The Analysis of the Reservation Strategy in The OVSF Tree for The WCDMA Systems

Abstract

The Orthogonal Variable Spreading Factor channelization codes are widely used to provide the variable data rate and support different bandwidth requirements for users in the WCDMA system. The code assignment has the significant impact on the code utilization and code blocking probability. The code assignment strategies are unfair for the large bandwidth requests. To improve the fairness in the code assignment, we reserve a part of bandwidth in the OVSF tree to reduce the blocking probability of the larger bandwidth request. The performance of the proposed scheme is simulated by programs to verify the outperformance.