• Journal of Broadcast Engineering
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• v.8 no.2
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• pp.116-125
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• 2003

In this paper, we introduce a newly developed DSP module and Software which Is applicable to DTV-OCR and is designed to cancel the interference signal. In general, RF repeater has problems of system oscillation and signal Quality degradation due to feedback interference signal coming from transmit antenna. In this paper, we demonstrate newly developed DSP HW and SW module for cancelling the interference signal by investigating the field data measured through a RF repeater. Also, the structure and signal processing method for non-regenerative repeater system based on the newly developed DSP HW and SW module is illustrated as well.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.11
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• pp.1320-1331
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• 1992

The error rate equation of FH/MFSK signal of repeated diversity received over m-distribution fading channel with partial-band interference has been derived and the error rate has been evaluated to show in figures as a function of signal to noise ratio, signal to interference ratio, fading figure, repeated number, partial-band interference fraction and power correlation coefficient between signal and interference. In this paper, we assumed that repeated diversity technique is used in transmitter against fading occurred in mobile radio channel. By comparing the error rate performance in diversity against fading and the obtainable degree of improvement of error performance with diversity technique has been found out. From the result, it is known that error rate performance deteriorates more as $\rho$ becomes small i.e., the partial-band interference gives more effect on error performance than full-band interference. Also when the values of $E_b/N_1$ and $\rho$ are small. as depth of fading diversity technique.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.3
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• pp.331-337
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• 2016

In this paper, we analyze performances of in-band full-duplex communication system and self-interference (SI) suppression methods in environment where there exists the SI signal. The SI has to be removed to achieve required error rate performance of the system in order - propagation domain, analog domain and digital domain. In propagation domain, the SI signal is attenuated by separating transmitted and received beams physically. In analog and digital domain, after reconstruction of the SI signal using channel estimates and transmit signal, the SI signal can be cancelled from the desired signal. In this paper, assuming that the SI signal can be sufficiently reduced in propagation domain, we demonstrate that the in-band full-duplex communication system can achieve the target error rate by suppressing the SI signal in order - analog and digital domain, based on channel estimates that can be obtained by the method of Least squares.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.359-364
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• 2006

Interference can seriously degrade the performance of GPS receiver because GPS signal has extremely low power at earth surface. This paper presents a Narrowband Interference Excision Filter (NIEF) in frequency domain that removes narrowband interferences with small signal loss. A NIEF transforms the received GPS signals with interferences into the frequency domain with FFT and then compute statistics such as mean and standard deviation to determine an excision threshold. All spectrums exceeding the threshold are removed and the remaining spectrums are restored by IFFT. A NIEF effectively can remove various and strong interferences with a simple structure. However, the signal power loss is unavoidable during FFT and IFFT. Besides the hamming window and overlap technique, a threshold-whitening technique and an adaptive detection threshold are adopted to effectively reduce the signal power loss. The performance of implemented NIEF is evaluated using real signals obtained by 12 bit GPS signal acquisition board. The output of NIEF is fed into the Software Defined Receiver to evaluate the acquisition and tracking performance. Experimental results shows that many types of interference such as single-tone CWI, AM, FM, swept CWI and multi-tones CWI are effectively mitigated with small signal power loss.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.6 no.3
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• pp.36-54
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• 1995

The error performance of digital radio signals (i.e., M-ary PSK signal, DQPSK signal, MSK signal, GMSK signal) interfered by impulsive noise and electromagnetic interference (EMI) is analyzed and discussed. In analysis at first, the error rate equations have been derived in an electromagnetic interference plus impulsive noise environment. And then, the error performance has been evaluated and shown in figures as a function of carrier-to-noise ratio, carrier-to-interference ratio, impu- lsive index, gaussian noise to impulsive noise power ratio, and interference index to measure the amount of error degradation in digital radio signals. From the obtained results we have known that in the presence of m-distributed tone interference plus inpulsive noise, the more significant the electromagnetic interference amplitude varies, the more significant performance degradation is produced. The listing the digital radio signals from the most degraded to the least is that DQPSK, GMSK, QPSK and MSK signal. In the constant amplitude tone interference plus impulsive noise environment, the effect of in- terference nearly disappears over about 20dB in CIR. The effect of constant tone interference on error rate performance is reduced more remarkably in the region from 10dB to 15dB in CIR. In both enviroments of m-distributed tone interference and constant amplitude tone interference, the more electromagnetic interference amplitude varies and CIR increases, the more error perfor- mance is improved. But it is found out that the performance can not be improved significantly even the electromagnetic interference becomes weak. This describes that the impulsive noise affects dominantly to the performance degradation.

