Neuro-fuzzy controller for reverse link power control of DS-CDMA system over multi-path fading

Abstract

This paper presents the Direct Sequence-Code Division Multiple Access (DS-CDMA) model and the algorithm to control the reverse link closed loop power of DS-CDMA cellular system by using the Neuro-Fuzzy Controller (NFC). The controller's parameters of this method are selected and adjusted by Genetic Algorithms (GAs). The controller's inputs are the error between the signal strength of each mobile station and signal strength target (P*) at base station, and the difference of this error. The controller's output is the increasing or decreasing power. The NFC was then tested to control DS-CDMA model which designed synchronous transmission. In the test, M sequence code used in spread spectrum was utilized under multipath fading. The experimental results by comparing the operation characteristic of the designed and implement NFC with fuzzy controller (FC) and IS-95 controller show that the NFC gives the power level closed to the target and a lower outage probability.