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Block Qpsk Modulation Codes With Two Levels Of Error Protection, Robert H. Morelos-Zaragoza, Shu Lin
Block Qpsk Modulation Codes With Two Levels Of Error Protection, Robert H. Morelos-Zaragoza, Shu Lin
Faculty Publications
A class of block QPSK modulation codes for unequal error protection (UEP) is presented. These codes are particularly suitable either for broadcast channels or for communication systems where parts of the information messages are more important than others. An example of the latter is coded speech transmission. Not much is known on the application of block UEP codes in combined coding and modulation schemes. We exhibit a method to combine binary linear UEP (LUEP) block codes of even length, using a Gray mapping, with a QPSK signal set to construct efficient block QPSK modulation codes with nonuniform error protection capabilities …
On A Class Of Optimal Nonbinary Linear Unequal-Error-Protection Codes For Two Sets Of Messages, Robert H. Morelos-Zaragoza, Shu Lin
On A Class Of Optimal Nonbinary Linear Unequal-Error-Protection Codes For Two Sets Of Messages, Robert H. Morelos-Zaragoza, Shu Lin
Faculty Publications
Several authors have addressed the problem of designing good linear unequal error protection (LUEP) codes. However, very little is known about good nonbinary LUEP codes. We present a class of optimal nonbinary LUEP codes for two different sets of messages. By combining t-error-correcting ReedSolomon (RS) codes and shortened nonbinary Hamming codes, we obtain nonbinary LUEP codes that protect one set of messages against any t or fewer symbol errors and the remaining set of messages against any single symbol error. For t ≥ 2, we show that these codes are optimal in the sense of achieving the Hamming lower bound …