Distributed DOA Estimation for Arbitrary Topology Structure of Mobile Wireless Sensor Network Using Cognitive Radio

In order to improve the frequency spectrum availability and evade insecurity frequency range, the cognitive radio is introduced in wireless sensor network (WSN), which constructs the cognitive wireless network (CWN). The dynamic spectrum access (DSA) is used in CWN as the spectrum access scheme. In this paper, sensor nodes of mobile wireless sensor network (MWSN) are deployed based on the prior information of the deployment environment. The idea of CWN is introduced in MWSN. A distributed direction-of-arrival (DOA) estimation algorithm is proposed. The clustering of nodes constructs a sub-NWSN which acts as the sensor array used for DOA estimation. The Fourier domain (FD) root multiple signal classification (root-MUSIC) algorithm is applied for DOA estimation of sub-MWSN with arbitrary topology structure. The weight values of sub-MWSNs can be formulated as a function of the number of nodes, snapshot number and battery capacity of nodes. The total cost spectrum function is achieved finally. The improved performance of distributed FD root-MUSIC algorithm is verified by comparing with the manifold separation technique.