Common control digital echo suppression

Claim 2

In combination; means connected to a first line for determining a first digital amplitude code approximating the peak signal amplitude on said first line; means connected to a second line for determining a second digital amplitude code approximating the peak signal amplitude on sAid second line; and means responsive to said digital amplitude codes for said first and second lines when said first line is active and said second line is idle for generating an echo suppression enable signal.

Claim 3

In combination; means for translating digital codes representing sampled signal levels on a first line into a first amplitude code representing the peak signal level on said first line; means for translating digital codes representing sampled signal levels on a second line into a second amplitude code representing the peak signal level on said second line; means responsive to said first and second amplitude codes for generating a line activity signal when the peak signal level on said second line exceeds the peak signal level on said first line; and means responsive to said line activity signal for generating an echo suppression inhibit signal.

Claim 4

In combination; means for translating digital codes representing sampled signal levels on a first line into a first amplitude code representing the peak signal level on said first line; means for translating digital codes representing sampled signal levels on a second line into a second amplitude code representing the peak signal level on said second line; means responsive to said first and second amplitude codes for generating a line activity signal when the peak signal level on said second line exceeds the peak signal level on said first line; and means responsive to said line activity signal for generating an echo suppression inhibit signal.

Claim 5

In combination; means for translating digital codes representing sampled signal levels on a first line into a first amplitude code; means for translating digital codes representing sampled signal levels on a second line into a second amplitude code; means responsive to said first amplitude code for selectively altering a stored signal level code representing the stretched signal envelope on said first line; means for comparing the said first amplitude code with a selected set of code signals to determine the current activity status of said first line; means for simultaneously comparing said second amplitude code with said stored signal level code to determine if said second line is idle; and means for generating a control signal when said first line''s assigned current activity status is an active status, and said second line is idle.

Claim 6

In combination; means for translating digital codes representing sampled signal levels on a first line into a first amplitude code; means for translating digital codes representing sampled signal levels on a second line into a second amplitude code; means responsive to said first amplitude code for selectively altering a stored signal level code representing the stretched signal envelope on said first line; means for comparing the said first amplitude code with a selected set of code signals to determine the current activity status of said first line; means for simultaneously comparing said second amplitude code with said stored signal level code to determine if said second line is idle; and means for generating a control signal when said first line''s assigned current activity status is an active status, and said second line is idle.

Claim 7

The combination of claim 3 further comprising; means responsive to said control signal for activating echo suppression.

Claim 8

A digital echo suppressor in a multiplexed digital transmission system serving a plurality of odd-even line pairs, which comprises; means for translating the digital codes generated by sampling a selected odd line in a given time slot into a first peak amplitude code; means for translating the digital codes generated by sampling a selected even line in said time slot into a second peak amplitude code; means for generating a stretched envelope level code which is a function of said first amplitude code and the first amplitude codes received during previous occurrences of said time slot; comparator means for generating a line activity signal when a selected relation exists between said second peak amplitude code and said stretched envelope level code; and control means responsive to said line activity signal for deactivating echo suppression.

Claim 9

A digital echo suppressor in a multiplexed digital transmission system serving a plurality of odd-even line pairs, which comprises; means for translating the digital codes generated by sampling a selected odd line in a given time slot into a first peak amplitude code; means for translating the digital codes generated by sampling a selected even line in said time slot into a second peak amplitude code; means for generating a stretched envelope level code which is a function of said first amplitude code and the first amplitude codes received during previous occurrences of said time slot; comparator means for generating a line activity signal when a selected relation exists between said second peak amplitude code and said stretched envelope level code; and control means responsive to said line activity signal for deactivating echo suppression.

Claim 10

The digital echo suppressor of claim 5 wherein said control means further comprises; means for combining said first peak amplitude code with a first stored status code that is a function of said first amplitude codes generated by digital codes received during previous occurrences of said time slot to determine the current activity status of said odd line; and means for combining said line activity signal with a code representing the pattern of occurrence of said line activity signals during previous occurrences of said time slot to determine the current activity status of said even line.

