隨著短距離通訊技術的進步，市面上的低功率射頻電機日益增多，像是智慧開關、藍牙耳機、無線鍵鼠等，此類射頻器材發射電功率皆小於1瓦特，且使用於免執照的2.4GHz頻段。這類射頻器材在頻譜管制上是屬於免執照的方式進行管理，但必須通過型式認證才可擁有與販賣。ISM頻段中，主要的應用是Wi-Fi網路，然而日益增長的低功率射頻電機，可能對Wi-Fi吞吐量存在潛在的干擾危險，因此Wi-Fi與低功率射頻電機間的訊號共存值得我們關注。本論文透過網路測速工具Iperf測試吞吐量以評估Wi-Fi頻寬效能是否會受到低功率射頻電機干擾，並且透過頻譜儀了解到低功率射頻電機於ISM頻段上的存在情形。
依照不同的電波特性設定實驗場景，依序觀察Wi-Fi、藍牙及無線鍵鼠作為干擾者時，Wi-Fi受害者的吞吐量變化情形，實驗結果以速率下降程度來評估Wi-Fi是否有被低功率射頻電機干擾，並且從頻譜儀上看到訊號的共存情形，在Wi-Fi作為干擾源時，頻譜圖上發現干擾者與被害者的訊號重疊，並在吞吐量測試中發現無論距離或是數量上的測試場景，都會造成至少40%以上的速率下降情形。在藍牙作為干擾源時，可從頻譜圖上發現藍牙訊號分佈於2.4GHz頻段上，並從吞吐量測試中得知，當待測設備為接收端時，無論在設備、距離及數量的測試場景，干擾源造成的速度下降率均小於2%，當待測設備為發射端時，數量增加會導致吞吐量下降。在無線鍵鼠作為干擾源時，可以從頻譜儀上發現無線鍵鼠出現頻率不高，並且在距離及設備的測試場景下，所造成的下降率小於2%。透過本研究實驗發現，Wi-Fi間的同頻干擾仍為影響吞吐量的主要原因，而藍牙及無線鍵鼠等低功率射頻電機對Wi-Fi吞吐量應無干擾之疑慮。

With the progress of short-range communication technology, there are more and more low power radio frequency devices in the market. This type of radio frequency (RF) equipment has emissive power of less than 1 Watt and is operated at the license-free 2.4 GHz band. This kind of low power devices, however, must satisfy type approval when rolling to the market.
The primary application in the ISM band is Wi-Fi wireless local area networks. However, the growing quantity of low power radio frequency devices may pose a potential interference to Wi-Fi throughput. Therefore, the coexistence of signals between Wi-Fi and low power radio frequency device deserves our attention. In this thesis, we use the Internet speed measurement tool, iPerf, to measure the throughput to evaluate whether the Wi-Fi bandwidth performance is degraded by low power radio frequency devices. The radio signal of low power radio frequency device in the ISM band is also observed by a spectrum analyzer.
In the measurements, we set up the experimental scenarios according to different wave characteristics and observe the change of throughput of Wi-Fi victim. Wi-Fi, Bluetooth, and wireless keyboard and mouse are used as interfering signals. Through this study, we can find that the throughput is significant affected by co-channel interference between Wi-Fi devices. The interfering impact of low power radio frequency devices, such as Bluetooth, wireless keyboard and mouse on the Wi-Fi throughput can be neglected.

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