Power allocation and control in wireless mobile communication networks

Abstract

Power management, such as power allocation and control in DS-CDMA communication systems is a significant factor for the effective and reliable communications on the radio channels between mobile users and fixed stations. The capacity of radio communication is greatly affected by the performance of power allocation and control mechanism. Link throughput and quality can be improved by an elaborate power allocation and control mechanism. This study is mainly concerned with power allocation and control in CDMA wireless mobile communication networks. First, we propose a hybrid channel assignment scheme using CDMA technique as a reference multiple access scheme and suggest a power level determination mechanism which enables each call to maintain the required link quality. In the proposed scheme, delay-sensitive voice traffic is accommodated in circuit mode and delay-nonsensitive data traffic is accommodated in packet mode. Power allocation mechanism employing voice activity detections is presented and this mechanism allocates power levels to the mobile users according to the traffic and varying inter-cell interference. The proposed scheme can achieve a high link efficiency with the reduced control and request access overheads in exploiting the statistical multiplexing of voice and data traffic. Second, we propose and evaluate a single-bit adaptive step-size closed-loop power control scheme which is adaptable to a dynamically changing radio channel. We also consider the effect of the power control constant of the AS-CLPC scheme on the power control performance. The proper power control constant of the AS-CLPC scheme is obtained by solving a polynomial equation. Compared with the IS-95 single-bit fixed step-size CLPC scheme, the proposed single-bit AS-CLPC scheme can reduce power increment level (PIL) by approximately 3 dB when the outage probability is below 0.03 and a single fading path reception in the base station is assumed. System performance, such as link avai...