Title :
Block QPSK modulation codes with two levels of error protection
Author :
Morelos-Zaragoza, Robert H. ; Lin, Shu
Author_Institution :
Graduate Sch. of Inf. Sci., Nara Inst. of Sci. & Technol., Japan
Abstract :
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 for bandwidth efficient transmission over AWGN (additive white Gaussian noise) and Rayleigh fading channels
Keywords :
Gaussian channels; Rayleigh channels; block codes; fading; linear codes; modulation coding; quadrature phase shift keying; AWGN channels; Gray mapping; QPSK signal set; Rayleigh fading channels; additive white Gaussian noise; bandwidth efficient transmission; binary linear UEP block codes; block QPSK modulation codes; block UEP codes; broadcast channels; code length; coded speech transmission; communication systems; information messages; modulation coding; nonuniform error protection; unequal error protection; AWGN; Bandwidth; Block codes; Broadcasting; Error correction codes; Modulation coding; Protection; Quadrature phase shift keying; Signal mapping; Speech;
Conference_Titel :
Personal, Indoor and Mobile Radio Communications, 1994. Wireless Networks - Catching the Mobile Future., 5th IEEE International Symposium on
Conference_Location :
The Hague
Print_ISBN :
90-5199-193-2
DOI :
10.1109/WNCMF.1994.529150
