Modulation method, decoding method, modulation device, and demodulation device
AssigneeNEC Corporation
InventorsNorifumi KAMIYA, Mamoru SAWAHASHI
Life of this patent
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Abstract
A modulation device includes a mapping circuit configured to map information bits to signal points on a plurality of concentric rings, when a signal space arrangement in which the number of signal points on all of the plurality of rings is the same is used as a basis, reduce the number of signal points on an innermost ring or a plurality of rings from inner to outer rings from among the plurality of rings, generate a new ring outside the signal space arrangement used as the basis, and arrange, on the generated ring, signal points which achieve the same frequency utilization efficiency as that of the signal space arrangement used as the basis.
Claims16
A modulation method for mapping information bits to signal points on a plurality of concentric rings, the modification method comprising:
- when a signal space arrangement in which the number of signal points on all of the plurality of rings is the same is used as a basis, reducing the number of signal points on an innermost ring or a plurality of rings from inner to outer rings from among the plurality of rings;
- generating a new ring outside the signal space arrangement used as the basis;
- and
- arranging, on the generated ring, signal points which achieve the same frequency utilization efficiency as that of the signal space arrangement used as the basis.
A decoding method comprising:
- for a signal modulated using a method for mapping information bits to signal points on a plurality of concentric rings, performing error correction decoding on (na−np) bits, which are a difference between lower na bits of amplitude bits of the signal and np bits of phase bits of the signal;
- reducing symbol replica candidates based on a posteriori log-likelihood ratio of the information bits and parity check bits output from an error correction decoder;
- and
- obtaining upper uncoded (ma−na) bits of the amplitude bits and upper uncoded (mp−np) bits of the phase bits for the reduced symbol replica candidates.
A modulation device comprising a mapping circuit configured to map information bits to signal points on a plurality of concentric rings, when a signal space arrangement in which the number of signal points on all of the plurality of rings is the same is used as a basis, reduce the number of signal points on an innermost ring or a plurality of rings from inner to outer rings from among the plurality of rings, generate a new ring outside the signal space arrangement used as the basis, and arrange, on the generated ring, signal points which achieve the same frequency utilization efficiency as that of the signal space arrangement used as the basis.
(canceled)
Dependencies are inferred from the claim text.