<p>A digital demodulation apparatus which has a detector (11) which receives transmission signals (Sin) modulated under a multivalue quadrature amplitude modulation method having a honeycomb structure signal point arrangement and which produces I channel and Q channel demodulation signals and a discriminator (13) which converts the analog demodulation signals (Sa) to digital demodulation signals (Sd), a memory (21) being introduced which successively receives said digital demodulation signals (Sd) and reproduces corresponding original data, said read only memory (21) storing data premapped in the same way as the honeycomb structure signal point arrangement and storing polarity bits (P) and error bits ( epsilon ) of the signal points.</p>
