• Journal of KIISE:Computing Practices and Letters
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• v.16 no.11
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• pp.1051-1055
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• 2010

Software defined radio(SDR) technology implements wireless communication protocols as software instead of dedicated hardware. SDR enables reconfiguration of wireless communication protocols without expensive hardware modification. However, as the SDR systems are equipped with additional programmable processors, they suffer significant power dissipation. This paper proposes a novel power management technique for SDR systems, called the combined modulation and voltage scaling (CMVS). Numerical analyses were performed to evaluate the effectiveness of CMVS. The results show that CMVS minimizes power dissipation while satisfying the given data transfer rate.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.2
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• pp.290-296
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• 2020

In this paper, we analyze the effect of mobility on the performance of full-duplex radio. For this, we implement a full-duplex radio prototype using a software-defined radio that is powered by a battery and can thus function in mobile environments. In addition, we compare the performance of self-interference cancellation schemes for two cases considering multi-antenna based full duplex radio and circulator based full duplex radio, respectively. Finally, we show a negative effect of mobility on the self-interference cancellation performance of the full-duplex radio system, and analyze the effect of the update period of the self-interference cancellation filter on the performance. In particular, when the update period is reduced by about 1000 times, the power of self-interference is reduced by 5.7dB for circulator-based full-duplex radio and 3.1dB for both antenna-based full-duplex radio.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.5
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• pp.65-72
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• 2013

ETSI(European Telecommunication Standards Institute), TC(Technical Committee), RRS(Reconfigurable Radio Systems)에서는 소프트웨어 모뎀 기반 멀티모드 단말기의 연구 및 표준을 개발하고 있다. 소프트웨어 모뎀 기반 멀티모드 단말기는 SDR(Software Defined Radio) 기술을 바탕으로 단말기 플랫폼에 독립적인 라디오 어플리케이션을 운용함으로써, 하나의 단말기에서 동시에 다양한 이동통신 표준을 이용할 수 있는 차세대 단말기이다. 본 논문에서는 TC RRS에서 정의한 라디오 어플리케이션 사이에서의 리소스 공유 방법과 라디오 어플리케이션의 배포 형태에 따른 멀티모드 단말기의 분류에 대해 소개한다. 또한, 여러 개의 라디오 어플리케이션을 동시에 운영할 수 있는 멀티모드 단말기의 아키텍처와 인터페이스에 대해 소개한다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.07a
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• pp.596-600
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• 2020

본 논문에서는 Xilinx 사(社)의 Spartan-6 FPGA 와 Analog Devices 社의 Transceiver 칩인 AD9361 을 이용한 소프트웨어 정의 라디오 장비인 Universal Software Radio Peripheral(USRP) B210 를 이용하여 디지털 방송 표준인 ATSC 의 실시간 영상 송수신 시스템을 신호 처리 소프트웨어인 그누 라디오로 구현하였다. ATSC 에서 사용하는 MPEG 트랜스포트 스트림 영상 신호가 송신부에서 소프트웨어로 디지털 신호 처리되고 Digital-to-Analog Conversion(DAC) 과정을 거쳐 영상 신호가 송출된다. 본 논문은 디지털 방송 수신부에서 핵심 기능을 하는 등화기 알고리즘을 소프트웨어를 통해 구현하여 신호의 왜곡을 보상하는 방법을 제안한다. 수신부에서는 신호를 수신하여 튜너, 매치 필터, 위상 고정루프, 등화기, 비터비 복호 알고리즘 등의 과정을 거쳐 수신한 후 영상을 확인하였다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.11
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• pp.1214-1219
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• 2010

