Abstract

In power-limited channels such as satellite links, error control codes are needed to provide high performance at very low Signal-to-Noise Ratios (SNRs). Turbo Codes or concatenated codes with iterative decoding, can achieve a performance very close to the Shannon limit. They are the most powerful codes known so far and are considered for use in various applications. In this thesis, we present the turbo codes using Reed-Muller (RM) codes as their component codes, and where the decoding method used is the trellis-based iterative Maximum A posteriori Probability (MAP) algorithm which provides an optimal performance. We aim to apply our turbo coding scheme to Asynchronous Transfer Mode (ATM) applications in Digital Video Broadcast - Return Channel via Satellite (DVB-RCS). Therefore, the shortened versions of ordinary RM-turbo codes are proposed. As well, we investigate the effect of phase offset on the shortened RM-turbo code performance with Quadrature Phase Shift Keying (QPSK) modulation scheme and the effect of preamble size used to recover carrier phase due to the problem of synchronization which is usually raised in practical systems