• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.6
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• pp.1014-1023
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• 2015

This paper presents the method of antenna polarization isolation and resource control for frequency interference reduction due to the frequency reuse between opposite sectors. We have examined the frequency interference between opposite sectors which is occurred by operating base station for reducing frequency interference. The base station has a frequency reusing structure in opposite sector. So, the base station can make a in-band frequency interference. In order to minimize frequency interference, we proposed two methods. The first is the antenna polarization isolation method. The CINR was improved to 27dB from 17dB when using the antenna polarization isolation. The second is resource control which is the method for lining up the RF power and limiting RF power control range of each link. In this paper, by using the proposed two methods, presents a scheme that reduces frequency interference in the frequency reusing structure.

• The Journal of the Korea Contents Association
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• v.5 no.6
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• pp.129-137
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• 2005

A performance analysis of LEO Satellite Communication Service is being made in a variety of ways. In this paper we examined the variation of interference caused by the distribution of terminals within a cell and the maximum number of users according to the average distance between terminals, which had not been considered in former researches. Also we examined the interference made by sopt beam isolation value of some antennas(tapered-apertured antenna, gaussian antenna) which are used on LEO Satellite Communication Service Assigning this interference to the bandwidth of channels in LEO Satellite Communication Service, and with principal parameters(bandwidth, number of carrier) we made a performance analysis. And comparing tapered-apertured antenna with gaussian antenna we will find out which one is more effective and more suitable for interference.

• Journal of Power Electronics
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• v.17 no.1
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• pp.305-313
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• 2017

A novel interference isolation method is proposed by using several designed coils in capacitive power transfer systems as isolation impedances. For each designed coil, its stray parameters such as the inter-turn capacitance, coil resistance and capacitance between the coil and the core, etc. are taken into account. An equivalent circuit model of the designed coil is established. According to this equivalent circuit, the impedance characteristic of the coil is calculated. In addition, the maximum impedance point and the corresponding excitation frequency of the coil are obtained. Based on this analysis, six designed coils are adopted to isolate the interference from power delivery. The proposed method is verified through experiments with a power carrier frequency of 1MHz and a data carrier frequency of 8.7MHz. The power and data are transferred parrallelly with a data carrier attenuation lower than -5dB and a power attenuation on the sensing resistor higher than -45dB.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2002.11a
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• pp.177-181
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• 2002

In this paper, the cancellation or suppression of the feedback interference from Tx antenna using the same frequency is studied. The major problems on the wireless communication system using the same frequency or on-frequency repeater (OFR) are the coupling and isolation between Rx and Tx antenna. In order to increase the isolation between Rx and Tx antenna and to Prevent the self-oscillation of the receiver system, this paper is verified the possibility of the application of interference cancellation system and proposed the design method of the OFR using interference cancellation system.

• Asian Oncology Nursing
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• v.12 no.4
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• pp.297-304
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• 2012

Purpose: This study was to identify the symptom severity, interference and their psychological predictors in thyroid cancer patients hospitalized for radioactive iodine administration. Methods: One hundred seventy-seven thyroid cancer patients admitted to the isolation room for Iodine ($I^{131}$) therapy were recruited. Subjects were asked to complete the questionnaire on core symptoms, thyroid cancer symptoms, interference, depression and state anxiety in the evening after receiving radioactive iodine therapy. Data was analyzed using frequency, percentage, mean, Pearson's correlation, and multiple regression with SPSS vs. 19. Results: Lack of appetite, drowsiness, sleep disturbance, fatigue, and nausea were the 5 most core symptoms. More than 20% of patients experienced moderate to severe thyroid cancer symptoms including feeling cold, hoarseness, swallowing difficulty, and feeling hot. More than 30% of subjects experienced moderate to severe interferences in mood, general activity, and 22% in walking. Depression and state anxiety were identified as predictors of core symptoms, thyroid symptom severity and interference. Conclusion: Nursing interventions to reduce the symptom severity and interference need to be developed by considering thyroid cancer patients' depression and anxiety when hospitalized in the isolation room for radioactive iodine administration.

