設計並實作多適性基於光纖的前程網路

Abstract

近年無線通訊快速發展，超高速傳輸儼然成為新一代無線通訊系統的發展重心。無線基站為了能夠接收處理大量高速輸入的資料流，同時發送大量資料給許多不同的使用者，前程網路(Fronthaul)作為無線基站前端的出入口，成為了替無線基站收集上行鏈線(Uplink Data)資料與分送下行鏈線資料(Downlink Data)的關鍵角色。 本論文提出一個前程網路的架構，以Xilinx Virtex7 FPGA 作為資料收集器，透過四條光纖與四個用來連接遠程射頻頭(RRH, Remote Radio Head)的Xilinx Virtex6 FPGA ，組成一個具有多種操作模式的前程網路。這個前程網路透過PCIe高速傳輸介面將Virtex7與無線基站作連接，可視無線基站的需求對不同的Virtex6前端送出下行鏈結資料，並且同時對不同的Virtex6提出回傳上行鏈結資料的要求。 由於光纖本身具有很強的抗干擾特性且能達到極高的傳送速度，提供了本前程網路架構一個高速收集並分送資料的解決方法。也因為光纖的這些特性，本前程網路架構也適用於無線基站與遠程射頻頭分隔較遠的情況，例如高樓層建築中的架設。 本論文將在第一章提出研究動機、目的以及整個架構的簡介，接著會在第二章介紹整個架構中使用到的相關高速傳輸技術、傳輸介面與其他模組、元件。實作的部分會在第三、四章敘述。第三章包含如何建立光纖傳輸鏈路以及如何使用PCIe介面讓FPGA與無線基站連接。第四章則會提出本論文完整的前程網路架構以及無線基站經由軟體操作整個前程網路的設定方法，除此之外也會大略說明在研究過程中產生出的其他版本架構，這些版本的架構雖然不符合本研究最終目的，但仍有一定的應用與參考價值。第五章會整理出整個架構的測試方法與測試結果。第六章則是本論文的結論與未來研究方向。

As the rapid growth of the developments of communication technologies in recent years, the high speed communication technologies have apparently become the focal of next-generation wireless communication systems. Because a wireless base station (BBU, Baseband Unit) is required to collect large amounts of data and transmit probably even more data to the users, the fronthaul, the main entrance and exit of the data stream of the BBU, plays an important role to collect the uplink data and to dispense the downlink data for the BBU. This thesis proposed a fronthaul architecture. This fronthaul is constructed by a data collector on Xilinx Virtex-7 FPGA and four RRH(Remote Radio Head) adapter on Xilinx Virtex-6 FPGA. Each RRH adapter on Virtex-6 is connected to the data collector on Virtex7 by a fiber channel. The interface between data collector and BBU is PCIe, providing a high speed connection between fronthaul and BBU. Depending on the demands of the BBU, this fronthaul data collector are able to distribute different downlink data to different users and send the uplink request to the different RRH adapter at the same time. As the characteristics of high interference resistance and high line rate of fiber, the fiber channel provides an excellent solution for the demand of collecting and transmitting massive data of fronthaul. And due to these property of fiber, this fronthaul can also be applied in some situations that the RRHs are far away from the data collector, such as the BBUs settled in high layers buildings. In the thesis, the chapter I will be the introduction of proposed architecture. Chapter II will contains the introduction of the high speed communication modules and components used in this architecture. Chapter III gives an description of how to implement the fiber channel and PCIe interface on FPGA. Chapter IV will be deep into the proposed architecture and some additional architectures. Chapter V and Chapter VI state the testing methods, testing results, conclusion and future works.