A modified data rate limiting method in FM IBOC broadcasting based on dynamic spectrum allocation in real time

The digital data rate transfer rate in FM In-band On-channel Broadcasting system based on dynamic spectrum allocation (DS-IBOC) scheme constantly changes. To ensure relatively stable data transfer rate and uninterrupted data stream, after adding buffer at the receiving end, it must meet the requirement that, after 2 or 3 frames delaying time, the average data transfer rate per frame not less than the minimum threshold 60kbps. As the pure language programs such as storytelling programs contain a considerable amount of mute time slots, the analog sound quality is sensitive to the change of the digital signal position due to the masking effect, in order to ensure the analog sound quality, the pure language program cannot meet the above requirement. This paper considers mute time slots and its characters, classifies audio frame statistically, proposes a modified data rate limiting method which based on real time dynamic spectrum allocation (RTDS). The limiting method take different data rate limiting processing ways according to different frame types. With 2 or 3 frames delaying time, guarantee the minimum data transfer rate threshold of 60kbps, so as to ensure the stable and uninterrupted data stream of digital and analog simulcast. At the same time, by means of audio quality compensation, the loss of sound quality is minimized so as to ensure the satisfied analog listening quality.