波包偵測降頻技術應用於W-band之無線射頻與光纖通訊整合系統

Abstract

近幾年來，網路及通訊技術的飛速發展，通訊傳輸在生活中扮演著越來越重要的角色。多媒體以及互動式娛樂影音的快速進步使得訊號傳輸量逐年攀升，因此有線與無線通訊對於頻寬的需求大幅增加，進而帶動高頻訊號的發展，V-band (57-64GHz) 與 W-band (75-110 GHz) 的寬敞頻帶成為高資料量傳輸的最佳選擇。但是由於高頻的訊號無論在傳統同軸電纜或是大氣中都會受到相當大的傳輸功率損耗，導致傳輸距離受限且增加高頻系統處理的複雜度。 在本研究中，我們將波包偵測降頻技術應用於W-band直接偵測之無線射頻與光纖通訊整合系統(DD-RoF system) 中，相較於利用混波器降頻之高頻通訊系統，波包偵測降頻技術不受限於本地震盪器的頻率與輸出功率限制，進而降低因高頻損耗快速造成傳輸功率不足之問題。因此，在此提出之架構中，不僅可減少訊號功率之衰減，還能達到簡化高頻無線通訊系統之複雜度。

Recent years, with the rapid development of modern network and wireless communication technology, wireless communications has become a very significant role. The increasing demand of wireless communication capacity due to high-definition interactive multimedia makes the signal frequency toward THz frequency range. In particular, the V-band (57-64 GHz) and W-band (75-110 GHz) are the promising candidates because of wider bandwidth. However, higher carrier frequency signals have great power lose for transmission not only in the air but also in the coaxial cables, which limits the transmitting distance and makes transmission processing complex in the high frequency. In this study, we proposed the W-band radio-over-fiber system with simple envelope detector down-conversion. For down-conversion, the electrical mixer with local oscillator (LO) is utilized. However, as the carrier frequency increases, the power of LO will be limited for mixer down-conversion due to the amplifier, which makes the base station (BS) more complex and expensive. Therefore, ED down-conversion of W-band signals has been proposed. It can support vector signal down-conversion and doesn’t need the LO in BS. The proposed W-band RoF system with ED down-conversion is low attenuation loss and decreases the complexity of signal processing for high frequency wireless communications.