Design of Circularly Symmetric 2-D FIR Filters Using a Novel Technique in Calculating the Coefficients of McClellan Transformation.

Document Type : Research Studies

Authors

1 Computer Engineering Department, Mu'tah University, Jordan

2 Computer Engineering Department, Mu'tah University, Jordan.

Abstract

In this paper, a novel analytic technique for the design of 2-D zero phase FIR circularly-symmetric filters is presented using the McClellan transformation. By this technique, a direct computation of the coefficients of McClellan transformation is derived by mapping the 2-D circular cutoff contour onto the /-D passband cut off and defining some deviation function, which is then freed to be zero for that contour. Then by comparing all the parameters in the resulting deviation function, one can easily determine the coefficients of McClellan transformation. This technique is formulated to assure that no scaling is needed. The McClellan coefficients in the presented technique may be simplified while a good approximation of the circular contour is maintained. The approximated version of the coefficients formulas appears to be the best to solve the problem of both accuracy and hardware implementation complexity. Using this approximation, one can get coefficients formulas which are suitable for real-time applications and can be easily implemented on a general-purpose signal processor.The design procedure is verified by several design examples and by comparison with previously published results.

Main Subjects