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| Analysis of the Overall Quantization Error for CORDIC Algorithm in Grating Digital Subdivision |
| WANG Xiao-na, ZHONG Yu-long,ZHU Wei-bin,YE Shu-liang |
| Institute of Industry and Trade Measurement Technique, China Jiliang University, Hangzhou, Zhejiang 310018, China |
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Abstract The overall quantization error (EOQ) of CORDIC algorithm is discussed based on grating digital subdivision technique. Simulations and circuit experiments are conducted according to the basic principles of CORDIC. The result shows that the difference between predicted and experimental values is inversely proportional to the number of iteration (n) under the conditions of different binary width (b). The difference between the two reaches 1.8×10-4rad, when n is equal to 12. It proves the effectiveness of the usage of EOQ to value the error of the algorithm in the calculation of angle. A quantitative analysis on error components and key parameters which influence the EOQ is presented. The result shows that the trend of EOQ becomes smaller with the increase of n and b, in which n plays a decisive role in the reduction of EOQ. Circuit test result shows that when the b remains unchanged, EOQ probably decreases by 50% with n adding once. The paper concludes the impact on the angle calculation based on CORDIC caused by EOQ. The conclusion has important significance and practical value to the error analysis in the process of digital subdividing for grating.
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Received: 06 March 2015
Published: 10 December 2015
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2016, Vol. 37 
