摘要
针对认知无线电中下变频处理中的信号抽取过程对信号频谱的影响进行了研究,信号抽取由积分梳状(CIC)滤波器、半带(HB)滤波器及多相滤波器级联而成,利用傅里叶变换对各环节处理后的信号频谱进行理论推导,得出各级抽取后信号频谱的变化规律及各参数选择要注意的问题。通过实验仿真,对整个抽取系统进行测试,仿真结果表明,采样率为fs的信号经过3级抽取,且抽取倍数为D_(CIC)·D_(HB)·D_(多相)时,输出信号的采样率变为fs/(D_(CIC)·D_(HB)·D_(多相)),与理论推导结果一致,实现了多速率信号处理。
The impact of signal decimation on the signal spectrum during the digital down conversion in cognitive radio is studied.The digital signal decimation is composed of cascaded integrator comb（ CIC） filter,half-band（ HB） filter and poly-phase filer.In order to get the rule of the signal spectrum and know the matters of the parameter selection,the paper gives the theoretical derivation of the signal spectrum in each step by use of the Fourier transform. The test of the whole decimation system is carried by simulation. Both theoretical analysis and simulation results show that the three-stage cascaded decimation system can make the sampling rate fsof the input signal fall to fs/（ D（CIC）·D（HB） D（多相））,which is consistent with the theoretical derivation,and the multi-rate conversion can be achieved.
出处
《无线电工程》
2017年第12期15-19,共5页
Radio Engineering
基金
国家自然科学基金资助项目(61561017)
海南省自然科学基金资助项目(20166214)
