IEEE 802.16 上行鏈路無線系統之動態優先次序資源分配

Abstract

隨著多媒體資訊在無線通訊系統上的傳輸量日益增加，提供傳輸服務品質保證（quality of service, QoS）是一個很重要的議題。為了有效使用系統資源並且提供傳輸服務品質的保證，我們在IEEE 802.16 上行鏈路系統提出了一個基於動態優先次序的資源分配(dynamic priority-based resource allocation, DPRA)機制。對於急迫性較高的服務，我們給予較高的優先次序值(Priority value)，使具有較高優先次序的使用者能優先被分配系統資源做傳輸。我們也會根據每一種服務在不同時間的急迫性，動態調整其優先次序。我們提出的DPRA機制會在子通道(subchannel), 調變方法(modulation order), 以及能量(power)三方面找尋最佳化的資源分配方法，並且對同一個使用者做一致性分配(consistent allocation)。由模擬結果顯示，我們提出的方法可以達到傳輸速率最佳化以及QoS的滿足，並且能減少標頭傳輸(transmission overhead)以及降低運算複雜度。

To efficiently utilize the system resource and satisfy the QoS requirements in current multimedia transmission environment, we propose a dynamic priority-based resource allocation (DPRA) algorithm for IEEE 802.16 uplink system in this thesis. The goal of DPRA algorithm is to maximize system throughput while satisfying diverse QoS requirements. Four types of multimedia traffic defined in IEEE 802.16 are considered, including unsolicited grant service (UGS), real-time polling service (rtPS), non-real-time polling service (nrtPS), and best effort (BE) service. These multimedia services are given urgency degrees via dynamic priority values, which will be calculated at the beginning of each frame. The radio resource will be allocated to users according to priority values. Also the DPRA algorithm performs consistent allocation in aspects of subchannel, modulation order, and power. Simulation results show that the proposed DPRA algorithm outperforms the conventional algorithm in terms of system throughput and satisfaction of various QoS requirements. Besides, the proposed DPRA algorithm is also designed to have lower cost of transmission overhead and complexity.