Claim 11

The digital echo suppressor of claim 6 wherein said control means further comprises; means responsive to selected combinations of said activity statuses of said odd and even lines for activating echo suppression.

Claim 12

A digital echo suppressor in a communication system, which comprises; a first time-shared threshold detector for translating the peak signal level on a first line into a first digital amplitude code; a second time-shared threshold detector for translating the peak signal level on a second line into a second digital amplitude code; and time-shared control means responsive to said first and second digital amplitude codes for controlling the activation of echo suppression.

Claim 13

A digital echo suppressor in a communication system, which comprises; a first time-shared threshold detector for translating the peak signal level on a first line into a first digital amplitude code; a second time-shared threshold detector for translating the peak signal level on a second line into a second digital amplitude code; and time-shared control means responsive to said first and second digital amplitude codes for controlling the activation of echo suppression.

Claim 14

A digital echo suppressor in a communication system, which comprises; a first time-shared threshold detector for translating the signal level on a first line into a first digital amplitude code in a selected time slot; a first time-shared status control means responsive to said first digital amplitude code for generating a first current activity status code for said first line; a second time-shared threshold detector for translating the signal level on a second line into a second digital amplitude code in said time slot; time-shared envelope stretching means responsive to said first amplitude code for selectively altering a stored signal level code; time-shared comparator means responsive to a selected combination of said stored signal level code and said second digital amplitude code for generating a line activity signal; a second time-shared status control means responsive to said line activity signals for generating a second current activity status code for said second line; and time-shared means responsive to selected combinations of said first and second activity status codes for enabling echo suppression.

Claim 15

A digital echo suppressor in a communication system, which comprises; a first time-shared threshold detector for translating the signal level on a first line into a first digital amplitude code in a selected time slot; a first time-shared status control means responsive to said first digital amplitude code for generating a first current activity status code for said first line; a second time-shared threshold detector for translating the signal level on a second line into a second digital amplitude code in said time slot; time-shared envelope stretching means responsive to said first amplitude code for selectively altering a stored signal level code; time-shared comparator means responsive to a selected combination of said stored signal level code and said second digital amplitude code for generating a line activity signal; a second time-shared status control means responsive to said line activity signals for generating a second current activity status code for said second line; and time-shared means responsive to selected combinations of said first and second activity status codes for enabling echo suppression.

Claim 16

The digital echo suppressor of claim 9 further comprising; a first time-shared timing means for generating a selected one of a first set of timing codes in said time slot; a second time-shared timing means for generating a selected one of a second set of timing codes in said time slot; wherein said first status control means is responsive to said first digital amplitude code and said selected timing code generated by said first timing means; and said second status control means is responsive to said line activity signal and said selected timing code generated by said second timing means.

Claim 17

The digital echo suppressor of claim 10 wherein said first timing means is responsive to said current activity status of said first line for varying the rate at which selected ones of the timing codes in said first set of timing codes is generated.

Claim 18

The digital echo suppressor of claim 10 wherein said second timing means is responsive to said current activity status of said second line for varying the rate at which selected ones of the timing codes in said second set of timing codes is generated.

Claim 19

A digital echo suppressor comprising; a first encoder for translating the analogue signal level on a first line into a digital code; a second encoder for translating the analogue signal level on a second line into a digital code; a first threshold detector for translating said digital code output of said first encoder into a first peak amplitude code; a second threshold detector for translating said digital code output of said second encoder into a second peak amplitude code; control means responsive to selected combinations of said first and second peak amplitude codes for enabling echo suppression.

Claim 20

A digital echo suppressor comprising; a first encoder for translating the analogue signal level on a first line into a digital code; a second encoder for translating the analogue signal level on a second line into a digital code; a first threshold detector for translating said digital code output of said first encoder into a first peak amplitude code; a second threshold detector for translating said digital code output of said second encoder into a second peak amplitude code; control means responsive to selected combinations of said first and second peak amplitude codes for enabling echo suppression.

