Soft decision value generation circuit to reduce calculation amounts and hardware scale

摘要

A soft decision value generation circuit capable of reducing amount of calculation and hardware scale for generating a soft decision value. The soft decision value generation circuit includes: a phase rotation unit rotating phases of received symbols after coherent detection; addition units calculating, by using the phase-rotated received symbols, absolute values of soft decision values for soft decision value candidates restricted in advance; minimum value selection units selecting minimum values out of the absolute values of the soft decision values; sign reflection units reflecting, based on the phases of the received symbols after the phase rotation, sign information to the minimum values; and soft decision value correction units multiplying outputs of the sign reflection units by a coefficient depending on a noise variance value and an amplitude value of a modulation symbol.

主权项

1. A soft decision value generation circuit, comprising:
phase rotation means for rotating a phase of a received symbol after coherent detection; addition means for calculating, by using the phase-rotated received symbol, absolute values of soft decision values for soft decision value candidates, wherein a number of the soft decision value candidates, of a number of possible soft decision value candidates, is restricted by the addition means in advance of the absolute value calculation; minimum value selection means for selecting a minimum value out of the absolute values of the soft decision values; and sign reflection means for assigning, based on the phase of the received symbol after the phase rotation, a sign to the minimum value to generate a soft decision value.