最新刊期
卷 38 ， 期 1 ， 2010
- 摘要：Currently, P2P-based applications, prevailing over internet, become one of the greatest internet network-bandwidth consumers. So, It's indispensable to reduce the network bandwidth consume of P2P application, especially of P2P media streaming. This paper proposes a fast-inferring method based on network tomography in order to limit the traffic in smaller network, to decrease network-cross traffic and backbone network-bandwidth consume internally, and to suppress the congestions. The simulation shows that such technique can adapt the high dynamics of P2P media streaming system, and effectively slow down the network-cross traffic and backbone network-bandwidth consume.关键词：P2P;media streaming system;network tomography;topology inference2|3033|4更新时间：2025-07-16
- 摘要：Three kinds of methods for constructing perfect quaternary array pairs are presented.They are the methods of constructing directly quaternary array pairs with the eriodic complementary binary array pairs,the interleaving recursive construction with perfect quaternary array pairs and quasiperfect array pairs and the recursive construction with almost perfect quaternary array pairs and perfect quaternary array pairs.
关键词：Signal design;array;array pairs;perfect quaternary array pairs2|1626|2更新时间：2025-07-16 - 摘要：Wireless sensor and actor networks (WSANs) are composed of a large number of sen sors and a small number of (mobile) resource-rich actors. Sensors gather informa tion about the physical phenomenon, while actors take decisions and then perform appropriate actions upon the environment. The paper analyzes the model of energy consumption, and solves the optimal number of hops when the total energy consumpt ion in a path is minimal under the ideal condition. After that, a hop-adaptive ro uting algorithm (HAR) is proposed to realize the balance between the real-time requirement of data collection and the total energy consumption of the network. The extensive simulations show that, HAR algorithm is advantage to HBMECT algorith m with the balance of real-time and energy-consuming, and it adapts to the case of mobile actor.
关键词：wireless sensor and actor networks;real-time;energy-efficient;routing2|1733|0更新时间：2025-07-16 - 摘要：Since the resources of mobile devices are scarcer and the network is dynamic,coo peration among mobile nodes is an important task.A novel flexible resource sharing and cooperating scheme among mobile nodes is proposed in the paper.A prediction algorithm of resources based on reliability theory for resources' requestor is also presented.According to the queue theory,a multilevel model of resource dispatching is put forward for resources' provider.While analysis and simulation results show that the prediction algorithm can increase success ratio of sharing resources’ cooperation task,the resources dispatching model can significantly improve the service quality,and reduce the loss rate of resource requests.
关键词：mobile P2P networks;queue model;cooperative sharing;reliability function2|2207|6更新时间：2025-07-16 - 摘要：In this paper,we exploit the fact that users contending for the wireless medium will have different transmission cost,and present a fairly scheduling scheme FSN C.FSNC adopts NC-aware scheduling while maintaining statistical short and long term fairness.FSNC makes scheduling policy based on the ARQ feedback message fro m users.Theoretic analysis and simulation results prove that FSNC can provide se rvice time fairness while improving the expected good for each user in multiuser diversity system.关键词：network coding;wireless Mesh network;fairly scheduling2|1649|0更新时间：2025-07-16
- 摘要：With regard to the problem of great data loss rate in the multicast application in wireless mesh network,it is specially valuable to use the way of M2U(Multicast to Unicast) in which packet’s MAC destination domain is modified in order that packet can be delivered to certain members of multicast group by unicast.With the increase of multicast group member,data loss rate is rising.In order to ensure the network performance not to be affected,M2UO(Multicast to Unicast Opportunistic Routing) scheme can be put forward,in which packet can be delivered to candidate nodes by unicast and to other nodes by multicast.A great many experiments in the real network indicate that the new scheme can decrease the packet lost ratio,can increase throughput and has a better video effect.关键词：wireless communication;opportunistic routing;wireless mesh network;optimize multicast2|2243|1更新时间：2025-07-16
