• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.5
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• pp.1608-1615
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• 2010

In this paper, we proposed the method called "DoublePico"(Double Piconet) forovercoming low data transmission rate in a scatternet. This needs a new Ad-hoc network topology to transmit with high rate. Every node performs the function of the relay station. DoublePico has two bluetooth devices that should form two different poconets; every node can make a link between two different piconets. Two different piconets are linked in one node by the link with two bluetooth divices thereby forming the Ad-Hoc network. In this paper, we shows the method of DoublePico which supports about 457kbps of the maximum data transmission rate. This method supports a higher data transmission rate than the traditional bluetooth's Ad-Hoc topology by using analysis and comparison of existing algorithm of bluetooth specification and simulation results. Specifically, this paper focuses on the impact of intererence on the PER (Packet Error Rate), throughput performance, and the throughput improvement with SAW(Stop and Wait)-ARQ scheme in DoublePico.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.2A
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• pp.55-62
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• 2003

This paper proposes an efficient and differentiated MAC scheduling algorithm for Bluetooth systems. The proposed algorithm guarantees QoS (Quality of Service) requirement of each master-slave pair or application. Conventional MAC scheduling algorithms for Bluetooth take priority of each pair into consideration and demonstrate relatively reasonable performance. However, their performances may depend on traffic characteristic, or they are limited by overheads for signaling. In this paper, we propose a new MAC scheduling algorithm superior to the conventional algorithms from the viewpoints of throughput, delay, and supporting QoS. Our proposed algorithm is evaluated via computer simulations under various environments and compared with the conventional scheduling algorithms. Simulation results indicate that the proposed algorithm shows better performance than the existing algorithms, and can support the QoS demand of each pair.

• Journal of Broadcast Engineering
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• v.12 no.2
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• pp.148-158
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• 2007

Recently, IEEE 802.15.4a(low-rate UWB) technique has been paid much attention to the LR-UWB communication system for WPAN. However, there are various interferences such as MPI(Multi Path Interference) or IPI(Inter Piconet Interference) in IEEE 802.15.4a wireless channel. In order to cancel various interferences occurred to WPAN environment, in this paper, we propose a UWB wireless communication system with high QoS(Quality of Service) which is a chaotic-OOK(On-Off Keying) system using unipolar ZCD(Zero Correlation Duration) spreading code in physical layer level. Furthermore, we analyze its performance via simulations and verify the availability of proposed system with prototype implementation.