| 摘要 |
PURPOSE: To decrease the amount of data by thinning out data after correlation processing without losing information included in the result of the correlation processing. CONSTITUTION: A reference data string 12 is converted by a fast Fourier transforming circuit 11 from data in a time area to data in a frequency are and multiplied by a specific window function through a multiplying circuit 13 to remove its high frequency component. A fast Fourier transforming circuit 15 converts the data into reference data 16 in the time area again and a correlating circuit 18 collates the reference data and a signal 17 with each other. The correlation result is thinned out at a specific rate by a thinning-out circuit 21. Even when the signal 17 has the influence of collation with the original reference data string exerted on only one correlation result, the influence appears in plural correlation results by collation with the reference data after the high frequency component is removed. Consequently, the information included in the signal can be left even in the correlation after the thinning-out process. |
