Method and apparatus for Digital Audio Broadcasting am with Tertiary subporadoras climbing with amplitude

摘要

A method of Digital Audio Broadcasting (DAB) - Band Channel (IBOs) that comprises the steps of providing a similar Modulated Carrier signal in a frequency band of a Central Radio Channel AM (Amplitude Modulation), providing a First Plurality of subportadores in a Brass Band Superior General of the radio channel.Providing a Second Plurality of subportadores in Upper sideband Channel AM Radio, providing a Second Plurality of subportadores in a Lower sideband Channel AM Radio, providing a Plurality of subportadores in a Third frequency band cen Of the AM radio channel by modulating a FirstA Plurality of second and Third subportadores with one or more Digitally coded signals, and transmitting the Modulated analog signal and the Plurality of First, second and Third subportadores,In the Third subportadores where the Plurality of subportadores are located closer to the center of the channel are transmitted to densities greater than subportadores Spectral Energy in the Third Plurality of subportadores are located farther from the center of the Channel.The Power Spectral densities of a First Group of the Plurality of subportadores in the Third subportadores can decrease linearly with Frequency separation from the center of the Channel. Transmissions and IBOC DAB receivers using the Composite Signal, are also included.