應用於具中繼點之正交分頻多工存取網路中的高能源效益資源分配法

Abstract

本論文探討在具中繼點之雙向正交分頻多工存取無線網路中資源分配的問題，此問題包含了次通道、傳送功率與相位持續時間的分配。中繼點的意義在於提供使用者與基地台之間額外的替代通道，但這同時也需要使用多個相位方能完成傳輸，且資源分配的問題變得更加複雜。相關的研究並沒有考慮到在具中繼點的網路中，各種不同的要素對資源分配的影響。由於節省能量消耗是一項重要議題，本論文根據四相位與雙相位兩種傳輸方式和網路編碼技術，提出對應的高能源效益資源分配法來決定次通道、傳送功率與相位持續時間配置的次佳解。不同的裝置因其能量的價值具有差異性，因此給予不同權重，高能源效益資源分配法的目的即為最小化加權過後之總體能量和。模擬結果顯示，本論文所提出的演算法在既定的服務質量目標之下，對於能量的保存與滿足服務質量的機率，和現有的機制相比均有一定程度的改善。

This thesis studies the problem of joint allocation of subchannel, transmission power, and phase duration in the relay-enhanced bidirectional orthogonal frequency-division multiple access (OFDMA) system. The challenges of this resource allocation problem arise from the complication of multiple-phase assignments within a subchannel since the relay station can provide an additional signal path from the base station to the user equipments (UEs). Existing research work does not fully consider all the influential factors to achieve feasible resource allocation for the relay-based networks. Considering the energy consumption is one of principal issues, the energy-efficient resource allocation (EERA) schemes are proposed in this thesis to design the allocation of subchannel, power, and phase duration for the UEs with the consideration of direct and two-hop communications. Both the four-phase and two-phase bidirectional relaying assignments and the network coding technique are considered to obtain the suboptimal solution for the proposed EERA schemes. Different weights are designed for the UEs to achieve the minimization of weighted system energy for the relay-enhanced networks. Simulation results show that the proposed EERA schemes can provide comparably better energy conservation and outage performance with the consideration of quality-of-service support.