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Conference of the North American Fuzzy Information Processing Society - NAFIPS

作者： S. Zahan Communications Department Technical University of Cluj Napoca Cluj-Napoca Romania

Within the paper a system that controls the adaptive coding scheme of time varying telecommunications channels is presented. It is implemented by Berenji's neuro-fuzzy network GARIC (Generalized Approximate Reasoning-Based intelligent Control). A major advantage of this approach is that the system does not rely on any specific model of the channel. Another important advantage is that the system is able to adapt itself both to short and long term changes of the channel characteristics. A large part of the paper is devoted to the experimental work. An important conclusion is that, due to its adaptation capability, the system proves a large degree of flexibility and, in the same time, performances comparable or even better than the ones obtained using systems that "know" the model of the channel they are working on.

关键词： Fuzzy neural networks Intelligent networks adaptive coding Communication channels Channel coding Control systems Programmable control adaptive control Fuzzy systems Forward error correction

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adaptive modulation, adaptive coding, and power control for fixed cellular broadband wireless systems: some new insights

Adaptive modulation, adaptive coding, and power control for ...

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IEEE Conference on Wireless Communications and Networking

作者： E. Armanious D.D. Falconer H. Yanikomeroglu Broadband Communications and Wireless Systems Centre Department of Systems and Computer Engineering Carleton University Ottawa Canada

It is well known that link adaptation techniques, when designed to track the channel variations, yield a higher network throughput. In this work, we investigate the throughput returns due to the employment of various combinations of adaptive modulation, adaptive coding, and adaptive power control in a fixed cellular broadband wireless access system incorporating the effects of shadowing, multipath fading, and multiple access interference. The system considered is a multipoint multichannel distribution system (MMDS) with carrier frequency 2.5 GHz. It is observed that among all the possible combinations, the combination of adaptive modulation and adaptive coding (without power control) is the most efficient type since the further employment of adaptive power control only adds a relatively small improvement in the throughput. The frequency of occurrence of different constellation sizes and code rates with the percentages of the successful and failing links, are reported as well in this study.

关键词： Programmable control adaptive control Modulation coding adaptive coding Power control Throughput Employment Frequency Shadow mapping Fading

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A Fast Algorithm for adaptive Prefix coding

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ALGORITHMICA 2009年第1期55卷 29-41页

作者： Karpinski, Marek Nekrich, Yakov Univ Bonn Dept Comp Sci D-5300 Bonn Germany

In this paper we present a new algorithm for adaptive prefix coding. Our algorithm encodes a text S of m symbols in O(m) time, i.e., in O(1) amortized time per symbol. The length of the encoded string is bounded above by (H+1)m + O(n log(2) m) bits where n is the alphabet size and H is the entropy. This is the first algorithm that adaptively encodes a text in O(m) time and achieves an almost optimal bound on the encoding length in the worst case. Besides that, our algorithm does not depend on an explicit code tree traversal.

关键词： Data compression Prefix-free codes adaptive coding

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Neural Network-Based adaptive Polar coding

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IEEE TRANSACTIONS ON COMMUNICATIONS 2024年第4期72卷 1881-1894页

作者： Miloslavskaya, Vera Li, Yonghui Vucetic, Branka Univ Sydney Sch Elect & Comp Engn Sydney NSW 2006 Australia

In this paper, we propose a novel artificial intelligence (AI) based adaptive polar coding scheme that adapts to various channel conditions and quality of service requirements. To ensure tight adaptation, we develop a new AI-based performance prediction framework for the precoded polar codes under the successive cancellation list (SCL) decoder. This AI-based framework relies on a neural network and recent advancements in the analysis of precoded polar codes, SCL and SC decoders. Then we apply the proposed framework to optimise precoded polar codes for various target frame error rates (FER), signal-to-noise ratios (SNR) and decoding list sizes L , where the code length is fixed to a power of two, but the code rate may vary. We predict the throughput and maximise it over the code rates with bit-level granularity. The proposed approach paves the way towards online adaptive polar coding with high error-correction capability. The constructed codes can be compactly specified using the reliability sequence from the 5G New Radio standard and a single parameter whose value is specific to each code. The simulation results show that the proposed codes outperform 5G polar codes with CRC11 under SCL decoding with various L.

关键词： Polar codes dynamic frozen bits adaptive coding performance analysis neural network

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adaptive-rate coding for frequency-hop communications over Rayleigh fading channels

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IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS 1999年第7期17卷 1224-1232页

作者： Pursley, MB Wilkins, CS Clemson Univ Dept Elect & Comp Engn Clemson SC 29634 USA

Because of the variability of the channels in frequency-hop wireless systems and networks, the performance of error-control coding can be improved by adapting the rate of the code to the channel conditions. In this paper, adaptive-rate error-control coding is investigated for slow frequency-hop communications with Reed-Solomon coding. Two methods are investigated that use decoder side information as a means for selecting the code rate. These methods are based on counts of errors and erasures, which are provided by the demodulator and the decoder. The performance of the adaptive-rate coding system is evaluated for channels with Rayleigh fading, partial-band interference, and thermal noise.

关键词： adaptive coding frequency-hop communications spread-spectrum communications

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A Practical Approach to adaptive coding for the Three-Node Relay Channel

A Practical Approach to Adaptive Coding for the Three-Node R...

