• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.5
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• pp.35-40
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• 2023

In this paper, a serial wireless LAN virtual communication module that allows microprocessors to communicate wirelessly with other peripheral devices is developed as part of a study to build an online virtual experiment system that allows them to practice virtually anytime, anywhere in microprocessor application education in electrical and electronic control engineering. The developed module is connected to the microprocessor in the virtual experiment system through serial interface. The serial data is sent to and received from peripheral devices through the wireless LAN interface of the host computer where the virtual experiment software is being performed. In order to verify the function of the developed serial wireless LAN virtual communication module, experiments were conducted in which a microprocessor in the virtual experiment system exchanged data with an Android smartphone through a wireless LAN interface of a host computer. The developed serial wireless LAN communication module is expected to enable virtual microprocessors to communicate with surrounding real devices through wireless LAN, which can be efficiently used in microprocessor application education.

• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.735-738
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• 2004

In this experiment, we developed a ubiquitous computing platform that can analyze vibration and noise in wireless environment by wireless LAN and sensors. In order to utilize the COTS(Commercial Off The Shell) concept, we used a PDA that supports wireless LAN and serial communication as a main board. Following platform is used to measure the noise level of heavy construction equipments in a remote area.

• Journal of information and communication convergence engineering
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• v.3 no.1
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• pp.9-12
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• 2005

In this research, we developed a ubiquitous computing platform that can analyze the vibration and noise in wireless environment by wireless LAN and sensors. In order to utilize the COTS(Commercial Off The Shelf) concept, we used a PDA that supports wireless LAN and serial communication as a main board. Following platform is used to measure the noise level of heavy construction equipments in a remote area.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.37 no.5
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• pp.85-92
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• 2000

In this paepr, a multicode CDMA scheme with serial and parallel structure as the transmission scheme of wireless LAN which can transmit high speed data under an indoor channel environment is modeled and optimal values of several parameters needed for implementing wireless LAN modern system are derived through computer simulation. it is verified that given the transmission bandwidth and maximum data rate, the system performance is improved if increasing spreading gain anf the number of channels or decreasing the data rate of each channel. Especially the parallel structure makes not only the system performance much more improved but also the hardware implementation easier than serial structure under the same condition because the effective chip rate is decreased.

• Proceedings of the IEEK Conference
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• 2002.06b
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• pp.153-156
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• 2002

FFT/IFFT block is very important module to determine the performance of OFDM system. This block has been implemented using several FFT algorithms such as radix-2, radix-4 etc. However SRFFT algorithm has not been implemented because of the complexity for implementation. This paper proposes a serial-pipeline SRFfT for OFDM system. The serial-pipeline SRFFT is optimized to use a serial input and serial output. We have implemented the SRFFT block using anam 0.25 Um five-metal process. The simulation show that the SRFFT block can operate about 200MHz. This architecture could be adapted to IEEE 802.lla wireless LAN standard.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.3
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• pp.570-576
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• 2004

In this paper, we design the IFFT/FFT (Inverse fast Fourier Transform/Fast Fourier Transform) modules for IEEE 802.11a-1999, which is a standard of the High-speed Wireless LAN using the OFDM (Orthogonal Frequency Division Multiplexing). The designed IFFT/FFT is the 64-point FFT to be compatible with IEEE 802.11a and the pipelined architecture which needs neither serial-to-parallel nor parallel-to-serial converter. We compare four types of IFFT/FFT modules for the hardware complexity and operation : R22SDF (Radix-2 Single-path Delay feedback), the R2SDF (Radix-2 Single-path Delay feedback), R2SDF (Radix-4 Single-path Delay Feedback), and R4SDC (Radix-4 Single-path Delay Commutator). In order to minimize the error, we design the IFFT/FFT module to operate with additional decimal parts after butterfly operation. In case of the R22SDF, the IFFT/FFT module has 44,747 gate counts excluding RAMs and the minimized error rate as compared with other types. And we know that the R22SDF has a small hardware structure as compared with other types.

• Information and Communications Magazine
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• v.24 no.8
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• pp.40-52
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• 2007

본고에서는 비/저활용(57-66GHz) 대역에 대한 새로운 주파수 자원을 개척하여 HDTV급 신호를 케이블 및 위성방송 셋톱박스, 게임콘솔, DVD플레이어, 캠코더 및 이동식 멀티미디어 장비와 무선으로 연결시키는 전송 기술 개발을 위하여 Intel, Philips, Motorola, IBM, SiBeam, Panasonic, Sony등 세계적인 기업들이 국제 표준화(IEEE802.15, ETSI/BRAN, ECMA International) 공동 협력 및 기술 개발 경쟁을 벌이고 있는 상황이다. 본 표준기술은 국내 기업이 세계 시장을 장악하고 있는 LCD, PDP 및 차세대 DVD플레이어 등에 적용될 Wireless HD-SDI(High Definition Serial Data Interface)/ DVI(Digital Visual Interface)와, 외장 하드 디스크, 메모리 등 외부 기억 장치와의 자원 공유에 사용될 Muti-Gbps급 Wireless LAN, Wireless PAN, Wireless SAN(System Area Network) 등에 적용될 무선 전송 기술이다. 비/저활용 $59{\sim}66GHz$ 대역에 대한 국제 표준화로 IEEE802.15.3c를 중심으로 활발히 일어나고 있는 표준기술과 표준화 동향을 살펴본다.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1255-1261
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• 2010

An operating information and fault recode of train is very important information for safety driving and maintenance. And these information is increased and need high speed as the number of trains is increased. Wireless LAN or CDMA network is efficient to report more complicated and various information from vehicle to server in control center. Existing wireless transmission system has weakness due to transmission system is separated with TDCS and standalone. At first, standalone system needs space to be installed and cost is increased. And data transmission capacity and speed is limited by complicated structure that transmission system receive data thru serial communication like RS232 and then data transmission system send data to server in control center. This article is study to develop embedded & wireless fault code transmission device to be installed in TDCS to overcome weakness of space and to have more cost effective and simple structure. It is adapted 802.11b/g WiFi for wireless communication and OS is used embedded Linux that can easily implement wireless communication environment and ensure TCP/IP communication’s security. We also implement simple server to test wireless communication between embedded & wireless fault code transmission device and server in control center.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.6C
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• pp.594-601
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• 2003

High-speed WLAN(Wireless Local Area Network) systems operating in 5GHz band use OFDM transmission technique. OFDM technique transmits data in parallel and has many advantage compared with the serial transmission system-for example, robustness to time variance of channel. OFDM technique use the orthogonal multicarriers. The ICI(InterChannel Interference) caused by the orthogonality destruction between subcarriers. hamper the BER performance. In this paper, we propose the synchronization techniques for high-speed WLAN system designed to support user data rates up to 54Mbps at 5GHz. The proposed synchronization techniques are the reduced complexity structure having the similar performance compared with the conventional synchronization techniques.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.6
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• pp.1200-1205
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• 2006

In this paper, it is presented to the designed and implemented care system fur health diagnosis. The designed handhold care system is implemented by embedded Visual C++4.0 and Pocket PC2003 software development kit (SDK) in an 802.11 wireless network, and we were conducted that the research provide sufficiently the usefulness of the U health system for the collection of care management information. The proposed system is consists of care management module for health diagnosis, personal record module, data transport module, image information management module for clinic. Also, fur emergency status, transmission function of clinic information is implemented by wireless LAN protocol and serial communication.