The CT-TCM decoder structure is based on the multi-dimensional turbo-decoder decoders,each for one component code.The variables involved in Fig.5.9.10 are the log-likelihood (LL)values,as detailed below. DEC-0 DEC-mDEC-(M-1)Output L1 L 7(m) APP → Fig.5.9.10.The global decoder"for delay of one iteration and"for interleaving. Lo) the a posteriori LL values for all information symbols after decoding the mth component code. Im) the LL values (log p(y))based on individual channel observations of the mth component code.Its elements are calculated as Lm- flog p(y.x). for un-punctured symbols 10. for punctured symbols Lthe a prioriLL values for all information symbols for the mth component code. It is initialized to zeroes,implying information the extrinsic information produced by the mth component code,defined by L)=-) The Mlocal decoders operate successively.L contains the accumulated extrinsic information generated by all the local decoders except DEC-m L=L+L2.+L-+L0+L四+.+L-10 The CT-TCM decoder structure is based on the multi-dimensional turbo-decoder incorporating the BCJR algorithm. The global decoder operating in the log domain for a CT-TCM code is shown in Fig. 5.9.10. It consists of M local APP (a posteriori probability) decoders, each for one component code. The variables involved in Fig. 5.9.10 are the log-likelihood (LL) values, as detailed below. Fig. 5.9.10. The global decoder: “T” for delay of one iteration and “π” for interleaving. (m) L the a posteriori LL values for all information symbols after decoding the mth component code. (m) Lc the LL values {log ( | ) k k p y x } based on individual channel observations of the mth component code. Its elements { } ( ) , m Lc k are calculated as ⎩ ⎨ ⎧ = 0, for punctured symbols log ( | ), for un - punctured symbols ( ) , m k k c k p y x L (m) La the a priori LL values for all information symbols for the mth component code. It is initialized to zeroes, implying no a priori information. (m) Le the extrinsic information produced by the mth component code, defined by ( ) ( ) (m) a m m Le = L − L . The M local decoders operate successively. (m) La contains the accumulated extrinsic information generated by all the local decoders except DEC-m,     "     " iteration from the current iteration from the previous ( ) ( +1) ( +2) ( −1) (0) (1) ( −1) = + + + + + + m e e e M e m e m e m La L L L L L L Output DEC-0 DEC-m DEC-(M-1) (m) La - APP T (m) π ( ) 1 [ ] m − π (m) L (m) Lc - (m) Le