In this paper, a software radio system, supporting the physical layer of IEEE 802.15.4 standard, has been developed using USRP(Universal Software Radio Peripheral) board and GNU Radio package of an open source development kit for software radio. The software radio system supports the standards of BPSK and OQPSK modulations for 868/915 MHz band and OQPSK modulation for 2.45 GHz band. To verify the operation of the developed system, it has been tested under the standard signals according to the frequency band and packet structures for the transmitting and receiving operation. At 2.4 GHz, the Smart RF EV board and CC2430 modules are used to check the proper operation of the software radio system. The system performance test shows that the emission power spectrum, the eye-pattern, and PER(Packet Error Rate) meet the standard. It has been confirmed that the developed system supports the PHY layer of IEEE 802.15.4.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2013.06a
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• pp.342-343
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• 2013

본 논문에서는 유럽의 디지털 라디오 방송 규격인 DAB+(Digital Audio Broadcasting Plus)와 DRM+(Digital Radio Mondiale Plus) 시스템을 수신하기 위한 소프트웨어 기반의 수신 시스템의 설계 및 구현에 대한 연구를 수행하였다. 기존의 아날로그 FM 수신기를 대체할 수 있도록 소프트웨어 기반의 디지털 라디오 수신 시스템을 구현하였으며, 각 시스템의 USB 수신기로부터 방송을 입력받아 메모리 공유기법을 통해 일괄 수신 처리함으로써 시스템의 부하를 감소시킨다.

• Journal of Broadcast Engineering
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• v.28 no.1
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• pp.149-152
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• 2023

In this paper, I present an approach to implement a real-time video transceiver using software-defined radio (SDR). Through this, it is expected that it will be able to lower the access threshold and provide new perspectives and insights to researchers who want to study the recently spotlighted Open Radio Access Network (O-RAN) and implement it through SDR devices and open software.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.12
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• pp.1650-1658
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• 2019

In recent years, IoT device and platform become widely popular and the computing performance and capabilities of IoT devices are also getting improved. However, the size and computing resources of IoT devices, especially small single board computer, are limited in a way that the design and implementation of the system should be carefully considered to operate on the devices. Recently, SDR technologies are adapting in IoT devices and can perform various radio systems. Thorough analysis and investigation of computer performances on small single board computer are necessary for its usage. In this paper, we present the results of computing resources measurement and analysis on small single-board computers. At first, we consider to design SDR based spectrum sensing for single board computer, investigate various key factors and propose a design procedure that can affect performance of the system with experiments.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.4
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• pp.508-514
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• 2020

To implement the continuously evolving mobile communication standards such as Long Term Evolution (LTE) and 5G, the Software Defined Radio (SDR) concept provides great flexibility and efficiency. For many years, a high-end Digital Signal Processor (DSP) System on Chip (SoC) has been developed to support multicore and various hardware coprocessors. This paper introduces the implementation of the SDR platform hardware using TI's TCI663x chip. Using the platform, LTE transport channel is implemented by interworking multicore DSP with Bit rate Coprocessor (BCP) and Turbo Decoder Coprocessor (TCP) and the performance is evaluated according to various implementation options. In order to evaluate the performance of the implemented LTE transport channel, LTE base station system was constructed by combining FPGA main board for physical channels, SDR platform board, and RF & Antenna board.

• Journal of Space Technology and Applications
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• v.2 no.2
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• pp.121-136
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• 2022

Automatic Identification System used in ship communication is required for marine control way, including monitoring of vessel operation in coastal and exchanging of information for safety navigation between them. But, it uses a very high frequency band of approximately 160 MHz, and at the same time, due to the curvature of Earth, there is a limit to the communication distance. Several demonstrations were made successfully over satellite, but not much work has been done yet through cube-satellite which has low-orbit at 500 km altitude. Here, we demonstrate a reception test of AIS (automatic identification system) receiver for a cube-satellites using software-defined radio (SDR). We collected AIS data from ship at port of Busan, Korea, using R8202T2 SDR and established to transmit them using Adam-Pluto and Matlab Simulink. The process of weakening the signal strength to a satellite was constructed using attenuator. Through above process, we demonstrated whether AIS data was successfully received from the AIS payload.