在WCDMA/TDD系統中支援高速率服務之動態通道配置機制

Abstract

第三代行動通訊主要是為了多媒體訊務服務而設計的，例如在個人通訊系統中高品質高速率的即時語音視訊的通聯。為了符合多媒體服務之需求，必須利用有效率的系統通道配置機制來增進系統之效能。 本篇論文探討在WCDMA/TDD系統中一種高速率傳輸的快速動態通道配置機制(HR-DCA)。高速率的訊務會經由基地台高功率而傳送並且透過一個稱為HRTS的時槽傳送。位置相依性的高速率動態通道配置機制 (Location dependent HR-DCA) 可在無線環境之中增進原有的高速率動態通道配置機制。每一個使用者所欲藉由HRTS傳輸的峰速率有位置相依的特性，為了完整的利用HRTS的頻寬，必須要慎重考慮一些啟動HRTS的資訊，例如﹕相鄰細胞對家細胞的干擾比以及給予傳輸用的碼通道數目。 在利用位置相依性的高速率動態通道配置機制模擬結果中，在小細胞範圍之下，我們可以發現整體系統的容量可以增加百分之十而平均延遲時間可以比傳統動態通道分配減少二分之一。因為WCDMA/TDD系統通常是運作在小細胞範圍之中，因此我們可以說位置相依性的高速率動態通道配置機制可以實際增加系統容量減少傳送延遲並且可在WCDMA/TDD系統之中符合多媒體服務之需求。

Third generation mobile radio systems are designed for multimedia services, such as high quality and high data rate real-time voice and video for personal communication. Therefore, in order to satisfy the requirement of multimedia services, efficient and flexible channel allocation strategies would be necessary to enhance the system performance. In this thesis, a fast DCA for high-rate services algorithm (HR-DCA) is proposed for WCDMA/TDD systems. The high rate services are transmitted by higher BS power and are occupied a time slot, namely HRTS. The location dependent HR-DCA is designed for enhanced HR-DCA. The peak rate of mobiles supported by one HRTS for each user is location dependent in the wireless environment. In order to fully exploit the bandwidth of HRTS, it should carefully consider the condition to initiate a HRTS, such as other-to-home cell interference ratio and the number of code channels in one time slot. In the simulation results, the overall throughput can be enhanced about 10% and the mean delay time can be reduced about 50% by the location dependent HR-DCA in micro cell environment. The WCDMA/TDD system is widely used in micro cell environment. Therefore, it is said that the location HR-DCA algorithm can realize the ability higher data rate transmission and lower delay bound so that achieve the criterion of the multimedia services in the WCDMA/TDD system.