Audio-data transmission system and audio-data transmission method

An audio-data transmitting method, comprising:

• receiving and encoding a bit signal for generating an encoding signal;
• receiving the encoding signal;
• modulating the encoding signal to become an audio signal whose frequency is on a frequency band, wherein the audio signal includes at least four different sub-audio signals, the frequency band includes at least four different sub-frequency bands of different frequencies, and the frequencies of the at least four sub-audio signals are on the at least four
• playing the audio signal which includes the at least four different sub-audio signals simultaneously.

An audio-data transmitting system, comprising:

• a microphone, utilized to receive an audio signal whose frequency is on a frequency band, wherein the audio signal includes at least four different sub-audio signals, the frequency band includes at least four different sub-frequency bands of different frequencies, and the frequencies of the at least four sub-audio signals are on the at least four sub-frequency bands respectively;
• a data demodulator, coupled to the microphone for demodulating the audio signal to become an encoding signal according to frequencies of the at least four sub-audio signals;
• and
• a channel encoder, utilized to receive and decode the encoding signal for generating a bit signal.

An audio-data transmitting method, comprising:

• receiving an audio signal whose frequency is on a frequency band, wherein the audio signal includes at least four different sub-audio signals, the frequency band includes at least four different sub-frequency bands of different frequencies, and the frequencies of the at least four sub-audio signals are on the at least four sub-frequency bands respectively;
• demodulating the audio signal to become an encoding signal according to frequencies of the at least four sub-audio signals;
• and
• receiving and decoding the encoding signal for generating a bit signal.