Figure 2.1. Systematic form of a codeword of a block code

Figure 2.2. Block diagram of a FEC system

Figure 2.3. Bit error probability for the three times repetition code

Figure 2.4. Block diagram of an ARQ system

Figure 2.5. Stop and Wait ARQ scheme

Figure 2.6. A Go-Back N ARQ scheme

Figure 2.7. Selective Repeat ARQ Scheme

Figure 2.8. Efficiency relative to for Stop-and-Wait, Go-Back-N and Selective Repeat ARQ schemes, with rb=262; k=262 n=254, N=4, 32 and 128 (Go-Back-N); and for td=0.01, 0.1 and 1 (Stop-and-Wait)

Figure 2.9. First alternative of the hybrid-ARQ Type 2 iterative scheme

Figure Second alternative of the hybrid-ARQ Type 2 iterative scheme