Optimization of cyclic prefix transceivers - Signal Processing and Optimization for Transceiver Systems - page 566

k | C [ k ] | | C [ k ] |

Ex. 17.3 Ex. 17.4

0 0.1154 0.1243

1 0.3044 0.2996

2 0.7875 0.7863

3 0.9999 1.0000

4 0.7875 0.7863

5 0.3044 0.2996

6 0.1154 0.1243

7 0.2243 0.2383

8 0.0526 0.0682

9 0.1586 0.1430

10 0.1784 0.1690

11 0.0107 0.0038

12 0.1784 0.1690

13 0.1586 0.1430

14 0.0526 0.0682

15 0.2243 0.2383

Dependence on block size M . For Ex. 17.3, the transmitted power per
symbol is shown in Fig. 17.25 as a function of the block size M (with b =8
and P e ( k )=10 − 6 ). It is seen that the power can increase or decrease as M

increases. There is no fixed pattern. Notice that the power per symbol is less
sensitive to the block size M when there is optimal bit allocation. Thus, if we
seek to reduce the bandwidth expansion factor owing to cyclic-prefix redundancy
by increasing M , this does not seriously increase the power. Figure 17.26 shows
the coding gains for the two examples as a function of block size M. Again, the
coding gain can increase or decrease with M. Figure 17.27 shows a similar plot,
with the value of M restricted to be powers of two.