By using the density evolution approach for BICM,it is demonstrated that there is noone g the best performance over all SNR regions [Tan05,IEEE Trans.Wireless 011 101 a.Gray Labelmg Bit 2 Bit 3 0114 001 100 111 110 110 b.Set-Partitioning Labelin 图5.1l.4给出了l6-QAM星座的binary labeling rule. 10 0i0 (a)Gray (b)Set partitioning Figure 5.11.4 Binary labeling rules for 16-QAM 2424 By using the density evolution approach for BICM, it is demonstrated that there is no one mapper having the best performance over all SNR regions [Tan05, IEEE Trans. Wireless, vol.4, no.2, 2005]. 图 5.11.4 给出了 16-QAM 星座的 binary labeling rule. (a) Gray (b) Set partitioning Figure 5.11.4 Binary labeling rules for 16-QAM