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Radio propagation prediction simulation methods based on deterministic technique such as ray launching is extensively used to accomplish radio channel characterization. However, the superiority of the simulation depends on the number of rays launched and received. This paper presented the indoor three-dimensional (3D) Minimum Ray Launching Maximum Accuracy (MRLMA) technique, which is applicable for an efficient indoor radio wave propagation prediction. Utilizing the novel MRLMA technique in the simulation environment for ray lunching and tracing can drastically reduce the number of rays that need to be traced, and improve the efficiency of ray tracing. Implementation and justification of MRLMA presented in the paper. An indoor office 3D layouts are selected and simulations have been performed using the MRLMA and other reference techniques. Results showed that the indoor 3D MRLMA model is appropriate for wireless communications network systems design and optimization process with respect to efficiency, coverage, number of rays launching, number of rays received by the mobile station, and simulation time. [ABSTRACT FROM AUTHOR]

To-date, most multipath propagation parameters are estimated in the element-space domain due to implementation simplicity. Although estimation in the beam-space domain can reduce both the dimensionality of the data size and numerical complexity, it is only beneficial if applied to arrays with a large number of uniformly spaced elements. A new implementation of the space-alternating generalised expectation-maximisation (SAGE) algorithm is presented in joint element-space and beam-space, namely the ‘hybrid-space’ (HS), such that the underlying features of these dual domains can be simultaneously exploited. The resultant algorithm, namely HS-SAGE algorithm, retains the advantages of the individual domains as the user can specify which parameter should be evaluated in each domain, thus optimising the overall performance. Here, the efficient execution flow of the HS-SAGE algorithm is presented, where the estimation quality is demonstrated through results obtained from both synthetic and real-measurement environments employing circular arrays. It is shown that the proposed algorithm can achieve significant timesaving when compared with the classical implementation approach, whilst maintaining accuracy. [ABSTRACT FROM AUTHOR]

In order for ray-tracing propagation models to analyze scattering from irregular terrain, some form of preprocessing must be performed to create a linearized terrain profile to approximate the actual profile. This paper describes a preprocessing algorithm that has proven effective in working with large terrain-data files (over 2,000 points) and a 16-ray, geometric theory of diffraction propagation model. The algorithm is based upon Fermat's principle, and it enables a quantitative evaluation of how well the linearized profile created approximates the actual terrain profile in terms of its effect on propagation. The accuracy of the fit can be adjusted to achieve a balance between overall model accuracy and propagation model execution time. [ABSTRACT FROM AUTHOR]

A useful method for monostatic RCS reduction of unavoidable shapes in desired frequency bandwidth and angle range is proposed. The proposed method is based on the concept of the random scatterer for RCS reduction and the genetic algorithm for optimization. PO, MEC, and SBR methods are used to obtain RCS. Target shapes whose RCS we want to reduce are basically a plate and finally a scale model tank. Results show that monostatic RCS of a fixed shape can be reduced by the proposed method. [ABSTRACT FROM AUTHOR]

New expressions for the narrow aperture dimension of the pyramidal horn are presented. They are obtained by using a differential evolution algorithm (DEA), and are used in successfully designing optimum gain pyramidal horns. The DEA is a simple, fast, and robust evolutionary algorithm for solving general type of numeric optimization problems. Design parameters of the horn are determined from the simple and explicit analytical formulas. These formulas do not need the application of the iterative methods, and are not restricted to the high-gain horn designs. The gain of a pyramidal horn is computed without approximating the path length error. Better accuracy with respect to the previous design methods is obtained for various pyramidal horn design examples. [ABSTRACT FROM AUTHOR]

Three-dimensional indoor radio-wave propagation is accurately modeled by solving the volume electric-field integral equation (VEFIE). The integral equation is discretized by the method of moments (MoM), in which the building walls, ceilings, floors, as well as any internal obstacles are represented by a collection of small volumetric cells. This discretization is capable of modeling a 3-D room structure to fine details. The solution to the MoM matrix equation is facilitated by the multilevel fast multipole algorithm (MLFMA), which significantly reduces memory requirements and CPU time. Numerical examples are shown to demonstrate the accuracy of the solution and the capability of modeling dielectric structures of nearly realistic sizes. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 168–175, 2001. [ABSTRACT FROM AUTHOR]

Provides information on a study which described a technique for the joint measurement of the angles, times and complex amplitudes of discrete path arrivals in an indoor radio propagation environment. Channel parameters; Spatial filter periodogram algorithm; Discrete maximum likelihood algorithm.