Robust H(inf) PI Power Control for CDMA Cellular Communication Systems

This thesis contributes in research about Power control, which defined here as adjusting ransmission power of mobile unit and maintaining Signal-to- Interference Noise Ratio (SINR) of received signal at a desired level. Power control helps to prolong the battery life of a mobile phone, reduces interference and increases the capacity of a system. All of these advantages contribute to preserve the Quality of Service (QoS) of a mobile communication link. As main power control constraints multi-path fading, multiple access interface (MAI) and round- trip delay have been taken. Two different controllers, to compensate the effect of these constraints, are proposed: 1) Proportional-Integral (PI) controller and 2) Robust H1 state-feedback controller. Controllers are tested through a velocity range of mobile units from 20 km/h to 300 km/h. Values for power tracking error and outage probability are obtained and compared with already existing controller designs.