Numerically Controlled Oscillator Used for Digital Frequency Synthesizer: Realization and Optimization

The advantages and disadvantages of NCOs developed with lookup table method and CORDIC method are discussed.The realization of cosine signal with CORDIC algorithm is also derived.By synthesizing the advantages of these methods,a new NCO was designed and realized by using FPGA technology.The Modelsim and Quartus Ⅱ simulation and verification results show that this design is feasible and easy to be implemented with FPGA.Compared with NCO using only lookup table method,this one has simpler structure,more precision,less resource consumption and higher speed.