System Capacity Design Based on Communication Quality for Cellular CDMA Systems
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In code division multiple access (CDMA) systems, call admission control (CAC) plays a very important role because it directly controls the number of users. CAC must be designed to guarantee a grade of service (GoS) the blocking rate, and quality of service (QoS) the loss probability for communication quality. However, there still exists difficulties in clarifying how the CAC thresholds control these GoS and QoS based on the relationship that exists between them and how to set effective CAC thresholds. This paper presents a design method for the CDMA reverse link capacity that guarantees the levels in both of these GoS and QoS. Theoretical expressions for these GoS and QoS levels are first derived, then a design method using these expressions is presented. At that time, two strategies for CAC are assumed: one is based on the number of users, and the other is based on the interference level. Computer simulation results are presented, which strongly support the proposed design method. In addition, numerical examples for various propagation parameters and a performance comparison between the two strategies are shown.
KeywordsMobile Station Code Division Multiple Access Loss Probability System Capacity Call Admission Control
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