Ahmed Rashed Kulaib

An overview of localization techniques for Wireless Sensor Networks

Localization of sensor nodes is an important aspect in Wireless Sensor Networks (WSNs). This paper presents an overview of the major localization techniques for WSNs. These techniques are classified into centralized and distributed depending on where the computational effort is carried out. The paper concentrates on the factors that need to be considered when selecting a localization technique. The advantages and limitation of various techniques are also discussed. Finally, future research directions and challenges are highlighted.

Hybrid RSS-DOA technique for enhanced WSN localization in a correlated environment

This paper proposes a modified hybrid method for WSN localization that combines Received Signal Strength (RSS) and Direction of Arrival (DOA) estimation based on MUSIC (Multiple Signal Classification) using circular antenna array with smoothing capability. Simulation results proves the enhanced performance obtained using the proposed hybrid method. This takes the form of successful detection of a mixture of correlated and uncorrelated signals at a higher accuracy and lower Root Mean Square Error (RMSE) in comparison with conventional method.

Investigation of a hybrid localization technique using Received Signal Strength and Direction of arrival

This paper investigates a hybrid technique that uses a combined version of Received Signal Strength (RSS) and Direction of arrival (DOA) localization techniques. Simulation results prove that using the hybrid technique in one node increases the localization accuracy and provides the node with the capability of localizing other nodes by itself without any assistance from other nodes. The performance of the hybrid technique has been evaluated under both Additive White Gaussian Noise (AWGN) and Rayleigh channel conditions. Moreover, the study shows when to use the hybrid node, and where to place such node in a given environment to get the optimum results.

Performance evaluation of linear and circular arrays in wireless sensor network localization

Direction of Arrival (DOA) is one of the positioning techniques that can be used to localize the position of sensor nodes in Wireless Sensor Networks (WSNs). This paper presents a comparison between linear and circular array geometry in DOA estimation using MUltiple SIgnal Classification (MUSIC). A full analytical model for each geometry is developed and a comparative study of the performance of both array geometries is carried out. The numerical comparative study shows the advantages and drawbacks of each method under different sensor array and signal conditions. This comparison concentrates on several attributes which are noise level, beamwidth, and accuracy for localization in WSNs.

Fast detection of coherent signals using pre-conditioned root-MUSIC based on Toeplitz matrix reconstruction

This paper presents a fast approach for detecting coherent signals encountered in mul-tipath propagation environment. The developed approach utilizes a Toeplitz matrix reconstruction method along with DOA estimation using Root-MUSIC. The proposed approach exhibits several features such as robustness, high accuracy, and computational efficiency. Nevertheless, the primary advantage of the proposed Toeplitz-based de-correlation scheme is the fast detection of the maximum possible number of coherent signals, without the need of iteration and re-estimation.

Hybrid method for enhanced detection of coherent signals using circular antenna arrays

This paper proposes a modified hybrid method that combines Received Signal Strength (RSS) and Direction of Arrival (DOA) estimation based on MUSIC (Multiple Signal Classification) using circular antenna array. Simulation results are carried out to verify the improved performance obtained using the proposed hybrid method. This takes the form of successful detection of coherent signals at a higher accuracy and lower Root Mean Square Error (RMSE) in comparison with conventional method.

Accurate and robust DOA estimation using uniform circular displaced antenna array

A major design factor for an accurate and successful DOA estimation in smart antenna systems is the appropriate choice of the antenna array configuration. This paper proposes a new array configuration called Uniform Circular Displaced Antenna Array (UC-DAA), which is especially useful for detecting coherent signals encountered in multipath environments. The proposed configuration is composed of two concentric uniform circular arrays with angular rotational separation. Numerical results show that the proposed UC-DAA configuration outperforms both uniform circular arrays (UCA) and uniform linear displaced antenna array (UL-DAA) configurations, in terms of reduced computational complexity and improved angular resolution of coherent signals without the need of spatial smoothing.

A new technique for UCA-based DOA estimation of coherent signals

This paper presents a new technique, that does not require the use of spatial smoothing, for detecting the directions of coherent signals impinging on a Uniform Circular Array (UCA). The new technique is based on transforming the original UCA into an equivalent Virtual Uniform Linear Array (VULA) upon which a Toeplitz re-construction is employed to alleviate the inaccuracies incurred in the equivalent VULA. Simulation results demonstrate the improved accuracy and higher detection capacity of the proposed technique.

Improved DV-hop localization using node repositioning and clustering

Localization of sensor nodes is an important aspect in Wireless Sensor Networks (WSNs). This paper presents an improved DV-hop localization algorithm which increases the accuracy of DV-hop algorithm without significant increase in the computational complexity. The first proposed algorithm utilizes K-means technique followed by node repositioning. The second proposed algorithm is also based on K-means technique followed by cluster division and Direction of Arrival (DoA) localization. The latter algorithm is used when node repositioning cannot be achieved due to restriction in certain applications. The proposed localization algorithm have been thoroughly evaluated through simulations and the results demonstrate a significant improvement in accuracy.

An Accurate Localization Technique for Wireless Sensor Networks Using MUSIC Algorithm

Wireless Sensor Networks (WSNs) are used in civilian as well as military applications to support a wide range of services. Combining sensor data with location information increases the range of applications, and the accuracy of data interpretation. There are several localization techniques that are presented in the literature. These techniques are classified into centralized and distributed depending on where the computational effort is carried out. In this paper, MUltiple SIgnal Classification (MUSIC) is used to localize the position of sensor nodes based on the intersection of different beams. Computer simulations show that the algorithm provides high localization accuracy at reasonable noise levels.