March 2011
Intermediate
680 pages
25h 12m
English
Figure 14.25 shows the effects of the decoding complexity on the TCM, TTCM, BICM and BICM-ID schemes’ performance in the context of an 8PSK scheme for transmissions over AWGN channels using a block length of 4000 information bits (2000 symbols). Again, the 64-state TCM, 64-state BICM, 8-state TTCM using four iterations and 16-state BICM-ID along with four iterations exhibit a similar decoding complexity. At a BER of 10−4, TTCM requires about 0.6 dB lower SNR than BICM-ID, 1.6 dB less energy than TCM and 2.5 dB lower SNR than BICM. When the decoding complexity is reduced such that 8-state codes are used in the TCM, BICM and BICM-ID schemes, their corresponding performance becomes worse than that of the 64-state codes, as shown in Figure 14.25. In order to be able to compare the associated performance with that of 8-state BICM-ID using four iterations, 8-state TTCM along with two iterations is employed. Observe that due to the insufficient number of iterations, TTCM exhibits only marginal advantage over BICM-ID.
Figure 14.25: Effects of decoding complexity on the TCM, TTCM, BICM and BICM-ID schemes’ performance in the context of an 8PSK scheme for transmissions over AWGN channels using a block length of 4000 information bits (2000 symbols).
Figure 14.26 shows the performance of TCM, TTCM and BICM-ID invoking 16QAM for transmissions over AWGN channels using a block length of 6000 ...
