Reverse link power control of DS-CDMA on multi-path fading and additive white Gaussian noise by using fuzzy and neuro-fuzzy controller

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 fuzzy controller (FC) and neuro-fuzzy controller (NFC). The controller's parameters of these methods 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. Both controllers were then tested to control DS-CDMA model which designed both the synchronous and asynchronous transmission. In the test, M and Gold sequence code used in spread spectrum were utilized under multi-path fading with AWGN. The experimental results by comparing the operation characteristic of the designed and implement FC and NFC show that the NFC gives the power level closed to the target and a lower outage probability.