- 摘要：Antibodies are diversified basically by hypermutation in the clonal selection a lgorithm (CSA) proposed by de Castro.However,there is another important mechanis m,namely,receptor editing in immune system.Inspired by the mechanism,an improved clonal selection algorithm with receptor editing is proposed,which adopted the good gene segment in the immaturity subpopulation to realize two receptor editi ng based on the principle of minimum cost and delay constrain.Thus,search for op timum solution can be achieved promptly by direct application of the improved a lgorithm without prepared routing set.The results of simulation tests of multica st routing with delay constrain indicated higher searching efficiency and lower computational complexity compared with the usual CSA and GA.关键词：receptor editing;the improved clonal selection algorithm;multicast routing;delay constrain2|1475|1更新时间：2025-07-16
- 摘要：The paper proposes an OWL-S based semantic web service matchmaking system mecha nism,which imports semantic elements into UDDI,and preserves semantic information in UDDI storage.The system employs a semantic service matchmaking algorithm to improve precision and recall of service matching,and uses a data mapping mechan ism to ensure the compatibility with present web service discovery standards,UDDI,and the transparency of UDDI APIs.The paper designs an ontology concept indexi ng mechanism for the system to improve the efficiency of service discovery.Moreover,in the processes of building and maintaining the indices,or alternatively,matching services,the system uses a similar concept searching algorithm to further enhance the efficiency of ontology concept searching and service matchmaking.关键词：web service discovery;web Ontology language for services (OWL-S);universal desc ription;discovery and integration (UDDI);semantic matchmaking system;data mapping mechanism2|1928|13更新时间：2025-07-16
- 摘要：The topology control strategies of wireless sensor network are very important to reduce the energy consumptions of sensor nodes and prolong the life-span of networks. SMECN is a known topology control algorithm for wireless sensor networks. Based on analyzing the shortcoming of SMECN, this paper propose a new topology control algorithm, which is named Improvement of Minimum-Energy Communication Network (IMECN). IMECN subtly transforms the regional coverage problem into the angle superimposition problem. In IMECN, we can know whether the wireless transmission region covers this direct transmission region through comparing the sum of central angles to 2π. Finally, we analyze the computational complexity of the IMECN and simulate the energy property of IMECN.关键词：Wireless sensor networks;topology control;minimum energy property;direct-transmission region2|1700|11更新时间：2025-07-16
- 摘要：In wireless sensor networks，most of the queries submitted by users are spatio-temporal queries such as “gathering the data in region A during a specified period of time”.Since the sensor nodes have very limited power supply,energy-efficient spatio-temporal query processing is an urgent problem to be resolved at present.In this paper,we point out that the existing algorithms have high energy consuming due to unreasonable query coordinator node.Then,we derive the theoretical optimal location of the query coordinator node and propose a class of energy-efficient spatio-temporal query processing algorithms called ECSTA based on the theory.Finally,the influence of node density and query region size on energy consumption is studied experimentally.Theoretical and experimental results show that our algorithms outperform the existing algorithms in the STWin framework.关键词：Wireless sensor networks;query processing;spatio-temporal query;query coordinator node2|2025|7更新时间：2025-07-16
- 摘要：In this paper,we study the power allocation problem in decode-and-forward coop erative diversity systems.We first present the mathematical model of the power allocation problem,which can minimize the total power consumption of the source and partner under the average bit error rate (BER) constraints at the partner an d the destination.Accordingly,the model not only can exploit the inherent spati al diversity in multiuser wireless systems,but also can reduce both the energy c onsumption of mobile nodes and the cochannel interference in wireless networks. We then derive the BER expressions at the partner and the destination which can characterize the performance of cooperative diversity systems over multipath fad ing channels.According to the expressions,we propose a distributed power alloca tion algorithm by which the source,the partner and the destination can compute t he optimal power allocation scheme (OPAS) on a message-by-message basis.The p roposed algorithm not only has little overhead but also adapts to the changes of channel state.Therefore,the algorithm can conform to the decentralized and dyna mic nature of wireless networks.In addition,we present simulations to confirm th e proposed algorithm.关键词：cooperative diversity;bit error rate;power allocation;distributed algorithm2|1723|2更新时间：2025-07-16
