Audio in-band signalling system based on a complementary pair of peak and notch equalizers

Abstract

Slow rate, in-band signalling embedded into audio content of digital or analog radio broadcast network is common but demanding design challenge. In this paper a solution based on complementary pair of notch-peak filters for audio in-band signalling system is proposed. The concept is illustrated with a series of examples, verifying the basics of the idea and indicating possible traps and challenges the engineer utilizing the described system may encounter. The simulations were performed with Matlab and the accuracy of filters was tested with the SHARC signal processor.