediate code as an alternative to classic convolutional intermediate codes. Because it is block-based, our intermediate code facilitates practical implementations with reduced memory and processing requirements. Furthermore, we demonstrate that it is simpler to analyze and optimize the iterative decoding process when our block-based intermediate code is employed, instead of a convolutional intermediate code. Finally, we demonstrate that the proposed block-based intermediate code facilitates significantly reduced error ratios in practical schemes when employing short transmission frames and a limited decoding complexity.

关键词： Block codes combined source channel coding iterative decoding modulation coding mutual information

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Maximum flatness criterion based on extrinsic information transfer charts for symbol mapping design

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IET COMMUNICATIONS 2011年第13期5卷 1889-1894页

作者： To, D. Choi, J. Swansea Univ Coll Engn Swansea W Glam Wales

In bit-interleaved coded modulation with iterative decoding (BICM-ID), the extrinsic information transfer (EXIT) function of the demapper can be parameterised. Using this parameterisation, in conjunction with the EXIT function of the decoder, a symbol mapping design criterion based on the flatness of the gap between the two EXIT functions (called the maximum flatness criterion) is proposed in this study. Simulation results confirm that a good performance can be achieved in terms of convergence rate for fast fading channels and outage probability for slow fading channels.

关键词： extrinsic information transfer charts interleaved codes convergence modulation coding fading channels maximum flatness criterion parameterisation fast fading channels symbol mapping design criterion Codes Radio links and equipment Other topics in statistics iterative decoding outage probability convergence rate error statistics bit-interleaved coded modulation slow fading channels

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Fundamental modulation Limits for Minimum Switching Frequency Inband-Error-Free High-Efficiency Power Amplifiers

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS 2011年第10期58卷 2543-2555页

作者： Garcia i Tormo, Albert Poveda, Alberto Alarcon, Eduard Guinjoan-Gispert, Francesc Tech Univ Catalunya UPC Dept Elect Engn Barcelona 08034 Spain

This paper explores the modulation bandwidth limits for switching amplifiers, by analyzing the fundamental tracking capabilities of two-level switching signals. With this aim, this work synthesizes two-level switching signals by obtaining the distribution of switching events providing both minimum average switching frequency and inband-error-free encoding, targeting to minimize the amplifier switching losses when tracking a generic bandlimited signal. This analysis also provides a framework reference to characterize the deviation from such limit in modulations used in actual amplifiers.

关键词： Encoding modulation modulation coding power amplifiers signal analysis

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Joint adaptive modulation scheme for two-way relay channel

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ELECTRONICS LETTERS 2011年第11期47卷 674-675页

作者： Zhao, Y. Wang, X. Li, S. Beijing Univ Posts & Telecommun Minist Educ Key Lab Universal Wireless Commun Beijing 100088 Peoples R China

A novel joint adaptive modulation scheme for the broadcast phase of a two-way relay channel is presented. Over Rayleigh flat fading channels, by jointly encoding and modulating the messages from both users according to each user's instantaneous channel quality, the relay can greatly improve its bits-per-symbol throughput during the broadcast phase. Also, each user can receive at the data rate decided by its instantaneous channel quality under the target average bit error ratio constraint by interference cancellation using its own information. Computer simulation shows the proposed scheme provides about 3 dB gain over the network coding based adaptive modulation scheme.

关键词： Rayleigh channels Rayleigh flat fading channel adaptive modulation bits-per-symbol throughput broadcast phase computer simulation interference cancellation interference suppression joint adaptive modulation scheme message encoding message modulating modulation coding network coding network coding two-way relay channel wireless channels

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Iterative Decoding between Two-Dimensional Soft Output Viterbi Algorithm and Error Correcting modulation Code for Holographic Data Storage

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JAPANESE JOURNAL OF APPLIED PHYSICS 2011年第9期50卷 09MB02-09MB02页

作者： Kim, Jinyoung Moon, Yong Lee, Jaejin Soongsil Univ Sch Elect Engn Seoul 156743 South Korea

We propose an iterative decoding scheme for holographic data storage that uses modulation codes with a trellis structure to obtain some coding gain. Furthermore, the iterative scheme between a channel detector and the modulation code can achieve more coding gain. In the simulation, when there are (10%, 10%) and (20%, 20%) misalignments, the proposed iterative scheme with a pseudorandom interleaver performs approximately 0.3 and 1 dB better, respectively, compared to the scheme without iteration. (C) 2011 The Japan Society of Applied Physics

关键词： Scheme error correction Data Storage Holography Iterative decoding Viterbi algorithm Codes coding gain modulation coding

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Hybrid symbols for parallel optical/RF channels using BICM-ID

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ELECTRONICS LETTERS 2011年第21期47卷 1189-U49页

作者： Kumar, K. Borah, D. K. New Mexico State Univ Klipsch Sch Elect & Comp Engn Las Cruces NM 88003 USA

Novel hybrid symbols for parallel free space optical and radio frequency links using bit-interleaved coded modulation with iterative detection are proposed. An asymptotic bit error performance analysis for the proposed hybrid symbols is developed. The proposed symbol mapping achieves gains of several dBs over conventional mappings.

