Hybrid location awareness in cognitive radio system

In this paper, we consider the performance of received signal strength (RSS) and time of arrival (TOA) under different areas of primary user (PU) position estimation. The areas of PU position can be separated into two cases: inner area and outer area of boundary of secondary user (SU) nodes. This boundary is created by convex hull algorithm. In simulation result, we found that RSS is appropriated to use in inner area and TOA is suitable to use in outer area. Therefore, in this paper, we propose two hybrid location estimation techniques that combine RSS and TOA in cognitive radio (CR) system. The proposed techniques include the hybrid TOA/RSS in serial and the hybrid TOA/RSS in parallel technique. Simulation results show that the proposed techniques have better performance than the methods that use only RSS or TOA. Moreover, the proposed techniques are faster than TOA about 60%.