Chapter 2

1. Chapter 2 Concatenated codes  Ammar Abh-Hhdrohss Islamic University -Gaza

2. Introduction • Single level Concatenation usualy done by using done by using non-binary outer code and binary simple inner code. • This reduce complexity and increase reliability of the code. • Multilevel concatenation can achieve very powerful codes with very simple inner and outer codes. • The decoding is done in multiple stages which reduce the overall complexity.

3. Single level Concatenation Codes

4. Single level Concatenation Codes • Reed-Solomon is used usually as the outer code. • First, the k1k2 binary information digits are divided into k2 bytes of k1 information digits each. These k2 bytes are encoded using C2. • The n2 codewords of C2 are encoded using C1. • The information is transmitted one codeword of C1 at time. • The resultant code (n1n2, k1k2) with minimum distance d1d2; • where d1,d2 are the minimum distances for C1, C2, respectively.

5. k2 n2 - k2 k1 n1 - k1

7. Interleaving with concatenation codes

8. Another example