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改进了蓝牙在通用频段的干扰问题,利用蓝牙系统跳频序列算法的改进实现了误码率的明显降低,笔者主要做了以下工作:在分析了蓝牙系统跳频序列算法的基础上进行了算法改进;采用了自适应的处理方法;设计了改进方案算法内核。算法的系统仿真及性能分析中得到:系统可以实现序列遍历于整个跳频频点范围内;变频干扰下,旧系统的误码率最高达到了0.006501,传输精度极差;新算法系统的抗变频干扰性能要远远强于原系统,可以抵抗大多数的干扰,平均误码率只有0.002900;与原系统相比,变频干扰下其误码率有了约55.4%的下降幅度,随机频率干扰下的误码率也降低了50%以上。这一研究在保持了跳频序列的较强功能的基础上显著的降低了误码率,具有较强的实用及理论价值。 相似文献
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蓝牙技术作为一种近距离无线连接的全球开放规范,已经得到了全球众多大企业的支持。本文对蓝牙无线通信的技术及系统组成进行了详细的论述,并对其应用及未来的发展前景作了讨论。 相似文献
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为了进一步改进蓝牙在通用频段的干扰问题,利用蓝牙系统跳频序列的改进算法实现了误码率的明显降低。通过算法的系统仿真及性能分析得到:新算法系统的抗变频干扰性能要远远强于原系统,可以抵抗大多数的干扰,平均误码率只有0.002 900;与原系统相比,变频干扰下其误码率有了约55.4%的下降幅度,随机频率干扰下的误码率也降低了50%以上。 相似文献
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在近距离的无线应用中,相互间的干扰是不同设备共存时值得考虑的问题。通过一些实验性数据简明地阐述了问题产生的根源及可能的解决途径。 相似文献
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建立了蓝牙微微网相互之间干扰的数学模型,根据此模型推导了蓝牙数据分组重传概率与微微网个数之间的关系表达式;编程实现了对跳频算法的模拟,得到了碰撞概率与微微网个数的关系曲线.最后得到的实测结果与仿真结果吻合很好. 相似文献
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Bluetooth is a cable replacement technology for Wireless Personal Area Networks. It is designed to support a wide variety of applications such as voice, streamed audio and video, web browsing, printing, and file sharing, each imposing a number of quality of service constraints including packet loss, latency, delay variation, and throughput. In addition to QOS support, another challenge for Bluetooth stems from having to share the 2.4 GHz ISM band with other wireless devices such as IEEE 802.11. The main goal of this paper is to investigate the use of a dynamic scheduling algorithm that guarantees QoS while reducing the impact of interference. We propose a mapping between some common QoS parameters such as latency and bit rate and the parameters used in the algorithm. We study the algorithm's performance and obtain simulation results for selected scenarios and configurations of interest. 相似文献
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De Morais Cordeiro C. Agrawal D.P. Sadok D.H. 《Wireless Communications, IEEE Transactions on》2003,2(6):1240-1246
The emergence of Bluetooth as a default radio interface has allowed handheld electronic devices to be instantly interconnected as ad hoc networks. These short-range ad hoc wireless networks, called piconets, operate in the unlicensed 2.4-GHz ISM (Industrial-Scientific-Medical) band where devices may be used to configure single or overlapping piconets, known as scatternet. As all piconets operate in the same frequency band, the presence of multiple piconets in the vicinity may create interference on signal reception. This paper employs a signal capture model to study the piconet MAC performance, taking inter-piconet interference into consideration. This model leads to several important mathematical relationships for Bluetooth networks, including successful packet transmission probability. Furthermore, our model and anticipated throughput are validated using extensive simulation. These results indicate that Bluetooth throughput is affected by multiple piconet interference. Definitely, our model can be considered to provide a solid foundation for future interference aware Bluetooth protocols. 相似文献
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主要针对蓝牙设备在IEEE802.11无线局域网环境下所受干扰的问题,提出了两种提高蓝牙系统性能的方案。 相似文献
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无线局域网在蓝牙干扰下的性能分析 总被引:2,自引:0,他引:2
IEEE802.11b是目前最主要的无线局域网组网方式,与蓝牙技术分享同一频段。通过建立两者的数据帧相互干扰的概率模型,从物理层与网络层两方面定量地分析了蓝牙设备对无线局域网整体性能的影响,为实际中无线局域网的建立提供了参考。 相似文献
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Interference Evaluation of Bluetooth and IEEE 802.11b Systems 总被引:1,自引:0,他引:1
The emergence of several radio technologies, such as Bluetooth and IEEE 802.11, operating in the 2.4 GHz unlicensed ISM frequency band, may lead to signal interference and result in significant performance degradation when devices are colocated in the same environment. The main goal of this paper is to evaluate the effect of mutual interference on the performance of Bluetooth and IEEE 802.11b systems. We develop a simulation framework for modeling interference based on detailed MAC and PHY models. First, we use a simple simulation scenario to highlight the effects of parameters, such as transmission power, offered load, and traffic type. We then turn to more complex scenarios involving multiple Bluetooth piconets and WLAN devices. 相似文献
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Energy-Efficient Operation through Interference Avoidance for Interconnected Bluetooth WPANs 总被引:2,自引:0,他引:2
Petar Popovski Hiroyuki Yomo Liljana Gavrilovska Sergio Guarracino Ramjee Prasad 《Wireless Personal Communications》2005,34(1-2):163-187
A Wireless Personal Area Network (WPAN) provides wireless networking among proximate devices, usually carried by an individual.
