• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.108-109
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• 2022

In this study analyzed experimental data on noise interference caused by engine operating apply surface wave communication in the engine room. For the experiment, 7 areas of the engine room on 256 ton tug boat and measured noise during engine on off using signal analyzer for effect surface wave communication. In order to construct and actual communication network based on the analysis of the noise and confirm the characteristics of surface wave communication in the area made metal bulkheads the actual communication network installed communication equipment between three metal bulkheads and conducted a comparative experiment with wireless communication. The difference was confirmed. As a result, in the case of surface wave communication, there was no significant difference in the transmission and reception rates before and after engine operation in an environment with three bulkheads, but in the case of Wi-Fi using wireless, the performance deteriorated significantly during operation. was confirmed. As a result of analyzing the experimental data, it was confirmed that noise caused by engine operation affects wireless communication but does not affect surface wave communication. Therefore, even in the area with a lot of electromagnetic wave noise in the ship, when the surface wave communication system is configured using the ship's metal structure, it is possible to replace the wireless communication and furthermore, it is possible to apply the surface wave communication in the enclosed space and the engine room in the ship.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.1
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• pp.139-146
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• 2017

The ISDB-T(Integrated Service Digital Broadcasting Terrestrial) can be used in the multipath and impulsive noise, also it provide good performance over mobile reception environment since it use the OFDM(Orthogonal Frequency Division Multiplexing) based transmission technology and time interleaving technology. One segment and full segment are divided according to the number of the assigned segment. And one-segment broadcasting receiver can design and implement without high levels of technology than the full-segment broadcasting receiver using 64QAM(64 Quadrature Amplitude Modulation) since it uses QPSK(Quadrature Phase Shift Keying) modulation/demodulation. However, it has a constraint in the display size and resolution due to data-rate limits. In this paper, we design and implementation of full-segment ISDB-T receiver module which support HD resolution for set-top box, digital TV, navigation. In experimental results, the implemented full-segment ISDB-T receiver module was satisfactory for all of the desired functions.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.3
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• pp.484-490
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• 2016

Full-duplex communication can enhance wireless capacity by enabling simultaneous transmission and reception of the signals on the same frequency spectrum. Such a benefit, however, is only achieved when strong self-interference is well canceled below a sufficient level. To achieve this goal, there have been several approaches for cancellation, each of which is combined with digital-domain cancellation for a higher gain. In this paper, we implement two self-interference cancellation techniques and integrate them with a software defined radio-based wireless communication testbed. Two cancellation techniques (antenna cancellation and noise subtraction) are implemented and the cancellation gain is measured via real experiments. The results show that the gain of the antenna placement technique highly depends on the placement of a receiving antenna and the highest gain is achieved at the expected point, and we show that combining the noise subtraction circuit with the antenna placement further improves the cancellation gain.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.5 no.2
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• pp.10-19
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• 1994

The error rate equation of Reed-Solomon/Convoutional concatenated coded MFSK signal transmitted over m-distributed fading channel with Additive White Gaussian Noise (AWGN) and re- ceived with Maximal Ratio Combining (MRC) diversity has been derived. The bit error probability has been evaluated using the derived equation and shown n figures as a function of signal to noise ratio, fading index and the number of diversity branches. From the results obtained, we have shown that the bit error probability of MFSK signal is improved by using coding technique in fading environment. The concatenated coding technique is found to be very effective. When concatenated coding and MRC diversity reception techniques are used together in fading environ- ment, the improvement of error performance attains about 6.6 dB in terms of SNR as compared with that of employing only concatenated coding case.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.2
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• pp.175-180
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• 2015

In this paper, GPS / GLONASS receiving a small active antenna is proposed. A microstrip patch antenna which supports dual-band (GPS and GLONASS) was optimized. The antenna size is $13{\times}13{\times}3.6mm$. The jig was changed to confirm the proposed antenna characteristic size, was adjusted to feed gap of the patch antenna, it was confirmed by change in LNA shield case or not. The antenna jig size is $65.6{\times}13{\times}0.8mm$. The maximum gain of the GPS band is 3.78dBi, the maximum gain of the GLONASS bands is 4dBi. To amplify the Satellite reception signal level, one-stage low noise amplifier(LNA) was designed. The LNA chip was using the BGA715 N7, the LNA gain is 19.9dB. The utilization possibility of the GPS / GLONASS receiving a small active antenna could be confirmed according to compare and analyze the simulation and measurement data.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.2 no.2 s.3
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• pp.1-12
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• 2003

