Hybrid OVSF Code Assignment Strategy for Differential QoS in WCDMA System

• Main Authors: Chiao-chu Li, 李巧筑
• Other Authors: Dong-Her Shih
• Format: Others
• Language: en_US
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/03926059262190213141

碩士 === 國立雲林科技大學 === 資訊管理系碩士班 === 95 === In 3GPP technical specification, the WCDMA standard will support data rates up to with Orthogonal Variable Spreading Factor (OVSF) codes. The use of OVSF codes can provide variable data rates to flexibly support applications with different bandwidth requirements. In this paper, we have proposed a hybrid strategy with switching function for code assignment in reducing candidate code computation time. Our proposed strategy takes advantage of two main code assignment methods to gain the best effect in computation time saving and takes into consideration mobile terminals with differential QoS requirements. Priority differentiation between traffic classes is considered in our hybrid strategy. According to the user level of QoS, bandwidth is determined, multi-rate code partition is preceded and multi-code assignment strategy is carried out. The design of hybrid strategy is based on the concept of MMCA and RFCB schemes and we proposed a switch function for flexible apply our strategy. Our strategy make system flexible in serving quality and increase the system bandwidth of utilization rate. Make limited wireless communication resources can give full play to efficiency and enable more people to get system service and resource.