MULTI-VALUE CODING SYSTEM

摘要

PURPOSE:To narrower a power spectrum by applying decrease processing decreasing one level of a multi-value code series {bn} at every time the value of an information series {an} changes from ''0'' to ''1'' or from ''1'' to ''0'' when a multi-value code series {bn} reaches L-1 from the highest level. CONSTITUTION:A binary information series {an} is inputted from an input terminal 1 to a code switching detection circuit 2. The code switching detection circuit 2 generates a pulse when the binary information series {an} changes from ''0'' to ''1'' or from ''1'' to ''0'' and outputs a pulse train 3. A reset signal generating circuit 4 is started at first ahead of the operation of the coder to reset an adder/subtraction circuit 5 and a counter 6. Then the output level of the adder/ subtractor circuit 5 is increased by one level at each output pulse of the code switching detection circuit 2. On the other hand, the adder/subtractor circuit 5 decreases the output level by one level at each input of the pulse 3. Then a multi-value code series {bn}L is outputted to an output terminal 8 from the adder/subtractor circuit 5.