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A multiaccess tree algorithm with free access, interference cancellation and single signal memory requirements

PERFORMANCE EVALUATION 2007年第9-12期64卷 1041-1052页

作者： Peeters, G. T. Van Houdt, B. Blondia, C. Univ Antwerp Dept Math & Comp Sci Performance Anal Telecommun Syst Res Grp IBBT B-2020 Antwerp Belgium

tree algorithms are a well studied class of collision resolution algorithms for solving multiple access control problems. Successive interference cancellation, which allows one to recover additional information from otherwise lost collision signals, has recently been combined with tree algorithms with blocked access [Y. Yu, G.B. Giannakis, SICTA: A 0.693 contention tree algorithm using successive interference cancellation, in: INFOCOM 2005. 24th Annual Joint Conference of the IEEE Computer and Communications Societies, Miami, USA, 2005, pp. 1908-1916], providing a substantially higher maximum stable throughput (MST): 0.693 for Poisson arrivals, given an infinite number of memory locations for storing signals. We propose a novel tree algorithm for a similar problem, but with two relaxed model assumptions: free access is supported and a single signal memory location suffices. A study of the maximal stable throughput of this algorithm is provided using matrix analytical methods;as a result, an MST of 0.5698 for Poisson arrivals is achieved. Our methodology also allows us to investigate the MST when the multiple access channel is subject to Markovian arrival processes. (c) 2007 Published by Elsevier B.V.

关键词： multiple access tree algorithm successive interference cancellation

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A robust high-throughput tree algorithm using successive interference cancellation

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IEEE TRANSACTIONS ON COMMUNICATIONS 2007年第12期55卷 2253-2256页

作者： Wang, Xin Yu, Yingqun Giannakis, Georgios B. Florida Atlantic Univ Dept Elect Engn Boca Raton FL 33431 USA Qualcomm Inc San Diego CA 92108 USA Univ Minnesota Dept Elect & Comp Engn Minneapolis MN 55455 USA

A novel random access protocol combining a tree algorithm (TA) with successive interference cancellation (SIC) has been introduced recently. To mitigate the deadlock problem of SICTA arising in error-prone wireless networks, we put forth a SICTA with first success (SICTA/FS) protocol, which is capable of high throughput while requiring limited-sensing and gaining robustness to errors relative to SICTA.

关键词： random access successive interference cancellation (SIC) tree algorithm

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Using a tree algorithm to determine the average synchronisation delay of self-synchronising T-codes

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IEE PROCEEDINGS-COMPUTERS AND DIGITAL TECHNIQUES 2002年第3期149卷 79-81页

作者： Fong, ACM Higgie, GR Massey Univ Inst Informat & Math Sci Albany New Zealand Univ Auckland Dept Elect & Elect Engn Auckland 1 New Zealand

First proposed in 1984, T-codes are a class of variable-length codes that exhibit exceptional tendency towards self-synchronisation. A number of industrial applications have been reported, ranging from moving-picture images to boundary markers. A number of attempts have been made to quantify the synchronisation performance of different T-codes. The first complete analytical method for calculating average synchronisation delays of T-codes was published in 1996 and refined in 1998. However, the computational efficiency of that algorithm is not optimal. notably when suffix conditions are encountered during the decoding process. The authors present a significant improvement on that algorithm. With the new method, computational efficiency is improved by reducing the average time required per code set, It produces average synchronisation delay values in less than one quarter of the time required by the original method to generate comparable results. Consequently, higher-degree code sets, which have wide-ranging practical applications. can have their sync performance analysed and compared.

关键词： decoding process average synchronisation delay variable length codes suffix conditions self-synchronising T-codes higher-degree code sets encoding Codes moving-picture images synchronisation variable-length codes Cryptography theory boundary markers computational efficiency tree algorithm decoding

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CALCULATION OF THE SEISMIC 1ST-BREAK TIME FIELD AND ITS RAY PATH DISTRIBUTION USING A MINIMUM TRAVEL-TIME tree algorithm

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GEOPHYSICAL JOURNAL INTERNATIONAL 1993年第3期114卷 593-600页

作者： CAO, SH GREENHALGH, S School of Earth Sciences Flinders University of South Australia GPO Box 2100 Adelaide S.A. 5001 Australia

