• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.5A
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• pp.529-535
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• 2011

The HF communication method is capable of communicating short and long distances without a separate relaying method and is used as the primary/secondary communication method in other nations. However, the Korean military strongly discouraged the use of the method due to issues regarding the skip zone and the fact that the usable frequency changes according to irregularities in the ionosphere. The NVIS communication is less susceptible to noise than typical communications using ionosphere reflection, and is also able to communicate short distances containing skip zones. In this paper, we inspect the NVIS communication methods of foreign nations in order to facilitate the use of HF communications, as well as provide solutions to the issues mentioned above. This paper explains the concept of NVIS communication, and investigates how the Korean military is implementing HF communications based on actual communications data of military corps. Based on this result, we have verified the possibility of overcoming skip zones through NVIS communications, and have considered the applicability of a prediction program in order to enhance the efficiency of HF communications.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.429-430
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• 2009

본 논문에서는 기존의 해상 통신망으로서 쓰이는 HF 채널 대역을 이용하여 HF 채널을 기반으로 릴레이 방식을 연구하였다. 위성통신을 이용하는 데이터 통신은 비싼 통신료로 인하여 해상통신(Maritime Communication)에서 대형선박에서는 사용이 가능하지만 중소형선박이나 여가용 선박에서 사용하기가 힘들기 때문에 저렴한 데이터 통신을 이용할 수 있는 기존의 해상 통신과 HF채널 대역을 사용하는 통신을 분석하여, HF 채널 대역에서의 릴레이의 적용 가능성에 대하여 분석하고 조사하여, 그에 따른 BER 성능을 HF 채널 대역 상에서 분석하여 제시하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.4
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• pp.1000-1005
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• 2008

The US government has designed new military standard vocoder algorithm, which is called MELP algorithm, to provide robust communication performance on poor channel environment. In this paper, we analyze transmission effect of security communication in MELP vocoder environment of HF channel. MELP vocoder develop properly application in environment of HF channel and influence of MELP vocoder and channel encoding apply to in envitonment of wireless burst and performance of plaintext communication and security communication study a matter from analysis of MOS and spectrum analysis.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.4
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• pp.774-781
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• 2004

The HF band SSB communication of coast radio station had operated with principal axis of maritime communication until early in the 1990. But, that is changed with development of data communication and satellite technique, which have operated a few by rapidly decrement of user with accomplishment of the CMDSS. Recently, the radio system of HF band is expanded to globe maritime communication, which is support to maritime safety information and data traffic service by low charge with the SSB high speed modem. This study have proposed the digitalize method for maritime communication system using HF band in domestic.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.153-158
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• 2007

The INMARSAT is able to long range maritime communications that can not use for expensive charge in non-SOLAS ship. Therefore, international discussion for the question that replacements use of MF/HF band for maritime distress and safety communications in maritime. HF data communications system may be effectively utilized for SOLAS ships as well as for the existing non-SOLAS vessels including the fishing boats, which navigate A2 and A3 sea areas. The HF data communications may have various functions such as e-mail services, broadcasting services of up-to-date information related to marine safety, position reporting services, polling services etc. However, the present HF e-mail communications protocols have a problem of increasing calling redundancy as the number of channels in operation increases. This paper new protocol and communication sequence proposed in this submission establishes a proper radio link automatically and adaptively by taking channel traffic into account.

• Proceedings of the KAIS Fall Conference
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• 2008.05a
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• pp.118-120
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• 2008

본 논문에서는 HF channel 환경에서 MELP부호화 방식을 이용한 보안 통신의 전송영향을 분석하였다. MELP부호화 방식은 HF채널에 적합하게 적용되도록 개발되었으며 무선 버스터 환경에서 MELP 부호화 영향과 채널부호화 방식을 적용함으로써 평문통신과 보안통신의 성능을 MOS와 스펙트럼 분석을 통해 성능을 고찰하였다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.12
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• pp.2549-2554
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• 2011

This paper describes on development of integrated interface and applications to support stable digital data communication service for small and midium sized crafts exploiting SSB modems and HF wireless sets. Firstly, integrated interface module between GPS (Global Positioning System) and communication devices was developed. Secondly, maritime map was implemented into a display terminal to provide location tracking service and voyage planning function. In addition, condition monitoring service of crafts and fishing report functions as well as alarm functions were developed to support secure fishery. Results of performance measure on developed application services shows that error rate was less than 3% and communication delay was shorter than 1 second when a message length was less than 1 Kbyte along with one-to-many communication type.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2016.06a
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• pp.73-74
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• 2016

본 논문에서는 ITU-R M.1798-1 에 기반한 해상 HF 데이터 통신을 위한 세 가지 종류의 디지털 통신 방식을 소개하고 비교한다. 처음 두 개의 시스템은 3 kHz 대역폭을 사용하는 디지털 통신 방식으로서 OFDM 방식과 멀티 톤 방식의 디지털 모뎀이며, 마지막 세 번째 방식은 10-20 kHz 의 대역폭을 사용하는 OFDM 방식의 디지털 통신 모뎀이다. 본 연구를 통하여 각각의 통신 방식에 대한 물리계층 규격을 비교 분석한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.81-85
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• 2008

The INMARSAT is able to long range maritime communications that can not use for expensive charge in small ship. Additional an opinion of unuseful NBDP that is international discussion for replacement methods for the effective data communications by using HF band. A feature of HF band communication is ionospheric propagation that have not the distance question as A2, A3 and A4 sea areas. Therefore all navigation ship should has supplied service such as MSI, VMS, E-mail beside of distress and public communication that is demanded a design of communication sequence for using SSB transceiver. This paper has designed the new packet and communication sequence of truly and automatically radio link for maritime data communications by SSB in HF band.

• Journal of Advanced Navigation Technology
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• v.16 no.1
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• pp.35-40
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• 2012

In this paper, we present the size reduction method of HF whip antenna for ship communication. To reduce the size of the HF whip, the end part of linear whip is modified to helical type. We designed the whip antenna with 60% size of the commercial whip antenna and carried out communication experiments using the commercial and the designed whip antennas. From the experimental results, we found that the proposed whip antenna can replace the commercial whip antenna for ship communication.