- 摘要：This paper considers antenna selection in the amplify-and-forward multiple-input multiple-output (MIMO) relay systems to maximize the capacity.Since the optimal antenna selection algorithm is of high complexity,a fast antenna selection algorithm is proposed.Through theoretical analysis and simulation,it is shown that if the source and destination have M and N antennas respectively,the relay only needs to use min(M,N) out of K antennas to achieve near optimal performance.The antenna selection criterion of the proposed algorithm is to maximize a lower bound of the capacity.This criterion reduces algorithmic complexity.This paper shows the derivation of the algorithm in detail,and analyze its complexity.Simulation results show that the proposed algorithm achieves comparable performance to the optimal algorithm,and has decreased complexity.关键词：wireless communication;wireless relaying;multiple-input multiple-output;antenna selection;amplify-and-forward;fast algorithm2|1858|3更新时间：2025-07-16
- 摘要：This paper addresses the problem of multiple-input multiple-output (MIMO) frequency selective channel estimation using implicit training without dc-offset (direct current). In order to remove the dc-offset directly without in troducing extra complexity, the ZCZ (Zero correlation zone) set with balance properties can be used as training sequences. Since the transmitted data from each antenna is first preprocessed and then arithmetically added onto the training s equences, thus the influence of the unknown data to the channel estimation existed in normal implicit method can be cancelled. In this paper, error variance of channel estimation vector is derived, and time-domain analysis is performed. Our theoretical analysis and simulation results validate the superiority of the new method compared with the conventional implicit estimation method.关键词：Multiple-Input Multiple-Output (MIMO);multi-path channels;zero correlation zone (ZCZ);implicit training2|1644|1更新时间：2025-07-16
- 摘要：The relay selection plays a very important role in cooperative communication systems. In many practical scenarios not all nodes between the source and the destination which can decode information from the source take part in relay, here we propose a cooperative diversity method which randomly selects a node from a set of available relays to forward information towards the destination and then analyze the outage probability of this method. Theoretical analysis and simulation results demonstrate that the upper bound of this outage probability almost does not vary to the number of potential relay nodes, but the bottom bound of this outage probability becomes much smaller as the number of potential relay nodes increases.关键词：cooperative diversity;outage probability;transmit diversity;fading channel;relay channel2|1391|0更新时间：2025-07-16
- 摘要：CDMA2000 1xEV-DO is one high data rate system based on 3G, in which access terminals have the abilities to quickly transmitdata from one rate to another and to sup port high burst rates. So the rise-over-thermal control algorithm in reverse link should be used to ensure the stability of reverse link. It is difficult for existing reverse load control algorithm to balance reverse link throughput and rise-over-thermal control in the CDMA systems. This paper designed incremental PID reverse link load control algorithm, which turned the related parameters based on fuzzy models. This algorithm can not only decrease calculation time but also realize the balance between reverse link throughput and rise-over-thermal control.3|1361|0更新时间：2025-07-16
- 摘要：Aiming at the characteristics of large multipath delay and fast channel variation in wideband ground-air communications with low elevation, a networking scheme of star-shape topology based on a novel multi-access mode is proposed. Its inbound link is an asynchronous CDMA mode based on Golay complementary sequences, while its outbound link uses code division multiplexing based on Walsh sequences M-ary spectrum spreading. The inbound link has very strong ability of anti-multi-access-interference, and the both links have very strong ability of anti-multi-path-fading since they employ filter-banks for frequency equalization(FB-F DE) in their receiving terminals, moreover they have the characteristics of high frequency efficiency and low complexity in implementation. The multi-access mode and networking scheme is quite suitable for the channel condition of wideband ground-air communication system with low elevation. The main performance of the system has verified by simulation experiments, and the results show that it is promising in practical applications.关键词：filter banks;frequency domain equalization;wideband ground-air communication;orthogonal code division multiplexing;CDMA (code-division multiple access)2|2115|1更新时间：2025-07-16
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- Technical support is provided by Beijing Founder electronics co., LTD 京ICP备09064830号-19
京公网安备11010802024621 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
0