Improved Predictive Power Control Algorithms to Increase CDMA System Capacity

Authors

  • A. Kurniawan School of Electrical Engineering and Informatics, Bandung Institute of Technology, Jalan Ganesa 10, Bandung 40132, Indonesia
  • Iskandar Iskandar School of Electrical Engineering and Informatics, Bandung Institute of Technology, Jalan Ganesa 10, Bandung 40132, Indonesia
  • Sayid Machdar School of Electrical Engineering and Informatics, Bandung Institute of Technology, Jalan Ganesa 10, Bandung 40132, Indonesia

DOI:

https://doi.org/10.5614/itbj.eng.sci.2009.41.2.7

Abstract

In this paper capacity of CDMA system is evaluated using an improved algorithm of channel prediction-based power control in Rayleigh fading channel environments. One of the most serious problems which degrades the performance of power control algorithm is the effect of feedback delay. To overcome the effect of feedback delay, power control algorithm relies on channel prediction techniques, which utilize the correlation property of the past channel measurements. In CDMA power control, however, the correlation property of channel measurements is destroyed because the transmit power is continuously updated for each power control interval. In order to restore the correlation property of the channel, the past channel measurements are compensated for by the same factors that were given by power updating for each power control interval. The prediction algorithm in this paper is proposed using the least mean square (LMS) technique. The result shows that the capacity of CDMA systems increase significantly when the improved predictive algorithm is used. Numerical evaluation shows that CDMA capacity increases by more than 40 % for fixed step algorithm and more than 50 % for variable step algorithm when the proposed algorithm is employed.

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References

Gilhousen, K.S., et al., On the Capacity of a Cellular CDMA System, IEEE Transaction on Vehicular Technology, 40, pp. 303-312, May 1991.

Kurniawan, A., Effect of feedback delay on fixed step and variable step power control algorithms in CDMA systems, in Proceedings of the 8th International Conference on Communication Systems (ICCS) 2002, Singapore, CD-ROM 3P-02-04, November 2002.

Lau, F.C.M. & Tam, W.M., Novel SIR-estimation-based power control in a CDMA mobile radio system under multipath environment, IEEE Transactions on Vehicular Technology, 50(1), pp. 314-320, January 2001.

Gilhousen, K.S., Jacobs, I.M., Padovani, R. & Weaver, L.A., Jr., Increase capacity using CDMA for mobile satellite communications, IEEE Journal on Selected Areas in Communications, 8(4), pp. 503-513, May 1990.

Chockalingam, A., Dietrich, P., Milstein, L.B. & Rao, R.R., Performance of closed-loop power control in DS-CDMA cellular systems, IEEE Transactions on Vehicular Technology, 47(3), pp. 774-778, August 1998.

Chung, C.J., Lee , J.H. & Ren, F.C., Design of power control mechanisms with PCM realization for the uplink of a DS-CDMA cellular mobile radio system, IEEE Transactions on Vehicular Technology, 45(3), pp. 522-530, August 1996.

Ariyavisitakul, S., SIR-based power control in a CDMA system, in Proceedings of IEEE Global Telecommunications Conference, Orlando, USA, pp. 868-873, December 1992.

Kurniawan, A., Predictive Power Control in CDMA Systems. PhD dissertation, Institute for Telecommunications Research, University of South Australia, 2002.

3GPP Consortium, Physical channels and mapping of transport channels onto physical channels (FDD), Third Generation Partnership Project (3GPP) Technical Specification TS 25.211, v2.5.0, October 1999.

Kurniawan, A., Iskandar & Mazdar, Sayid, Predictive power control of CDMA systems in Rayleigh Fading Channel, Jurnal Makara Seri Technology Vol. 13, No. 1, hlm. 1-6, April 2009.

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How to Cite

Kurniawan, A., Iskandar, I., & Machdar, S. (2013). Improved Predictive Power Control Algorithms to Increase CDMA System Capacity. Journal of Engineering and Technological Sciences, 41(2), 187-200. https://doi.org/10.5614/itbj.eng.sci.2009.41.2.7

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