A grid search method, analogous to Huygens' Principle, is employed to find the first-break seismic traveltime field in a seismic model. By defining a set of directions in space, a dynamic directed graph (digraph) containing the first-break time information can be constructed during the minimum traveltime tree-searching process. The dynamic di-graph has far fewer edges than the global graph suggested by previous researchers. An efficient sorting algorithm (heapsort) is adapted to the traveltime data structure by employing an indirect heap strategy. The computational speed can thus be improved several times over other approaches. The minimum traveltime tree algorithm is an efficient and flexible method to simultaneously calculate the first-break time field and the corresponding ray paths. It produces a robust and global result in comparison with traditional ray tracing methods. Later seismic phases can also be handled by imposing constraints on the ray paths. A subgrid technique is better than the normal grid technique in terms of accuracy and efficiency. The construction of the di-graph uses the local directional information of ray-paths and therefore local anisotropic information can be naturely incorporated. The first-break time field and its ray paths in an anisotropic model can be calculated as easily as those for an isotropic model.

关键词： MINIMUM TRAVEL-TIME RAYS SEISMIC MODEL tree algorithm

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A Fast tree algorithm for Electric Field Calculation in Electrical Discharge Simulations

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IEEE TRANSACTIONS ON MAGNETICS 2018年第3期54卷 1-4页

作者： Zhuang, Chijie Zhang, Yong Zhou, Xin Zeng, Rong He, Jinliang Liu, Lei Tsinghua Univ Dept Elect Engn Beijing 100084 Peoples R China NYU Courant Inst Math Sci New York NY 10011 USA China Southern Grid Elect Power Res Inst Guangzhou 510663 Guangdong Peoples R China

The simulation of electrical discharges has been attracting a great deal of attention. In such simulations, the electric field computation dominates the computational time. In this paper, we propose a fast tree algorithm that helps to reduce the time complexity from O(N-2) (from using direct summation) to O(N log N). The implementation details are discussed and the time complexity is analyzed. A rigorous error estimation shows the error of the tree algorithm decays exponentially with the number of truncation terms and can be controlled adaptively. Numerical examples are presented to validate the accuracy and efficiency of the algorithm.

关键词： Disc model electric field electrical discharge error estimation tree algorithm

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A Practical tree algorithm with Successive Interference Cancellation for Delay Reduction in IEEE 802.16 Networks

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18th International Conference on Analytical and Stochastic Modelling and Applications (ASMTA)

作者： Andreev, Sergey Pustovalov, Eugeny Turlikov, Andrey Tampere Univ Technol FIN-33101 Tampere Finland SUAI St Petersburg Russia

ISBN: (纸本)9783642217135

This paper thoroughly studies a modification of tree algorithm with successive interference cancellation. In particular, we focus on the algorithm throughput and account for a single signal memory location, as well as cancellation errors of three types. The resulting scheme is robust to imperfect interference cancellation and is tailored to the up-link bandwidth request collision resolution in an IEEE 802.16 cellular network. The mean packet delay is shown to be considerably reduced when using the proposed approach.

关键词： tree algorithm successive interference cancellation throughput mean packet delay

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Enhancing the Performance of tree algorithm using Re-split Mechanism 12

Enhancing the Performance of Tree Algorithm using Re-split M...

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IEEE 12th International Symposium on Autonomous Decentralized Systems (ISADS)

作者： Srichavengsup, Warakorn Thai Nichi Inst Technol Dept Comp Engn Fac Engn Bangkok Thailand

ISBN: (纸本)9781479982615

In shared wireless communication channel, the collision occurs when multiple users transmit the packet simultaneously. tree algorithm has been proposed to resolve the collision. However, tree algorithm may suffer from high delay when the number of users gets large due to the collisions cause by too many users attempting to access the limited slots. To enhance the system delay of the tree algorithm, in this paper we introduce a Re-split mechanism that can be utilized in conjunction with the tree algorithm. As can be seen from the results that under heavy loads, the proposed mechanism offers better performance compared to the existing tree algorithm in terms of average delay, which signifies that the Re-split mechanism can be used to enhance the efficiency of the tree algorithm.

