• Proceedings of the KIEE Conference
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• 2004.11d
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• pp.63-66
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• 2004

It is widely known that the ultra high frequency (UHF) method that detects the electromagnetic wave of the PD pulses in the gas insulated space is one of the most competitive methods for its high sensitivity. From the above point of view, this paper describes the characteristics of GIS PD signals measured with ultra wide band (UWB) GIS PD defecting system in which PD signals are defected into the dual UHF band. Thc UWB PD detection system consists of the UWB UHF coupler, the UWB low noise amplifier (LNA) and the oscilloscope. The dual bands for PD signals are 0.5-2GHz(full band) and 1-2GHz(high band). As results, it was found that the partial discharges of each defect have their own characteristic pattern and the ratio of High hand to Full band increases with gas pressure.

• TTA Journal
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• s.88
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• pp.133-140
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• 2003

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.1
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• pp.39-50
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• 2010

In this paper, we analyze and simulate the performance of a tactics mobile communication system based on ultra wide band (UWB) in multi-user interference (MUI) environments. This system adopts a double binary turbo code for forward error correction (FEC). Wireless channel is modeled a modified Saleh and Valenzuela (SV) model. We employ a space time block coding (STBC) scheme for enhancing system performance. System performance is evaluated in terms of bit error probability. From the simulation results, it is confirmed that the tactics mobile communication system based on UWB, which is encoded with the double binary turbo code, can achieve a remarkable coding gain with reasonable encoding and decoding complexity in multi-user interference environments. It is also known that the bit error probability performance of the tactics mobile communication system based on UWB can be substantially improved by increasing the number of iterations in the decoding process for a fixed cod rate. Besides, we can demonstrate that the double binary turbo coding scheme is very effective for increasing the number of simultaneous users for a given bit error probability requirement.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.9C
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• pp.1316-1322
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• 2004

Recently, the UWB (ultra wide-band) wireless communication technology, which provides high data transmission and is capable of linearly trading between throughput and signal-to-noise ratio (SNR), has drawn much attention for short-range wireless networks. Fully exploiting its notable features and minimizing its interference to coexisting other systems require the knowledge of SNR's at receivers In this paper, we propose an algorithm for estimating the pulse energy to noise ratio Ep/No of UWB signal with utilization of outputs from a correlator at a receiver, and evaluate the performance of the proposed algorithm through computer simulation. According to simulation results, the maximum standard deviation is about 1 13 dB with a block size of 500. Except for Ep/No=O and 2 dB cases with a block size of 500, no errors greater than 3 dB were observed in all the remaining experiments. Generally speaking, it improves as the true Ep/No, increases and as the block size increases A notable feature of the proposed algorithm is that it does not reduce the effective throughput because the estimation process does not require sending additional training signal of any specific format.

• Journal of information and communication convergence engineering
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• v.9 no.6
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• pp.652-656
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• 2011

In this paper, a transmitter-based multipath processing and inter-channel interference (ICI) cancellation scheme for a ultra-wideband (UWB) spatial multiplexing (SM) multiple input multiple output (MIMO) system is presented. It consists of taps delayed lines and zero-forcing (ZF) filters in the transmitter and correlators in the receiver. For a UWB SM MIMO system with N transmit antennas, M receive antennas, and Q resolvable multipath components, the BER performance of a linear transmit ZF scheme is analyzed in a log-normal fading channel and also compared with that of a receiver-based ICI rejection approach. It is found that when M ${\leq}$ N, the transmit ZF processing approach outperforms the ZF receiver while making the mobile units low-cost and low-power.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.446-449
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• 2003

In recent years, the research of an efficient transmission method is going to meet a demand for high speed and large capacity radio communication. These systems make use of ultra-short duration pulses which yield UWB(Ultra Wide Band) signals characterized by low power spectral densities. The wavelet synthesis wave is able to set up the scale freely. So it is possible to use as the transmission wave of UWB by compressing time. In this paper, we present a general analytical expression for the average BER(Bit Error Rate) performance of UWB data transmission using wavelet system as a function of the cross-correlation between the users' signatures in an additive white Gaussian noise(AWGN) channel.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.8A
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• pp.836-846
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• 2007

