• The Journal of Korean Institute of Communications and Information Sciences
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• v.14 no.3
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• pp.216-226
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• 1989

In this paper, we explain about an outline of the decoding method for double encoding system using the error correcting capacitance and a simple decoding method. We have been taken formation two-dimension code word of doubly-encoded code using $C_1$(32, 28, 5) and $C_2$(32, 26, 7) Reed-Solomon codes, and had computer simulation of the erroe correcting processes in frequency domain. On these processes, the newly developed digital signal processing technology such as error correction using Berlekamp-Massey algorithm in frequency domain have been proven.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.12
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• pp.1698-1704
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• 2018

This paper presents a implementation of a chaotic Lorenz system for data secure communication applications. Here we have used PIC18F family-based microcontroller to generate the chaotic signal, and simulated waveform patterns confirm that the chaotic behavior of the microcontroller based discrete time chaotic Lorenz system. There are three R-2R ladder type A/D converters have been implemented for conversion of direct microcontroller digital output into analog waveform, utilizing this specific microcontroller relevant to this experiment work, microcontroller ports B, C and D have been utilized for its time waveform outputs X, Y and Z respectively. XC8 compiler used for the compilation of the program. MATLAB and PROTEUS software platforms are used for simulation. Finally, chaotic time wave forms, 2D chaotic attractors were obtained and secure communication analog waveforms were also verified by experimental measurement.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.7 no.4
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• pp.156-160
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• 1982

A Comb Filter(C.F.) is constucted with a N-stages one-dimensional B.B.D.(Bucket-Brigade Device) delay line. One channel of the B.P.F. (Band Pass Filter) Bank is experimented, which includes a R.F.(Recursie Filter) using S/H circuits cascaded to the C.F. This algorithm of the C.F.B.(Comb Filter Bank) becomes the parallel spectrum analyzer circuit. The algorithm has less number of multiplication than that of FFT and improves the SNR.

• Electronics and Telecommunications Trends
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• v.9 no.1
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• pp.149-157
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• 1994

위성통신, 이동통신 등의 통신 시스템의 보급이 활발해짐에 따라 통신용 부품의 기술 개발이 한층 시급해지고 있다. 본 고에서는 이동통신용 단말기 및 기지국 RF 회로의 필수적인 부품인 아이솔레이터, 서큘레이터 등에 사용되는 기본 재료인 페라이트의 재료적 성질, 제조 공정 및 각국의 기술 현황에 대해 알아보고자 한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37C no.9
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• pp.791-801
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• 2012

Currently, SEAMCAT has been widely used as a tool to evaluate the effects of interference among a variety of wireless communication systems. This supports various channel propagation models, all of which are based on some statistical models for the channel propagation and do not exploit any specific terrain characteristics. Thus it is not appropriate for assessing the effects of interference between wireless systems, given some specific terrain features. In order to overcome this limit in its use, it is necessary to extend the capability of SEAMCAT to support a channel propagation model which takes into account terrain informations. The ITU-R P.526 is a familiar channel propagation model which calculates the path loss considering the terrain features. In this paper, we present an enhanced version of SEAMCAT which supports the ITU-R P.526 and provide a few examples of interference evaluation using it.

• Electronics and Telecommunications Trends
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• v.9 no.1
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• pp.25-36
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• 1994

통신 시스템의 확실한 연속 서비스 목표를 만족시키기 위한 최적의 spare part 수준을 결정하는 데에는 고장률과 spare part의 인도기간이 크게 기여한다. 따라서 본고는 관련 비용인자와 함께 통신시스템의 최적 spare part 수준결정모델의 결정에 관해 중점을 두고 서술하였다. 이 모델은 통신시스템을 구성하는 plug-in PBA의 spare 수준을 결정하는데 유용하게 적용될 것이며 또한 연도별 시설 공급계획에 의거 운용보전국(OMC) 단위로 적용할 때 특히 유용할 것이다.

• TTA Journal
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• s.178
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• pp.101-105
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• 2018

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37C no.12
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• pp.1211-1221
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• 2012

This paper describes separation distance to protect radiocommunication services from the interference of inductive systems using frequencies below 30 MHz for the co-existence between radiocommunication services and inductive systems. For the analysis, the interference scenario model is proposed between inductive system and radiocommunication services. Then the calculation method of protection distance is suggested by comparing the radiation power of inductive system with the allowable interference level of victim services, radiocommunication services, according to the applied propagation model. Also, the protection distance for protecting radiocommunication services in the 30 MHz below is calculated through the interference analysis from RFID(Radio Frequency IDentification) and PDP(Plasma Display Panel) TV based on the suggested method. The proposed calculation method was adopted as ITU-R recommendation in related with resolution 63 at ITU-R SG(Study Group) 1 meeting in June, 2012. It will be available to use for the protection of radiocommunication services from the interference of wireless power transfer system and power line telecommunication system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.12A
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• pp.1209-1216
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• 2008

In order to maximize spectrum efficiency and data rate MIMO(Multiple Input Multiple Output) is adopted to wireless system. OFDM-based WiMAX and LTE accommodate MIMO as mandatory technology. STC(Space Time Coding) and SM(Spatial Multiplexing) are used in downlink while in uplink C-MIMO(Collaborative MIMO) is used to improve data throughput. In this paper conventional pairing schemes, RPS(Random Pairing Scheduling) and DPS(Determinant Pairing Scheduling) are analyzed. From the analysis the performance of DPS algorithm is better than that of RPS because DPS measures orthogonal factor between paired users. However, there are potential problems such as hardware complexity and performance. To overcome the issues Power-Based Scheduling(PBS) algorithm is proposed for C-MIMO. PBS can provide higher performance compared to RPS and dramatically reduce hardware complexity compared to DPS

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.2
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• pp.105-111
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• 2024

This paper deals with the minimum linear arrangement(MinLA) of a lattice graph, to which an approximate algorithm of linear complexity O(n) remains as a viable solution, deriving the optimal MinLA of 31,680 for 33×33 lattice. This paper proposes a partitioning arrangement algorithm of complexity O(1) that delivers exact solution to the minimum linear arrangement. The proposed partitioning arrangement algorithm could be seen as loading boxes into a container. It firstly partitions m rows into r₁,r₂,r₃ and n columns into c₁,c₂,c₃, only to obtain 7 containers. Containers are partitioning with a rule. It finally assigns numbers to vertices in each of the partitioned boxes location-wise so as to obtain the MinLA. Given m,n≥11, the size of boxes C₂,C₄,C₆ is increased by 2 until an increase in the MinLA is detected. This process repeats itself 4 times at maximum given m,n≤100. When tested to lattice in the range of 2≤n≤100, the proposed algorithm has proved its universal applicability to lattices of both m=n and m≠n. It has also obtained optimal results for 33×33 and 100×100 lattices superior to those obtained by existing algorithms. The minimum linear arrangement algorithm proposed in this paper, with its simplicity and outstanding performance, could therefore be also applied to the field of Very Large Scale Integration circuit where m,n are infinitely large.