Expanded information capacity for existing communication transmission systems

摘要: A system for transmitting digital programming includes a program source providing information, circuitry modulating the information onto visual carrier modulated with analog television programming, and transmitter coupled to circuitry. Using phase modulation method, modulates carrier, reduces baseband frequencies of amplitude phase-modulated video signal. The amplified encoded signal are combined an sound transmitted. additive sidebands carrier. data-modulated phase-shifted such that they will be in quadrature amplitude-modulated combines sidebands. With blended multiplicative/additive provides sideband addition provide optimized result.