On the capacity of rate adaptive modulation systems over fading channel

Abstract

This thesis studies the capacity achieved by rate adaptive modulation systems over fading channel. The BER performance and the channel capacity of adaptive modulation systems with and without channel estimation error are investigated. An approximate method to evaluate the BER performance is proposed under small estimation error. The channel capacity and some performance metrics of an optimal channel allocation system over flat fading channel are derived. An SNR-priority-based channel allocation scheme and a scheme to accommodate QoS and best effort services are proposed and studied. The system capacity of rate adaptive CDMA systems over frequency selective fading channel is investigated. Various adaptive power control schemes taking advantage of the information of channel fading and location of individual user are proposed. The system capacity achieved by these schemes with a proposed combined adaptive processing gain and MQAM technique are studied. The variance of MAI of multiple chip rate system is derived under a practical model. Capacity comparison for multiple chip rate and multiple processing gain systems are studied for the first time.