• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.07a
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• pp.436-436
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• 2004

• Journal of Korea Multimedia Society
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• v.15 no.3
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• pp.345-355
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• 2012

The WiMedia Alliance has specified a Distributed Medium Access Control (D-MAC)/WUSB protocol based on UWB for high speed wireless home networks and WPANs. In this paper, we propose a novel SoQ-based cooperative communication protocol adaptive to current UWB link transmission rate and QoS measure. The proposed SoQ-based cooperative communication protocol has compatibility with current WiMedia D-MAC/Wireless USB standard and is executed at each device according to a SoQ-based Relay Node Selection (RNS) criterion.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.5C
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• pp.556-561
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• 2006

In this study, an ultra-wideband(UWB) signal model is considered to estimate the angle-of-arrivals(AOAs) of clusters in an UWB indoor-to-outdoor communication environment having random angle spreads. A conventional AOA algorithm for UWB estimates the directions of both clusters and multipath signals together and so has complex estimation procedure. In order to solve that problem, we propose a new clustered AOA estimation algorithm. The estimation technique based a well-known MUSIC algorithm is proposed and the estimates of the AOA on received clusters are obtained using the proposed technique. The proposed model and estimation technique are verified through computer simulations.

• International Journal of Internet, Broadcasting and Communication
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• v.8 no.4
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• pp.1-10
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• 2016

This paper considers WiMedia UWB network based wireless ship area network (WSAN) so as to support high-quality multimedia video data services and important shipboard control data. In this paper, prioritized contention access (PCA) and distributed reservation protocol (DRP) based on WiMedia UWB (ECMA-368) MAC protocols are combined and proposed to support mixed high-quality video traffic and shipboard control data traffic applying varying DRP and PCA data periods according to channel condition and link parameter ptimization. It is shown that the proposed dynmaic channel allocation of WiMedia UWB MAC protocol can provide reliable mixed video and shipboard control data traffic as well.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.519-523
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• 2003

In this paper, we proposed a new ultra wide-band(UWB) antenna for UWB communication applications. The proposed antenna is composed of a rectangular plate having two steps, single slot on plate and partial ground plane. This antennas operated from 3.2 to 13 GHz. Details of the proposed antenna design and measured results are presented discussed.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2003.06a
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• pp.213-216
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• 2003

UWB 통신 기술은 초광대역 특성 때문에 높은 전송 속도와 저전력 통신이 가능하여 의료장비에 응용이 가능하며, 특히 유선이라는 제약성으로 큰 불편을 겪고 있는 ECG시스템에 적용되어질 수 있다. 따라서 근거리 무선 통신 기술로 급부상하고 있는 UWB 통신 기술의 응용을 위해 UWB 신호 특성 및 변조 방식의 연구가 행하여져야 한다. 이에 본 논문에서는 UWB에 사용가능한 각종 펄스의 특성과 적용하고자 하는 시스템 환경에서 발생할 수 있는 UWB 신호의 간섭 영향을 분석하였으며, 간단한 UWB 송수신 시스템을 시뮬레이션 하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.7C
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• pp.475-480
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• 2011

Ultra-wideband (UWB) signal energy spreads over multiple correlator outputs due to rich multipaths, making the output of each correlator have only a small portion of the total energy. Thus, in the proposed two-stage UWB signal detection scheme for cognitive radio communication systems, the decision variable is formed by combining multiple correlator outputs, making it possible to collect the signal energy spread by the multipaths, Simulation results show that the proposed scheme can provide a gain of about 0.6 dB over the conventional schemes in various UWB channel environments.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.12 s.354
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• pp.9-15
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• 2006

In this paper, signal processing techniques for noncoherent impulse-radio-based UWB (IR-UWB) communication system are proposed to provide system implementation of low power consumption and low complexity. The proposed system adopts a simple modulation technique of OOK (on-oft-keying) and noncoherent signal detection based on signal amplitude. In particular, a technique of a novel high speed digital sampler using a stable, lower reference clock is developed to detect nano-second pulses and recover digital signals from the pulses. Also, a 32 bits Turyn code for data frame synchronization and a convolution code as FEC are applied, respectively. To verify the proposed signal processing techniques for low power, low complexity noncoherent IR-UWB system, the proposed signal processing technique is implemented in FPGA and then a short-range communication system for wireless transmission of high quality MP3 data is designed and tested.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.7C
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• pp.443-450
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• 2011

Recently, various transmission techniques for communication and broadcasting systems have been developed to meet the dramatically increasing requirement of consumers. Because UWB (Ultra-Wideband) is a wireless communication technique that supports high data rate with low power, it can satisfy the requirement and can be applied to various wireless communication services. The multi-band orthogonal frequency division multiplexing (MB-OFDM) system, one of UWB system, is the wireless communication system that satisfies the transmission characteristic for UWB and so it can be used for various wireless communication services. In this paper, we propose a scheme that uses hierarchical modulation which is applied in digital video broadcasting system at the source and adaptive modulation based on the channel quality at the relays. The simulation results have shown that the proposed scheme has both the advantages of the increased throughput by 33% and similar BER performance to conventional scheme.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.4
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• pp.489-495
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• 2018

In this paper, we designed and fabricated WLAN / UWB communication antennas operating at 3.3 [GHz] and 5 [GHz] bands in order to effectively use the high-speed communication network system that improved antenna miniaturization, gain and radiation pattern. Microstrip patch antennas were chosen to improve the bandwidth. The slot width, length, and transmission line width were calculated using the theoretical formula for each step. Simulation results show that the return loss is -14.053 [dB] at 3.3 [GHz] and -13.118 [dB] at 5 [GHz]. The gain showed a value of 2.479 [dBi] at 3.3 [GHz] and a value of 3.317 [dBi] at 5 [GHz]. After optimizing it with the CST Microwave Studio 2014 program, which can be 3D-designed, Based on these results, we investigated the performance of antennas by measuring their characteristics. In recent years, WLAN, which is a variety of wireless technologies that are continuously developing, and UWB, which is a communication technology which is increasing in frequency band due to an increase in demand of the technology users, is used for a high speed wireless communication system. Communication seems to be possible.