The Design And Backend Implementation Of Digital Down Converter In The Mixed SoC

As the develop orientation of the. communication and the radio technology in the future, Software Radio is based on modern communication theory, takes the Digital Signal Processing technology as the core. On the basic platform connected by hardware units, Software Radio realize all sorts of radio communication by loading softwares. Digital Down Conversion is an important part of the Software Radio implementation, down-converts the intermediate frequency signals outputted by Analog to digital converter to digital base band, and then, reduces the sampling velocity and demodulate the base band.This paper concerns the design and backend implementation of Digital Down Conversion in mixed SoC. The mixed SoC is integrate the complicated analog circuits and mixed circuits besides digital parts. The reusing of IP core in the SoC system, reduces the design time cycle, and improves the design success rate.First, introduce the system frame of mixed SoC, including analog circuits and digital parts. Also refer to CPU and reusing IP core of the digital circuits.Present the design of Digital Down Conversion, basing on theory, basic structure, technique target and function. Down-converting100MHz double inputs signals, with20times decimating rate, output5MHz double signals. Digital Down Converter consists of Digital Mixer, Direct Digital Frequency Synthesizer and Low-passed Filter. Especially, by using a new arithmetic to implementate the Numerically Cont rolled Oscillator in the Direct Digital Frequency Synthesizer,Depending on the ASIC chip design flow, this paper accomplishs SoC system design, RTL implement with HDL and function simulation validation, emphasize particularly on backend implementation of the DDC. Including of RTL code logic synthesis, physical layout implementation, Design Rule Check, Layout with Schematic check, parasitic parameter extraction, Static Timing Analysis and format validation.