Title :
Iterative demapping and decoding for multilevel modulation
Author :
Ten Brink, Stephan ; Speidel, Joachim ; Yan, Ran-Hong
Author_Institution :
Inst. of Telecommun., Stuttgart Univ., Germany
Abstract :
Iterative decoding algorithms for spectrally efficient modulation have become a vital field of research in digital communications. We show how iterative demapping reduces the bit error rate in conventional communication systems applying multilevel modulation combined with simple channel coding. For this the soft demapping has to be modified in order to accept a priori information. The system can be regarded as a serially concatenated iterative decoding scheme whereby the inner decoder is replaced by the soft demapping device. A design rule based on mutual information to find the `best´ mapping is proposed. Numerical results are presented for 4-PAM and 16-QAM examples
Keywords :
channel coding; digital communication; error statistics; iterative decoding; pulse amplitude modulation; quadrature amplitude modulation; 16-QAM; 4-PAM; BER reduction; bit error rate; channel coding; design rule; digital communications; inner decoder; iterative decoding algorithms; iterative demapping; mapping; multilevel modulation; mutual information; serially concatenated iterative decoding; soft demapping; spectrally efficient modulation; Additive white noise; Concatenated codes; Convolutional codes; Digital communication; Digital modulation; Gaussian noise; Iterative algorithms; Iterative decoding; Mutual information; Quadrature amplitude modulation;
Conference_Titel :
Global Telecommunications Conference, 1998. GLOBECOM 1998. The Bridge to Global Integration. IEEE
Conference_Location :
Sydney,NSW
Print_ISBN :
0-7803-4984-9
DOI :
10.1109/GLOCOM.1998.775793
