• Journal of Korea Multimedia Society
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• v.10 no.1
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• pp.66-73
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• 2007

SDR technology is a fundamental wireless access technology that combines and accommodates multiple wireless communication standards in one transceiver system through just modifying software using modular communication platforms without any hardware modifications for RF and IF signal processing on the basis of high performance DSP devices. Various communication systems that are designed under diverse and complex network environments require the communication platforms on the basis of SDR supporting reorganization to guarantee simple and fast communication interfaces among the respective wireless networks. This paper introduces a main idea on the implementation of platform on the basis of SDR and a communication platform is designed for experiments that is composed of a DSP board with TMS320C6713 CPU, a FPGA board processing IF signals, and a module with RF transceiver processing wireless LAN frequency bandwidth. Various modulation schemes(BPSK, QPSK, and 16QAM) used in communication systems are applied and tested on the designed platform and the test results shows that it is possible to design a reconfigurable communication terminal platform.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.23 no.4
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• pp.409-417
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• 2005

This study is aimed to develop a remote control robot-ship system using wireless communication and DGPS, which it is an automatic system for measuring exact depth and bed topography of reservoir or dam. Robot-ship is equipped with GPS and echosounder, and it is controled remotely using wireless internet. Robot-ship is consist of frame, each module and control board. Control segment is consisted of a processing system for positioning data and remote control system. A wireless communication system is developed which can communicate interactively between robot-ship and control segment, and it is developed in two channel system of RF modem and wireless internet. The robot-ship could be used acquire economically and exactly the water depth and bed topography of reservoirs, dams, rivers and so on.

• Proceedings of the IEEK Conference
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• 2004.06b
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• pp.411-414
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• 2004

This paper introduces a modulation method for digital wireless communication based on general DS-QPSK. The design and fabrication is for home networking application to a typical RF transmitter with DS-QPSK modulator. This modulator implemented using VHDL hardware programming language, the fabrication of IC chip $5{\times}5 mm^2$ was carried by 27th IDEC MPW(Multi Project Wafer) process in 0.35${\mu}m$ rule at Samsung Inc. This paper presented the important of this technology for the future application in wireless sensor. This module can be efficient usage for home network to transmit the RF wireless sensor system.

• Information and Communications Magazine
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• v.32 no.4
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• pp.93-96
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• 2015

기존 MIMO 시스템에서는 안테나의 개수가 늘어날수록 선형적으로 RF 모듈의 개수도 늘어나 전체 시스템의 복잡도와 전력소모가 심하다. 이를 해결하기 위해 단일 RF 송신구조가 제안되었고, 본 논문에서는 임피던스를 가변하여 안테나에서 방사되는 패턴을 조절하는 기술을 제안한다. 기존 MIMO 시스템의 RF 회로부가 가지는 복잡도와 전력 효율 문제를 해결하기 위해 임피던스 로딩 부분의 실험시제품 제작 및 검증을 수행한다. BPSK와 QPSK 변조방식을 지원하는 임피던스 로딩 보드를 제작하고, 3 m거리에서 무선 송수신 실험을 성공적으로 수행하였다.

• Information and Communications Magazine
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• v.32 no.6
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• pp.59-61
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• 2015

기존 MIMO 시스템에서는 안테나의 개수가 늘어날수록 선형적으로 RF 모듈의 개수도 늘어나 전체 시스템의 복잡도와 전력 소모가 심하다. 이를 해결하기 위해 단일 RF 송신구조가 제안되었고, 본 논문에서는 임피던스를 가변하여 안테나에서 방사되는 패턴을 조절하는 기술을 제안한다. 기존 MIMO 시스템의 RF 회로부가 가지는 복잡도와 전력 효율 문제를 해결하기 위해 임피던스 로딩 부분의 실험시제품 제작 및 검증을 수행한다. BPSK와 QPSK 변조방식을 지원하는 임피던스 로딩 보드를 제작하고, 3 m거리에서 무선 송수신 실험을 성공적으로 수행하였다.

• Journal of the Semiconductor & Display Technology
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• v.15 no.4
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• pp.16-21
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• 2016

In this paper, we have designed and fabricated a receiver module for 5.8GHz Microwave Wireless Power Transmission. The receiver module was composed of an antenna, BPF (Band Pass Filter) and RF-DC converter. The antenna was designed to RHCP (Right Hand Circular Polarization). And we used ${\lambda}g/2$ open-circuited stubs for the BPF. In addition, the RF-DC converter used the tripler voltage circuit for voltage multipliers. The integrated receiver RF module for 5.8GHz Microwave Wireless Power Transmission has been designed and fabricated. The voltage was measured to the distance of 50cm.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.719-722
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• 2016

These days there have been trying to fuse the various of IoT (Internet of Things) technology over the industrial field. However the complicated IoT System structure comprised of sensor devices, gateway, network server, and application server causes the difficulties to the system implementation and the increment of installation cost, thereby preventing IoT system deployment in the industry fit for small size network environment. In this paper, authors propose a novel IoT system architecture that is useful in the industry field to be implemented by the small size network with low cost. Also, we implement the infrastructure to RF433 wireless sensor network, the gateway on ARDUINO YUN, and the application server using AMP (Apache, PHP, MySQL) package and then present a power efficient management scheme for sensor devices.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3064-3066
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• 1999

The existing equipment with wire communication can expect the stability of data transmission. However, according to increasing a number of DTE (Data Terminal Equipment), wiring work becomes a heavy burden. Restriction to application about portable DTE and the lack of flexibility are another drawback of wire communication. This paper presents the design and implementation of a RF (Radio Frequency) based wireless communication system. The RF based module is designed to the multi communication between DTEs. The RF based module consists of RF circuit and microprocessor. The main properties of RF circuit are maximum 5Kbps transmission rate, maximum 90m transmission distance and 433MHz frequency band. The microprocessor rearrange the data into AHDLC(Advanced High level Data Link Control) format and then instructs RF circuits to transmit/receive the data. The RF module have a wide application field such as fire/security alarm, remote control/measurement etc..

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.2011-2012
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• 2011

본 논문은 댁내 전력정보표시장치의 무선 통신을 위한 지그비 모듈의 설계 및 구현에 관한 기술이다. 제작된 지그비 모듈은 크게 전원부, MCU부, 통신 인터페이스부, 안테나 및 RF 매칭회로 등으로 구성되며, MCU로는 32비트 ARM$^{(R)}$ Cortex$^{TM}$-M3 프로세서 기반의 EM357 모듈을 사용하였다. 또한, 댁내 전력정보표시장치가 네트워크상에서 코디네이터 또는 노드 역할을 수행하는 상황을 모두 고려하여 RS-485 통신 인터페이스를 추가 구성하였다. 데이터 송수신 성능 시험 결과 주택 내에서는 5%이하의 PER을 보이며, LOS 상에서 최대 400m까지 통신이 가능함을 확인하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.05a
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• pp.1593-1596
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• 2005

홈 네트워크 기술에서 무선 통신의 중요성이 날로 커져가고 있다. 본 논문에서는 무선 통신 방식으로 구현함에 있어서 중요한 것을 저전력 특성을 가져야 한다는 것이다. 저전력 특성 구현을 위하여 센서, CPU, RF 모듈의 선택에 대해 알아보고, 저전력 무선 보드 센서 설계 및 실제 구현 방식을 제시한다. 저전력 방식으로 설계된 센서는 AA 배터리 2 개로 1 년 이상의 성능을 낼 것으로 판단된다.