Wireless Communication is playing a key role in implementing the ubiquitous society. However, due to the increasing wireless and mobile devices occupying the spectrum, the frequency resources are believed to become more and more limited. In order to deal with the problem, coexistence is considered to be a effective method to improve the efficiency of spectrum utilization between several different systems. Here, we utilize the UWB system to realize the coexistence, because it is an ultra wide band system which can co-exist with other narrow band systems. On the other hand, Cognitive Radio technology is an intelligent technology which can sense the spectrum environment and adaptively adjust the parameters for wireless transmission. In this paper, by using Cognitive UWB, the spectrum efficiency of the transmission channels is largely improved; Furthermore, the interference to other systems can be effectively avoided.

• Journal of the Korea Safety Management & Science
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• v.21 no.4
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• pp.1-6
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• 2019

This study relates to acquiring biological signal without attaching directly to the user using UWB(Ultra Wide Band) radar. The collected information is the respiratory rate, heart rate, and the degree of movement during sleep, and this information is used to measure the sleep state. A breathing measurement algorithm and a sleep state detection algorithm were developed to graph the measured data. Information about the sleep state will be used as a personalized diagnosis by connecting with the medical institution and contribute to the prevention of sleep related diseases. In addition, biological signal will be linked to various sensors in the era of the 4th industrial revolution, leading to smart healthcare, which will make human life more enriching.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.253-256
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• 2008

In this paper, we analyze the performance of RAKE receiver for impulse radio-ultra wide band (IR-UWB) systems in indoor multipath radio channel. Pulse position modulation-time hopping (PPM-TH) signal is considered. And we also consider three types of RAKE receivers, which are ideal RAKE, selective RAKE, and partial RAKE receivers. The indoor channel is modeled as the modified Saleh and Valenzuela (SV) model which has been proposed as a UWB channel model by the IEEE group, IEEE 802.15.SG3a.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.2119.1_2120.1
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• 2009

UWB(Ultra Wide Band)는 차세대 무선통신 기술로 무선 디지털펄스라고도 한다. GHz대의 주파수를 사용하면서도 초당 수천~수백만 회의 저출력 펄스로 이루어진 것이 큰 특징이다[1]. 기존 무선통신 기술의 양대 축인 IEEE 802.11과 블루투스 등에 비해 속도와 전력소모 등에서 월등히 앞서고 있으며, SoC(System on a Chip)의 저전력 구현에 대한 연구가 활발히 진행되고 있다. OFDM은 크게 FFT(Fast Fourier Transform) 블록, Interpolation /decimation 필터 블록, 비터비 블록, 변복조 블록, 등화기 블록 등으로 구성된다. 고속 시스템에서는 대역효율성이 우수한 OFDM(Orthogonal Frequency Division Multiplexing) 방식을 사용하고 있으며, OFDM 전송방식은 직렬로 입력되는 데이터 열을 병렬 데이터 열로 변환한 후에 부반송파에 실어 전송하는 방식이다. 이와 같은 병렬화와 부반송파를 곱하는 동작은 IFFT와 FFT로 구현이 가능한데, FFT 블록의 구현 비용과 전력소모를 줄이는 것이 핵심사항이라고 할 수 있다. 기존논문에서는 OFDM용 FFT 구조로 단일버터플라이연산자 구조, 파이프라인 구조, 병렬구조 등의 여러 구조가 제안되었다[2]. 본 논문에서는 Radix-8 FFT 알고리즘 기반의 New partial Arithmetic 저전력 FFT 구조를 제안하였다. 제안한 New partial Arithmetic 저전력 FFT구조는 곱셈기 대신 병렬 가산기를 이용 하여 지금까지 사용되는 FFT 구조보다 전력소모를 줄일 수 있음을 보였다.