关键词： tree algorithm Re-Split Delay performance

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On the performance of the free-access tree algorithm with MPR, SIC, and single-slot memory

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AD HOC NETWORKS 2024年 156卷

作者： Stefanovic, Cedomir Beko, Marko Vukobratovic, Dejan Aalborg Univ Dept Elect Syst Frederikskaj 12 DK-2450 Copenhagen Denmark Univ Lisbon Inst Telecomunicacoes Inst Super Tecn P-1049 Lisbon Portugal Univ Lusofona COPELABS P-1749 Lisbon Portugal Univ Novi Sad Trg Dositeja Obradov Novi Sad 21000 Serbia

In this paper, we investigate performance of a random access scheme that exploits binary-tree algorithm (BTA) with the free access. We assume a scenario where the receiver is capable to perform both multi-packet reception (MPR) and successive interference cancellation (SIC), where for the purpose of the latter only the last received and undecoded signal can be stored. We distinguish between two variants of the algorithm, where in the first the SIC can be triggered by a decoding event but also executed blindly among yet undecoded slots, while in the second the receiver can only execute the SIC after the decoding event. We analytically derive the maximum stable throughput (MST) of the scheme assuming Poisson arrivals. The evaluation shows that the scheme is able of achieving a favorable performance in comparison to the scenarios when only either MPR or SIC with single-slot memory is used, making it a suitable candidate for an access solution in applications that are characterized with a massive number of users and sporadic traffic arrivals. We also compare the performance of the scheme with the best performing BTA scheme that also exploits K-MPR and SIC and does not have memory limitations, showing that the relative difference in the MST's of the two schemes diminishes with K.

关键词： Random access tree algorithm Maximum stable throughput Successive interference cancellation Multi-packet reception

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Improvement of ZigBee Cluster-tree routing algorithm based on energy saving 5

Improvement of ZigBee Cluster-Tree routing algorithm based o...

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Fifth International Conference on Instrumentation & Measurement, Computer, Communication, and Control (IMCCC)

作者： Fan Jian-Ying Wang Xiao-Dong Wang Yang Fu Yao Harbin Univ Sci & Technol Higher Educ Key Lab Measuring & Control Technol & Inst Measurement Control Technol & Commun Engn Harbin Peoples R China

ISBN: (纸本)9781467377232

In order to realize the energy balance of ZigBee, prolonging the survival time of the network, avoiding the paralysis of the network, this paper improves the tree algorithm. This paper firstly introduces ZigBee and the results of some routing algorithms, and then analyzing and comparing the original tree algorithm and AODVjr algorithm, finding out the inadequacies. The original tree algorithm is improved by routing table, eliminating invalid neighbor nodes and balancing energy. Experiment results of simulation show that: Sending 1000 packets, the improved algorithm is 750 hops less than the original algorithm, and high load nodes 5 less than the original. Therefore, the improved algorithm is effective, it saves the number of hops, that is to save energy.

关键词： ZigBee energy balance tree algorithm neighbor node

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Design and analysis of cross-layer tree algorithms for wireless random access

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2008年第3期7卷 909-919页

作者： Wang, Xin Yu, Yingqun Giannakis, Georgios B. Florida Atlantic Univ Dept Elect Engn Boca Raton FL 33431 USA Qualcomm Inc San Diego CA USA Univ Minnesota Dept Elect & Comp Engn Minneapolis MN 55455 USA

In this paper, we develop a random access scheme which combines the widely used binary exponential backoff (BEB) algorithm with a cross-layer tree algorithm (TA) that relies on successive interference cancellation (SIC) with first success (FS). BEB and SICTA/FS complement each other nicely in enabling the novel protocol to attain a maximum stable throughput (MST) as high as 0.6 without packet loss. Although BEB-SICTA/FS avoids the deadlock problem caused by the error propagation commonly present in successive interference cancellation (SIC) algorithms, it may still suffer from deadlock effects induced by the "level skipping" caused by harsh wireless fading effects. We further develop a novel BEB-SICTAXI protocol, which is a modified version of BEB-SICTA/FS. Analysis and simulations demonstrate that this simple modification leads to high-throughput random access while completely avoiding deadlock problems.

关键词： random access successive interference cancellation tree algorithm binary exponential backoff

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