Non-linear signal processor

A device for the compensatory adjustment of a sampled signal in accordance with the statistical deviation thereof from a preselected statistical model and comprising:

• an address counter;
• a first random access memory having a write-input responsive to the cumulative number of occurrences of each of a plurality of preselected amplitude samples for the sampled signal, and a read/write address input responsive to an output of said address counter for providing an output indicative of an amplitude density function (d(x)) for the sampled digital input, (x);
• a second random access memory having a write-input responsive to the integral of the output of said first random access memory with respect to the amplitude of the sampled digital input (x), a write-address input responsively coupled to said output of said address counter, and a read address responsive to said sampled digital input (x) for providing a read-output indicative of an amplitude distribution function, D(X);
• and
• a read only memory corresponding to an arbitrary inverse function generator, having an address input responsive to said read-output of said second random-access memory for providing an output corresponding to a compensatorily-adjusted, sampled input signal, (x).

A device for the correction of signal distortion occurring in a signalling channel and comprising:

• an address counter for preselected successive discrete values of a sampled signal amplitude,
• a first random access memory having a "1" write-input, a write-address responsive to the digitized value of the applied input (x), and a read address responsively coupled to an output of said address counter;
• a second random access memory having a write-input, a read-output and a read/write address input responsive to said output of said address counter;
• digital arithmetic combining means responsive to said read-outputs of said first and second random access memories, for providing an output indicative of an amplitude density function (d(x)) for the sampled digital input, (x);
• digital integrating means having an input responsive to the output d(x) of said second random access memory means for providing an output D(x) indicative of the integral of the input thereto and corresponding to an amplitude distribution function, D(x);
• a third random access memory having a write-input responsive to the output of said digital integrating means, a write-address input responsively coupled to said output of said address counter, and a read address responsive to said sampled digital input (x) for providing a read-output indicative of said amplitude distribution function D(x);
• a read only memory corresponding to an arbitrary inverse function generator, having an address input responsive to said read-output of said third random access memory for providing an output corresponding to a compensatorily-adjusted, sampled input signal (x).

A device for the compensatory adjustment of a sampled signal in accordance with the statistical deviation thereof from a preselected statistical model and comprising:

• an address counter for preselected successive discrete values of the sampled signal amplitude;
• a first random-access memory having write-input and a read/write address input responsive to an output of said address counter;
• a second random access memory having a write-input, a write-address input responsively coupled to said output of said address counter, and a read address responsive to said sampled digital input (x);
• a read only memory corresponding to an arbitrary inverse function generator, having an address input responsive to said read-output of said second random-access memory for providing an output corresponding to a compensatorily-adjusted, sampled input signal (x);
• first arithmetic means cooperating with said address counter and the read-out of said first random access memory and interposed at a write-input of said first random access memory for providing an input thereto corresponding to the cumulative number of occurrences of each of a plurality of preselected amplitudes of the sampled input signal;
• and
• second arithmetic means cooperating with said address counter and the read-out of said first random access memory and interposed at a write-input of said second random access memory for providing an input thereto corresponding to the cumulative number of occurrences of amplitudes equal to or less than each addressed amplitude.