Geometric Dilution of Precision (GDOP) has always played an important role in satellite navigation system. This paper presents the extension of GDOP as a location estimation technique to determine the location of a Relay Station (RS). The proposed RS scheme and architecture showed a promising potential in increasing the network coverage and extending the range of a base station. The simulation results indicate that the application of GDOP to optimize RS position has improved the Mobile station (MS) estimation accuracy.