Abstract: Based on the classical system design flow, a custom digital down converter (DDC) was designed and implemented for Homenet wireless communication system. At the system level, the behavior model of DDC was constructed with the assistant of system modeling tool MATLAB. At the circuit level, considering implementation complexity, a large number of digital filter optimizing schemes such as CSD and RAG were adopted; in our design, numerically controlled oscillators (NCO) was based on a new hybrid scheme, which combines the respective advantages of LUT and CORDIC algorithm. Homenet system verification flat including our custom digital down converter was implemented with Xilinx VirtexII XC2V1000-4FG256 FPGA.

Key words: DDC, ADC, bandpass sampling, CSD, RAG, NCO, LUT, CORDIC

摘要： 基于经典的系统设计流程，设计并实现了一种应用于家庭网络核心SoC平台中无线通信系统接收机的专用数字中频下变频器。在系统级，利用系统建模工具MATLAB，完成了数字下变频器的行为建模及其功能划分；在电路级，完成了数字下变频器中主要功能模块的VLSI实现及其功能仿真。考虑到系统实现的复杂性及其硬件资源，对于数字滤波器，采用CSD和RAG等优化策略；对于数控振荡器，采用一种新型的结合LUT和CORDIC算法优点的混合算法实现方案。最后，搭建了基于Xilinx VirtexII XC2V1000-4FG256 FPGA的家庭网络无线通信系统验证平台，完成了数字中频下变频器的功能验证。

关键词: 数字下变频器, 模数转换器, 带通采样, CSD, RAG, 数控振荡器, 查找表, CORDIC