Adaptive filter including signal path compensation

Claim 2

An adaptive filter having first and second inputs and being adapted to be connected in circuit relationship with a transmission path; CHARACTERIZED BY first means for converting digital signals from a first digital code to a second digital code and being connected in circuit relationship to supply signals in said second digital code to said first input of said adaptive filter and to said transmission path so that a similar nonlinearity is introduced into signals supplied to said transmission path and to said first input of said adaptive filter.

Claim 3

The filter as defined in claim 1 CHARACTERIZED IN THAT said first code digital signals have a predetermined number of bits which number is greater than a number of bits of said second code digital signals.

Claim 4

The filter as defined in claim 2 CHARACTERIZED IN THAT said adaptive filter is adapted for processing incoming signals in said first code, and further includes second means for converting signals in said second digital code to signals in said first digital code and being connected in circuit relationship between an output of said first means and said first input of said adaptive filter.

Claim 5

The filter as defined in claim 3 CHARACTERIZED IN THAT said first code is linear and said second code is p-law PCM.

Claim 6

The filter as defined in claim 4 CHARACTERIZED IN THAT said adaptive filter comprises an adaptive transversal filter employed as an echo canceler and said transmission path includes a return signal path adapted to be connected in circuit relationship with said second input of said adaptive filter.

Claim 7

An adaptive filter having first and second inputs and being adapted to be connected in circuit relationship with a transmission path; CHARACTERIZED BY first means for converting incoming digital signals from a first digital code to a second digital code to be supplied to said transmission path; and second means for converting said incoming digital signals from said first code to said second code and from said second code to said first code and being connected in circuit relationship with said first input of said adaptive filter, so that a nonlinearity substantially identical to a nonlinearity introduced into signals supplied to said transmission path from said first means is introduced into signals supplied to said first input of said adaptive filter.

Claim 8

An adaptive filter having first and second inputs and being adapted to be connected in circuit relationship with a transmission path; CHARACTERIZED BY first means for converting incoming digital signals from a first digital code to a second digital code to be supplied to said transmission path; and second means for converting said incoming digital signals from said first code to said second code and from said second code to said first code and being connected in circuit relationship with said first input of said adaptive filter, so that a nonlinearity substantially identical to a nonlinearity introduced into signals supplied to said transmission path from said first means is introduced into signals supplied to said first input of said adaptive filter.

Claim 9

The filter as defined in claim 6 CHARACTERIZED IN THAT said first code digital signals have a predetermined number of bits which number is greater than a number of bits of said second code digital signals.

Claim 10

The filter as defined in claim 7 CHARACTERIZED IN THAT said first code is linear and said second code is p-law PCM.

Claim 11

The filter as defined in claim 8 CHARACTERIZED IN THAT said adaptive filter comprises an adaptive transversal filter employed as an echo canceler and said transmission path includes a return signal path adapted to be connected in circuit relationship with said second input of said adaptive filter.

Claim 12

An adaptive filter including first and second inputs and being adapted to be connected in circuit relationship with a transmission path; CHARACTERIZED BY first means for converting incoming digital signals from a first digital code to a second digital code to be supplied to said transmission path; and third means for converting said incoming digital signals from said first code to said second code and from said second code to a third digital code and being connected in circuit relationship to supply said third code signal to said adaptive filter first input, so that a nonlinearity substantially identical to a nonlinearity introduced into signals supplied from said first means to said transmission path is introduced into signals supplied by said third means to said adaptive filter first input.

Claim 13

An adaptive filter including first and second inputs and being adapted to be connected in circuit relationship with a transmission path; CHARACTERIZED BY first means for converting incoming digital signals from a first digital code to a second digital code to be supplied to said transmission path; and third means for converting said incoming digital signals from said first code to said second code and from said second code to a third digital code and being connected in circuit relationship to supply said third code signal to said adaptive filter first input, so that a nonlinearity substantially identical to a nonlinearity introduced into signals supplied from said first means to said transmission path is introduced into signals supplied by said third means to said adaptive filter first input.

Claim 14

The filter as defined in claim 10 CHARACTERIZED IN THAT said first code digital signals have a predetermined number of bits which number is greater than a number of bits of said second code digital signals.

Claim 15

The filter as defined in claim 11 CHARACTERIZED IN THAT said first code is linear, said second code is p-law PCM and said third code is floating point.

Claim 16

The filter as defined in claim 12 CHARACTERIZED IN THAT said adaptive filter comprises an adaptive transversal filter employed as an echo canceler and said transmission path includes a return signal path adapted to be connected in circuit relationship with said second input of said adaptive filter.