Simulación de un sistema OFDM con diversidad de antena en recepción usando Matlab

Abstract

Wireless communications are important since they allow communication without the need to physically connect devices. Currently, several standards of wireless communications use OFDM (Orthogonal Frequency Division Multiplexing), technique, due to its great advantages as high transmission rate, high spectral efficiency and avoids ISI (Inter-Symbol Interference) in multipath environments. A technique used to counteract the negative effects in multipath propagation environments is the diversity. Antenna diversity in reception uses methods of combining signals to obtain a single robust resulting signal and improve the performance of the system. This article presents the results of the simulation of a wireless OFDM system with antenna diversity reception and the implementation of three methods of combination: SC (Selection Combining), MRC (Maximum Ratio Combining) and EGC (Equal Gain Combining). Results are present using curves of BER (Bit Error Rate) vs Eb/No (Energy per-bit to noise power spectral density ratio) and tables with diversity gains, for three different modulations and the use of two to four receiving antennas. The results show that the best method is MRC with QPSK modulation and four receiving antennas.