Transcoder for digital differential phase modulation
AssigneeCompagnie Industrielle des Telecommunications Cit-Alcatel
InventorClaude Aillet
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Abstract
Transcoder for digital differential phase modulation designed for accumulating, separately, partial trains of pulses which are mutually shifted and whose rhythm is an integral fraction of that of the original train. The partial accumulations are finally gathered together in a common adder. The invention enables a differential modulation on adjacent bits at a speed which is not limited by the accumulation loop delay.
Claims6
Transcoder for digital differential phase modulation for m binary input pulse trains, m being an integer, characterized in that it comprises a plurality of accumulators each having m inputs, cyclic distributor means for feeding the consecutive pulses of each pulse train, in a cyclic manner, to a respective input of each accumulator in succession and adder means including a modulo 2.sup.m adder for adding the contents of said accumulators.
Transcoder for phase jump differential modulation for m input binary pulse trains, characterized in that it comprises an accumulator having a delay comprised between p bit moments and p + 1 bit moments of the input pulse trains and being provided with m inputs and m outputs, p being an integer, a plurality of delay lines, p delay lines being connected in series to each respective output of the accumulator, each delay line having a delay duration of one bit moment, and a modulo 2.sup.m adder having first inputs connected respectively to the output of a respective delay line and second inputs connected directly to respective outputs of said accumulator.
Dependencies are inferred from the claim text.