US 6,647,403 B2 · Method and digital signal processing equipment for performing digital signal processing calculation

Abstract

The invention relates to a method and digital signal processing equipment for performing a digital signal processing calculation, the method employing a look-up table in which predetermined numerical values, which are inverse values of square roots of numbers, have been stored. In the method, the look-up table is searched for the inverse value of the square root of a desired number. If the value is found in the look-up table, it is retrieved. If the value is not found in the look-up table, the number is scaled such that the inverse value of the square root of the scaled number is found in the look-up table. The found value is then retrieved from the look-up table and descaled to produce the inverse value of the square root of the number. The inverse value of the square root of the number is used to carry out a calculation.

Claims18

Dependent claims

A method for performing a digital signal processing calculation comprising:

employing a look-up table in which predetermined numerical values have been stored, wherein the predetermined numerical values are inverse values of square roots of numbers;
searching the look-up table for an inverse value of a square root of a desired number;
retrieving the inverse value of the square root of the desired number from the look-up table, when the inverse value of the square root of the desired number is found in the look-up table;
wherein, when the inverse value of the square root of the desired number is not found in the look-up table, the method further comprises:
scaling the desired number to produce a scaled number such that an inverse value of a square root of the scaled number is found in the look-up table;
retrieving the inverse value of the square root of the scaled number from the look-up table;
descaling the inverse value of the square root of the scaled number to produce the inverse value of the square root of the desired number;
and
using the inverse value of the square root of the desired number to carry out a calculation.

6 more elements

Dependencies are inferred from the claim text.

Method and digital signal processing equipment for performing digital signal processing calculation

Life of this patent

Method and digital signal processing equipment for performing digital signal processing calculation

Life of this patent

Abstract

Claims18