Fast power control for third generation DS-CDMA mobile radio systems

Abstract

The DS-CDMA spread spectrum protocol has a better spectral efficiency than TDMA or FDMA, which makes this modulation scheme the best candidate for third generation mobile communication systems. Nevertheless, this spectral efficiency is only achieved at the cost of an advanced power control of the mobile stations. The DS-CDMA protocol uses in all mobile telephone systems a closed loop power control scheme controlled by the base station receiver. This control system is, unfortunately, not fully efficient in certain critical cases. This paper presents a much faster method than the traditional power control scheme for a given data command rate, while keeping the traditional scheme of power control bit transmission used with the IS-95, CDMA2000 and W-CDMA standards. This method makes it possible to improve the QoS (quality of service) in the difficult cases without cost.