Implementing cooperative communication protocols: Decode and forward case study

Cooperative communication technique is an emerging trend in communication systems and offers benefits of multiple-input-multiple-output (MEMO) systems. Decode-and-forward (DF) method is one of most the known methods that is utilized in cooperative communication systems. Its lower complexity and higher practicality benefits make DF very useful. However, DF is affected negatively by erroneous transmission and performance could be limited. Several approaches are proposed for this drawback. An effective solution is a maximum likelihood (ML) detector that is based on maximization of probability density function in orthogonal transmissions. In this study, ML detector is utilized with orthogonal frequency division multiple access (OFDMA) technique and performance are measured by using software defined radio (SDR) nodes. In order to further improve that solution, a low complex suboptimal detector based on ML detector is proposed. The performance of the suboptimal detector is also quantified with SDR nodes.