Coverage design aspects of L-band DAB with transmission modes II and IV

The Eureka 147 DAB system has been designed to operate in one of four different transmission modes, each one being well suited to a particular operational context. Mode II and mode IV are suggested for a DAB service at L-band (1452-1492 MHz). At such high frequencies, distributed emission techniques such as single frequency networks (SFN) will be needed to provide coverage over large areas. The number of transmitters, the complexity and the overall cost of these networks are very much a factor of the spacing between the transmission sites which, in turn, depends on the mode used, more specifically on the duration of the guard interval. This paper compares transmission modes II and IV, and discusses their applicability at L-band, as determined by coverage simulations for a few Canadian cities