Non-linear coding system

Claim 1

A non-linear coding system comprising a comparator means (8) and a local decoder means (19), said comparator means (8) comparing a sample magnitude signal with the reference magnitude signal out of said local decoder means (19) and codes the difference between said signals, said local decoder means (19) comprising: (a) a non-linear characteristic conrolling means (22), a lead (21) connecting an output of said comparator means (8) with an input of said non-linear characteristic controlling means 22, said non-linear characteristic controlling means (22) selecting a non-linear characteristic according to the forecast sample magnitude and characterizing the output of the comparator means (8) with the non-linear characteristic, said non-linear characteristic controlling means (22) having an output (27), (b) a digital to analog converter means (26) having an input connected to said output (27) of said non-linear characteristic controlling means (22) for converting the output of said non-linear characteristic controlling means (22) to the reference magnitude signal, and (c) memory forecast means (23) having an output (25) connected to said non-linear characteristic controlling means (22) for providing a forecast sample magnitude signal from a preceding sample magnitude signal, said non-linear characteristic controlling means (22) comprising: (a) first digital to digital converter means (41') (b) means connecting said first digital to digital converter means (41') to said forecast means (23) for converting the forecast sample magnitude signal in accordance with the conversion characteristic of a fundamental non-linear characteristic, (c) an output (45a, 45b, 45c, 45d), (d) subtraction circuit means (33) connected to the output of said first digital to digital converter means (41') for producing difference signals indicating the difference between the output of the comparator means (8) and the output of the first digital to digital converter means (41') and providing an overflow signal when an overflow occurs in said subtraction circuit means (33), (e) first switch means (35a, 35b, 35c, 35d) supplied with the output of said comparator means (8) and the difference signals out of said subtraction circuit means (33) and controlled by said overflow signal, (f) second digital to digital converter means (41) connected to said first switch means (35a, 35b, 35c, 35d) for connecting an output of said first switch means (35a, 35b, 35c, 35d) in accordance with the fundamental non-linear characteristic, said second digital to digital converter means (41) having an output, (g) second switch means (44a, 44b, 44c) supplied with the forecast sample magnitude signal out of said forecast means (23) and controlled by said overflow signal, and (h) adder means (42) connected to the output of said second digital to digital converter means (41) and supplied with the forecast sample magnitude signal via said second switch means (44a, 44b, 44c) for adding said second output and the forecast sample magnitude signal.