Best mapping for LDPC coded modulation on SISO, MIMO and MAC channels
Junhong Wu, Heung-No Lee · 2004
Mapping has a significant impact on multilevel modulation schemes. These schemes for conventional codes with iterative demapping and decoding on static channel and Rayleigh fading channel have been studied previously. In this paper, we first investigate the mapping influence on LDPC-code based multilevel modulations on static and Rayleigh fading channels. Then we extend our work to multiple-input multiple-output (MIMO) fading channels and MIMO multiple access channels (MAC). A conclusion can be made as that the Gray map is the best with both iterations and super-iterations for all these channels, which is different from the results of conventional codes.