CAJ | 학술논문

针对目前多种通信模式的共存和发展趋势,对传统DDC结构进行改进,以适用于多模系统。提出了多模数字下变频改进结构与参数设计,完成了各模块Verilog代码编写和Modelsim仿真,并对Modelsim仿真结果进行分析和验证,验证了改进数字下变频的可行性；最后将代码移植到FPGA,并结合ETTUS射频板、自主设计的中频板以及友晶TR4 FPGA开发板多模硬件平台进行了板级调试,验证了多模功能的可行性,充分证明该结构能兼容WCDMA和TD-LTE两种模式,具有较高的实用性和通用性。
침대목전다충통신모식적공존화발전추세,대전통DDC결구진행개진,이괄용우다모계통。제출료다모수자하변빈개진결구여삼수설계,완성료각모괴Verilog대마편사화Modelsim방진,병대Modelsim방진결과진행분석화험증,험증료개진수자하변빈적가행성；최후장대마이식도FPGA,병결합ETTUS사빈판、자주설계적중빈판이급우정TR4 FPGA개발판다모경건평태진행료판급조시,험증료다모공능적가행성,충분증명해결구능겸용WCDMA화TD-LTE량충모식,구유교고적실용성화통용성。
According to the coexistence of various communication modes and the development trend, the tra-ditional DDC( Digital Down Converter) structure is modified to apply to the multimode system. The improved construction and parameter design of multimode DDC are proposed, the Verilog coding and Modelsim simula-tion is completed,and results are analyzed and validated. Finally,code is transplanted into FPGA,and based on the board debugging on the ETTUS RF board,IF board designed independently and Terasic TR4 FPGA board,the feasibility of multimode functionality has been verified. It has been fully proved that this structure can be compatible with two modes( WCDMA and TD-LTE) and has high practicality and generality.