conv_d.c File Reference

Polynomial convolution in direct form. More...

Functions
void	spr_conv_d (float a[], int La, float b[], int Lb, float c[])

Detailed Description

Polynomial convolution in direct form.

Author

Stefaan Van Gerven

Date

22 mei 1992

A direct implementation of a convolution of two vectors.

Formulas:

c[i] = SUM(j) b[j]*a[i-j]  with j=0:Lb for i=0:La+Lb
// assume the vector a is zero extended at both sides

Arguments:

a[]

is an array with indices 0:La (input)

b[]

is an array with indices 0:Lb (input)

La+1 and Lb+1

are the lengths of the above defined input arrays

c[]

is the resulting output array with indices 0:La+Lb

Note

the actual implementation is different from the above formula, since no zero extensions is used and the sum of products (SOP) is calculated slightly different as a function of i in order to have the minimum number of multiplications

if conv is used for signals, beware that no history nor future of the signal is taken into account, this is a completely dif- ferent approach as in fir_d