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3-상태 전파 채널에서 DS/CDMA-BPSK 신호의 성능 해석
조성언,조경룡 順天大學校 1999 論文集 Vol.18 No.1
To model and analyze the realistic terrestrial mobile satellite channel, this paper suggests the 3-state propagation model in which the channel occupation probability of Rayleigh fading, Rician fading, and Shadow Rician fading is varied. Also to verify its reliability, the BER performance of DS/CDMA-BPSK signal altered by the suggested 3-state channel model is shown using as parameters channel occupation probability ??, processing gain (PG), the number of simultaneous users, and Rician fading depth ??. From the results, the BER performance is much more affected with the Heavy Shadow Rician fading than the Light and the Average Shadow Rician fading, which accordingly shows that coding or diversity technique must be used to improve the system performance in the Heavy Shadow Rician channel. Also in the case of BER performance with respect to the variation of channel occupation probability, when the probability of Rayleigh fading is fixed, the increment of the probability of Rician fading and the decrement of the probability of Light Shadow Rician fading shows the improvement of BER performance. Especially it is known that, with the variation of channel occupation probability, Rayleigh fading and Light Shadow Rician fading affects the radio channel much more than others. With the analysis of the BER performance of DS/CDMA-BPSK signal according to the PG and the number of users, BER is not affected significantly by the PG when the number of users are small. However, when the number of users are large, BER is seriously affected by PG. So, to design the system more efficiently, it is needed to make PG as small as possible in the case of small user.
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