Patent ID: 6094623
Filing Date: 2000-07-25
Classification: G06F

Abstract:
A method of applying adaptive filtering in non-ideal noise environments comprising sending an output signal C, collecting a primary signal P containing an information signal component S1 representing said output signal C and a first noise signal N1, collecting a reference signal R containing a second noise signal N2 and a second information signal S2 representative of said output signal C in said reference signal R, generating a compensation signal X based on said reference signal R, said output signal C and weighting factors W, said compensation signal X being derived using a first equationX=N3+S3where;N3=a manipulated input derived from the error component N2 in reference signal R, andS3 is a manipulated input derived from the information component S2 of the reference signal Rand subtracting X from said primary signal P to generate a corrected said output signal C based on a second equationC=S1+N1-Xtaking a third equation C=(S1-S3)+(N1-N3) derived from said second equation and squaring to provide a fourth equationC.sup.2 =(S1-S3).sup.2 +2(S1-S3)(N1-N3)+(N1-N3).sup.2taking the expectation of said fourth equation to obtain a fifth equation E[C.sup.2 ]=E[(S1+S2).sup.2 ]+2E[(S1-S3)(N1-N3)]+E[(N1-N3).sup.2 ] and noting that E[(S1-S3)(N1-N3)]=0 a sixth equation E[C.sup.2 ]=E[(S1+S2).sup.2 ]+E[(N1-N3).sup.2 ] is obtained, said sixth equation is minimized for adaptive compensation to provide a seventh equationmin E[C.sup.2 ]=min E[(S1-S3).sup.2 ]+min E[(N1-N3).sup.2 ]manipulating the values ofN3+S3=(N2+S2).multidot.e.sup.(a+b.vertline.N2+S2.vertline./d)selecting values for a, b and d by computer modeling for information and noise signal components S1 and N1 of said primary signal P and S2 and N2 in said reference signal R while controlling iterative adjustments using quantitative analysis of cross correlation coefficients between corresponding intervals of said output signal in an ideal noise environment and said output signal in the non-ideal noise environment after convergence time had lapsed.