• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2002년도 하계종합학술대회 논문집(5)
• /
• pp.55-58
• /
• 2002

This paper describes an RF module for 2.4GHz wireless audio/video transmission. The pre-processed baseband input signals are FM-modulated using a VCO and then transmitted through an antenna after RF filtering. The designed circuits are implemented using a Teflon board of which the size is 52mm${\times}$62mm. The measured maximum output signal levels are around -3dBm and the harmonics are less than -450dBc. The manufactured module consumes 130mA from a 8V supply.

• 한국멀티미디어학회논문지
• /
• 제23권9호
• /
• pp.1164-1170
• /
• 2020

In this paper, we consider the wireless-powered backscatter communication which consists of a power beacon, a source, a relay, and a destination. For the proposed wireless-powered backscatter communication, the source transmits its signals to both the relay and the destination via a backscattering channel and the relay which has a rechargeable battery performs an energy harvesting as well as an information forwarding based on the time switching relay (TSR) protocol. Based on the decode-and-forward (DF) relay transmission, we investigate performances of the proposed system in terms of outage probability and transmission rate in which the exact performance analysis of outage probability is given. Finally, some numerical examples are given to verify our provided analytical results for different system conditions.

• 방송공학회논문지
• /
• 제18권3호
• /
• pp.491-494
• /
• 2013

본 논문은 60 GHz 채널을 사용하는 무선장치들이 멀티홉 애드혹 네트워킹의 형태로 배치되어 있을 때에 일부 무선 장치들에서 발생한 비디오 트래픽을 에너지 효율적이며 버퍼가 안정적인 형태로 전달하는 동적/추계적 라우팅 알고리즘을 제안한다. 제안하는 알고리즘은 모든 장치가 정보를 공유할 필요 없이 분산적으로 운영이 되기 때문에 중앙에서 알고리즘을 운영하는 제어장치가 필요 없다. 제안하는 알고리즘에 대한 성능은 시뮬레이션을 통하여 검증되었다.

• 디지털콘텐츠학회 논문지
• /
• 제11권2호
• /
• pp.277-282
• /
• 2010

본 연구에서는 생체 계측 모듈에서 획득된 혈중 산소 포화도(SpO2) 신호를 PC에 무선으로 전송할 수 있는 무선통신 모듈을 개발하였다. 개발된 무선통신 모듈은 개인의 의료정보 보안을 고려하여 지그비 또는 블루투스 등과 같은 개방형 프로토콜 대신 비개방형 프로토콜로 설계되었다. 또한 응급이송 시 전송된 혈중 산소 포화도 신호를 의료진에게 정보 손실 없이 다양한 형태의 데이터 및 그래프로 정보를 제공할 수 있도록 하는 디스플레이 프로그램을 개발하였다.

• Journal of information and communication convergence engineering
• /
• 제9권5호
• /
• pp.562-566
• /
• 2011

As telecommunication technologies in telemedicine services are developed, the expeditious development of wireless and mobile networks has stimulated wide applications of mobile electronic healthcare systems. However, security is an essential system requirement since many patients have privacy concerns when it comes to releasing their personal information over the open wireless channels. Due to the invisible feature of mobile signals, hackers have easier access to hospital networks than wired network systems. This may result in several security incidents unless security protocols are well prepared. In this paper, we analyzed authentication and authorization procedures for healthcare system architecture to apply secure M-health systems in the hospital environment. From the analyses, we estimate optimal requirements as a countermeasure to its vulnerabilities.

• 한국공간구조학회논문집
• /
• 제18권2호
• /
• pp.51-58
• /
• 2018

Recently, measuring instruments for SHM of structures had being developed. In general, the wireless transmission of sensor signals, compared to its wired counterpart, is preferable due to its absence of triboelectric noise and elimination of the requirement for cumbersome cable. However, the research on the tall buildings with relatively small vibration levels is insufficient. Therefore, in this paper, we used the wireless MEMS sensor and iPad to compare and analyze the vibration measurements of three tall buildings and two towers.

• 전기학회논문지
• /
• 제67권8호
• /
• pp.1099-1105
• /
• 2018

Wireless sensor networks have been shown to be an effective method for health monitoring of civil structures. In this paper a wireless strain sensor system which will allow easier collection of accurate strain signals in small sized structures is described. The experiment result shows that the developed wireless sensor system and the proposed network system are fit for health & safety monitoring and control of structures.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2002년도 ITC-CSCC -3
• /
• pp.2059-2062
• /
• 2002

For detection of digitally modulated signals, the receiver must be provide with accurate carrier phase and symbol timing estimates. So far, tots of algorithms have been suggested for those purposes. In general, a interpolation filter with TED(Timing Error Detection) like Gardner algorithm is popularly used for symbol timing estimate of digital communication receiver. Apart from the performance point of view, a multiplicative operation of any interpolation filter limits the symbol rate of the system. Hence, we suggest a new symbol timing estimate algorithm for high speed burst-mode fixed wireless communication system and analyze its performance in the AWGN channel.

• 한국공간구조학회논문집
• /
• 제17권3호
• /
• pp.57-64
• /
• 2017

Recently, measuring instruments for SHM of structures had being developed. In general, the wireless transmission of sensor signals, compared to its wired counterpart, is preferable due to its absence of triboelectric noise and elimination of the requirement for cumbersome cable. Preliminary studies on the continuous vibration measurement of high-rise buildings using MEMS sensors have been carried out. However, the research on the low-rise buildings with relatively small vibration levels is insufficient. Therefore, in this paper, we used the wireless MEMS sensor to compare and analyze the vibration measurements of three low-rise buildings.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2005년도 추계학술대회논문집
• /
• pp.883-886
• /
• 2005

This paper proposed a wireless measurement system (WMS) for an effective condition monitoring using wireless communication. WMS consists of two parts: transmitter(TM) acquired a dynamic signal from physical system using ICP type accelerometer sensor. An acquired signal modulated through the low/high pass filter and amplifier in DAQ board, which converted to digital signal. Embedded board(E-board) transferred digital signals to base station(BS) through the socket IEEE.802.11.b. BS is adopted IOCP server structure. Because it can acquired signal well during transferred digital signal. Signal processing used LabVIEW Library, BS(server) designed to realize multi-thread using visual C++.NET for 1 many meaning data processing