MODULATOR, DEMODULATOR, TRANSMITTER, AND RECEIVER

摘要

The present invention provides a modulator, a demodulator, a transmitter, and a receiver for highly noise-tolerant digital data. The modulator in one embodiment of the present invention has a modulation mapping unit (15) which, when an LDPC code rate is 93/120, performs 16 APSK mapping with a radius ratio of 2.87. Furthermore, the modulator in another embodiment of the present invention has a modulation mapping unit (15) which, when an LDPC code rate is 93/120, performs 32 APSK mapping with a second inner circumferential circle/first inner circumferential circle radius ratio of 2.87 and an outer circumferential circle/first inner circumferential circle radius ratio of 5.33. The modulator is provided to a transmitter (1). This demodulator has a quadrature detection unit (21) for performing demodulation corresponding to the modulator. The modulator is provided to this receiver (2).