Bluetooth is a first instance of the WPAN technology. The basic networking entity in Bluetooth is a piconet. Several piconets
(WPANs) can be interconnected into a scatternet, which can be considered as an extendable multi-hop ad hoc networking structure.
Since Bluetooth operates in the unlicensed ISM band, each piconet uses pseudorandom frequency hopping. If collocated piconets
use the same channel simultaneously, the piconets interfere with each other and the transmitted packets are lost in collisions.
This interference is termed self-interference. The piconets that are networked into scatternet exhibit spatial overlapping
and naturally produce multi-piconet self-interference. The collisions cause retransmissions and increase the energy spent
per data portion, which results in energy-inefficient operation. To tackle this problem, in our previous work we have proposed
a self-interference avoidance (SIA) mechanism. However, this basic SIA mechanism is oblivious with respect to the physical
topology and does not account for the mitigation of self-interference due to the propagation effects. Furthermore, the basic
SIA mechanism relies on the assumption that all piconets are using packets of identical and fixed length. In this paper we
will generalize the SIA mechanism to overcome the stated restrictions. We propose the adaptive SIA (A-SIA) algorithm, which adapts the SIA algorithm to the actual interference. The simulation results show that A-SIA largely retains
the energy gain offered by the SIA algorithm, while significantly improving the goodput. We also design an instance of the
SIA mechanism that operates with variable-length packets, referred as generalized SIA (G-SIA) algorithm. Our simulation results show that the G-SIA algorithm offers good performance in terms of goodput and energy efficiency,
but the goodput is degraded if inappropriate segmentation/reassembly policy is used.
Petar Popovski received the Dipl.-Ing. in electrical engineering and M.Sc. in communication engineering from the Faculty of Electrical Engineering,
Sts. Cyril and Methodius University, Skopje, Macedonia, in 1997 and 2000, respectively and a Ph.D. degree from Aalborg University,
Denmark, in 2004. He is currently Assistant Research Professor at the Department of Communication Technology at the Aalborg
University. His research interests are focused on wireless ad hoc networks, wireless sensor networks, and high-speed wireless
multi-carrier communications.
Hiroyuki Yomo received B.S. degree in communication engineering from Department of Communication Engineering, Osaka University, Osaka,
Japan, in 1997, and M.S. and Ph.D. degrees in communication engineering from Department of Electronic, Information, and Energy
Engineering, Graduate School of Engineering, Osaka University, Osaka Japan, in 1999 and 2002, respectively. From April 2002
to March 2004, he was a Post-doctoral Fellow in Department of Communication Technology, Aalborg University, Denmark. From
April 2004 to September 2004, he was working at NEC Corporation, Japan. Since October 2004, he has been an Assistant Research
Professor in Center for TeleInfrastructure (CTIF), Aalborg University, Denmark. His research interests include medium access
protocols, link-layer techniques, routing protocols, and their interactions in wireless networks.
Liljana Gavrilovska received her B.Sc., M.Sc. and Ph.D. from University of Skopje (76), University of Belgrade (85) and University of Skopje
(95) respectively. She joined the Faculty of Electrical Engineering, University of Skopje, Republic of Macedonia, where she
currently holds positions of Professor at the Institute for Telecommunications, chief of Telecommunications Laboratory and
head of CWMC (Center for Wireless and Mobile Communications), working in the area of networking and mobile communications.
During 2001–2002 she joined the Centre for PersonKommunikation, Aalborg University, Denmark, where she was holding a position
as Associate Research Professor and was involved in several EU (ASAP, PACWOMAN, MAGNET) and national/international projects.
She is still working part-time for CTiF, Aalborg University, Denmark. Her major research is concentrated on ad hoc networking,
wireless and personal area networks, cross layer optimizations, future mobile systems, traffic analysis and admission techniques.
She is a senior member of IEEE and serves as a Chair of the Macedonian Communications Chapter.
Ramjee Prasad is a distinguished educator and researcher in the field of wireless information and multimedia communications. During February
1988–May 1999 he has been with the Telecommunications and Traffic-Control Systems Group of Delft University of Technology
(DUT), The Netherlands, where he was actively involved in the area of wireless personal and multimedia communications (WPMC).
He was head of the Transmission Research Section of International research Centre for Telecommunications Transmission and
Radar (IRCTR) and also Founding Program Director of the Centre for Wireless Personal Communications (CWPC). As from June 1999
Ramjee Prasad joined as the Wireless Information Multimedia Communications chair and co-director of Centre for PersonKommunikation
at Aalborg University, Denmark. From January 2004 he is Founding Director of the “Centre for Teleinfrastruktur (CTIF)”. He
has published over 500 technical papers, and authored and co-edited 15 books about Wireless Multimedia Communications (Artech
House). His research interest lies in wireless networks, packet communications, multiple access protocols, adaptive equalisers,
spread-spectrum CDMA systems and multimedia communications. Prof. Prasad is the founding chairperson of the European centre
of Excellence in Telecommunications known as HERMES Partnership. He is the General Chairman of International Wireless Summit
(IWS 2005) to be held in Aalborg, Denmark in September 17–22, 2005. He is a fellow of the IEE, a fellow of IETE, a senior
member of IEEE, a member of NERG, and a member of the Danish Engineering Society (IDA). He is advisor to several multinational
companies. 相似文献