The present invention relates to a music information transmission system, and, in particular, relates to such a system in which music information is multiplexed with a television signal.
Conventionally, a music signal is transmitted through a wireless system or a cable to a reception side by transmitting an analog signal. In the conventional system, music information which is recorded on a record or a magnetic tape is converted to an electrical signal, which is then modulated to AM (amplitude modulation), or FM (frequency modulation), and a transmission station transmits that FM or AM signal over the air. Then, a reception side receives the signal, and demodulates that AM or FM signal, to reproduce music information which generates the music sound through a speaker.
However, that analog transmission system has the disadvantage that it needs a wide frequency band, thus, the information quantity transmitted in each unit frequency band is rather small, and the S/N (signal to noise ratio at a reception side) is deteriorated by noise in on a transmission path.
A digital transmission system in which an anglog music signal is sampled and quantized solves the problem of deterioration of S/N. However, it still has the disadvantage of wide frequency band.
Further, a prior music information transmission system has the disadvantage that the music information signal can not be multiplexed to a conventional television signal. Therefore, a teletext in which character information is multiplexed to a television signal can not generally play background music with characters on a screen.
USPTO Backgrounds
USPTO Backgrounds