关键词: 认知无线电, 能量检测检测概率, 基于测距的定位, 下界

Abstract:

A detection probability based iterative localization algorithm using weighted least square is proposed to solve the secondary users' problem of locating the primary users in cognitive radio networks. the primary users' transmission modal is described as a 2-state Markov modal and ennergy detection is used by secondary users for sensing.The proposed algorithm leverages the cooperative spectrum sensing to locate the primary users and is working transparently to the primary system. Furthermore, the proposed localization algorithm is able to acquire the three-dimensional position information of the primary user. Next, a simplified version of the algorithm is introduced to reduce the complexity. We have also conducted theoretical evaluation and obtained the Cramer-Rao lower bound (CRLB) in terms of the mean square error of the algorithm. Simulationshow that the performance of the improved algorithm approaches the CRLB and is able to estimate the three-dimensional positions of the primary user effectively and promote the lcalization precision.

Key words: cognitive radio ；energy detection, detection proability;range-based localization;weight-ed least squares method;Cramer-Rao lower bound