• ETRI Journal
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• v.33 no.5
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• pp.670-678
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• 2011

This paper investigates the design and performance of a digital on-channel repeater (DOCR) for use in Advanced Television Systems Committee (ATSC) digital television (DTV) broadcasting. The main drawback of a DOCR is the echo interference caused by coupling between transmitter and receiver antennas, which induces system instability and performance degradation. In order to overcome this problem, an echo canceller based on the adaptive echo channel estimation (ECE) technique has been researched and applied for a DOCR. However, in the case of ATSC, the pilot signal, which is used for carrier synchronization, may cause a DC offset error and reduce the isolation performance of the echo canceller for a DOCR in an ATSC network. Moreover, since the multipath fading effect of a radio channel usually occurs in a real environment, it should be minimized to improve the overall performance of a DOCR. Therefore, due to the limited isolation performance of echo canceller and the multipath fading effect, an interference cancellation system (ICS) is proposed for a DOCR in an ATSC network. The performance of the proposed DOCR with an ICS is evaluated by software simulation and hardware test results.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.6
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• pp.295-302
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• 2011

In this paper we consider technological requirements to broadcast digital television signals using single frequency networks(SFN) in the Advanced Television Systems Committee(ATSC) transmission systems and propose Interference Cancellation Digital On Channel Regenerative Repeater(IC-DOCR) thar overcomes the limitation of EDOCR(Equalization Digital On Channel Repeater) proposed by ETRI. The proposed IC-DOCR maintains the benefits of EDOCR that have good output signal quality removing multi-path, additive white Gaussian noise(AWGN). In additional, since the Interference Cancellation algorithm using the 8-VSB symbol demodulation of received signal removes the Interference of feedback signal, IC-DOCR improve the weakness of EDOCR that have low isolation between receive and transmit antenna so that can overcome the limitation of output signal power. we did analysis and verification of the proposed system performance using computational simulation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.9C
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• pp.735-742
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• 2010

In this paper, we propose adaptive algorithms for interference cancellation in RF repeaters with multiple transmit and receive antennas. When multiple antennas are used in a repeater, the imperfect isolation between transmit and receive antennas causes the feedback interference which is modeled as multi-input multi-output (MIMO) channel. To remove the feedback interference, we derive the least mean square (LMS) algorithm and the recursive least squares (RLS) algorithm for interference cancellation based on adaptive signal processing techniques. Through computer simulations for the proposed algorithms, we analyze the convergence characteristics and compare the steady-state performance for interference cancellation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.6
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• pp.1227-1232
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• 2011

Using the notch and isolation, we investigated the insertion loss and isolation characterics of the fabricated dielectric duplexers and bandpass filters for CDMA and W-CDMA dualband. Insertion loss(Tx band) and isolation(between Tx and Rx) of duplxer were about -2.1708dB and 45dB at CDMA band, respectively. Also, in the case of W-CDMA, the insertion loss(Tx band) and isolation(between Tx and Rx) showed about -2.6946 and 100dB, respectively. Summering the aboved results, fabricated the dielectric duplexers and bandpass filters will be contributed the increase of atttenuation and the decrease of interference at CDMA and W-CDMA dualband.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.1
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• pp.27-32
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• 2019

This study describes the design and implementation of a simulated signal generator to demonstrate the performance of VHF band radar for the detection of small targets in RCS(Radar Cross Section). The transmission and reception antenna beam widths used in the simulated signal generating apparatus may be large, which may cause problems in the degree of isolation. Interference signal immunity and isolation characteristics are improved by considering operating conditions of VHF radar to solve isolation of antennas. Simulated signal generator performs the following: VHF radar transmission and reception correction, simulation signal generation, target Doppler, RCS and distance simulation, remote control, and GPS clock synchronization function. After the fabrication of the simulated signal generator, the main characteristics, such as the output characteristics and the reflection signal simulations, were tested. When the microwave radar assembly is completed in the future, it will be utilized for the performance evaluation of VHF radar.