• Information and Communications Magazine
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• v.19 no.11
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• pp.109-122
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• 2002

최근 Software Defined Radio(혹은 Software Radio) 관련 연구가 국내외에서 활발해지면서 RF부품 및 시스템에 적용하기 위한 연구가 새로운 주제로 부각되고 있다. 본 고에서는 이러한 추세에 맞추어 RF 대역에서 부품 및 시스템의 연구 내용 검토하며, 가장 문제가 된다고 판단되는 대역통과여파기의 설계를 중심으로 논의하고자 한다.

• Journal of electromagnetic engineering and science
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• v.3 no.2
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• pp.91-98
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• 2003

Software Communication Architecture(SCA) has been made to reduce the development period of new waveform applications by reusing design modules. Software Defined Radio(SDR) forum adopted SCA specification and follows its design concept. However, SCA specification does not describe interfaces and deployments of resources in details, which are software components, and how to implement them as well as how to communicate each other are another missing points in specification. In this paper, we propose a resource design methodology and details of adapter implementation for Core Framework(CF) that is a core set of open interface and services providing an abstraction of the underlying software and hardware layer. We also present SDR prototype system which communicates with resources implemented in different programming languages and processors in legacy environment through our design methodology.

• Journal of electromagnetic engineering and science
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• v.18 no.1
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• pp.58-62
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• 2018

In this study, we propose a software-defined radio-based frequency interference emulator in the space-time domain. This emulator can easily model actual interference environments because of the versatile programming capability of the universal software radio peripheral and LabVIEW. As an example of an interfering network using the contention-based multiple access scheme in the time domain, we emulate a coordinated Wi-Fi network that consists of one access point and two Wi-Fi nodes. Results show that our emulator can successfully model multiple interfering signals in the Wi-Fi network and easily adjust various space-time domain parameters.

• Information and Communications Magazine
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• v.19 no.12
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• pp.97-104
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• 2002

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

• Journal of IKEEE
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• v.26 no.4
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• pp.568-576
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• 2022

Automatic modulation classification(AMC) is a core technique in Software Defined Radio(SDR) platform that enables smart and flexible spectrum sensing and access in a wide frequency band. In this study, we propose a simple yet accurate deep learning-based method that allows AMC for variable-size radio signals. To this end, we design a classification architecture consisting of two Convolutional Neural Network(CNN)-based models, namely main and small models, which were trained on radio signal datasets with two different signal sizes, respectively. Then, for a received signal input with an arbitrary length, modulation classification is performed by augmenting the input samples using a self-replicating padding technique to fit the input layer size of our model. Experiments using the RadioML 2018.01A dataset demonstrated that the proposed method provides higher accuracy than the existing methods in all signal-to-noise ratio(SNR) domains with less computation overhead.

• 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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.5A
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• pp.494-499
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• 2008

In this study, a Software Defined Radio(SDR) technology-based digital filtering technique applicable to a multiple channel processing system such as a wireless mobile communication system using Code Division Multiple Access(CDMA) technology is proposed. The technique includes a micro-processor to redesign Finite Impulse Response(FIR) filter coefficients according to specific system information and to download the filter coefficients to one digital Band Pass Filter(BPF) to reconfigure another system. The feasibility of the algorithm is verified by implementing a multiple channel signal generator that is reconfigurable to other system profiles, including those for a CDMA system and a WCDMA system on identical hardware platform.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.1
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• pp.57-63
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• 2014

In this paper, we have proposed a wide band antenna for manpack SDR(Software Defined Radio). The proposed antenna consists of feeding post, flexible gooseneck and two radiating elements composed of a upper and lower radiators. The upper radiator has a longer electrical length than the lower radiator in order to operate in the lower frequency. Also, the resonant frequency and impedance characteristics of the antenna can be adjusted independently for two radiators. Therefore, the proposed antenna can be achieved wide impedance bandwidth by the combination of two independent resonance modes. To analyze the characteristics of the antenna in the design process is employed the equivalent circuit theory and EM(Electro-Magnetic) simulation. The measurement results show that the proposed antenna have the sufficient wide bandwidth, above -3.4dBi of the gain and fairly good radiation pattern over the wide bandwidth.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.969-972
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• 2009

With the advent of the era of ubiquitous computing, the number of wireless communication devices has been exponentially increasing, which phenomenon requires for the preparation for the upcoming shortage of frequency resource. Recently, in consequence, the concept of Cognitive Radio (CR) was introduced in which the wireless nodes periodically recognize and learn the external conditions of communication including the usage of the frequency spectrum. It is essential to assure sufficient range of frequency to satisfy the users of the increasing wireless network devices. However, since not only the frequency band for wireless communication is finite, but most part of them had already been assigned for the primary users of the wireless network service, it is very difficult to ensure the band of frequency for additional communication service. In this contribution, we analyze and describe the issues of designing and implementation of CR networks.