DDFS spurious signals due to amplitude quantization in absence of phase-accumulator truncation  

作　　者：Tian Xinguang Liu Xin Chen Hong Duan Miyi 

机构地区：[1]Inst. of Computing Technology, Beijing Jiaotong Univ., Beijing 100029, P. R. China [2]Inst. of Computing Technology, Chinese Academy of Sciences, Beijing 100080, P. R. China

出　　处：《Journal of Systems Engineering and Electronics》2009年第3期485-492,共8页系统工程与电子技术（英文版）

基　　金：supported by the National Grand Fundamental Research 973 Program of China(2004CB318109);the National High Technology Research and Development Program of China(863 Program)(2006AA01Z452).

摘　　要：Spurious signals in direct digital frequency synthesizers （DDFSs） are partly caused by amplitude quantization and phase truncation, which affect their application to many wireless telecommunication systems. These signals are deterministic and periodic in the time domain, so they appear as line spectra in the frequency domain. Two types of spurious signals due to amplitude quantization are exactly formulated and compared in the time and frequency domains respectively. Then the frequency spectra and power levels of the spurious signals due to amplitude quantization in the absence of phase-accumulator truncation are emphatically analyzed, and the effects of the DDFS parameter variations on the spurious signals are thoroughly studied by computer simulation. And several important conclusions are derived which can provide theoretical support for parameter choice and spurious performance evaluation in the application of DDFSs.Spurious signals in direct digital frequency synthesizers （DDFSs） are partly caused by amplitude quantization and phase truncation, which affect their application to many wireless telecommunication systems. These signals are deterministic and periodic in the time domain, so they appear as line spectra in the frequency domain. Two types of spurious signals due to amplitude quantization are exactly formulated and compared in the time and frequency domains respectively. Then the frequency spectra and power levels of the spurious signals due to amplitude quantization in the absence of phase-accumulator truncation are emphatically analyzed, and the effects of the DDFS parameter variations on the spurious signals are thoroughly studied by computer simulation. And several important conclusions are derived which can provide theoretical support for parameter choice and spurious performance evaluation in the application of DDFSs.

关 键 词：spurious signal direct digital frequency synthesizer amplitude quantization phase truncation power level. 

分 类 号：TN741[电子电信—电路与系统] TN74