Long Term Evolution (LTE) is the latest standard to come to the mobile communications market. To achieve its performance, LTE networks use several techniques, such as multi carrier technology, Multiple-Input Multiple-Output (MIMO) and cooperative communications. Inside cooperative communications, this paper focuses on the fixed relaying technique, presenting a way for determining the relay (Relay Station (RS)) optimized position within the Node B coverage area and also to quantify the associated performance gain using different cluster size configurations. The RS optimized position was obtained through realistic simulations, which set it as the middle of the cell’s circumference arc. Additionally it was also confirmed that networks performance is improved when the RS number is increased. Finally, a given scenario with a larger number of RS, can experience the same performance as an equivalent scenario without RS but with higher reuse distance. This should conduce to a compromise solution between RS installation and cluster size, in order to maximize capacity as well as performance.