Turbo Codes: Promises and Challenges

Channel coding is a powerful technique to get reliable communication over noisy channels. The performance of the coding system is bounded by Shannon limit. Lately, the proposal of parallel-concatenated convolutional code (PCCC), called turbo codes, has increased the interest in the coding area since these codes give most of the gain promised by the channel-coding theorem. Because turbo codes did not actually results from applying a pre existing theory, most of their outstanding features remain to be explained. The objective of this paper is to introduce turbo codes and the key elements to their superiority. Open problems and unresolved issues will be highlighted