Location-Based Adaptive Detection Threshold for Dynamic Spectrum Access

In this paper we propose a heuristic algorithm that exploits additional information that can be in general known by a secondary network willing to opportunistically access the spectrum allocated to a primary network. The algorithm aims at finding the maximum allowed transmission power with which a secondary node can transmit while respecting primary constraints. It is designed to be used in the presence of multiple primary transmitters with known positions but without information about their activity patterns. The estimation of the allowed transmission power is derived using a semi-analytical model characterizing interference probability. The latter is defined as the probability that the interference generated by the secondary node to any of the users in a primary cell exceeds a fixed threshold. The main idea is to autonomously determine a detection threshold based on the relative position of the secondary node towards base stations. Simulation results in a simple scenario are analyzed in order to explain the behavior of the algorithm. In addition, more results are introduced to evaluate the performance of the algorithm in more realistic scenarios.