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부분대역 재밍하에서 FH/CPFSK 시스템의 성능 분석
정근열,박진수 한국정보통신학회 2002 한국정보통신학회논문지 Vol.6 No.4
본 논문에서는 열잡음과 부분대역 재밍잡음 그리고 인접한 8개의 비트 패턴에 대한 심볼간 간섭을 고려하여 FH/CPFSK 시스템의 성능을 분석하였다. 이와 같은 FH/CPFSK 시스템의 분석을 위한 파라메타 비트율(bit rate)과 변조지수를 사용하였으며, 차동검파기(Differential Detector)를 이용한 최적 수신 상관함수 제시하고, FH/CPFSK 시스템과 FH/BFSK 시스템을 비교평가 하였다. 그 결과, 근사식과 실제식의 비트 오류 확률은 높은 신호대 잡음비에서 거의 일치함을 알 수 있었고, 재밍율에 따른 성능은 차동검파를 사용한 FH/CPFSK 시스템이 리미터-변별기를 사용한 FH/CPFSK 시스템 보다 3dB 성능이 떨어지나 FH/CPFSK 시스템보다는 2dB 성능이 우수함을 입증하였다. In this paper, we analyzed the performance of FH/CPFSK system with differential detection in thermal noise, partial-band jamming noise and adjacent interference of all eight bit pattern. The parameters to analize performances of FH/CPFSK system have been used the bit rate, modulation index and performances of FH/CPFSK system with the differential detector have been presented with the optimum correlation function. And, we were compared with performance of FH/CPFSK and FH/BFSK system. In result, we could know that bit error probability of the approximation equation and exact equation nearly accorded in the high signal-to-noise ratio. And, we have been proved that FH/CPFSK system with differential detection according to jamming fraction ${\gamma}$ was worst to 3dB than FH/CPFSK system with limiter-discriminator. but was superior to 2dB than FH/BFSK.
OFDM 통신 시스템에 대한 Blind 반송파 옵셋 추정에 관한 연구
정근열,황재문,박진수 청주대학교 산업과학연구소 2001 産業科學硏究 Vol.18 No.2
In this paper, OFDM modulation and demodulation are expressed in matrix notation. The carrier offset and channel effects are introduced we have compared the acquisition performance of this blind algorithm with the cyclic-prefix based ML(Maximum Likelihood) algonthm. It results. The structure of OFDM signals enables high performance carrier offset estimation.
정근열,곽진규,양정모,강찬석,강경식,박진수 청주대학교 산업과학연구소 1995 産業科學硏究 Vol.13 No.-
In this paper, the performances of FH/CPFSK system we have been analyzed for thermal noise, partial-band jamming noise and adjacent interference of all eight bit pattern. The parameters to analize performances of FH/CPFSK system have been used the bit rate, modulation index and performances of FH/CPFSK system with the differential detector and with limiter-discriminator have been presented with optimum correlation function And, we were compared with performance of FH/CPFSK and FH/BFSK system In result, we could know that bit error probability of the approximation equation and exact equation nearly accorded in the high signal-to-noise ratio And, we have been proved that FH/CPFSK system with differential detection according to jamming fraction γ was worst to 3㏈ than FH/CPFSK system with limiter-discriminator, but was superior to 2㏈ than FH/BFSK
확산신호를 기초로한 OFDM-CDMA시스템의 최대전력 감소에 관한 연구
정근열,강경식,박진수 청주대학교 산업과학연구소 1999 産業科學硏究 Vol.17 No.1
In this paper, we discuss the construction method of orthogonal sequences for downlink OFDM-CDMA, in terms of peak to average power ratio(PAPR) of the transmitted signals. PAPR property is studied based on two orthogonal sets of sequences: Walsh-Hadamard and complementary sequences. It is shown that for relatively few active users, Walsh-Hadamard sequences tend to have very large PAPR, while PAPR of complementary sequences remains stable mear its theoretical value. A simple but effective peak reduction scheme is also proposed for OFDM-CDMA.
