Abstract: Cooperative relaying can combat multi-path fading and shadowing effect in wireless networks to enhance communication quality and bandwidth efficiency. A two-hop relaying system model is provided in this paper, and the analytical evaluations of non-regenerative and regenerative relaying system with non-diversity or maximal ratio combining are introduced. Considering the complexity and cost-effectiveness of the receiver, this paper investigates the performance of the selection diversity in terms of probability of outage and error with different positions of relays. The numerical results show that non-regenerative relaying system outperforms the others, and selection diversity is a cost-effective method to improve system performance.