METHOD AND APPARATUS FOR ENCODING AND DECODING INFORMATION IN A DIGITAL COMMUNICATION SYSTEM

A communication system (100) encodes and decodes information utilizing at least four modulation levels for transmitting the information as symbols representing symbol bits in symbol bit positions. At least one of the symbol bit positions exhibits an error rate higher than that of another of the positions. A processor (204) encodes (702) the information into an even number of code words and transmits the code words as an interleaved data stream. The processor (204) rearranges (706, 708) the transmission order of the code word bits in a predetermined way to form a modified transmission order such that the code words are transmitted (710) with substantially equal error rates. A receiver (110) receives and demodulates (712) the interleaved data stream to derive the code word bits, and then reorders (714, 716) the code word bits to undo bit modifications resulting from the modified transmission order, thereby restoring the code words. The receiver then decodes the code words to recover the information.