IEEE 802.11ax 基於OFDMA隨機接取效能分析

Abstract

下一代無線區域網路802.11ax面對密集場景對接取層(MAC),物理層(PHY)層都做出巨大修改。它提出一個基於OFDMA的多通道隨機接取機制。 該論文通過拓展Bianchi的二維馬爾科夫鏈模型完成對這個基於正交頻分多址(OFDMA)的隨機接取機制的穩態的行為進行預測,預測是在飽和數據量的條件下進行的。 模擬的結果也驗證了該馬爾科夫鏈模型的準確性。最終,我們也分析了關鍵系統參數的影響,包括多通道的數量,初始競爭窗口以及最大競爭窗口大小。

Confronting the dense scenario, 802.11ax, the next generation WLAN, makes revolutionary modifications on both MAC and PHY layers, exploiting MU-OFDMA PHY and centralized MAC scheme. A multi-channel random access mechanism, OFDMA-based random access (OBRA) is proposed. This work extends Bianchi’s bi-dimension Markov chain model to depict the steady-state behavior of the OBRA under saturation condition. And simulations validate the accuracy of the Markov chain model. Finally, the effects of system parameters, including the number of resource units (RUs) for random access, initial and maximum contention window, are evaluated.