Unequal error protection for digital broadcasting using channel classification

摘要

The invention provides methods and apparatus for processing information, e.g., audio, video or image information, for transmission in a communication system. In an illustrative embodiment, interference characteristics are determined for a set of n channels to be used to transmit audio information bits, where n is greater than or equal to two. The audio information bits are separated into n classes based on error sensitivity, for example, the impact of errors in particular audio data bits on perceived quality of an audio signal reconstructed from the transmission. The classes of bits are then assigned to the n channels such that the classes of bits having the greatest error sensitivity are transmitted over the channels which are the least susceptible to interference. The interference characteristics associated with the n channels can be determined by, for example, measuring interference levels for one or more of the channels, or obtaining information regarding known interference levels for one or more of the channels. The channels may correspond to different frequency bands, time slots, code division slots or any other type of channels. The invention can provide UEP for different classes of audio information bits even in cases in which the same convolutional code, or the same complementary punctured pair convolutional (CPPC) code pair, is used to encode the classes. The assignment of the classes of bits to the channels, as well as the characteristics of the classes and the channels, may be fixed or dynamic.