Claim 21

In a time-divided transmission system, the echo suppressor comprising; a first scanner for repetitively scanning signal levels on a plurality of transmit lines in said transmission system; a second scanner for repetitively scanning analogue signal levels on a plurality of receive lines in said transmission system; a first encoder for translating the analogue signal level present on a transmit line associated with a selected time slot into a digital code signal; a second encoder for translating the analogue signal level present on a given receive line associated with said time slot into a digital code signal; a first threshold detector for translating the digital code output of said first encoder into a first peak amplitude code; a second threshold detector for translating the digital code output of said second encoder into a second peak amplitude code; means responsive to selected combinations of said first and second peak amplitude codes for generating a control signaL; and means responsive to said control signal for controlling the operation of echo suppression in said time slot.

Claim 22

In a time-divided transmission system, the echo suppressor comprising; a first scanner for repetitively scanning signal levels on a plurality of transmit lines in said transmission system; a second scanner for repetitively scanning analogue signal levels on a plurality of receive lines in said transmission system; a first encoder for translating the analogue signal level present on a transmit line associated with a selected time slot into a digital code signal; a second encoder for translating the analogue signal level present on a given receive line associated with said time slot into a digital code signal; a first threshold detector for translating the digital code output of said first encoder into a first peak amplitude code; a second threshold detector for translating the digital code output of said second encoder into a second peak amplitude code; means responsive to selected combinations of said first and second peak amplitude codes for generating a control signaL; and means responsive to said control signal for controlling the operation of echo suppression in said time slot.

Claim 23

In a time-divided transmission system, the echo suppressor comprising; a first time-shared encoder for translating the analogue signal level on a first line into a digital code in a selected time slot; a second time-shared encoder for translating the analogue signal level on a second line into a digital code in said time slot; a first time-shared threshold detector for translating said digital code output of said first encoder into a first peak amplitude code; a second time-shared threshold detector for translating said digital code output of said second encoder into a second peak amplitude code; and time-shared control means responsive to selected combinations of said first and second amplitude codes for controlling echo suppression in said time slot.

Claim 24

In a time-divided transmission system, the echo suppressor comprising; a first time-shared encoder for translating the analogue signal level on a first line into a digital code in a selected time slot; a second time-shared encoder for translating the analogue signal level on a second line into a digital code in said time slot; a first time-shared threshold detector for translating said digital code output of said first encoder into a first peak amplitude code; a second time-shared threshold detector for translating said digital code output of said second encoder into a second peak amplitude code; and time-shared control means responsive to selected combinations of said first and second amplitude codes for controlling echo suppression in said time slot.

Claim 25

An echo suppressor comprising; means connected to a first line for approximating the peak signal amplitude on said first line; means connected to a second line for approximating the peak signal amplitude on said second line; envelope stretching meanS responsive to the approximated peak signal amplitude on said first line for statistically altering a stored signal level code representing the stretched signal envelope on said first line; and means responsive to the approximated peak signal amplitude for said second line and said stored signal level code for controlling the activation of echo suppression for said first and second lines.

Claim 26

An echo suppressor comprising; means connected to a first line for approximating the peak signal amplitude on said first line; means connected to a second line for approximating the peak signal amplitude on said second line; envelope stretching meanS responsive to the approximated peak signal amplitude on said first line for statistically altering a stored signal level code representing the stretched signal envelope on said first line; and means responsive to the approximated peak signal amplitude for said second line and said stored signal level code for controlling the activation of echo suppression for said first and second lines.

Claim 27

The echo suppressor of claim 16 wherein said envelope stretching means further comprises; a storage means containing said signal level code; and arithmetic means responsive to selected relationships between the approximated peak amplitude code for said first line and said stored signal level code for altering said signal level code.