IEEE 802.16j Multi-hop Relay系統中以SINR預測為基礎之新型路徑選擇演算法

Abstract

IEEE 802.16j Multi-hop Relay系統為一新興之技術標準，其目的在於強化以IEEE 802.16e為基礎之行動式WiMAX系統之效能，並藉由中繼站 (Relay Station)的佈放以降低整體系統的佈建成本。先前的研究顯示在蜂巢式系統中佈建中繼站有可能會導致系統整體容量下降，其原因在於透過中繼站轉傳的訊號須佔用額外的無線資源。本研究之目的在於透過良好的路徑選擇演算法以減輕中繼站轉傳訊號對系統資訊與容量的損耗，並進一步透過預測選擇不同路徑之下各接收端的SINR及對系統容量的貢獻，以設計出可進一步提升系統容量之新型路徑選擇演算法。模擬結果顯示所提出之方法確實可提升系統容量。此外，本論文並提出一種精簡之SINR預測方法以減少訊號量測過程中所衍生之控制訊號交換，並整合至所提出之路徑選擇演算法中。模擬結果亦顯示所提出之演算法配合此精簡之SINR演算法仍有相當不錯的效能表現。

IEEE 802.16j is an amendment to the IEEE 802.16 broadband wireless access standard to enable the operation of multi-hop relay stations (RSs). It aims to enhance the coverage, per user throughput and system capacity of IEEE 802.16e. Previous researches have showed that, however, use of RSs may not always be beneficial from the system capacity aspect because of the extra radio resource needed for the relay link. In other words, direct communication with base station can be more spectral efficient for a mobile station in some cases. This problem of selecting a suitable communication path for a mobile station to the base station is called path selection in a multi-hop relay network. In this thesis, the issue of path selection is investigated for the IEEE 802.16j multi-hop relay network. Novel SINR prediction-based path selection algorithms are proposed. Simulation results show that path selection algorithms that reflect overhead in relay links can significantly improve the system capacity.