• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.1
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• pp.35-46
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• 1994

In this paper, the performance of DS/SS acquisition system over frequency nonselective Rician fading channel is analyzed by means of packet loss probability. The power ratio of the fading component to the specular compnent. seccessive constant fadong chips k. and correlation coefficient among k chipe are taken for channel parameters. The false alarm probabilities and detection probabilities are derived, and packet loss probability is evaluated in terms of these probablities in the stats transition diagram. From the results of the performance test, these exists the region of packet loss probability in crease because of autocorrelation sidelobe. As k increases, the packet loss probabolotoes decrease.

• Journal of Digital Contents Society
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• v.5 no.1
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• pp.28-34
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• 2004

In this paper, we have analyzed the block error probability of orthogonal multicarrier 16 QAM signal in a frequency selective Rician fading environment. The block error probability is evaluated with several parameters such as normalized propagation delay $(\gamma/T_S),$, bit energy to noise power ratio $(E_b/N_0),$ and desired signal to undesired signal power ratio (DUR) in fast fading and slow fading channels. In the fast fading channel, The result shows that the block error probability rather in the fast fading channel achieves better performance than in the slow fading channel, when the error correction capability is one or two.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.4
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• pp.34-40
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• 2012

In wireless communication system, fading is an unavoidable problem. Hence, errors in form of BER are introduced with the transmitted signal. It is necessary to recognize the behavior of these errors in different fading channels. To obtain the mathematical solution for the average bit error rate(BER) of coherent MPSK, some techniques are presented. In this paper, the impact of diversity is also analyzed over slow and flat Rician fading channel. In here, the value of modulation index, M is varied and the effects of its variation are also depicted. So, these performance curves with different diversity values and fading parameter are useful to design and evaluate the radio channel for faithful communication system.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.7 no.1
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• pp.61-70
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• 1996

M-ary differential phase shift keying(DPSK)is a bandwidth efficient digital modulation technique and recently has attracted increased attention in mobile satellite communication application where the available radio bandwidth is limited. Coherent detection offers good BER performance in AWGN channel. However, it requires long acquisition times in fading environment. In this paper, we analyze the BER performance of M-ary DPSK signal using the Multiple Differ- ential Feedback Detection(MDFD) technique in Rician fading and shadowed Rician fading channel. MDFD is an efficient scheme to decrease the performance gap between differential and coherent reception by increasing the complexity of the conventional differential receiver to some extent. Compared to the multiple symbol maximum likelihood detection technique, the multiple differential feedback detection technique has a much simpler structure for hardware implementation. Espe- cially, this technique has application to land mobile satellite channel which can vary in time and space between AWGN and rapidly fading channel.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.10a
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• pp.693-696
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• 2001

본 논문에서는 무선 홈네트워킹 시스템으로 대두되고 있는 Wireless LAN(802.11), HomeRF, Bluetooth 성능을 간섭이 고려되지 않는 경우의 실내 무선 환경하에서 시스템의 변조 방식만을 고려하였으며 실내환경에서 발생되는 에러에 대한 제어 기술로 Truncated Type-B Hybrid ARQ를 적용하였다. 무선 홈네트워킹 시스템의 채널 수 및 주파수 대역은 동일하며 실내 무선 환경을 라이시안 페이딩 환경으로 고려하였을 경우, 직직접파 대 반사파 전력비(K)가 6[dB]인 라이시안 페이딩 환경하에서 오율 $10^{-3}$을 기준으로 할 때 2FSK가 DQPSK보다는 E$_{b}$ /N$_{o}$ 가 약 3[dB] 정도 우수하며 오율 $10^{-6}$을 기준으로 비교하여 보면, DPSK 방식이 4FSK 보다 약 E$_{b}$ /N$_{o}$ 가 5[dB] 우수하였다. 또한 K=6인 라이시안 환경하에서 변조 방식만을 고려한 경우보다 성능 개선 기법을 채용한 무선 홈네트워킹 시스템의 E$_{b}$ /N$_{o}$ 가 더 우수함을 알 수 있었다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.1
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• pp.60-71
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• 1998

The propagation environment is effected by Rayleigh fading, Rician fading, path loss and lognormal shadowing in microcellular mobile radio system. In these surroundings we analysed the performance on received Rician signals among L Rician interferers and the characteristics of lognormal shadowing for various parameters such as reuse distance, cluster size, signal to interference power ratio and protection ratio using outage probability. We also studied various channels Rayleigh signal and Rician interferer, Rician signal and Rayleigh interferer, Rician signal and Rician interferer and so on using outage probability. The theoretical extention and computer simulation effectively analysed the characteristic of lognormal shadowed Rician channel.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1996.06a
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• pp.574-577
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• 1996

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1996.10a
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• pp.75-81
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• 1996

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1996.10a
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• pp.82-86
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• 1996

• Proceedings of the Korea Contents Association Conference
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• 2005.11a
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• pp.359-363
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• 2005

본 논문에서는 다양한 무선 통신 채널 환경에서 레일리 페이딩과 라이시안 페이딩 등을 모두 포함할 수 있고 이동 통신과 위성 통신에서도 적용할 수 있는 페이딩 모델로서 나카가미 페이딩 모델을 도입하고 전자기기에서 방출되는 임펄스 간섭파를 채널 환경으로 모델링하여 결합변조기법을 채용한 DS-CDMA 시스템의 성능을 분석하였다. 변조방식으로는 대역폭 효율 개선을 위해 MFSK와 MDPSK를 고려한 결합변조기법을 채용하였으며 실내 무선 페이딩 채널로써 직접파대 반사파 전력비를 나카가미 페이딩 심도지수 m으로 산출하여 임펄스 지수A와 가우스 잡음 전력 대 임펄스 잡음 전력비 $\Gamma'$를 파라미터로 하여 시스템 오율성능을 분석하였다.