Sharif Digital Repository

Numerous methods for direction of arrival (DOA) estimation, used in smart antennas have been already reported in previous studies. The precision of DOA estimation depends on the choice of the algorithm and the geometrical configuration of the antenna array. In this work, the performance of new geometrical configurations, i.e. 2D with equal area and 3D with equal volume including circular, square, triangular, hexagonal and star geometries, with equal number of antenna elements, are examined and compared to each other to find the most proper geometry. Monte-Carlo simulations are performed to evaluate the DOA precision of the proposed arrays using the MUSIC algorithm. It is shown that in three... 

Novel two-dimensional (2D) and three-dimensional (3D) antenna array geometries for smart antenna application are introduced. Minimum mean square error beamforming algorithm, using these arrays, in presence of signal, noise and interferences is implemented. Beamforming approach is used for every type of array assuming uniform and log-normal distributions for the interference amplitudes. Equal volume cylindrical or prism type arrays with circular, hexagonal, triangular, square and star cross-sections with equal number of elements are considered. Novel geometries consisting of rotated cross-sections are studied as well. In each case, the relative signal-to-interference ratios (SIRs) are... 

Novel two-dimensional (2D) and three-dimensional (3D) antenna array geometries for smart antenna application are introduced. Minimum mean square error beamforming algorithm, using these arrays, in presence of signal, noise and interferences is implemented. Beamforming approach is used for every type of array assuming uniform and log-normal distributions for the interference amplitudes. Equal volume cylindrical or prism type arrays with circular, hexagonal, triangular, square and star cross-sections with equal number of elements are considered. Novel geometries consisting of rotated cross-sections are studied as well. In each case, the relative signal-to-interference ratios (SIRs) are... 

Smart antennas are widely used to enhance the capacity of the wireless communication systems in urban areas. To enhance the capacity by increasing the signal to noise ratio, one should estimate the angle of arrival precisely. In urban areas, the scattering from the lampposts in a boulevard or a highway is not negligible and its effect should be considered in direction finding algorithms. In this paper the lampposts are modelled by thick and long cylindrical scatterers and the scattered electric field is computed in terms of the cylindrical harmonics analytically. Then the total electric field is evaluated to estimate the angle of arrival by MUSIC direction finding algorithm. The computed... 

Three-dimensional dipole arrays are normally used at the proximity of a reflective structure. Filamentary short-circuited dipoles are proposed to model the effect of the reflector structure. The computational burden is significantly reduced by using mutual impedance matrices. An analytical method of modelling the effect of the cylindrical reflector in a three-dimensional cylindrical geometry of dipole antenna arrays is introduced both for direction finding and beamforming applications in the presence of mutual coupling. The results of the implementation of the MUSIC (multiple signal classification) direction-finding algorithm show that the proposed model for accounting the cylindrical... 

The direction of arrival (DOA) error in dipole 3D arrays is estimated through Monte-Carlo simulations using the standard MUSIC algorithm. Novel 3D geometries are implemented which demonstrate better precision given the same lateral area. The mutual coupling effect is included by changing the search vector in the MUSIC DOA algorithm for the novel 3D geometries. A simple straight forward method is used which does not need complex electromagnetic computations. Simulations show that the proposed method can successfully account for the mutual coupling effects in two dimensional direction finding (both azimuth and elevation angle) with novel 3D array geometries. Reduced DOA estimation error is...