隨著科技日新月異，電子產品從有線連接往無線連接邁進。從過去之軍用衛星、商用設備直至現今民生電子產品連接皆趨向無線化，頻譜資源也因無線網路的蓬勃發展而日趨擁擠，眾多設備因應用途不同而發展出各自的規格。頻譜之中區分為授權頻譜與非授權頻譜；授權頻譜由支付高額使用費的設備所使用，其餘未支付使用費的設備只能在非授權頻譜上使用；因此，非授權頻譜頻段非常擁擠，導致在非授權頻譜上運行的設備時常面臨異質網路設備的干擾。基於上述問題，本篇論文使用bladeRF開發版實現非授權頻譜之通道預留機制。 在此設計中，以不影響到原有設備的傳輸為前提下進行通道預留。為此將通道分割為控制子通道與資料子通道。設定通道之RSSI 臨界值，bladeRF 偵測該通道RSSI值是否低於所設定的臨界值，若低於臨界值，bladeRF 發送干擾訊號於控制子通道將該通道預留，避免異質網路設備使用該通道，且自己的設備可以使用資料通道傳送資料，達成通道預留機制；反之則改變所偵測之通道，不影響該通道上正在傳輸之設備。 本篇論文在GNU Radio開源軟體下完成實作上之通道預約機制，並且在真實環境下進行測試，藉由在各個情況下吞吐量之不同來驗證所設計之通道預約機制有效性。;With the rapid development of science and technology, electronic products are also moving forward from wired connection to wireless connection. From the previous military satellite, commercial equipment to today′s civil electronic products, the connection tends to be wireless. Therefore, spectrum resources are increasingly crowded due to the vigorous development of wireless networks. Various specifications are developed according to their different usage cases. As the unlicensed spectrum becomes crowded, devices accessing unlicensed spectrum will often be interfered by heterogeneous network devices. To tackle such issue, this thesis aims to use the bladeRF, which is a software defined radio platform, to realize the channel reservation mechanism over unlicensed spectrum. In this design, channel reservation will be performed without affecting the ongoing transmission from any device. According to the predefined RSSI threshold, the bladeRF will detect whether the channel is idle or not. For a channel, it is separated as control subchannel and data subchannel. if the detected RSSI value is lower than the threshold, bladeRF will transmit jamming signal over control subchannel to reserve the whole channel and consequently prohibit heterogeneous network devices from accessing that channel. Moreover, data can be transported over data subchannel via the other transceiver. Otherwise, the bladeRF will switch to another channel for sensing in order to ensure that the proposed channel reservation mechanism will not affect the ongoing transmissions. This thesis uses GNU Radio to develop the channel reservation mechanism, and verifies the development in a real environment. The effectiveness of the designed channel reservation mechanism is validated by means of observing the throughput variation of Wi-Fi network.
