Abstract:

This paper presents a comparative study of two different multicarrier modulation schemes (MCMs). The first MCM is Orthogonal Frequency Division Multiplexing (OFDM) [1]. OFDM is a widely used MCM for frequency selective channels, due to the simplicity of the required equalization, and also to its robustness toward Inter Symbol Interference (ISI) thanks to Cyclic Prefix (CP) insertion. The second MCM is Filter Bank-based Multi-Carrier modulation (FBMC) [2] which uses Offset Quadrature Amplitude Modulation (OQAM), known as FBMC/OQAM. FBMC/OQAM provides an attractive alternative to the conventional cyclic prefix-based orthogonal frequency division multiplexing (CP-OFDM), especially in terms of increased robustness to frequency offset, Doppler spread, and high bandwidth efficiency. Nevertheless, the two MCM schemes have a major drawback consisting in the increase of the Peak-to-Average Power Ratio (PAPR) that causes nonlinearities and clipping distortion. In this paper, we propose a performance comparison in terms of PAPR reduction between OFDM MCM and FBMC MCM in both SISO (Single Input Single Output) and MIMO (Multiple Input Multiple Output) system. Such comparative process is fulfilled through the use of PII (Poly-phase Interleaving and Inversion), proposed at [3], CARI 1(Cross antenna rotation And Inversion 1) and CARI 2 (Cross Antenna Rotation and Inversion 2) methods proposed at [4].

Abstract:

In this paper, we present a numerical method to obtain a solution for the time domain electric field integral equation applied to finite conducting thin wire. TD-EFIE is solved by applying the Method of Moments particularly Galerkin’s Method that involves separate spatial and temporal testing procedures. The transient behaviors are expressed in terms of weighted Laguerre polynomials. The Piecewise Functions are used as spatial basis functions. Numerical results involving transient currents are presented.

Abstract:

The purpose of this paper is to elaborate a comparative study between two types of test functions used in the Galerkin method. In fact, we have chosen as electromagnetic modeling method, generalized equivalent circuits method (MGEC) supported by the Galerkin method. We performed a convergence study for each type of test functions (extended and Piecewise linear). In order to compare these two types of functions, we used a simple structure which is a Micro-strip line. We determine for each, the required number of mode and test functions and as well as the running time.