Computer simulation of protection ratio for digital audio broadcasting

Since the new digital audio broadcasting system may be co-operated with the existing system for a few years, we should consider the interference between the new and the existing system. The allowance of interference is often described in terms of protection ratio (PR), defined as the minimum value of wanted-to-unwanted signal ratio. In several previous works, the PR was often obtained by using prototype equipment in a real environment. In this paper, we propose the simulation method for obtaining the PR. Since the analog signal may be considered as an additive Gaussian noise to go into the digital system, we can simplify the analog system as an additive colored Gaussian noise (ACGN) source. Through simulation for the Eureka-147 DAB system with NTSC or PAL, we show that the proposed method is eligible and comparable to the previous method.