infobit pairs (d.dd.d.d,d)= 8PSK symbols 00,01,11,10,00,11 0,2,7,5,1,6 0,3,7,4,1,7 .selector output TTOT 0,3,6,4,0,7 00,01,11,10,00,11 11.00100.10 =g44444) equence of infobit pairs 1 6,7,0,3,0,4 8PSK symbols TOTT Figure 5.9.4 From [Robertson98] polynomials of some co ponent TCM codes that can be employed in the TTCM scheme.These polynomials were obtained by Robertson and Worz using an exhaustive computer search method.In Table 5.9.1,denotes the number of information bits to be encoded from the m information bits contained in an input symbol. -PUNCTURED"TCM CODES WTTH BEST MINIMAL DISTANCE FOR S-PSK AND QAM (IN OCTAL NOTATION) Code m H(D)H(D) H2(D) H(D).e/△ 2-dim.8-PSK.8 states 02 04 4-dim.8PSK.states 4dim.8-Psk 16 state 2.dim 72 8 states 11 05 0 2.dim 22 16 states 3 210204 10 2-dim.22 8 states 2 1104 02 2-dim.22.16 states 2 210410 5.9.2.2 TTCM Decoder The iterative dec oder for TTCM is similar to that used to decode binary turbo codes except that i the nature of the informtion passed from one decoder to the other.Fig.5.9.5 illustrates the concept of a priori,a posteriori and extrinsic information used inTTCM decoder. a6 Figure 5.9.4 From [Robertson98] Table 5.9.1 lists the generator polynomials of some component TCM codes that can be employed in the TTCM scheme. These polynomials were obtained by Robertson and Worz using an exhaustive computer search method. In Table 5.9.1, m denotes the number of information bits to be encoded from the m information bits contained in an input symbol. 5.9.2.2 TTCM Decoder The iterative decoder for TTCM is similar to that used to decode binary turbo codes, except that there is a difference in the nature of the information passed from one decoder to the other. Fig. 5.9.5 illustrates the concept of a priori, a posteriori and extrinsic information used in TTCM decoder