• 한국정보통신설비학회:학술대회논문집
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• 2005.08a
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• pp.141-145
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• 2005

In this paper, UWB system did research about effect that interference effect with neighborhood single equipment or nearby group equipment gets In DMB service. 2.6425GHz satellite digital multimedia broadcasting service(SDMB) that electric wave interference special quality is contiguity frequency-band including interference of signal by unnecessary radiation level that is radiated in UWB system, and 3.4125GHz broadcasting relay net that is In-band frequency-band and interference effect degree that get in service did comparative analysis. SDMB system was BER $1{\times}10^{-4}$ that interference effect happens from 6.5m point and broadcasting signal reception is possible at 4m point. Also, it was BER $1{\times}10^{-4}$ that interference effect begins to happen from 5.0m point about center frequency 3.4126GHz and broadcasting signal reception is possible at 2m point. And, confirmed that UWB system of impulse method is less interference effect about 2 dB than UWB system of OFDM method, to electric wave of UWB system that is small output

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.5
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• pp.23-32
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• 2015

The advanced receiver which can manage inter-cell interference is required to cope with the explosively increasing mobile data traffic. 3rd Generation Partnership Project (3GPP) has discussed network assisted interference cancellation and suppression (NAICS) to improve signal-to-noise-plus-interference ratio (SINR) and receiver performance by suppression or cancellation of interference signal from inter-cells. In this paper, we propose the novel hybrid receiver Full Suppression Cancellation (FSC) to reduce the interference from neighbor cell in backhaul system. The proposed receiver can suppress and cancel the interference by combining Interference Rejection Combining (IRC) with Successive Interference Cancellation (SIC). We perform the system level simulation based on 20MHz bandwidth of 3GPP LTE-Advanced system. Simulation results show that the proposed receiver can improve error rate and throughput of conventional system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.7A
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• pp.440-450
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• 2003

The reverse link of a spectrally overlaid macrocell/microcell cellular CDMA system supporting multimedia traffic is characterized in terms of the required signal power, interference, and capacity. Several narrowband subsystems are overlaid with a wideband subsystem in macrocells, while a single wideband subsystem is operated in a microcell with the same spectrum as the macrocell wideband subsystem. Using a typical propagation model the reverse link signal power and interference are characterized as the relative user signal power and the cross-tier interference factors between the macrocell and the microcell. The reverse link capacity of the overlay system is then analyzed. Analytical results show that the dominant parameters affecting the system performance are the spectral overlay ratio and the distance between the microcell and macrocell base stations. In particular, when the distance equals a half of macrocell radius, optimum performance can be achieved by minimizing the cross-tier interference factors. These results can be applied to CDMA multimedia network planning in heavily populated traffic areas.

• Journal of Satellite, Information and Communications
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• v.7 no.1
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• pp.122-127
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• 2012

The purpose of this study is to know about the interference on FM Radio channel from HD Radio signal. In Korea, a data service channel, named DARC is operated by a major FM radio broadcaster which has national wide service area. Therefore, an analysis of the interference on FM radio channel with DARC data channel from HD Radio, most recently developed digital radio system. Technical parameters of FM radio with DARC data channel and HD Radio system are considered for this simulation. As results some interference generated because of HD Radio signal according to its signal allocation and service mode of HD Radio.

• Journal of information and communication convergence engineering
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• v.19 no.3
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• pp.131-135
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• 2021

The interference between closely placed co-coverage satellites was analyzed. In general, a satellite network may use different orthogonal polarizations and frequencies to increase the throughput of a satellite. However, when orthogonal linear polarization (horizontal polarization and vertical polarization) or orthogonal circular polarization (left-handed circular polarization and right-handed circular polarization) is used, the signal from one polarization sense to another may be coupled, resulting in cross-polarization interference. This signal-coupling arises due to the finite value of the cross-polarization discrimination of the earth station. In this study, field equations were used to analyze the interference between adjacent satellites using co-frequency. The level of interference was compared to that when two adjacent satellites used the same polarization. The simulation results show that the interference mainly depends on the off-axis co-polar pattern and the cross-polar pattern of the earth station antenna.