Digital audio broadcasting: high-grade service quality through on board processing techniques

A digital audio broadcasting (DAB) satellite system is presented, providing optimized service and guaranteeing an high-grade quality service for some hundreds of channels. This with minimum cost of the radio set and of the broadcasting station, greatly improving the radio broadcasting service throughout the world, especially in areas where deployment of conventional relay infrastructures is difficult and not yet cost-effective. Potential broadcasters located in the visible hemisphere can directly up-link their programming to the DAB satellites. Broadcasters can also copy each up-link channel and steer flexibly to any beam or combination of satellite beams. The paper illustrates the advantages and the feasibility of a DAB system based on geostationary satellites on board processing generating of MCPC (multiple channel per carrier) type. This multiplexing technique allows large system margins. This solution allows the satellite L-band TWTA amplifiers to be operated in saturation and eliminates the intermodulation noise associated with the transmission of FDMA channels. A powerful coding scheme has been selected to create a “robust” down-link. In this way several high power DAB channels of radio programming, with selectable data rate, are directly delivered to the users