Improvement and implementation of CIC interpolation filter in ophthalmology ultrasonography digital image based on FPGA
Chin-mao Cheng, Jianjun Ji, Yanqun Wang · Guoji shengwu yixue gongcheng zazhi · 2010
Objective The aim of this study was to improve cascaded integrator comb (CIC) interpolation filter for the enhancement of sampling frequency in the ophthalmology ultrasonagraphy digital imaging system. Methods CIC filter was improved base on the analysis of it and the combined introduction of COSINE and interpolated second-order polynomials(ISOP) filters. Results The modified structures were implemented in field programmable gate array(FPGA) using verilog hardware description language. The algorithm was validated by simulation. Conclusion The results showed that the improved CIC not only had the advantage of high efficiency and saving more resources, but also ameliorated its pass band and stop band. It is applicable in high frequency uhrasonography digital signal processing. Key words: CIC interpolation filter; , Ophthalmology ultrasonography; Field programmable gate array