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IEEE Conference on Wireless Communications and Networking

作者： Zhongwei Si Ragnar Thobaben Mikael Skoglund ACCESS Linnaeus Center School of Electrical Engineering Royal Institute of Technology Stockholm Sweden

In this paper we propose a new adaptive coding scheme for distributed channel coding for the three-node relay channel. In order to make it feasible for application in wireless sensor networks, the distributed code is built from standard components like Turbo and convolutional codes, and adaptation at the relay is obtained by puncturing the input and output of the employed channel code. The proposed code structure includes distributed Turbo codes and distributed serially concatenated codes as special cases. As the results of our optimization show, significant improvements in terms of rate and coverage are obtained. Compared to theoretical limits a decent performance is achieved considering that the focus is on feasibility.

关键词： adaptive coding Relays Turbo codes Concatenated codes Parity check codes Robustness Decoding Wireless sensor networks Convolutional codes Design optimization

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An adaptive coding Technique For PAPR Reduction

An Adaptive Coding Technique For PAPR Reduction

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IEEE GLOBECOM 2007 - IEEE Global Telecommunications Conference

作者： Zafar Q. Taha Xian Liu Department of Systems Engineering University of Arkansas Little Rock Little Rock AR USA

In this work, we present an adaptive technique to reduce high peak-to-average power ratio in coded orthogonal frequency division multiplexing. High peak-to-average power ratio has been a primary hurdle for the use of orthogonal frequency division multiplexing in low cost applications. Our coding approach for reduction of peak-to-average power ratio combines the error correction capability of the channel encoder and achieves peak-to-average power ratio reduction in the OFDM system. Our technique is easily implemented in terms of encoding as well as decoding. We develop analytical analysis of the maximum peak-to-average power ratio reduction achievable by this method. We consider the effect on bit error rate based on general analysis of antipodal signals.

关键词： adaptive coding Peak to average power ratio Decoding Error correction codes WiMAX Digital modulation OFDM modulation Power engineering and energy Systems engineering and theory Costs

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CARE: Corruption-Aware Retransmission with adaptive coding for the Low-Power Wireless

CARE: Corruption-Aware Retransmission with Adaptive Coding f...

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International Conference on Network Protocols

作者： Wei Dong Jie Yu Xiaojin Liu College of Computer Science Zhejiang University

Wireless communications are inherently unreliable, especially for low-power wireless networks like 802.15.4. Packet corruptions typically occur because of interference, fading or noise. In this paper, we investigate the problem of corruption aware retransmission with adaptive coding in commercial-off-the-shelf (COTS) low-power devices. We propose an accurate corruption detection algorithm for identifying the number of corrupted bytes in a packet based on the RSSI time series during packet reception. Based on the corruption level, we design an adaptive coding scheme based on Reed Solomon (RS) codes. We carefully select the coding parameters so as to optimize the network performance. Finally, we design and implement CARE, a Corruption-Aware REtransmission protocol by incorporating corruption detection and adaptive coding. We conduct extensive experiments based on COTS low-power devices. Results show that CARE significantly improves the performance for weak and highly interfered links while incurring no additional overhead for good links.

关键词： Automatic repeat request adaptive coding Redundancy Forward error correction IEEE 802.11 Standard IEEE 802.15 Standard Encoding

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A data link control protocol for wireless ATM networks with adaptive coding rate

A data link control protocol for wireless ATM networks with ...

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IEEE Workshop on High Performance Switching and Routing

作者： K.S. Chan S. Chan K.T. Ko Department of Electronic Engineering City University of Hong Kong Kowloon Hong Kong China

We propose a new data link control protocol for wireless ATM networks. This new protocol can support both real time and non-real-time services by adopting different error control mechanisms. For real-time traffic, only forward error control (FEC) is used for error correction. For non-real-time traffic, a hybrid automatic repeat request (ARQ) scheme is adopted to reduce the cell loss ratio to a minimum level. In both the FEC and hybrid ARQ schemes, the coding rate is adapted to the channel conditions. When the signal-to-noise ratio (SNR) is high, the coding rate may be higher; while when the channel is bad, the coding rate is adjusted to be lower. The automatic coding rate adaptiveness guarantees the high utilization of the scarce wireless channel resources.

关键词： Wireless application protocol adaptive coding Error correction Forward error correction Automatic repeat request Delay Bandwidth Bit rate Radio link Cyclic redundancy check

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A note on adaptive coding scheme based on control quality for wireless feedback control systems

A note on adaptive coding scheme based on control quality fo...

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International Conference on Emerging Technologies and Factory Automation (ETFA)

作者： Shingo Hattori Kentaro Kobayashi Hiraku Okada Masaaki Katayama Graduate School of Engineering Nagoya University Nagoya Japan EcoTopia Science Institute Nagoya University Nagoya Japan

Packet loss is the major weakness of wireless feedback control systems. In this paper, we discuss the improvement of the control quality of wireless feedback control systems with Forward Error Correction (FEC) coding. If FEC coding is used, packet losses may decrease. But its redundancy decreases the packet transmission rate under the same bit rate, so that the control quality will be worse. Therefore, we propose an adaptive coding scheme to improve the control quality. In this scheme, FEC coding is used adaptively based on a predicted state of the controlled plant. Our proposal is the first approach in the field of adaptive channel coding for wireless feedback control systems because this scheme adapts channel coding to the quality of the control layer (application layer). In this paper, we show that the proposed adaptive coding scheme improves the control quality more than that of the fixed rate coding in Rayleigh fading channels.

关键词： Channel coding Wireless communication Feedback control Packet loss adaptive coding

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