关键词： BICM-ID asymptotic bit error performance analysis bit-interleaved coded modulation interleaved codes iterative detection iterative methods modulation coding optical links parallel free space optical links parallel optical-RF channels radio links radiofrequency links symbol mapping

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A cross-layer scheduling scheme for wireless multimedia transmissions with adaptive modulation and coding

A cross-layer scheduling scheme for wireless multimedia tran...

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International Conference on Broadband Networks (BroadNets)

作者： Hui Chen Henry C. B. Chany Victor C. M. Leung Department of Electrical and Computer Engineering The University of British Columbia Vancouver BC Canada Hong Kong Polytechnic University Kowloon HK

It is a big challenge to design an effective scheduling algorithm for multimedia transmissions over a wireless channel that employs adaptive modulation and coding (AMC). On one hand, the scheduling algorithm needs to schedule user transmissions by taking advantages of the channel diversity so that the overall system performance can be improved. On the other hand, the algorithm also needs to maintain fairness among users and to provide QoS guarantee based on user requirements. In this paper, we propose a novel scheduling algorithm called QoS-based cross-layer scheduling algorithm (QoS-CLS) to address the aforementioned issues. To maximize the system throughput, the algorithm takes into consideration both the physical layer and data link layer information to schedule user transmissions. Using the cross-layer information, the scheduling problem is formulated into a Markov decision process (MDP) and the optimum decision policy (based on the channel status, traffic state and buffer status of each traffic flow) is precalculated by linear programming and stored in the system for scheduling in real-time. Results show that QoS-CLS can greatly enhance the channel throughput compared to the opportunistic scheduling algorithm because of its cross-layer QoS consideration and the optimization method. Moreover, it can provide QoS guarantee and facilitate resource sharing among different traffic flows.

关键词： modulation coding Scheduling algorithm Throughput Buffer storage Algorithm design and analysis System performance Physical layer Linear programming Real time systems Optimization methods

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Erlang Capacity of Multi-Class TDMA Systems with Adaptive modulation and coding

Erlang Capacity of Multi-Class TDMA Systems with Adaptive Mo...

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IEEE International Conference on Communications (ICC)

作者： H. Wang V. B. Iversen Department of Communications Optics & Materials Technical University of Denmark Kongens Lyngby Denmark

Erlang capacity is traditionally defined as the maximum value of offered traffic among different service classes that the system can support when the blocking probabilities at the call admission control (CAC) level do not exceed certain thresholds. That is valid when a fixed amount of bandwidth is allocated to each user in each frame during the whole service time. However, with the introduction of adaptive modulation and coding (AMC) scheme employed at the physical layer, outage might occur due to the fact that the allocation of bandwidth is dynamic based on the time-varying wireless channel conditions. In this paper, we evaluate the Erlang capacity of a TDMA system with AMC supporting voice and data traffics, by taking both the blocking and the outage probabilities into account. The analytical models for calculating the blocking and the outage probabilities are developed separately, and a joint algorithm for determining the Erlang capacity of the system is proposed with some numerical examples.

关键词： Time division multiple access Adaptive systems modulation coding Capacity planning Bandwidth Call admission control Physical layer Traffic control Analytical models Probability

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The Capacity Loss of Adaptive modulation and coding Schemes with Channel Feedback Delay

The Capacity Loss of Adaptive Modulation and Coding Schemes ...

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IEEE International Conference on Communications (ICC)

作者： D. Li M. Al-Shalash Wireless Research and Development Department Huawei Technologies Company Limited Plano TX USA

Adaptive modulation and coding is a commonly used technique to improve throughput in wireless system. Due to the delay in channel condition feedbacks, the actual channel condition may change at the time of transmission and results in capacity loss. In this paper, we establish a model to analyze the capacity loss due to channel condition feedback delay. Simulation results show that our approach is more accurate to calculate the capacity loss, compared to traditional K-step Markov approach. The results can be used to design channel update frequency adaptive to channel conditions and diversity reception.

关键词： modulation coding Feedback Channel capacity Probability Delay effects Throughput Bandwidth Communications Society Research and development USA Councils

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Cross-Layer Design Combining Adaptive modulation and coding with ARQ on Frequency Domain Subcarrier of OFDM

Cross-Layer Design Combining Adaptive Modulation and Coding ...

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International Conference on Wireless Communications, Networking and Mobile Computing (WiCom)

作者： Ju-Ling Zeng Bing Xie Wen-An Zhou Jun-De Song Sch. of Electron. Eng. Beijing Univ. of Posts & Telecommun. Beijing

The system model and the algorithm for a cross-layer design combining the adaptive modulation and coding with ARQ based on frequency domain subcarrier of OFDM is developed at first. And then the effect of high speed move to the performance of that is analyzed. In order to compensate the degraded performance of wireless link due to high-speed move, a novel finite-state Markov channel model is formed to represent the frequency domain subcarrier of OFDM modeled as random process with Nakagami-m fading distribution. A correction of the threshold of modulation and coding scheme and the channel quality information as well as the method for link prediction in Chase combining is investigated. On this foundation, an improved cross-layer design combining of adaptive modulation and coding with H-ARQ is proposed. The computer simulation results reveal that the improved design and modified algorithm has higher average throughput and lower FER than the original one when the terminal moves in high speed.

关键词： Cross layer design modulation coding OFDM modulation Automatic repeat request Frequency domain analysis Performance analysis Degradation Random processes Nakagami distribution Fading

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