Abstract
In conventional power control design of direct-sequence code division multiple access (DS-CDMA) systems, Smith prediction filter has been employed to compensate for the fixed round-trip delay to track a target signal to interference and noise ratio (SINR). However, Smith prediction filter is sensitive to the variation of round trip delay. In this study, a multiple-mode Smith predictor is proposed to cooperate with to treat efficiently the compensation problem of time-varying round-trip delay in the power control design of DS-CDMA systems. The likelihood function based on the probability density function of tracking errors is employed to compute the weighting of cooperation for each mode of Smith predictor. From simulation results, it is shown that the proposed multiple-mode power control method is robust to time-varying round-trip delay in CDMA cellular radio systems.