On the impact of primary user localization on rate performance of CR systems

This paper investigates how localization knowledge of primary users impacts the sum-rate performance of a secondary system in an underlay cognitive radio setting. Two different probabilistic models for the primary users´ location information are assumed, one uniform distribution and the other with Gaussian distribution. The interplay between the achievable rate of the secondary system and the primary users´ location information under the AWGN and a fading channel model are presented and analyzed. Investigations are carried out for different propagation environments, localization models and primary-secondary user settings. Results show that the relationship between the secondary system sum-rate and the primary users´ location information depends on the number of primary and secondary users, as well as the propagation environment. Empirical expressions for the sum-rate are proposed for different localization probability distributions.