• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.1
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• pp.201-209
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• 2000

In this paper, the bit error rate (BER) performance of Multicode DS/CDMA-BPSK communication system is investigated in the presence of multi user interference and Nakagami fading channel environments. The DS/CDMA-BPSK communication system adopts multicode technique to enhance the data transmission rate. Using the calculated BER performance, BER figures of Multicode DS/CDMA-BPSK communication system are shown to discuss the effect of the number of multi user interference, Nakagami fading index, and data transmission rate. From the results, the transmission rate of DS/CDMA-BPSK signal improve by adopting Multicode technique. And we know that the major parameter of BER performance degradation in Multicode DS/CDMA system is the effect of multi user interference than the fading depth.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.11
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• pp.9-15
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• 1997

The Nakagami m-distribution is used to model different fading environments and shown to fit experimental resutls more accurately than other distributions. In this paper, the probability of symbol error for M-ary QAM with square signal constellation in frequency-nonselective shlow Nakagami fading and additive white Gaussian noise is derived. When Nakagami fading index is integer, the derived resutls leads to the closed-form of a finite series.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.1
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• pp.9-18
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• 2003

In this paper, we analyzed the throughput of DS/CDMA system applying packet combining scheme combined with Type- I Hybrid ARQ scheme over AWGN channel and Nakagami fading channel with RAKE receiver. As the parameter for analysis, we used number of combined packet(L), number of diversity branch$({L_c})$, fading index(m), and length of packet(N), and used CRC-12 error detection code and (2,1,3) convolutional code. As a results, we found that throughput of system over Nakagami fading channel with RAKE receiver was superior to throughput over AWGN channel, and throughput of system decreases rapidly as channel degrades when number of combined packet(L) was increased. However throughput of system with the combining scheme was achieved even at low ${E_b}/{N_o}$. Also, we found that throughput of system was increased when fading index(m) and number of diversity branch$({L_c})$ were increased, but it was decreased when number of user(K) and length of packet(N) were increased.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.12A
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• pp.1796-1805
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• 2000

고속무선 이동 통신에서 가장 문제가 되는 것이 다중전송로에 의한 페이딩잡음이며, 이러한 페이딩의 문제점을 이동성을 보장하면서도 효율적으로 해결할 수 있는 방법이 최근 제안된 STTD(Space Time Transmitter Diversity) 기법이다. 본 논문에서는 상관된 Nakagami 페이딩 채널환경에서 적용될 수 있는 수신신호의 확률밀도함수를 유도하고 이 유도된 새로운 화률밀도함수를 이용하여 비동기 송신 다이버시티 시스템의 성능을 비교 분석한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.12A
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• pp.1948-1959
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• 1999

The error rate performance of the proposed $\pi$/4-differential quadructure phase shift keying( $\pi$/4-DQPSK) with nonredundant multiple error correction is analyzed for Nakagami fading channel. The scheme for differential detection of $\pi$/4-QPSK with nonredundant multiple error correction utilizes the output that employ the received signal delayed by more than two time slots. It was observed that the performance increased as the error correction capability increased.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.6
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• pp.825-834
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• 1999

In this paper we derive the probability density function of the phase error and that of the envelope of the received signal over Nakagami fading channel. Using the new probability density functions we analyze the performance of coherent BPSK, noncoherent FSK, DPSK and noncoherent ASK on Nakagami fading by means of new methods.

• Journal of IKEEE
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• v.5 no.1 s.8
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• pp.85-90
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• 2001

In this paper, we analyzed the envelope correlation of wideband signals modulated on two separate subcarriers in a Nakagami-Rice fading channel with exponential power delay profile. The results show that the envelope correlation of resolvable paths is implicated by the ratio of the specular wave power to the mean multipath power as well as the signal bandwidth and the rms delay spread of the multipath waves.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.8C
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• pp.754-761
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• 2005

We derive and analyze a bit error rate(BER) expression of a Gray coded rectangular QAM(R-QAM) signal with maximal ratio combining diversity(MRC) reception over Nakagami-n(Rician) fading channels. The derived result is provided in terms of the Whittaker function and the confluent hypergeometric function. In addition, by performance comparison with M-PSK, we see the Nakagami-n fading channel characteristics. Because the derived expression is general, it can readily allow numerical e·valuation for various cases of practical interest such as line-of-sight (LOS) or satellite communication channel analysis.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.3A
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• pp.391-398
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• 2000

In this paper, MRC(Maximum Ratio Combine) diversity, (23, 12) Golay code, (7, 5) Reed-Solomon code, and (3, 1) majority selection code are employed to improve the performance of DS/CDMA BRSK in Nakagami fading channel. and MRC diversity combined with other coding techniques is suggested, with which, the performance of DS/CDMA BRSK is compared and analyzed. Also, system required Eb/N0 to meet BER=10-5 for multi user data communication is obtained according to each techniques. From the results, when each techniques is employed to DS/CDMA BRSK system. coding employed system shows better performance than diversity employed system. Especially, Golay code shows better performance than oter codes. also MRC diversity is employed, the number of multiple access user to meet data communication requirement of BER=10-5 can accomodate up to 8 users. and when each code is employed, Golay code, majority selection code, and Reed-Solomon code shows the capacity of 14, 12, and 10 user respectively. But MRC diversity combined with coding techniques can reduce restriction of multiple access user. However, it is desirable these combined technique are employed according to service types and requirements provided.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.3A
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• pp.257-265
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• 2004

General closed-form expression is derived and analyzed for the exact bit error rate (BER) performance of the arbitrary rectangular Gray coded QAM signal in conjunction with maximal-ratio combining (MRC) diversity on frequency non-selective slow m-distributed Nakagami fading channel in the presence of co-channel interference. Numerical results demonstrate error performance improvement with the use of MRC diversity reception. The new expressions presented here are suitable for evaluating various cases of practical interest on wireless communication channels.