Novel adaptive transmitter power and rate control schemes for W-CDMA systems

Abstract

This paper proposes novel adaptive power control and rate change schemes and investigates the performance of a wideband code division multiple access (W-CDMA) system in conjunction with these adaptive techniques. In these schemes, the power and rate are adapted to the variations of the fading channel as forecasted by a novel long-range prediction algorithm. This algorithm characterizes the channel as an autoregressive model with lower channel sampling rate compared to the conventional data rate methods of fading estimations. The performance of this scheme is evaluated using a detailed block diagram simulation of a W-CDMA system. All major components of the system are modeled and simulated, including an accurate model for realistic mobile channels. The performance of these systems is compared to that of a system without adaptive power and rate control. The proposed novel scheme is superior to the traditional approach of transmitter power control and rate change based on the channel estimation and signal to interference calculation at the receiver.