在過去的十幾年中，眾多用於進一步改善感知無線電(CR)系統中合作式頻譜感測(CSS)準確度的方法不斷湧現。這些研究的目的主要集中於減少回報階段的信令開銷以及能源消耗。在本文中，我們提出一種高效的回報及累積(ERA)方案來同步地提升感測與回報的效益。然而，由於各個次級用戶(SU)感測階段的縮減是獨立進行的，因此勢必會產生我們所不希望看到的碰撞問題。為此，我們開發了一些後撤方案來緩解該碰撞問題。通過分析及模擬結果的驗證，我們所提出的ERA方案能夠實現更高的能源效益及頻譜利用率。此外，通過採用後撤方案，對漏檢概率的影響將小到可以忽略不計。

During the past dozen years, numerous approaches have been proposed to enhance the effi ciency of the cooperative spectrum sensing (CSS) technique in the cognitive radio (CR) systems. Reducing the signaling overheads and energy consumption during the reporting period are the main targets of these works. In this paper, we propose an effi cient reporting and accumulating (ERA) scheme to jointly improve the sensing and reporting e ciency. However, owing to individually reducing the sensing period for each secondary user (SU), the undesired collision problem during the reporting period can be incurred. To alleviate the collision problem, several retreat schemes are developed. As verifi ed by the analytical and simulation results, higher energy effi ciency and spectrum utilization can be achieved by using the proposed ERA scheme. Moreover, the miss-detection probability can become negligibly small by using the proposed retreat schemes.

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