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Modeling for parallel scheduling and performance evaluation of MANET using stochastic Petri nets

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Journal of Systems Engineering and Electronics 2004年第4期15卷 553-558页

作者： XuWenchao JiaShilou communicationresearchcenter HarbinInstituteoftechnologyHarbin150001P.R.China

In this paper, Petri nets technique is introduced into mobile ad hoc networks (MANET) and a packet-flow parallel scheduling scheme is presented using Stochastic Petri Nets (SPN). The flowing of tokens is used in graphics mode to characterize dynamical features of sharing a single wireless channel. Through SPN reachability analysis and isomorphic continuous time Markov process equations, some network parameters, such as channel efficiency and, one-hop transmission delay, can be obtained. Compared with Those of The conventional performance evaluation methods, the above parameters are mathematical expressions instead of test results from simulator.

关键词： mobile ad hoc network parallel scheduling performance evaluation stochastic Petri nets

Receiver design of UWB radio systems for an impulsive noise environment

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Journal of Systems Engineering and Electronics 2004年第1期15卷 31-38,45页

作者：贾琳张中兆 communicationresearchcenter HarbinInstituteofTechnologyHarbin150001P.R.China

The performance of UWB (ultrawide bandwidth) radio systems under an impulsive noise environment is first investigated. In the analysis, the Middleton's class A model is used as a model of the impulsive noise. At first, the statistical characteristics of the inphase and quadrature components of the impulsive noise are investigated, and it is proved that unlike Gaussian noise, these components are dependent especially on the impulsive noise with small impulsive indices. The probability that the high amplitude noise is emitted in the inphase component which becomes firstly larger and then smaller for the larger quadrature component of impulsive noise is presented. Next, the performance of conventional UWB radio systems designed for the Gaussian noise under the impulsive noise is evaluated and numerical results show that the performance of the conventional UWB radio systems is much degraded by the effect of the impulsive noise. Using the dependence between the inphase and quadrature components of the impulsive noise, a novel UWB receiver designed for impulsive noise is proposed and the performance improvement achieved by the receiver is evaluated. Numerical results show that the performance of UWB radio systems is much improved by employing the proposed receiver.

关键词： ultrawide bandwidth radio time hopping spreadspectrum impulsive noise impulse radio

Optimal design of basic pulse waveforms for THSS UWB radio systems

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Journal of Systems Engineering and Electronics 2005年第1期16卷 1-10页

作者： JiaLin ZhangZhongzhao communicationresearchcenter HarbinInstituteofTechnologyHarbin150001P.R.China

Ultrawide bandwidth (UWB) radio, a very promising technique carrying information in very short basic pulses, has properties that make it a viable candidate for short-range wireless communications. In this paper, several short-pulse waveforms based on Gaussian genetic monocycle as well as Gaussian pulse waveform, as candidates of basic UWB pulse waveforms, are firstly proposed and investigated. Their spectrum characteristics, bit transmission rate (BTR), and bit error rate (BER) performance in AWGN channel using time hopping spread spectrum (THSS) and pulse position modulation (PPM) are simulated and evaluated. The numerical results are compared and show that the basic pulse waveforms determine the spectrum characteristics of UWB signals and have much effect on the performance of UWB radio system. The performance of UWB radio system achieved by the proposed basic pulse waveforms is much better than that of UWB radio system realized by other used basic pulse waveforms under the uniform conditions. Also, the polarity of these short basic pulses does not affect the performance of UWB radio system.

关键词： ultrawide bandwidth radio impulse radio time hopping spread spectrum pulse position modulation AWGN.

Efficient medium access control protocol for geostationary satellite systems

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Journal of Systems Engineering and Electronics 2004年第4期15卷 684-689页

作者： WangLina GuXuemai communicationresearchcenter HarbinInstituteofTechnologyHarbin150001P.R.China

This paper proposes an efficient medium access control (MAC) protocol based on multifrequency-time division multiple access (MF-TDMA) for geostationary satellite systems deploying multiple spot-beams and onboard processing, which uses a method of random reservation access with movable boundaries to dynamically request the transrnission slots and can transmit different types of traffic. The simulation results have shown that our designed MAC protocol can achieve a high bandwidth utilization, while providing the required quality of service (QoS) for each class of service.

关键词： MB-DRRAA geostationary satellites medium access control protocol multimedia traffic

Self-configuring scheduling scheme for IPv6 traffic with multiple QoS classes

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Journal of Systems Engineering and Electronics 2004年第3期15卷 377-381页

作者：陈宇张乃通 communicationresearchcenter HarbinInstituteofTechnologyHarbin150001P.R.China

This paper proposes a new queuing model and adaptive scheduling scheme which realizes multi-class QoS mechanism under DiffServ architecture. The queuing model is composed of two parallel output subqueues, each output sub-queue adopts random drop algorithm by setting different buffer threshold for different class traffic, so it can provide multi-class QoS. The new proposed scheduling scheme which adaptively changes the parameter A can guarantee the performance target of high class traffic, in the mean time, improve the QoS of low classes traffic.

关键词： multi-class QoS classes DiffServ adaptive scheduling scheme.

Delay performance of the CFDAMA-RPR protocol via satellite

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Journal of Systems Engineering and Electronics 2004年第4期15卷 467-471页

作者： ZhouXi JiaShilou SheYang communicationresearchcenter HarbinInstituteofTechnologyHarbin150001P.R.China ChongqingCommunicationInstitute Chongqing400035P.R.China

The relative performance of the combined free/demand assignment multiple access (CFDAMA) protocol with different terminal request strategies is examined. A new scheme is proposed employing combined round robin/ piggybacking request strategy (CFDAMA-RPR), which is compared with the CFDAMA-RR (employing round robin request strategy) and CFDAMA-PB (employing piggy-backing request strategy). Simulation results demonstrate that compared with CFDAMA-PB and CFDAMA-RR protocol, the CFDAMA-RPR scheme can offer better delay/throughput performance of satellite channel.

关键词： CFDAMA-RPR MAC 延时卫星通信

A distributed adaptive multi-hop certification authority schemefor mobile Ad Hoc networks

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Journal of Systems Engineering and Electronics 2005年第2期16卷 265-272页

作者： TanXuezhi WuShaochuan JiaShilou communicationresearchcenter HarbinInstituteofTechnologyHarbin150001P.R.China

This paper theoretically analyzes a deficiency of the existing scheme, and proposes a distributed multi-hop certification authority scheme for mobile Ad Hoc networks. In our design, we distribute the certification authority functions through a threshold secret sharing mechanism, in which each node holds a secret share and multiple nodes jointly provide complete services. Certification authority is not limited in a local neighborhood but can be completed within multi-hop location. In addition, we replace broadcast by multicast to improve system performance and reduce communication overhead. This paper resolves some technical problems of ubiquitous certification authority services, and presents a wieldy multi-hop certification authority algorithm. Simulation results confirm the availability and effectiveness of our design.

关键词： mobile Ad Hoc networks threshold secret share certification authority.