• Title, Summary, Keyword: VSG-CDMA

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Performance Analysis of VSG-CDMA Supporting Multi-Rate Date Service in the Reverse Link (다중 전송률을 지원하는 VSG-CDMA 역방향 링크 성능 분석)

  • Lee, Young-Ho;Kim, Hang-Rae;Kim, Nam
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.14 no.3
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    • pp.268-275
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    • 2003
  • In this paper, the capacity of VSG-CDMA system supporting multi-media service in the reverse link is analyzed by considering the two models according to the power control and user distribution. In analysis model I, assuming perfect power control and uniform distribution of users, the equation of blocking probability is calculated and the maximum number of voice and data user is derived in accordance with 1 % blocking probability. In analysis model II, it is analyzed by assuming power control error and non-uniform distribution of users. The result of analysis model I means the upper bound of system capacity in the 5 MHz wideband VSG-CDMA system, and the result of analysis model II shows the lower bound of system capacity. Also, the improved plan of performance for VSG-CDMA system is suggested by the analyzed result according to data activity and the value of $E_b/N_o$ in model II.

The Correlation Parameters and the Optimization of a PN Sequence Phase for Variable Spreading Gain (VSG) Multi-Rate DS/CDMA System (멀티레이트 서비스를 지원하는 VSG-DS/C음 시스템에서의 PN 시퀀스 상관 파라미터 특성과 최적화)

  • 이연우;김응배;차균현
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.1A
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    • pp.10-17
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    • 2000
  • In this paper, we evaluate the correlation properties and the optimization of PN sequence phase for multi-media DS/CDMA system with variable spreading gain (VSG) scheme. In multi-media multi-rate DS/CDMA systems, the optimization of PN sequence phase is not a tractable problem, since the sequences should be optimized against both sequences of the same length and other sequences with different length. Hence, we verify the correlation properties of PN sequence phase in multi-rate system environment and furthermore, we propose the new phase criterion, MIN-AIP (minimum-average interference parameter), to minimize the bit error rate (BER). As the results of performance evaluations, it is shown that the performance of MIN-AIP criteria gives the best results.

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Effects of PN Sequence Phase on Performance of Variable Spreading Gain (VSG) Multi-media Multi-Rate DS/CDMA (가변 확산이득 구조의 멀티미디어 멀티레이트 DS/CDMA 시스템에서 PN 시퀀스 위상에 따른 성능 영향 분석)

  • 이연우;차균현
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.24 no.12A
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    • pp.1833-1843
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    • 1999
  • in this paper, we analyze the effects of PN sequence phase on the multiple access interference (MAI) of multi-media multi-rate DS/CDMA system with variable spreading gain (VGS) scheme, and furthermore derive the bit error rate (BER) equation for MAI users with different powers and spreading gains. In the sequel, we verify the influences of deterministic sequences on the bit error rate performance. As the results of the bit error rate of a desired user against interfering users with different spreading gains and different transmit powers, it is shown that the domain factor to determine the MAI component could be different according to the data transmission rate of a desired user. We also show that any kind of PN sequence phase does not yield considerable advantage, unless $E_b/N_o$ is considerably greater than 10dB, since below that value AWGN dominates. However, when the higher $E_b/N_o$, the performance of both MSQCC/CO and CO/MSQCC criterion give the better results.

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