DAB(Digital audio broadcasting) is a next generation radio broadcasting system which provides CD quality audio, various data services and superior reception ability when moving. Also, it can show traffic informations and news literally or graphically. In this paper, we design and fabricate the DAB tuner for ITS service that follows Eureka-147 and ETSI 300 401 specifications. This small-sized tuner can be adopted to mny electronic equipments such as a Hi-Fi audio, DVD player, car audio system etc.. The overall performance of the tuner depends on a phase noise of VCO and the sensitivity of the receiving system is influenced by LNA, image rejection filter and channel selection filter. All our measurement results satisfy the specification for a DAB system with the return loss of 9dB, the noise figure of 6dB for both Band 111 and L-band and the sensitivity of -97dBm.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.9
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• pp.1856-1863
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• 2012

Two separate antennas are usually adopted in high performance radar systems to achieve the high degree of isolation since the transmission and reception of signals cannot be separated in time. However, even though two spatially separated antennas are installed in the system, strong signals from a transmission antenna can cause the serious interference problem in a receiving antenna. These strong interference signals from the transmission antenna can cause serious problems in detection and analysis of much weaker echo signals which are reflected by small targets. Also the increased level of background noise power due to interference can cause the serious degradation of the system performance. Therefore, in this paper, the proper cancellation method is suggested and results are shown and analyzed for removal of strong interference and background noise power.

• Journal of Convergence for Information Technology
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• v.10 no.11
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• pp.23-29
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• 2020

As IoT devices increase exponentially, minimizing MIMO interference and increasing transmission capacity for sending and receiving IoT information through multiple antennas remain the biggest issues. In this paper, secret key-level distribution mechanism using deep learning is proposed to minimize MIMO-based IoT communication noise. The proposed mechanism minimizes resource loss during transmission and reception process by dispersing IoT information sent and received through multiple antennas in batches using deep learning. In addition, the proposed mechanism applied a multidimensional key distribution processing process to maximize capacity through multiple antenna multiple stream transmission at base stations without direct interference between the APs. In addition, the proposed mechanism synchronizes IoT information by deep learning the frequency of use of secret keys according to the number of IoT information by applying the method of distributing secret keys in dimension according to the number of frequency channels of IoT information in order to make the most of the multiple antenna technology.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.5
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• pp.63-70
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• 2020

In this paper, the transmit-receive module for military seekers has been designed and fabricated in 35 GHz. To increase the performance of substrates and high integration of circuits in millimeter-wave band, a 4-layer LCP(Liquid Crystal Polymer) substrate was developed. This substrate was implemented with three FCCL substrates and two adhesive layers, and a process using the difference in melting point between the substrates was used for lamination. Using a strip line and a microstrip line was confirmed by the transmission loss along the length of the substrate, and the performance of LCP substrates was validated with a power divider in 35 GHz. After confirming the performance of individual blocks such as power amplifier and low noise amplifier, a single channel Ka-band transmission/reception module was developed using a 4-layer liquid crystal polymer substrate. The transmit power of this module has above 1.1W in pulse duty 10% and has an output power of 1.1W and it has receive noise figure less than 8.5 dB and receive gain more than 17.6 dB.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.6 no.3
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• pp.55-67
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• 1995

The error rate equations of MPSK and DS/MPSK radio signals transmitted through the m-distributed fading channel in Gaussian noise and tone interference environments have been derived. Using the derived equations, the error rate performance is evaluated and shown as functions of carrier-to-noise ratio, carrier-to-interference ratio, processing gain, fading index and the number of diversity branches. The derivation has been done for two cases. The first case assumes that only the signal is undergoing the influence of fading, and the second case assumes that both signal and interference are undergoing the influence of fading simultaneously. From the obtained results, we have known that the error performance of MPSK signal is improved by using diversity technique and direct sequence spread spectrum technique even in a fading environment. Also comparing the error rate performance of two cases, the latter is worse than the former.