• Title/Summary/Keyword: Radio Resources

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A Method for Quantifying Spectrum Use (스펙트럼 이용 계량화 방법)

  • 김영수;이형수;정영호;김상원;정진욱
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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    • v.6 no.3
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    • pp.24-35
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    • 1995
  • In this paper, we study the Spectrum Use Measure(SUM) model for quantifying the extent of spectrum use by existing radio communication systems. This model calculates the interference level between transmitters and receivers by applying the EMC analysis technique of interference prediction process such as antenna radiation pattern model and propagation model which are well known. While several previous works have described the spectrum resources by constructing the interference contours around existing radio systems, the SUM technique is developed for quantifying and portraying the spectrum resources used by radio communication systems in a geographic area. Computer simula- tion results are illustrated to verify the calculations for the Spectrum Use Bandwidth(SUB) and Spectrum Use Factor (SUF) performed by the SUM model and find the usefulness of the SUM model.

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Resource Allocation based on Hybrid Sharing Mode for Heterogeneous Services of Cognitive Radio OFDM Systems

  • Lei, Qun;Chen, Yueyun
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.1
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    • pp.149-168
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    • 2015
  • In cognitive radio networks (CRNs), hybrid overlay and underlay sharing transmission mode is an effective technique for improving the efficiency of radio spectrum. Unlike existing works in the literature, where only one secondary user (SU) uses overlay and underlay modes, the different transmission modes should be allocated to different SUs, according to their different quality of services (QoS), to achieve the maximal efficiency of radio spectrum. However, hybrid sharing mode allocation for heterogeneous services is still a challenge in CRNs. In this paper, we propose a new resource allocation method for hybrid sharing transmission mode of overlay and underlay (HySOU), to achieve more potential resources for SUs to access the spectrum without interfering with the primary users. We formulate the HySOU resource allocation as a mixed-integer programming problem to optimize the total system throughput, satisfying heterogeneous QoS. To decrease the algorithm complexity, we divide the problem into two sub-problems: subchannel allocation and power allocation. Cutset is used to achieve the optimal subchannel allocation, and the optimal power allocation is obtained by Lagrangian dual function decomposition and subgradient algorithm. Simulation results show that the proposed algorithm further improves spectrum utilization with a simultaneous fairness guarantee, and the achieved HySOU diversity gain is a satisfactory improvement.

Investigation of ITU Radio Regulations Regarding KPS Service Band

  • Subin Lee;Kahee Han;Jong-Hoon Won
    • Journal of Positioning, Navigation, and Timing
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    • v.12 no.2
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    • pp.177-184
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    • 2023
  • In order to reserve frequency bands for stable operation of the Korean Positioning System (KPS), it must be demonstrated that the impact of interference caused by KPS on other services operating in the same bands is tolerable. The International Telecommunication Union (ITU) provides the radio regulations and a compatibility assessment methodology for the coexistence of different services in limited frequency resources. The purpose of this paper is to investigate the radio regulations regarding the compatibility issues between the KPS and other services sharing the same frequency bands. The results of the investigation show that the RNSS system can be operated in the L5-band under the condition that the Power Flux Density (PFD) and Aggregated Equivalent PFD (AEPFD) thresholds specified in the radio regulations are met. In addition, the ITU recommends that the interference-to-noise ratio (INR) protection criteria be met to prevent degradation of the performance of radar systems operating in the L2/L6-band. In the case of the S-band, coordination of allocations for RDSS space stations with respect to terrestrial services is not required if the PFD does not exceed regulated thresholds regulated by ITU.

A Study on Appropriate Licensing of Convergence Products through Comparative Analysis of Domestic Radio Station and Other Industrial Licensing (국내 무선국 및 타 산업 인·허가제도 비교분석을 통한 융합상품의 적정 인·허가제도 조성방안에 관한 고찰)

  • Yeon, In-Won;Choi, Joo-Pyoung;Lee, Won-Cheol
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.28 no.12
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    • pp.974-981
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    • 2017
  • Globally, owing to the rapid expansion of radio stations overseas, the frequency coordination system is managed as a preconditioning system. As a result, it is predicted that many types of radio stations will be established for domestic purposes, such as 5G, low-power IoT devices with long distance, based on licenses and non-license in the future. Many problems such as unnecessary launching of radio resources and spectrum-sharing technology exist, and it is necessary to consider the introduction of the abovementioned system and other plan system. In this paper, we explore the outline of radio station licensing and introduce the contents of the survey on another industry licensing. The plans were studied by discussing problems that may occur in future, through comparative analysis of radio stations and other industry licensing. Moreover, the differences were compared and analyzed using graphs. Finally, we discussed the problems convergence products such as drone may offer in the future.

A Resource Design Methodology and Adapters Implementation for Core Framework for Software Defined Radio

  • Son, Jin-Ho;Tai M. Chung
    • 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.

A Study on the Frequency Sharing between HEO FSS System and GSO FSS Network in the 12GHz Band (12GHz 대역에서 HEO 위성시스템과 GSO 위성망간의 주파수 공유 방법 연구)

  • Lim, Sang-Hee;Seong, Hyang-Suk
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2003.11a
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    • pp.567-571
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    • 2003
  • Owing to the insufficient satellite resources such as frequency and orbit, the interest in the sharing of these resources has been increasing. ITU-R has been studying on the power limitation, the interference mitigation techniques etc. in order to facilitate the frequency sharing between different systems. Therefore, we studied on the interference mitigation techniques between HEO FSS system and GSO FSS network. We performed the simulation using four mitigation techniques and, based on the results of simulation, evaluated these techniques.

