| 摘要 |
<p>PURPOSE:To utilize a high-quality digital sound signal and independent data in the distribution of shared reception by transmitting the digital data transmitted in the PCM width carrier component of a satellite broadcast with multiplexing them to a video signal in the one channel transmission band of the VHF band and a UHF band of a ground broadcast wave, and receiving and reproducing them. CONSTITUTION:The carrier generated in a carrier generating circuit 104 in an amplitude modulating wave generating circuit 102 is amplitude modulated by the video signal added to an input terminal 101 in a modulating circuit 103, and outputted as a first modulated wave. A sub-carrier generated in a sub-carrier generating circuit 107 is modulated by a digital data signal, which is to be multiplexed, added to an input terminal 105 in a modulating circuit 106, and becomes a second modulated wave. Further, the phase of the carrier generated in the generating circuit 104 is changed by 90 deg. by a phase shifting circuit 108, the carrier is modulated by the second modulated wave signal from the modulating circuit 106 by a modulating circuit 109, and becomes a third modulated wave. The third and first modulated waves are synthesized by a synthesizing circuit 110, and they are transmitted from an antenna (or a cable) 111.</p> |
