Michele Ludovico

CAD of Waveguide Components for Space Applications Based on Hybrid MMFE Techniques

A hybrid MMFE (Mode Matching Finite Elements) computed aided design technique is presented and its application to the analysis of several space waveguide components is discussed. The novelty of the formulation consists on the expansion of transversal electric and magnetic fields using edge elements. The hybrid approach is the key for an accurate characterization of arbitrary cross-section waveguides, where modal expansions cannot be computed analytically. The results of the analysis of a septum polariser, a square to circular transition and a stepped twist are shown: in all the cases considered the technique proposed has lead to a good agreement between numerical and experimental results with a moderate amount of computing resources.

Transmitted power statistics in W-CDMA radio access networks

In a CDMA-based mobile radio access system, power represents one of the main resources to be shared among users. For such a reason, the analysis of statistical distributions of transmitted power plays a fundamental role in the planning and optimization process of UMTS-FDD radio access networks. The aim of the present paper is to investigate several factors affecting power levels such as: cell deployment and geometry factors, QoS (quality of service) requirements of UMTS services (in particular in terms of E/sub b//N/sub 0/ targets), multi-service traffic characteristics, propagation conditions, power planning of signaling downlink channels, radio resource management (power control loops, soft handover, admission control). The paper presents several case studies developed with the help of an advanced Montecarlo simulator, considering both the uplink and the downlink.