Turbo-coded HARQ scheme in multi-hop cooperative wireless networks

Abstract

To date, Cooperative wireless systems exist in classical three node network to achieve diversity. The concept of multi-hop relayed Cooperative wireless system is proposed to bring further improvements in the BER performance as compared to single hop cooperative wireless system. In this paper, Turbo Codes with Maximum a-posteriori (MAP) decoding algorithm are integrated in multi-hop cooperative wireless system as Forward Error Correction (FEC) technique in order to combat the drastic effects of fading environment. Use of such a powerful coding scheme leads to overall coding gain of the system. To make the system more robust, Hybrid Automatic Repeat re-Quest (HARQ) protocol is also incorporated in the system as retransmission scheme to rectify the errors that are detected at receiver side. Finally integrate all technologies together to enhance the end to end system performance. The BER results of multi-hop cooperative system justify the usage of multiple relays in cooperative wireless systems in comparison to single-hop systems. In addition the proposed technique also provides cost effective solution to get diversity gains.