【正文】 .......................................... 53 改進限幅算法在認知無線電實驗系統(tǒng)中的實現(xiàn) ..................................................... 54 本章小結(jié) ..................................................................................................................... 56 5 認知無線電終端的硬件和軟件框架測試 ........................................................................ 57 認知無線電實驗系統(tǒng)終端硬件測試 ......................................................................... 57 電源模塊測試 ...................................................................................................... 57 時鐘信號測試 ...................................................................................................... 59 高速數(shù)字信號傳輸?shù)男盘柾暾詼y試 .............................................................. 61 認知無線電實驗系統(tǒng)軟件框架測試 ......................................................................... 62 底層硬件配置測試 .............................................................................................. 62 各算法模塊間的接口測試 .................................................................................. 63 任務時序和算法實時性測試 .............................................................................. 64 本章小結(jié) ..................................................................................................................... 64 6 結(jié)論與展望 ........................................................................................................................ 65 工作總結(jié) ..................................................................................................................... 65 后續(xù)工作及展望 ......................................................................................................... 65 致 謝 .................................................................................................................................... 66 參考文獻 ................................................................................................................................ 67 附 錄 認知無線電實驗系統(tǒng)終端實物圖 ........................................................................ 69 攻讀學位期間取得的研究成果 ............................................................................................ 70 聲明 CONTENTS VII CONTENTS 1 Preface ....................................................................................................................................1 Reasearch Status of Cognitive Radio ..............................................................................1 Thesis Background and Brief Introduction of CR Experimental System .......................2 Main work and the Arrangement of Contents .................................................................5 2 Design and Implementation of Hardware in CR Terminals ...................................................7 Design of Hardware Framework Based On SDF ............................................................7 Circuit Design of the Base Band Processing Board ........................................................8 Selection of the Key Devices .......................................................................................9 Circuit Design of Interface .......................................................................................9 Circuit Implementation...........................................................................................13 Circuit Design and Implementation of the IF Boards ...................................................21 IF Transmitter Board ..............................................................................................21 IF Receiver Board...................................................................................................24 Selection of RadioFrequency Module..........................................................................28 Brief Summary ..............................................................................................................28 3 Design and Implementation of the Software Framework in CR Terminals .........................29 Algorithm Flow in CR Terminals ..................................................................................29 Dispatch of Base Band Algorithms ...............................................................................29 Algorithm Flow in DSP .................................................................................................32 Design of Multitask Software Frameword Based On DSP/BIOS................................34 Brief Introduction of Realtime Multitask Operating System and DSP/BIOS .....34 Design method of software Based on DSP/BIOS ..................................................36 Software Frameword in Transmitting DSP ............................................................36 Software Frameword in Receiving DSP.................................................................39 Brief Summary ..............................................................................................................42 4 Reasearch of Algorithm Reducing the PAPR in CR Experimental System .........................43 Brief Introduction of PAPR Problem of OFDM Signal ................................................43 Definition of PAPR.................................................................................................43 Statistical Properties of PAPR of OFDM Signal ....................................................44 Impact to CR Experimental System Caused by High PAPR .........................................45 Common Algorithms Reducing the PAPR of OFDM signal .........................................47 Signal Distortion Techniques..................................................................................47 Coding Techniques .................................................................................................48 Probability Techniques 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