Energy-Efficient Resource Allocation for Uplink Transmissions in OFDMA-based Cognitive Radio Networks

在現代各式各樣的網路，包括像是無線電視、手機、衛星通訊等等，大多是由特定業者租用特定頻段並提供專門的服務。然而在網路發達的現代，稀少的頻段資源漸趨珍貴，因此出現感知無線網路的技術，能重新分配利用原本網路浪費掉的頻段資源。 與此同時，人們對行動裝置的使用習慣與日俱增，行動裝置大多是使用電池來運作，因此節能的議題也越來越重要。 在本篇論文中，我們提出一個演算法用來優化感知無線網路上的節能問題，透過此演算法，我們能夠處理在感知無線網路上降低耗能的同時，並且也能夠同時維持資料傳輸流量的品質。 我們透過實驗模擬，來驗證我們的演算法對於處理此問題的效能與結果。Cognitive radio has attracted great attention as it offers potential means to resolve the critical spectrum shortage problem caused by both the spectrum resource scarcity and the growing demand in wireless services. The concept of allowing opportunistic spectrum access can improve the overall spectrum utilization by exploiting underutilized and unused frequency bands. In general conditions, cognitive secondary users are mobile nodes powered by battery and consuming power is one of the most important problem that facing cognitive networks, therefore, the power consumption is considered as a main constraint. In this paper, we aims to investigate an efficient power allocation algorithm for OFDMA cognitive radio systems that uses the peak power constraint. Simulation results indicate that using the proposed efficient method to reduce the power consumption close to that of the optimal power allocation algorithm