Analysis of cooperataive communication systems with relay selection under error propagation

In this study, we propose the analysis of cooperative communication systems with relay selection under error propagation both theoretically and as a simulation. The decode and forward protocol is considered in the relays. Firstly, we present expressions of bit error probability when there is a relay in the environment. Secondly, the error propagation probabilities are derived theoretically in order to get the endto- end system performance where all the relays are active when there are three relays in the environment. Then, in the scenario where there are three relays, the theoretical expression of the end-to-end system performance (bit error probability) is obtained and verified with the simulations. Then, the relay selection techniques are compared in cooperative communication scenarios where M relays are found in the environment. Firstly, the error propagation probability and the end-to-end bit error probability for the threshold based selection cooperative technique are obtained. In this technique, the optimum threshold values are numerically obtained since the threshold values used are very effective on the system performance. The theoretical results giving the error performance for the Max-Min relay selection technique, which is another relay selection technique, are obtained approximately under error propagation. All theoretical results are verified by simulations. Keywords: Cooparative communication, error propagation, relay selection.