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Software structure design for processing various tactical data

  • Kim, Jin Woo;Lee, Woo Sin;Lee, Seung Chan;Kim, Young Don;Jin, So Yeon
    • Journal of the Korea Society of Computer and Information
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    • v.22 no.11
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    • pp.39-47
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    • 2017
  • In this paper, we propose a message transmission processing structure for efficient use of radio resources. Existing tactical data links have more data and accumulate more data than the amount of tactical data planned according to the situation. This may result in delays in operations and additional problems. To prevent this, priority is assigned to the message and transmission is performed according to the priority on a single basis. And we design a processing structure that can update duplicate messages and delete old messages in order to prevent waste of radio resources. Experiments are conducted to verify that these structures can be implemented and applied to data links.

Revising Passive Satellite-based Soil Moisture Retrievals over East Asia Using SMOS (MIRAS) and GCOM-W1 (AMSR2) Satellite and GLDAS Dataset (자료동화 토양수분 데이터를 활용한 동아시아지역 수동형 위성 토양수분 데이터 보정: SMOS (MIRAS), GCOM-W1 (AMSR2) 위성 및 GLDAS 데이터 활용)

  • Kim, Hyunglok;Kim, Seongkyun;Jeong, Jeahwan;Shin, Incheol;Shin, Jinho;Choi, Minha
    • Journal of Wetlands Research
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    • v.18 no.2
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    • pp.132-147
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    • 2016
  • In this study the Microwave Imaging Radiometer using Aperture Synthesis (MIRAS) sensor onboard the Soil Moisture Ocean Salinity (SMOS) and Advanced Microwave Scanning Radiometer 2 (AMSR2) sensor onboard the Global Change Observation Mission-Water (GCOM-W1) based soil moisture retrievals were revised to obtain better accuracy of soil moisture and higher data acquisition rate over East Asia. These satellite-based soil moisture products are revised against a reference land model data set, called Global Land Data Assimilation System (GLDAS), using Cumulative Distribution Function (CDF) matching and regression approach. Since MIRAS sensor is perturbed by radio frequency interferences (RFI), the worst part of soil moisture retrieval, East Asia, constantly have been undergoing loss of data acquisition rate. To overcome this limitation, the threshold of RFI, DQX, and composite days were suggested to increase data acquisition rate while maintaining appropriate data quality through comparison of land surface model data set. The revised MIRAS and AMSR2 products were compared with in-situ soil moisture and land model data set. The results showed that the revising process increased correlation coefficient values of SMOS and AMSR2 averagely 27% 11% and decreased the root mean square deviation (RMSD) decreased 61% and 57% as compared to in-situ data set. In addition, when the revised products' correlation coefficient values are calculated with model data set, about 80% and 90% of pixels' correlation coefficients of SMOS and AMSR2 increased and all pixels' RMSD decreased. Through our CDF-based revising processes, we propose the way of mutual supplementation of MIRAS and AMSR2 soil moisture retrievals.

Finding Candidate Frequency Bands for Spectrum Sharing in the Frequency Range of 1~4.5 GHz (1~4.5 GHz 대역 내의 공동사용 후보 주파수 대역 발굴)

  • Oh, Se-Jun;Kang, Young-Heung;Bae, Jong-Kee;Park, Duk-Kyu
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.24 no.8
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    • pp.820-830
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    • 2013
  • As wireless traffic drastically increase with the expansion of smart equipment, it is necessary to develop spectrum sharing technologies and introduce spectrum sharing policy for utilizing limited radio resources efficiently. In order to meet these new changes, this parper investigated the government-held (or license) spectrum to seek candidate frequency bands of spectrum sharing. Based on the database of the existing radio station, the investigated candidate frequency bands of spectrum sharing was experimented locally, considering the central frequency, bandwidths, and the region where the radio station is usedIn conclusion, we found out about 901 MHz bandwidths for regional spectrum sharing within the spectrum of 1~4.5 GHz. These bandwidths can be utilized in M2M and WiFi services, etc. based on spectrum sharing technology in the future.

Spectrum Sensing with Diversity Combining Technique in Cognitive Radio (인지 라디오 시스템에서 다이버시티 기법을 사용한 스펙트럼 검출)

  • Lee, So-Young;Kim, Eun-Cheol;Cha, Jae-Sang;Park, Yong-Woon;Hwang, Sung-Ho;Kim, Ki-Hong;Min, Joon-Ki;Kim, Seong-Kweon;Cho, Ju-Pill;Kim, Jin-Young;Kang, Jang-Mook
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.9 no.3
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    • pp.179-185
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    • 2009
  • Cognitive radio (CR), which is proposed as a technology that utilizes the frequency resources effectively, has studied to relive scarcity of the frequency resources. CR provides opportunistically unused frequency to the secondary user when the primary user is not detected. Spectrum sensing is the most important technology to detect primary user. However, in the wireless channels, according to the effect of multipath fading channel, spectrum sensing performance is compromised. Therefore, in this paper, we apply diversity scheme that is a useful technique for combating multiple fading in wireless communications. There are several classes of diversity scheme, which are time diversity, antenna diversity, muitipath diversity, frequency diversity, and so on. In this paper, we adopt antenna diversity that is a kind of space diversity. By using the proposed method, we can overcome fading effect and improve spectrum sensing performance.

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