The Riemann sum method for the design of sum-of-cisoids simulators for Rayleigh fading channels in non-isotropic scattering environments

In this paper, we introduce the Riemann sum method (RSM) as an effective tool for the design of sum-of-cisoids (SOC) simulators for narrowband mobile Rayleigh fading channels under non-isotropic scattering conditions. We show that the RSM results in an excellent approximation of the channel´s autocorrelation function (ACF). Furthermore, we compare the performance of the RSM with that of the generalized method of equal areas (GMEA) and L_p-norm method (LPNM), which were until now the only methods available for the design of SOC simulators for non-isotropic scattering channels. The obtained results indicate that the RSM is better suited than the GMEA and the LPNM to approximate the channel´s ACF, whereas the latter two methods provide better results regarding the emulation of the envelope distribution. Owing to its simplicity and good performance, the RSM can be used to design flexible simulation platforms for the analysis of mobile communication systems operating in non-isotropic scattering environments.