다중톤 재밍이 존재하는 나카가미-m 페이딩 환경에서 BFSK 변조방식을 이용한 Hybrid DS/SFH 확산대역 시스템의 성능분석
정근열,박진수 한국정보통신학회 2003 한국정보통신학회논문지 Vol.7 No.8
In this paper, we analyzed the performance of a hybird DS/SFH(DirectSequencySlow FrequencyHopping) Spread Spectrum system with BFSK modulation over Nakagamim fading channel with multitone jamming. The performance of the system was improved when a frequency bowing rate increased. In case that process gain of hybrid DS/SFH Spread Spectrum system to be fixed, the hybrid DS/SFH Spread Spectrum takes the low bit error probability than a DS Spread Spectrum system. Also, when the fading index m increases, the fading effect decrease, when the JSR(jamming to signal power ratio) increases ,the performance of a hybrid DS/SFH Spread Spectrum system improved than DS Spread Spectrum system. The result, we have been proved that performance of a hybrid DS/SFH Spread Spectrum was superior to DS Spend Spectrum system over Nakagamim fading with tome jamming. 본 논문에서는 다중톤 재밍이 존재하는 나카가미m 페이딩 환경하에서 BFSK 변조방식을 사용한 Hybrid DS/FH 확산대역 시스템의 성능을 분석하였다. 분석 결과 주파수 도약율이 증가할수록 시스템의 성능이 향상되었으며, 확산대역 시스템의 복합비를 고정하였을 경우 DS확산대역 방식의 시스템보다 더 낮은 비트 에러 확률을 가짐을 증명하였다. 또한 m값이 증가함에 따라 페이딩의 영향이 감소함을 알 수 있었으며, 신호대 방해신호의 전력비(SJR)가 증가할수록 DS 확산대역 시스템보다 성능이 향상됨을 알 수 있었다. 결과적으로 재밍이 존재하는 나카가미m 페이딩 환경 하에서 Hybrid DS/SFH 확산대역 시스템의 성능이 DS 확산대역 시스템의 성능보다 우수함을 입증하였다.
MRC 다이버시티를 이용한 DS/CDMA 셀룰라 시스템의 성능분석
김원섭,정근열,강경식,박진수 청주대학교 산업과학연구소 2001 産業科學硏究 Vol.18 No.2
In this paper, It is considered DPSK modulation and the channel is modeled as multipath Nakagami fading type which has been recently taken as a general model in the communication environments. Most paper assumed that nakagami fading index(m) of each branch of Rake receiver was fixed the same value in recent years. However, Nakagami fading index(m) of each branch of Rake receiver takes serveral value through communication environments. In this case, the branch, which takes a small Nakagami fading index(m), exclude. So we can improve performance When nakagami fading index(m) takes voluntary value, we analyze BER of wideband DS/CDMA cellular system. Finally, When the branch, which takes a small Nakagami fading index(m), exclude, we analyze BER of wideband DS/CDMA cellular system.
이상적인 자기 상관 특성을 갖는 이진 시퀀스의 Trace 함수 표현에 기초한 부울 함수 표현
원장식,정근열,박진수 청주대학교 산업과학연구소 1998 産業科學硏究 Vol.16 No.-
Pseudorandom sequences of period N(=2^(m)-1) with ideal autocorrelation apply to spread spectrum communication systems, radar systems and CDMA systems and some of well-known examples are m-sequences. These sequences(m-sequences, GMW sequences, Legendre sequences, Hall's sextic residue sequences, and so forth) are best described in terms of trace functions Generally, binary sequences of period N(=2^(m)-1) are expressed as Trace function on the GF(2^(m), but Trace function representation is so difficult that we can't find properties of sequences. By the way, binary sequences of period N(=2^(m)-1) can be expressed as the combination of m-variable Boolean function, f(x_(l) ,x_(2), ,x_(m)) In this case, properties of sequences can be found easily. So I implemented the Boolean function representation for above mentioned the family of sequences with relation that the property of Trace function. So far, the study to find binary pseudonoise sequences with ideal autocorrelation property is being done so we need the procedure to transform sequences into Boolean function.