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 anillustrativeembodiment, interference characteristics are determined for a set of nchannels to be used totransmit audio information bits, where n is greater than or equal to two. Theaudioinformation bits are separated into n classes based on error sensitivity, forexample, the impactof errors in particular audio data bits on perceived quality of an audiosignal reconstructedfrom the transmission. The classes of bits are then assigned to the n channelssuch that theclasses of bits having the greatest error sensitivity are transmitted over thechannels which arethe least susceptible to interference. The interference characteristicsassociated with the nchannels can be determined by, for example, measuring interference levels forone or moreof the channels, or obtaining information regarding known interference levelsfor one or moreof the channels. The channels may correspond to different frequency bands,time slots, codedivision slots or any other type of channels. The invention can provide UEPfor differentclasses of audio information bits even in cases in which the sameconvolutional code, or thesame complementary punctured pair convolutional (CPPC) code pair, is used toencode theclasses. The assignment of the classes of bits to the channels, as well as thecharacteristicsof the classes a.nd the channels, may be fixed or dynamic.