Approximation Technique for Correlation Computations of Companded Signals
Original Publication Date: 1986-Jan-01
Included in the Prior Art Database: 2005-Mar-08
This disclosure describes a technique that utilizes the logarithmic properties of digitized signals that have been companded in pulse code modulation (PCM) form. The logarithmic properties are utilized to compute correlation values for signals without requiring the use of a multiplier. Simple shifting and adding steps can be performed instead. The approximation permits calculation of the complex correlation functions to be performed on simple microprocessors not having multipliers. The general use of logarithmic relations for replacing multiplication by addition is well known. The logarithmic properties of companded digitized PCM signals is not so apparent.