级联COSINE滤波器在抽取滤波中的研究

为了解决高速抽取滤波器系统中传统CIC滤波器旁瓣抑制不够的问题,通过对级联COSINE抽取滤波器和传统CIC抽取滤波器的原理推导进行对比,分析出级联COSINE滤波器在幅频特性上同CIC滤波器具有很大相似之处,且在满足高速抽取滤波器的情况下,同时具备很好的低通特性和硬件实现性。通过MATLAB仿真实验得到,级联COSINE滤波器在进行32倍整数抽取时,第一旁瓣衰减约是传统CIC滤波器的2倍,进而说明相对于传统CIC滤波器,级联COSINE滤波器具有更好的旁瓣抑制性能。

Research on cascaded COSINE filter in decimation filter

In order to solve the problem that side lobe suppression of traditional Cascaded Integrator Comb(CIC) filter is not enough in high-speed decimation filter system,this paper compares cascade COSINE decimation filter and principle derivation of conventional CIC decimation filter,and analyses that cascade COSINE filter has great similarities with CIC filter on the frequency characteristics,along with a good low-pass characteristics and the implementation of hardware,meeting the case of high-speed decimation filter.According to the simulation by MATLAB,it can obtain that during taken the 32-fold integer,the first side lobe attenuation of cascade COSINE filter is about 2 times that of traditional CIC filter.That means,cascade COSINE filter has better side lobe suppression than that of conventional CIC filter.