• 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.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10a
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• pp.355-357
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• 2003

최근 급속한 발전으로 인해 다양해지고 있는 무선 통신 기술들은 각자의 고유한 주파수, 채널 부호화 기법. 변복조 기법을 쓰는 경우가 많다. 이로 인해, 다양한 무선 통신 기술간의 비호환성 문제가 제기되고 있다. 이러한 문제를 해결하기 위한 기술이 SDR(Software Defined Radio)이다. SDR은 신호 처리(Signal Processing)를 소프트웨어적으로 구현하는 것이다. 이러한 SDR 기술은 하나의 하드웨어를 이용해서 설러 무선 통신 기술들을 이용할 수 있게 한다. 현재 대부분의 SDR의 연구는 재구성 가능한 하드웨어 로직과 코어 프레임워크인 SCA(Software Communication Architecture)로 초점이 맞추어지고 있다 하지만 SDR 시스템의 특성을 고려했을 때, 실시간성(Real-Time)과 유연성(Flexibility), 재구성(Reconfigurability)을 위한 기능을 추가하기 위해 이에 적합한 운영체제의 연구가 필요하다. 본 논문에서는 휴대 기기에서의 SDR 시스템에 대해 간략히 알아보고 이를 위한 운영체제의 요구사항을 설명하여 그에 적합한 운영체제의 구조와 재구성 기법을 설명한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.3
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• pp.674-680
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• 2008

An SDR (Software Defined Radio) system based on general purpose computing platform has benefits of ease of software development process, high degree of software compatibility, and cost-effectiveness of general purpose processors. This paper discusses design and implementation of a dual-mode SDR system that supports both cordless phone and walkie-talky system running on Linux-based general purpose computing platform. For this purpose, we designed modulation and demodulation software on open source-based GNU radio middleware. We also designed a customized RF front-end hardware which performs frequency conversion between RF and IF. The proposed SDR system successfully exhibited its ability to operate both cordless phone and walkie-talky communication on Intel processor-based general purpose computing platform. But experience with the prototype SDR system shows that further research is required for run-time software reconfiguration and efficient integration with conventional TCP/IP protocol stacks.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04d
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• pp.319-321
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• 2003

IMT2000다음으로 개방형 구조를 갖는 차세대 통신 시스템(SDR: Software Defined Radio)에 적용할 수 있는 정보보안 메커니즘으로 블록암호화 알고리즘인 'SEEO'를 구현하였다. SDR의 플랫폼은 주로 프로그래머블(Progammable)한 FPGA가 DSP가 주를 이루는데. 본 논문은 이러한 SDR 시스템 대상으로 적용할 수 있는, 한국형 블록 암호 알고리즘인 'SEED'를 DSP, FPGA로 구현하고 성능비교. 분석을 통하여 효과적이고 합리적인 SDR 암호화 모듈 구현의 방향을 모색해 보았다.

• Journal of Positioning, Navigation, and Timing
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• v.7 no.4
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• pp.189-203
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• 2018

In this paper, a Software Defined Radio (SDR) architecture was designed and implemented for rapid prototyping of GNSS receiver. The proposed SDR can receive various GNSS and direct sequence spread spectrum (DSSS) signals without software modification by expanded input parameters containing information of the desired signal. Input parameters include code information, center frequency, message format, etc. To receive various signal by parameter controlling, a correlator, a data bit extractor and a receiver channel were designed considering the expanded input parameters. In navigation signal processing, pseudorange was measured based on Coordinated Universal Time (UTC) and appropriate navigation message decoder was selected by message format of input parameter so that receiver position can be calculated even if SDR is set up various GNSS combination. To validate the proposed SDR, the software was implemented using C++, CUDA C based on GPU and USRP. Experimentation has confirmed that changing the input parameters allows GPS, GLONASS, and BDS satellite signals to be received. The precision of the position from implemented SDR were measured below 5 m (Circular Error Probability; CEP) for all scenarios. This means that the implemented SDR operated normally. The implemented SDR will be used in a variety of fields by allowing prototyping of various GNSS signal only by changing input parameters.

• Journal of Korea Society of Digital Industry and Information Management
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• v.14 no.4
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• pp.93-99
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• 2018

This paper presents an implementation method using NDK (Network Developer's Kit) of GNU (GNU is Not Unix) Radio and Multicore DSP (Digital Signal Processor) to implement LTE (Long Term Evolution) SDR (Software Defined Radio) Platform. In order to satisfy 1.4MHz, 3MHz, 5MHz and 10MHz of the bandwidth supported by LTE, USRP (Universal Software Radio Peripheral) X series which is an RF (Radio Frequency) transceiver of Ettus Research was used. To control this, GNU Radio which is an open source software radio toolkit was used. We also used NDK from TI (Texas Instruments) DSP to transfer data between USRP and DSP. Experimental results show throughput results according to each bandwidth, thus confirming the feasibility of implementing LTE SDR Platform using GNU Radio and NDK of TI DSP.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.6
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• pp.657-664
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• 2014

In this paper, we described evaluation software that can propose rating scale and evaluate automatically on SDR(Software-Defined Radio) transmitter system. To deduct suitable rating scale, we extracted requirements based on the operating environment, operating application and operating method because SDR operating software is subordinative to the hardware. And we implementation evaluation software to automatically quality evaluation using rating scale draw from the requirements. The implemented evaluation software has automatically evaluation functions using script, can update the evaluation factor and show visual evaluation result. The implemented evaluation software is used to useful the high quality SDR operating software development.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.2
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• pp.81-87
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• 2013

In this paper, we present an implementation of Long Term Evolution (LTE) Uplink (UL) system on a Software Defined Radio (SDR) platform using a conventional Personal Computer (PC), which adopts Graphic Processing Units (GPU) and Universal Software Radio Peripheral2 (USRP2) with URSP Hardware Driver (UHD) for SDR software modem and Radio Frequency (RF) transceiver, respectively. We have adopted UHD because UHD provides flexibility in the design of transceiver chain. Also, Cognitive Radio (CR) engine have been implemented by using libraries from UHD. Meanwhile, we have implemented the software modem in our system on GPU which is suitable for parallel computing due to its powerful Arithmetic and Logic Units (ALUs). From our experiment tests, we have measured the total processing time for a single frame of both transmit and receive LTE UL data to find that it takes about 5.00ms and 6.78ms for transmit and receive, respectively. It particularly means that the implemented system is capable of real-time processing of all the baseband signal processing algorithms required for LTE UL system.

• ETRI Journal
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• v.38 no.3
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• pp.455-462
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• 2016

Frequency hopping (FH) is a common characteristic of a wide variety of communication systems. On the other hand, software-defined radio (SDR) is an increasingly utilized technology for implementing modern communication systems. The main challenge when trying to realize an SDR FH system is the frequency tuning time, that is, the higher the hopping rate, the lower the required frequency tuning time. In this paper, significant universal hardware driver tuning options (within GNU Radio software) are investigated to discover the tuning option that gives the minimum frequency tuning time. This paper proposes an improved SDR frequency tuning algorithm for the generation of a target signal (with a given target frequency). The proposed algorithm aims to improve the frequency tuning time without any frequency deviation, thus allowing the realization of modern communication systems with higher FH rates. Moreover, it presents the design and implementation of an original GNU Radio Companion block that utilizes the proposed algorithm. The target SDR platform is that of the Universal Software Radio Peripheral USRP-N210 paired with the RFX2400 daughter board. Our results show that the proposed algorithm achieves higher hopping rates of up to 5,000 hops/second.

• TTA Journal
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• s.82
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• pp.72-79
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• 2002