Energy efficient optimal node-source localization using mobile beacon in ad-hoc sensor networks

Sensor node tracking using semi-supervised Hidden Markov Models

“…The performance of the proposed algorithm in indoor scenario is presented next. [28]. The actual CRLB plot is shown in Fig.…”

An Efficient Compartmental Model for Real-Time Node Tracking Over Cognitive Wireless Sensor Networks

“…In our earlier work [16], [25], a log model for the attenuation of signals in the context of indoor and outdoor node localization has been described. In [17], regression based second degree and third degree methods using non-linear least square approach is described.…”

“…Here, and are defined as amplitude components, while and are damping components of RSP. The parameters and are computed from the RSP vector which is collected at radial distances of one meter interval throughout the given network, similar to our earlier work [16], [25]. At each position, two hundred snap-shots of radio signal are collected for an interval of one minute.…”

“…Substituting the derivatives with respect to and from (11) and (12) into (10) to get the following (13) Observations are collected from all the anchors which the node can hear. These observations are arranged in a block matrix form as (14) where, (15) and (16) Equation (14) can be now compactly written as (17) Since, the number of observations are greater than the number of unknown variables, the least squares approach [37] is used to solve the resultant overdetermined system of equations. The differential increments in and at every iteration are computed as (18) This system of equations can be solved efficiently when matrix is rank deficient or ill-conditioned using singular value decomposition.…”

“…DOA-based methods requires a special hardware to estimate the angle at which the signal arrives at the antenna array [12]. The localization algorithms can be further categorized as range-based [16], [17] and range-free [18] methods. Range-based methods utilize inter-node distances, but they provide good location resolution.…”