SISO and SIMO Indoor Wireless Transmission Systems Simulations using the FDTD Method

A SISO (Single Input Single Output) and a SIMO (Single Input Multiple Output) wireless transmission system operating in a Rayleigh distributed environment at the 434 MHz ISM band are investigated. The two systems are simulated using the Finite Difference Time Domain (FDTD) method, which enables the simultaneous characterization of the propagation channel and the immersed wire dipoles antennas. A novel procedure to evaluate the method’s accuracy for this type of systems is introduced, through the convergence of the SISO system’s Transfer Function (H). The results show that a numerical phase error of 1 per wavelength is acceptable for accurate estimation of H for a propagation distance of about 12 wavelengths. Moreover, the instantaneous correlation coefficient and the received power ratio versus dipoles’ separation distance are estimated and presented for the SIMO system. Key-Words: FDTD, numerical dispersion error, transfer function, dipoles, multipath, correlation coefficient.