Digital broadcasting satellite system, and information transmission method, error correction coding system and method

The system comprises a message source encoder, a code division multiplex (CDM) modulator, a transmitter, a satellite, a CDM demodulator and a message source decoder. Said CDM modulator comprises a HD-LDPC error correction encoding module. Said CDM demodulator comprises a HD-LDPC error correction decoding module. When digital signal message signals in multi channels are coded through the message source encoder, they are inputted into the CDM modulator; through error correction coding, interlace, spread spectrum and modulation, they are multiplexed in same frequency range; the transmitter transmits them to satellite, and the satellite broadcasts them to the service area; the CDM demodulator receives the satellite signals; through de-multiplex, demodulation, de-spread, de-interlace, de-error-correction-coding, the signals are inputted into the broadcast receivers of users.